Narrow Search
 
 

Remove

  1. 1998
Advanced Search

Search Results: All Fields similar to 'Viking' and When equal to '1998'

Printer Friendly
1 2 3
1-50 of 139
     
     
Five to Mars
Title Five to Mars
Explanation Come December 2003 - January 2004, an armada of five new invaders [ http://www.planetary.org/rrgtm/missions5.html ] from Earth should arrive on the shores of the Red Planet -- the Japanese ( ISAS [ http://www.isas.ac.jp/ ]) Nozomi [ http://www.isas.ac.jp/e/enterp/missions/nozomi/ index.html ] orbiter, the European Space Agency's Mars Express [ http://sci.esa.int/home/marsexpress/ ] orbiter carrying the Beagle 2 [ http://www.beagle2.com/index.htm ] lander, and NASA's own two Mars Exploration [ http://mars.jpl.nasa.gov/mer/ ] Rovers. While Nozomi began [ http://antwrp.gsfc.nasa.gov/apod/ap980904.html ] its interplanetary voyage in 1998, the other spacecraft are scheduled for launch windows beginning this June. Clearly, earthdwellers remain intensely curious about Mars and the tantalizing [ http://antwrp.gsfc.nasa.gov/apod/ap030221.html ] possibility of past or present martian life [ http://cmex-www.arc.nasa.gov/SiteCat/sitecat2/ stratex.htm ], with these robotic missions focussing on investigating the planet's atmosphere and the search for water [ http://www.psrd.hawaii.edu/Sept98/GusevMars.html ]. This mosaic [ http://nssdc.gsfc.nasa.gov/photo_gallery/caption/ marsglobe2.txt ] of over 100 Viking 1 orbiter images of Mars [ http://nssdc.gsfc.nasa.gov/photo_gallery/ photogallery-mars.html ] was recorded in 1980 and is projected to show the perspective seen from an approaching spacecraft at a distance of 2,000 kilometers. Exceptional [ http://skyandtelescope.com/observing/objects/planets/ article_929_1.asp ] views of Mars will be possible from earthbound telescopes in August and September.
The 'Face on Mars'
title The 'Face on Mars'
Description Shortly after midnight Sunday morning (5 April 1998 12:39 AM PST), the Mars Orbiter Camera (MOC) on the Mars Global Surveyor (MGS) spacecraft successfully acquired a high resolution image of the 'Face on Mars' feature in the Cydonia region. The image was transmitted to Earth on Sunday, and retrieved from the mission computer data base Monday morning (6 April 1998). The image was processed at the Malin Space Science Systems (MSSS) facility 9:15 AM and the raw image immediately transferred to the Jet Propulsion Laboratory (JPL) for release to the Internet. The images shown here were subsequently processed at MSSS. The picture was acquired 375 seconds after the spacecraft's 220th close approach to Mars. At that time, the 'Face', located at approximately 40.8° N, 9.6° W, was 275 miles (444 km) from the spacecraft. The 'morning' sun was 25° above the horizon. The picture has a resolution of 14.1 feet (4.3 meters) per pixel, making it ten times higher resolution than the best previous image of the feature, which was taken by the Viking Mission in the mid-1970's. The full image covers an area 2.7 miles (4.4 km) wide and 25.7 miles (41.5 km) long. In this comparison, the best Viking image has been enlarged to 3.3 times its original resolution, and the MOC image has been decreased by a similar 3.3 times, creating images of roughly the same size. In addition, the MOC images have been geometrically transformed to a more overhead projection (different from the mercator map projection of PIA01440 & 1441) for ease of comparison with the Viking image. The left image is a portion of Viking Orbiter 1 frame 070A13, the middle image is a portion of MOC frame shown normally, and the right image is the same MOC frame but with the brightness inverted to simulate the approximate lighting conditions of the Viking image. Photo Credit: NASA/JPL/Malin Space Science Systems
Mars Orbiter Camera Views th …
PIA01442
Sol (our sun)
Mars Orbiter Camera
Title Mars Orbiter Camera Views the "Face on Mars" - Comparison with Viking
Original Caption Released with Image Shortly after midnight Sunday morning (5 April 1998 12:39 AM PST), the Mars Orbiter Camera (MOC) on the Mars Global Surveyor (MGS) spacecraft successfully acquired a high resolution image of the "Face on Mars" feature in the Cydonia region. The image was transmitted to Earth on Sunday, and retrieved from the mission computer data base Monday morning (6 April 1998). The image was processed at the Malin Space Science Systems (MSSS) facility 9:15 AM and the raw image immediately transferred to the Jet Propulsion Laboratory (JPL) for release to the Internet. The images shown here were subsequently processed at MSSS. The picture was acquired 375 seconds after the spacecraft's 220th close approach to Mars. At that time, the "Face", located at approximately 40.8° N, 9.6° W, was 275 miles (444 km) from the spacecraft. The "morning" sun was 25° above the horizon. The picture has a resolution of 14.1 feet (4.3 meters) per pixel, making it ten times higher resolution than the best previous image of the feature, which was taken by the Viking Mission in the mid-1970's. The full image covers an area 2.7 miles (4.4 km) wide and 25.7 miles (41.5 km) long. In this comparison, the best Viking image has been enlarged to 3.3 times its original resolution, and the MOC image has been decreased by a similar 3.3 times, creating images of roughly the same size. In addition, the MOC images have been geometrically transformed to a more overhead projection (different from the mercator map projection of PIA01440 & 1441) for ease of comparison with the Viking image. The left image is a portion of Viking Orbiter 1 frame 070A13, the middle image is a portion of MOC frame shown normally, and the right image is the same MOC frame but with the brightness inverted to simulate the approximate lighting conditions of the Viking image. Processing Image processing has been applied to the images in order to improve the visibility of features. This processing included the following steps: * The image was processed to remove the sensitivity differences between adjacent picture elements (calibrated). This removes the vertical streaking. * The contrast and brightness of the image was adjusted, and "filters" were applied to enhance detail at several scales. * The image was then geometrically warped to meet the computed position information for a mercator-type map. This corrected for the left-right flip, and the non-vertical viewing angle (about 45° from vertical), but also introduced some vertical "elongation" of the image for the same reason Greenland looks larger than Africa on a mercator map of the Earth. * A section of the image, containing the "Face" and a couple of nearly impact craters and hills, was "cut" out of the full image and reproduced separately. See PIA01440-1442 for additional processing steps. Also see PIA01236 for the raw image. Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer, mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.
Mars Orbiter Camera Views th …
PIA01439
Sol (our sun)
Mars Orbiter Camera
Title Mars Orbiter Camera Views the "Face on Mars" - Best View from Viking
Original Caption Released with Image Shortly after midnight Sunday morning (5 April 1998 12:39 AM PST), the Mars Orbiter Camera (MOC) on the Mars Global Surveyor (MGS) spacecraft successfully acquired a high resolution image of the "Face on Mars" feature in the Cydonia region. The image was transmitted to Earth on Sunday, and retrieved from the mission computer data base Monday morning (6 April 1998). The image was processed at the Malin Space Science Systems (MSSS) facility 9:15 AM and the raw image immediately transferred to the Jet Propulsion Laboratory (JPL) for release to the Internet. The images shown here were subsequently processed at MSSS. The picture was acquired 375 seconds after the spacecraft's 220th close approach to Mars. At that time, the "Face", located at approximately 40.8° N, 9.6° W, was 275 miles (444 km) from the spacecraft. The "morning" sun was 25° above the horizon. The picture has a resolution of 14.1 feet (4.3 meters) per pixel, making it ten times higher resolution than the best previous image of the feature, which was taken by the Viking Mission in the mid-1970's. The full image covers an area 2.7 miles (4.4 km) wide and 25.7 miles (41.5 km) long. This Viking Orbiter image is one of the best Viking pictures of the area Cydonia where the "Face" is located. Marked on the image are the "footprint" of the high resolution (narrow angle) Mars Orbiter Camera image and the area seen in enlarged views (dashed box). See PIA01440-1442 for these images in raw and processed form. Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.
Detailed View of Cliff-face …
PIA01479
Sol (our sun)
Mars Orbiter Camera
Title Detailed View of Cliff-face in the North Polar Layered Deposits
Original Caption Released with Image On Earth, geologists use layers of rock to "read" the history of our planet. Where rocks were initially formed as layers of sediment, the historic record of Earth is deciphered by knowing that older layers are found beneath the younger layers. Scientists investigating changes in Earth's climate over the past few million years also use this principle to examine cores of ice from Greenland and Antarctica. Layered rock and layered polar deposits on Mars may also preserve a comparable record of that planet's geologic and environmental history. The martian north and south polar regions are covered by large areas of layered deposits. Since their discovery in the early 1970's, these polar layered deposits have been cited as the best evidence that the martian climate experiences cyclic changes over time. It was proposed that detailed investigation of the polar layers ("e.g.,", by landers and/or human beings) would reveal a climate record of Mars in much the same way that ice cores from Antarctica are used to study past climates on Earth. On January 3, 1999, NASA's Mars Polar Lander and Deep Space 2 Penetrators will launch on a journey to study the upper layers of these deposits in the martian southern hemisphere. Meanwhile, investigation of the north polar layered deposits has advanced significantly this year with the acquisition of MGS data. The Mars Orbiter Laser Altimeter acquired new topographic profiles over the north polar deposits in June and early July, 1998, and dozens of new high resolution images were taken by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) from mid-July to mid-September, 1998. When it was proposed to NASA in 1985, one of the original objectives of MOC was to determine whether the polar layered deposits--then thought to consist of 10 to 100 layers each between 10 and 100 meters (33 to 330 feet) thick--have more and thinner layers in them. The layers were proposed to have formed by slow accumulation of dust and ice--perhaps only 100 micrometers (0.004 inches) per year. A layer 10 meters (33 feet) thick would take 100,000 years to accumulate, roughly equal to the timescale of climate changes predicted by computer models. The image shown here (right image) was taken at 11:52 p.m. PDT on July 30, 1998, near the start of the 461st orbit of Mars Global Surveyor. The picture shows a slope along the edge of the permanent north polar cap of Mars that has dozens of layers exposed in it. The image shows many more layers than were visible to the Viking Orbiters in the 1970s (left images). The layers appear to have different thicknesses (some thinner than 10 meters (33 feet)) and different physical expressions. Some of the layers form steeper slopes than others, suggesting that they are more resistant to erosion. The more resistant layers might indicate that a cement (possibly ice) is present, making those layers stronger. All of the layers appear to have a rough texture that might be the result of erosion and/or redistribution of sediment and polar ice on the slope surface. The presence of many more layers than were seen by Viking is an important and encouraging clue that suggests that future investigation of polar layered deposits by landers and, perhaps some day, by human explorers, will eventually lead to a better understanding of the of the polar regions and the climate history recorded there. Our view of these deposits will be much improved--starting in late March 1999--when the Mapping Phase of the MGS mission begins, and MOC will be able to obtain images with resolutions of 1.5 meters (5 feet) per pixel. [The Viking Images (left)]: Regional and local context of MOC image 46103. The small figure in the upper right corner is a map of the north polar region, centered on the pole with 0° longitude located in the lower middle of the frame. A small black box within the polar map indicates, the location of the Viking Orbiter 2 image used here for local context. The Viking image, 560b60, was taken in March 1978, toward the end of Northern Spring. The thin strip superposed on the Viking image is MOC image 46103, reduced in size to mark its placement relative to the Viking context image. The black box on the MOC image shows the location of the subframe highlighted here (right image). Illumination is from the left in the Viking image. The 10 kilometer scale bar also represents approximately 6.2 miles. Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.
Mars Orbiter Camera Acquires …
PIA01443
Sol (our sun)
Mars Orbiter Camera
Title Mars Orbiter Camera Acquires High Resolution Stereoscopic Images of the Viking One Landing Site
Original Caption Released with Image Two MOC images of the vicinity of the Viking Lander 1 (MOC 23503 and 25403), acquired separately on 12 April 1998 at 08:32 PDT and 21 April 1998 at 13:54 PDT (respectively), are combined here in a stereoscopic anaglyph. The more recent, slightly better quality image is in the red channel, while the earlier image is shown in the blue and green channels. Only the overlap portion of the images is included in the composite. Image 23503 was taken at a viewing angle of 31.6° from vertical, 25403 was taken at an angle of 22.4°, for a difference of 9.4°. Although this is not as large a difference as is typically used in stereo mapping, it is sufficient to provide some indication of relief, at least in locations of high relief. The image shows the raised rims and deep interiors of the larger impact craters in the area (the largest crater is about 650 m/2100 feet across). It shows that the relief on the ridges is very subtle, and that, in general, the Viking landing site is very flat. This result is, of course, expected: the VL-1 site was chosen specifically because it was likely to have low to very low slopes that represented potential hazards to the spacecraft. Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.
Ancient Lakes on Mars? Resul …
PIA01494
Sol (our sun)
Mars Orbiter Camera
Title Ancient Lakes on Mars? Results for Elysium Basin
Original Caption Released with Image The Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) was designed--in part--to test the variety of hypotheses about the history of Mars that have been proposed since the Mariner and Viking missions of the 1960s and 1970s. In April 1998, one of the efforts undertaken by the MOC science team was to test two competing ideas about the history of the Elysium Basin--a huge depression that stretches about 3,000 kilometers(1,865 miles) east-to-west in the region south of the Elysium volcanic rise. There were two competing ideas about the Elysium Basin. One hypothesis held that the depression was once the site of a vast lake approximately 1,500 meters (4,900 feet) deep. Because the floor of Elysium Basin has very few small, fresh impact craters, it was proposed that this lake dried up relatively recently in martian history--that is, the lake would have been younger than most of the volcanoes, craters, and even the Ares Vallis flood channel in which is located the Mars Pathfinder landing site. At some point, the lake in Elysium Basin was thought to have reached such a depth that it began to spill over arise on its east end. The water spilling out the east end of Elysium Basin was thought to have created Marte Vallis--a channel containing streamlined islands that stretches for hundreds of kilometers (miles)to the northeast. The lake bed and channel, it was proposed, might make good places to land future rovers that could travel around and collect samples that might contain evidence of past martian life. The other hypothesis held that the Elysium Basin floor was covered with flows that were emplaced as extremely fluid lava (molten rock). It was suggested that a lake of water could have been in the basin long, long ago, but that the most recent geologic events had erupted huge volumes of very fluid lava across the basin floor. Some of this lava was proposed to have even poured out of the basin and travelled down Marte Vallis. In this hypothesis, it was assumed that Marte Vallis--named for the Spanish word for "Mars"--was first carved by water, and then was a conduit for lava from volcanic eruptions. The lavas were proposed to have been very fluid--behaving almost limewater. Such fluid lavas are known on Earth to result from molten rock that has a low concentration of silica, a high temperature, and/or a high eruption rate. This MOC image, and MOC images 21904 and23804, of the floor of Elysium Basin taken in April 1998 revealed that the basin floor is covered with lava, not lake sediment. In other words, MOC has found that the Elysium Basin might "not", be a good place to look for evidence of martian life that might have existed in a lake. However, the lava textures that MOC found are striking and indicate something very important about the geologic history of Mars. The surface texture of this lava includes giant plates that appear to have been broken up and floated on the surface of a fluid. In this case, the fluid was molten lava. The implication is that the Elysium Basin was once the site of giant, ponded lava flows that were many hundreds of kilometers (miles) across. With the MOC images in hand, it is now quite easy to understand the older, lower-resolution Viking images ( Elysium Basin and Marte Vallis region,Viking 1 base map from 631st orbit,Viking 1 mosaic of local context)These Viking images showed a surface of dark plates with intervening bright surfaces. But they did not make sense--some thought they could somehow be volcanic, others thought they might be related to differences in the way that wind had eroded a dried lakebed. Now it can be seen that there are many dark plates that once floated on molten lava. When the lava was erupted, the upper surface crusted and cooled. The textures in these lavas indicate that they flowed and became cracked. Some cracks widened, and portions of the surface crust became rafts of solid rock--a few many kilometers (miles) across--that moved in the direction that the lava underneath was flowing. Other Viking and MGS images have shown similar platey lava textures in Marte Vallis, suggesting the possibility that some of the lava spilled into this valley and flowed thousands of kilometers (hundreds of miles) to the northeast. The sparse occurrence of younger impact craters on the platey lava surfaces suggests that the eruptions happened relatively recently in Mars history. These eruptions would be much younger than the youngest of the large martian volcanoes like Ascraeus Mons and Olympus Mons in the Tharsis region, but they would still have occurred many, many millions of years ago ("i.e.," the pictures are "not", evidence that Mars is volcanically active today). The MOC science team is continuing to study the images of Marte Vallis and Elysium Basin. Similar lava textures have been seen elsewhere on the planet, and are leading to some interesting revisions of our understanding of the volcanic and geologic history of the red planet. It should be noted that the observation of a volcanic surface in Elysium basin does not rule out the possibility that the depression was also once the site of a water lake, nor is it clear whether Marte Vallis is the result of volcanism alone, or volcanism that occurred some time after water had been present to carve the channel system. The results of the initial study of the Elysium Basin are given in a paper entitled "Mars Global Surveyor Camera Tests the Elysium Basin Controversy: It's Lava, Not Lake Sediments," by Alfred S. McEwen, K. S. Edgett, M. C. Malin, L. Keszthelyi, and P. Lanagan, presented at the Geological Society of America Annual Meeting on October 29, 1998. Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.
Ancient Lakes on Mars? Resul …
PIA01494
Sol (our sun)
Mars Orbiter Camera
Title Ancient Lakes on Mars? Results for Elysium Basin
Original Caption Released with Image The Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) was designed--in part--to test the variety of hypotheses about the history of Mars that have been proposed since the Mariner and Viking missions of the 1960s and 1970s. In April 1998, one of the efforts undertaken by the MOC science team was to test two competing ideas about the history of the Elysium Basin--a huge depression that stretches about 3,000 kilometers(1,865 miles) east-to-west in the region south of the Elysium volcanic rise. There were two competing ideas about the Elysium Basin. One hypothesis held that the depression was once the site of a vast lake approximately 1,500 meters (4,900 feet) deep. Because the floor of Elysium Basin has very few small, fresh impact craters, it was proposed that this lake dried up relatively recently in martian history--that is, the lake would have been younger than most of the volcanoes, craters, and even the Ares Vallis flood channel in which is located the Mars Pathfinder landing site. At some point, the lake in Elysium Basin was thought to have reached such a depth that it began to spill over arise on its east end. The water spilling out the east end of Elysium Basin was thought to have created Marte Vallis--a channel containing streamlined islands that stretches for hundreds of kilometers (miles)to the northeast. The lake bed and channel, it was proposed, might make good places to land future rovers that could travel around and collect samples that might contain evidence of past martian life. The other hypothesis held that the Elysium Basin floor was covered with flows that were emplaced as extremely fluid lava (molten rock). It was suggested that a lake of water could have been in the basin long, long ago, but that the most recent geologic events had erupted huge volumes of very fluid lava across the basin floor. Some of this lava was proposed to have even poured out of the basin and travelled down Marte Vallis. In this hypothesis, it was assumed that Marte Vallis--named for the Spanish word for "Mars"--was first carved by water, and then was a conduit for lava from volcanic eruptions. The lavas were proposed to have been very fluid--behaving almost limewater. Such fluid lavas are known on Earth to result from molten rock that has a low concentration of silica, a high temperature, and/or a high eruption rate. This MOC image, and MOC images 21904 and23804, of the floor of Elysium Basin taken in April 1998 revealed that the basin floor is covered with lava, not lake sediment. In other words, MOC has found that the Elysium Basin might "not", be a good place to look for evidence of martian life that might have existed in a lake. However, the lava textures that MOC found are striking and indicate something very important about the geologic history of Mars. The surface texture of this lava includes giant plates that appear to have been broken up and floated on the surface of a fluid. In this case, the fluid was molten lava. The implication is that the Elysium Basin was once the site of giant, ponded lava flows that were many hundreds of kilometers (miles) across. With the MOC images in hand, it is now quite easy to understand the older, lower-resolution Viking images ( Elysium Basin and Marte Vallis region,Viking 1 base map from 631st orbit,Viking 1 mosaic of local context)These Viking images showed a surface of dark plates with intervening bright surfaces. But they did not make sense--some thought they could somehow be volcanic, others thought they might be related to differences in the way that wind had eroded a dried lakebed. Now it can be seen that there are many dark plates that once floated on molten lava. When the lava was erupted, the upper surface crusted and cooled. The textures in these lavas indicate that they flowed and became cracked. Some cracks widened, and portions of the surface crust became rafts of solid rock--a few many kilometers (miles) across--that moved in the direction that the lava underneath was flowing. Other Viking and MGS images have shown similar platey lava textures in Marte Vallis, suggesting the possibility that some of the lava spilled into this valley and flowed thousands of kilometers (hundreds of miles) to the northeast. The sparse occurrence of younger impact craters on the platey lava surfaces suggests that the eruptions happened relatively recently in Mars history. These eruptions would be much younger than the youngest of the large martian volcanoes like Ascraeus Mons and Olympus Mons in the Tharsis region, but they would still have occurred many, many millions of years ago ("i.e.," the pictures are "not", evidence that Mars is volcanically active today). The MOC science team is continuing to study the images of Marte Vallis and Elysium Basin. Similar lava textures have been seen elsewhere on the planet, and are leading to some interesting revisions of our understanding of the volcanic and geologic history of the red planet. It should be noted that the observation of a volcanic surface in Elysium basin does not rule out the possibility that the depression was also once the site of a water lake, nor is it clear whether Marte Vallis is the result of volcanism alone, or volcanism that occurred some time after water had been present to carve the channel system. The results of the initial study of the Elysium Basin are given in a paper entitled "Mars Global Surveyor Camera Tests the Elysium Basin Controversy: It's Lava, Not Lake Sediments," by Alfred S. McEwen, K. S. Edgett, M. C. Malin, L. Keszthelyi, and P. Lanagan, presented at the Geological Society of America Annual Meeting on October 29, 1998. Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.
Ancient Lakes on Mars? Resul …
PIA01494
Sol (our sun)
Mars Orbiter Camera
Title Ancient Lakes on Mars? Results for Elysium Basin
Original Caption Released with Image The Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) was designed--in part--to test the variety of hypotheses about the history of Mars that have been proposed since the Mariner and Viking missions of the 1960s and 1970s. In April 1998, one of the efforts undertaken by the MOC science team was to test two competing ideas about the history of the Elysium Basin--a huge depression that stretches about 3,000 kilometers(1,865 miles) east-to-west in the region south of the Elysium volcanic rise. There were two competing ideas about the Elysium Basin. One hypothesis held that the depression was once the site of a vast lake approximately 1,500 meters (4,900 feet) deep. Because the floor of Elysium Basin has very few small, fresh impact craters, it was proposed that this lake dried up relatively recently in martian history--that is, the lake would have been younger than most of the volcanoes, craters, and even the Ares Vallis flood channel in which is located the Mars Pathfinder landing site. At some point, the lake in Elysium Basin was thought to have reached such a depth that it began to spill over arise on its east end. The water spilling out the east end of Elysium Basin was thought to have created Marte Vallis--a channel containing streamlined islands that stretches for hundreds of kilometers (miles)to the northeast. The lake bed and channel, it was proposed, might make good places to land future rovers that could travel around and collect samples that might contain evidence of past martian life. The other hypothesis held that the Elysium Basin floor was covered with flows that were emplaced as extremely fluid lava (molten rock). It was suggested that a lake of water could have been in the basin long, long ago, but that the most recent geologic events had erupted huge volumes of very fluid lava across the basin floor. Some of this lava was proposed to have even poured out of the basin and travelled down Marte Vallis. In this hypothesis, it was assumed that Marte Vallis--named for the Spanish word for "Mars"--was first carved by water, and then was a conduit for lava from volcanic eruptions. The lavas were proposed to have been very fluid--behaving almost limewater. Such fluid lavas are known on Earth to result from molten rock that has a low concentration of silica, a high temperature, and/or a high eruption rate. This MOC image, and MOC images 21904 and23804, of the floor of Elysium Basin taken in April 1998 revealed that the basin floor is covered with lava, not lake sediment. In other words, MOC has found that the Elysium Basin might "not", be a good place to look for evidence of martian life that might have existed in a lake. However, the lava textures that MOC found are striking and indicate something very important about the geologic history of Mars. The surface texture of this lava includes giant plates that appear to have been broken up and floated on the surface of a fluid. In this case, the fluid was molten lava. The implication is that the Elysium Basin was once the site of giant, ponded lava flows that were many hundreds of kilometers (miles) across. With the MOC images in hand, it is now quite easy to understand the older, lower-resolution Viking images ( Elysium Basin and Marte Vallis region,Viking 1 base map from 631st orbit,Viking 1 mosaic of local context)These Viking images showed a surface of dark plates with intervening bright surfaces. But they did not make sense--some thought they could somehow be volcanic, others thought they might be related to differences in the way that wind had eroded a dried lakebed. Now it can be seen that there are many dark plates that once floated on molten lava. When the lava was erupted, the upper surface crusted and cooled. The textures in these lavas indicate that they flowed and became cracked. Some cracks widened, and portions of the surface crust became rafts of solid rock--a few many kilometers (miles) across--that moved in the direction that the lava underneath was flowing. Other Viking and MGS images have shown similar platey lava textures in Marte Vallis, suggesting the possibility that some of the lava spilled into this valley and flowed thousands of kilometers (hundreds of miles) to the northeast. The sparse occurrence of younger impact craters on the platey lava surfaces suggests that the eruptions happened relatively recently in Mars history. These eruptions would be much younger than the youngest of the large martian volcanoes like Ascraeus Mons and Olympus Mons in the Tharsis region, but they would still have occurred many, many millions of years ago ("i.e.," the pictures are "not", evidence that Mars is volcanically active today). The MOC science team is continuing to study the images of Marte Vallis and Elysium Basin. Similar lava textures have been seen elsewhere on the planet, and are leading to some interesting revisions of our understanding of the volcanic and geologic history of the red planet. It should be noted that the observation of a volcanic surface in Elysium basin does not rule out the possibility that the depression was also once the site of a water lake, nor is it clear whether Marte Vallis is the result of volcanism alone, or volcanism that occurred some time after water had been present to carve the channel system. The results of the initial study of the Elysium Basin are given in a paper entitled "Mars Global Surveyor Camera Tests the Elysium Basin Controversy: It's Lava, Not Lake Sediments," by Alfred S. McEwen, K. S. Edgett, M. C. Malin, L. Keszthelyi, and P. Lanagan, presented at the Geological Society of America Annual Meeting on October 29, 1998. Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.
Ancient Lakes on Mars? Resul …
PIA01494
Sol (our sun)
Mars Orbiter Camera
Title Ancient Lakes on Mars? Results for Elysium Basin
Original Caption Released with Image The Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) was designed--in part--to test the variety of hypotheses about the history of Mars that have been proposed since the Mariner and Viking missions of the 1960s and 1970s. In April 1998, one of the efforts undertaken by the MOC science team was to test two competing ideas about the history of the Elysium Basin--a huge depression that stretches about 3,000 kilometers(1,865 miles) east-to-west in the region south of the Elysium volcanic rise. There were two competing ideas about the Elysium Basin. One hypothesis held that the depression was once the site of a vast lake approximately 1,500 meters (4,900 feet) deep. Because the floor of Elysium Basin has very few small, fresh impact craters, it was proposed that this lake dried up relatively recently in martian history--that is, the lake would have been younger than most of the volcanoes, craters, and even the Ares Vallis flood channel in which is located the Mars Pathfinder landing site. At some point, the lake in Elysium Basin was thought to have reached such a depth that it began to spill over arise on its east end. The water spilling out the east end of Elysium Basin was thought to have created Marte Vallis--a channel containing streamlined islands that stretches for hundreds of kilometers (miles)to the northeast. The lake bed and channel, it was proposed, might make good places to land future rovers that could travel around and collect samples that might contain evidence of past martian life. The other hypothesis held that the Elysium Basin floor was covered with flows that were emplaced as extremely fluid lava (molten rock). It was suggested that a lake of water could have been in the basin long, long ago, but that the most recent geologic events had erupted huge volumes of very fluid lava across the basin floor. Some of this lava was proposed to have even poured out of the basin and travelled down Marte Vallis. In this hypothesis, it was assumed that Marte Vallis--named for the Spanish word for "Mars"--was first carved by water, and then was a conduit for lava from volcanic eruptions. The lavas were proposed to have been very fluid--behaving almost limewater. Such fluid lavas are known on Earth to result from molten rock that has a low concentration of silica, a high temperature, and/or a high eruption rate. This MOC image, and MOC images 21904 and23804, of the floor of Elysium Basin taken in April 1998 revealed that the basin floor is covered with lava, not lake sediment. In other words, MOC has found that the Elysium Basin might "not", be a good place to look for evidence of martian life that might have existed in a lake. However, the lava textures that MOC found are striking and indicate something very important about the geologic history of Mars. The surface texture of this lava includes giant plates that appear to have been broken up and floated on the surface of a fluid. In this case, the fluid was molten lava. The implication is that the Elysium Basin was once the site of giant, ponded lava flows that were many hundreds of kilometers (miles) across. With the MOC images in hand, it is now quite easy to understand the older, lower-resolution Viking images ( Elysium Basin and Marte Vallis region,Viking 1 base map from 631st orbit,Viking 1 mosaic of local context)These Viking images showed a surface of dark plates with intervening bright surfaces. But they did not make sense--some thought they could somehow be volcanic, others thought they might be related to differences in the way that wind had eroded a dried lakebed. Now it can be seen that there are many dark plates that once floated on molten lava. When the lava was erupted, the upper surface crusted and cooled. The textures in these lavas indicate that they flowed and became cracked. Some cracks widened, and portions of the surface crust became rafts of solid rock--a few many kilometers (miles) across--that moved in the direction that the lava underneath was flowing. Other Viking and MGS images have shown similar platey lava textures in Marte Vallis, suggesting the possibility that some of the lava spilled into this valley and flowed thousands of kilometers (hundreds of miles) to the northeast. The sparse occurrence of younger impact craters on the platey lava surfaces suggests that the eruptions happened relatively recently in Mars history. These eruptions would be much younger than the youngest of the large martian volcanoes like Ascraeus Mons and Olympus Mons in the Tharsis region, but they would still have occurred many, many millions of years ago ("i.e.," the pictures are "not", evidence that Mars is volcanically active today). The MOC science team is continuing to study the images of Marte Vallis and Elysium Basin. Similar lava textures have been seen elsewhere on the planet, and are leading to some interesting revisions of our understanding of the volcanic and geologic history of the red planet. It should be noted that the observation of a volcanic surface in Elysium basin does not rule out the possibility that the depression was also once the site of a water lake, nor is it clear whether Marte Vallis is the result of volcanism alone, or volcanism that occurred some time after water had been present to carve the channel system. The results of the initial study of the Elysium Basin are given in a paper entitled "Mars Global Surveyor Camera Tests the Elysium Basin Controversy: It's Lava, Not Lake Sediments," by Alfred S. McEwen, K. S. Edgett, M. C. Malin, L. Keszthelyi, and P. Lanagan, presented at the Geological Society of America Annual Meeting on October 29, 1998. Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.
Ancient Lakes on Mars? Resul …
PIA01494
Sol (our sun)
Mars Orbiter Camera
Title Ancient Lakes on Mars? Results for Elysium Basin
Original Caption Released with Image The Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) was designed--in part--to test the variety of hypotheses about the history of Mars that have been proposed since the Mariner and Viking missions of the 1960s and 1970s. In April 1998, one of the efforts undertaken by the MOC science team was to test two competing ideas about the history of the Elysium Basin--a huge depression that stretches about 3,000 kilometers(1,865 miles) east-to-west in the region south of the Elysium volcanic rise. There were two competing ideas about the Elysium Basin. One hypothesis held that the depression was once the site of a vast lake approximately 1,500 meters (4,900 feet) deep. Because the floor of Elysium Basin has very few small, fresh impact craters, it was proposed that this lake dried up relatively recently in martian history--that is, the lake would have been younger than most of the volcanoes, craters, and even the Ares Vallis flood channel in which is located the Mars Pathfinder landing site. At some point, the lake in Elysium Basin was thought to have reached such a depth that it began to spill over arise on its east end. The water spilling out the east end of Elysium Basin was thought to have created Marte Vallis--a channel containing streamlined islands that stretches for hundreds of kilometers (miles)to the northeast. The lake bed and channel, it was proposed, might make good places to land future rovers that could travel around and collect samples that might contain evidence of past martian life. The other hypothesis held that the Elysium Basin floor was covered with flows that were emplaced as extremely fluid lava (molten rock). It was suggested that a lake of water could have been in the basin long, long ago, but that the most recent geologic events had erupted huge volumes of very fluid lava across the basin floor. Some of this lava was proposed to have even poured out of the basin and travelled down Marte Vallis. In this hypothesis, it was assumed that Marte Vallis--named for the Spanish word for "Mars"--was first carved by water, and then was a conduit for lava from volcanic eruptions. The lavas were proposed to have been very fluid--behaving almost limewater. Such fluid lavas are known on Earth to result from molten rock that has a low concentration of silica, a high temperature, and/or a high eruption rate. This MOC image, and MOC images 21904 and23804, of the floor of Elysium Basin taken in April 1998 revealed that the basin floor is covered with lava, not lake sediment. In other words, MOC has found that the Elysium Basin might "not", be a good place to look for evidence of martian life that might have existed in a lake. However, the lava textures that MOC found are striking and indicate something very important about the geologic history of Mars. The surface texture of this lava includes giant plates that appear to have been broken up and floated on the surface of a fluid. In this case, the fluid was molten lava. The implication is that the Elysium Basin was once the site of giant, ponded lava flows that were many hundreds of kilometers (miles) across. With the MOC images in hand, it is now quite easy to understand the older, lower-resolution Viking images ( Elysium Basin and Marte Vallis region,Viking 1 base map from 631st orbit,Viking 1 mosaic of local context)These Viking images showed a surface of dark plates with intervening bright surfaces. But they did not make sense--some thought they could somehow be volcanic, others thought they might be related to differences in the way that wind had eroded a dried lakebed. Now it can be seen that there are many dark plates that once floated on molten lava. When the lava was erupted, the upper surface crusted and cooled. The textures in these lavas indicate that they flowed and became cracked. Some cracks widened, and portions of the surface crust became rafts of solid rock--a few many kilometers (miles) across--that moved in the direction that the lava underneath was flowing. Other Viking and MGS images have shown similar platey lava textures in Marte Vallis, suggesting the possibility that some of the lava spilled into this valley and flowed thousands of kilometers (hundreds of miles) to the northeast. The sparse occurrence of younger impact craters on the platey lava surfaces suggests that the eruptions happened relatively recently in Mars history. These eruptions would be much younger than the youngest of the large martian volcanoes like Ascraeus Mons and Olympus Mons in the Tharsis region, but they would still have occurred many, many millions of years ago ("i.e.," the pictures are "not", evidence that Mars is volcanically active today). The MOC science team is continuing to study the images of Marte Vallis and Elysium Basin. Similar lava textures have been seen elsewhere on the planet, and are leading to some interesting revisions of our understanding of the volcanic and geologic history of the red planet. It should be noted that the observation of a volcanic surface in Elysium basin does not rule out the possibility that the depression was also once the site of a water lake, nor is it clear whether Marte Vallis is the result of volcanism alone, or volcanism that occurred some time after water had been present to carve the channel system. The results of the initial study of the Elysium Basin are given in a paper entitled "Mars Global Surveyor Camera Tests the Elysium Basin Controversy: It's Lava, Not Lake Sediments," by Alfred S. McEwen, K. S. Edgett, M. C. Malin, L. Keszthelyi, and P. Lanagan, presented at the Geological Society of America Annual Meeting on October 29, 1998. Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.
Ancient Lakes on Mars? Resul …
PIA01494
Sol (our sun)
Mars Orbiter Camera
Title Ancient Lakes on Mars? Results for Elysium Basin
Original Caption Released with Image The Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) was designed--in part--to test the variety of hypotheses about the history of Mars that have been proposed since the Mariner and Viking missions of the 1960s and 1970s. In April 1998, one of the efforts undertaken by the MOC science team was to test two competing ideas about the history of the Elysium Basin--a huge depression that stretches about 3,000 kilometers(1,865 miles) east-to-west in the region south of the Elysium volcanic rise. There were two competing ideas about the Elysium Basin. One hypothesis held that the depression was once the site of a vast lake approximately 1,500 meters (4,900 feet) deep. Because the floor of Elysium Basin has very few small, fresh impact craters, it was proposed that this lake dried up relatively recently in martian history--that is, the lake would have been younger than most of the volcanoes, craters, and even the Ares Vallis flood channel in which is located the Mars Pathfinder landing site. At some point, the lake in Elysium Basin was thought to have reached such a depth that it began to spill over arise on its east end. The water spilling out the east end of Elysium Basin was thought to have created Marte Vallis--a channel containing streamlined islands that stretches for hundreds of kilometers (miles)to the northeast. The lake bed and channel, it was proposed, might make good places to land future rovers that could travel around and collect samples that might contain evidence of past martian life. The other hypothesis held that the Elysium Basin floor was covered with flows that were emplaced as extremely fluid lava (molten rock). It was suggested that a lake of water could have been in the basin long, long ago, but that the most recent geologic events had erupted huge volumes of very fluid lava across the basin floor. Some of this lava was proposed to have even poured out of the basin and travelled down Marte Vallis. In this hypothesis, it was assumed that Marte Vallis--named for the Spanish word for "Mars"--was first carved by water, and then was a conduit for lava from volcanic eruptions. The lavas were proposed to have been very fluid--behaving almost limewater. Such fluid lavas are known on Earth to result from molten rock that has a low concentration of silica, a high temperature, and/or a high eruption rate. This MOC image, and MOC images 21904 and23804, of the floor of Elysium Basin taken in April 1998 revealed that the basin floor is covered with lava, not lake sediment. In other words, MOC has found that the Elysium Basin might "not", be a good place to look for evidence of martian life that might have existed in a lake. However, the lava textures that MOC found are striking and indicate something very important about the geologic history of Mars. The surface texture of this lava includes giant plates that appear to have been broken up and floated on the surface of a fluid. In this case, the fluid was molten lava. The implication is that the Elysium Basin was once the site of giant, ponded lava flows that were many hundreds of kilometers (miles) across. With the MOC images in hand, it is now quite easy to understand the older, lower-resolution Viking images ( Elysium Basin and Marte Vallis region,Viking 1 base map from 631st orbit,Viking 1 mosaic of local context)These Viking images showed a surface of dark plates with intervening bright surfaces. But they did not make sense--some thought they could somehow be volcanic, others thought they might be related to differences in the way that wind had eroded a dried lakebed. Now it can be seen that there are many dark plates that once floated on molten lava. When the lava was erupted, the upper surface crusted and cooled. The textures in these lavas indicate that they flowed and became cracked. Some cracks widened, and portions of the surface crust became rafts of solid rock--a few many kilometers (miles) across--that moved in the direction that the lava underneath was flowing. Other Viking and MGS images have shown similar platey lava textures in Marte Vallis, suggesting the possibility that some of the lava spilled into this valley and flowed thousands of kilometers (hundreds of miles) to the northeast. The sparse occurrence of younger impact craters on the platey lava surfaces suggests that the eruptions happened relatively recently in Mars history. These eruptions would be much younger than the youngest of the large martian volcanoes like Ascraeus Mons and Olympus Mons in the Tharsis region, but they would still have occurred many, many millions of years ago ("i.e.," the pictures are "not", evidence that Mars is volcanically active today). The MOC science team is continuing to study the images of Marte Vallis and Elysium Basin. Similar lava textures have been seen elsewhere on the planet, and are leading to some interesting revisions of our understanding of the volcanic and geologic history of the red planet. It should be noted that the observation of a volcanic surface in Elysium basin does not rule out the possibility that the depression was also once the site of a water lake, nor is it clear whether Marte Vallis is the result of volcanism alone, or volcanism that occurred some time after water had been present to carve the channel system. The results of the initial study of the Elysium Basin are given in a paper entitled "Mars Global Surveyor Camera Tests the Elysium Basin Controversy: It's Lava, Not Lake Sediments," by Alfred S. McEwen, K. S. Edgett, M. C. Malin, L. Keszthelyi, and P. Lanagan, presented at the Geological Society of America Annual Meeting on October 29, 1998. Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.
Coprates Chasma
title Coprates Chasma
Description Mars Orbiter Camera (MOC) image of a 10 km by 12 km area of Coprates Chasma (14.7 degrees S, 55.8 degrees W), a ridge with a flat upper surface in the center of Coprates Chasma, which is part of the 6000-km-long Valles Marineris. Rock layers are visible just below the ridge. The gray scale (4.8 m/pixel) MOC image was combined with a Viking Orbiter color view of the same area. The faults of a graben offset beds on the slope to the left. Figure caption from Science Magazine Photo Credit: NASA/JPL/Malin Space Science Systems Cover, Science 13 March 1998, 279 (5357):1676
Once Pitted, Twice Spied: A …
PIA02007
Sol (our sun)
Mars Orbiter Camera
Title Once Pitted, Twice Spied: A New High Resolution View Inside Escalante Crater
Original Caption Released with Image During the year spent waiting to achieve the planned circular, polar Mapping Orbit, the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) took about 1170pictures that had resolutions in the 2 to 20 meters (7-66 feet) per pixel range. These pictures were obtained between September 1997 and September 1998, and are now archived with NASA and available to the public at NASAPDS--http://ida.wr.usgs.gov/ [ http://ida.wr.usgs.gov/ ] . Although these pictures were generally a vast improvement in spatial resolution compared to the previous images from Viking and Mariner, the latest pictures from MOC--taken this month (April 1999) from the proper Mapping Orbit--demonstrate the power of the MOC when in focus and operating at the correct altitude (~380 km or 235 miles). The Viking Orbiter picture on the left, above, shows the 83 kilometers-(52 miles)-wide crater, Escalante. Located on the martian equator at 245°W longitude, a portion of this crater's floor was seen by MOC before the mapping mission began, at a resolution of 9.4 meters (31 feet) per pixel as shown in the middle image. The new picture--on the right--peers down into one of the pits seen in the earlier MOC image--only now it is viewed at 1.8 meters (6 feet) per pixel. The new high resolution image (right) covers an area only 1.5 kilometers (0.9 miles)wide and shows that the crater floor--which appears relatively smooth in the context view on the left--is actually quite rough at the scale that a human being would notice if trying to hike around in this landscape. The latest picture also shows small, bright windblown dunes that were not visible in the earlier MOC image. MOC2-120a is a mosaic of Viking Orbiter images 381s62 and 379s47, and MOC2-120b is a subframe of MGS MOC image SPO-2-382/04. The large white box shows the location of MOC2-120b, and the small white box shows the location of MOC2-120c. In MOC2-120a and MOC2-120b, illumination is from the right/upper right, in MOC2-120c it is from the left. Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.
Once Pitted, Twice Spied: A …
PIA02007
Sol (our sun)
Mars Orbiter Camera
Title Once Pitted, Twice Spied: A New High Resolution View Inside Escalante Crater
Original Caption Released with Image During the year spent waiting to achieve the planned circular, polar Mapping Orbit, the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) took about 1170pictures that had resolutions in the 2 to 20 meters (7-66 feet) per pixel range. These pictures were obtained between September 1997 and September 1998, and are now archived with NASA and available to the public at NASAPDS--http://ida.wr.usgs.gov/ [ http://ida.wr.usgs.gov/ ] . Although these pictures were generally a vast improvement in spatial resolution compared to the previous images from Viking and Mariner, the latest pictures from MOC--taken this month (April 1999) from the proper Mapping Orbit--demonstrate the power of the MOC when in focus and operating at the correct altitude (~380 km or 235 miles). The Viking Orbiter picture on the left, above, shows the 83 kilometers-(52 miles)-wide crater, Escalante. Located on the martian equator at 245°W longitude, a portion of this crater's floor was seen by MOC before the mapping mission began, at a resolution of 9.4 meters (31 feet) per pixel as shown in the middle image. The new picture--on the right--peers down into one of the pits seen in the earlier MOC image--only now it is viewed at 1.8 meters (6 feet) per pixel. The new high resolution image (right) covers an area only 1.5 kilometers (0.9 miles)wide and shows that the crater floor--which appears relatively smooth in the context view on the left--is actually quite rough at the scale that a human being would notice if trying to hike around in this landscape. The latest picture also shows small, bright windblown dunes that were not visible in the earlier MOC image. MOC2-120a is a mosaic of Viking Orbiter images 381s62 and 379s47, and MOC2-120b is a subframe of MGS MOC image SPO-2-382/04. The large white box shows the location of MOC2-120b, and the small white box shows the location of MOC2-120c. In MOC2-120a and MOC2-120b, illumination is from the right/upper right, in MOC2-120c it is from the left. Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.
Once Pitted, Twice Spied: A …
PIA02007
Sol (our sun)
Mars Orbiter Camera
Title Once Pitted, Twice Spied: A New High Resolution View Inside Escalante Crater
Original Caption Released with Image During the year spent waiting to achieve the planned circular, polar Mapping Orbit, the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) took about 1170pictures that had resolutions in the 2 to 20 meters (7-66 feet) per pixel range. These pictures were obtained between September 1997 and September 1998, and are now archived with NASA and available to the public at NASAPDS--http://ida.wr.usgs.gov/ [ http://ida.wr.usgs.gov/ ] . Although these pictures were generally a vast improvement in spatial resolution compared to the previous images from Viking and Mariner, the latest pictures from MOC--taken this month (April 1999) from the proper Mapping Orbit--demonstrate the power of the MOC when in focus and operating at the correct altitude (~380 km or 235 miles). The Viking Orbiter picture on the left, above, shows the 83 kilometers-(52 miles)-wide crater, Escalante. Located on the martian equator at 245°W longitude, a portion of this crater's floor was seen by MOC before the mapping mission began, at a resolution of 9.4 meters (31 feet) per pixel as shown in the middle image. The new picture--on the right--peers down into one of the pits seen in the earlier MOC image--only now it is viewed at 1.8 meters (6 feet) per pixel. The new high resolution image (right) covers an area only 1.5 kilometers (0.9 miles)wide and shows that the crater floor--which appears relatively smooth in the context view on the left--is actually quite rough at the scale that a human being would notice if trying to hike around in this landscape. The latest picture also shows small, bright windblown dunes that were not visible in the earlier MOC image. MOC2-120a is a mosaic of Viking Orbiter images 381s62 and 379s47, and MOC2-120b is a subframe of MGS MOC image SPO-2-382/04. The large white box shows the location of MOC2-120b, and the small white box shows the location of MOC2-120c. In MOC2-120a and MOC2-120b, illumination is from the right/upper right, in MOC2-120c it is from the left. Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.
Once Pitted, Twice Spied: A …
PIA02007
Sol (our sun)
Mars Orbiter Camera
Title Once Pitted, Twice Spied: A New High Resolution View Inside Escalante Crater
Original Caption Released with Image During the year spent waiting to achieve the planned circular, polar Mapping Orbit, the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) took about 1170pictures that had resolutions in the 2 to 20 meters (7-66 feet) per pixel range. These pictures were obtained between September 1997 and September 1998, and are now archived with NASA and available to the public at NASAPDS--http://ida.wr.usgs.gov/ [ http://ida.wr.usgs.gov/ ] . Although these pictures were generally a vast improvement in spatial resolution compared to the previous images from Viking and Mariner, the latest pictures from MOC--taken this month (April 1999) from the proper Mapping Orbit--demonstrate the power of the MOC when in focus and operating at the correct altitude (~380 km or 235 miles). The Viking Orbiter picture on the left, above, shows the 83 kilometers-(52 miles)-wide crater, Escalante. Located on the martian equator at 245°W longitude, a portion of this crater's floor was seen by MOC before the mapping mission began, at a resolution of 9.4 meters (31 feet) per pixel as shown in the middle image. The new picture--on the right--peers down into one of the pits seen in the earlier MOC image--only now it is viewed at 1.8 meters (6 feet) per pixel. The new high resolution image (right) covers an area only 1.5 kilometers (0.9 miles)wide and shows that the crater floor--which appears relatively smooth in the context view on the left--is actually quite rough at the scale that a human being would notice if trying to hike around in this landscape. The latest picture also shows small, bright windblown dunes that were not visible in the earlier MOC image. MOC2-120a is a mosaic of Viking Orbiter images 381s62 and 379s47, and MOC2-120b is a subframe of MGS MOC image SPO-2-382/04. The large white box shows the location of MOC2-120b, and the small white box shows the location of MOC2-120c. In MOC2-120a and MOC2-120b, illumination is from the right/upper right, in MOC2-120c it is from the left. Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.
New Cydonia Picture
PIA02092
Sol (our sun)
Mars Orbiter Camera
Title New Cydonia Picture
Original Caption Released with Image The Mars Orbiter Camera (MOC) onboard the Mars Global Surveyor (MGS) orbiter, was designed specifically to bridge the gap between what can be seen from orbit in typical Mariner 9 and Viking orbiter images, and what can be seen from the ground by landers such as Viking 1 and Mars Pathfinder. The camera, therefore, takes pictures of extremely high resolution. These images are often comparable to aerial photographs used by geologists when they are exploring Earth. The highest resolution images that can be obtained are in the range of 1.4 to 2.0 meters (4.6 to 6.5 feet) per pixel. Last year, several pictures of a portion of the Cydonia region of Mars were photographed at lower resolution than is now possible in the Mapping Phase of the MGS mission. The Cydonia region is perhaps most "famous" for being the location of a feature that--in Viking Orbiter images--seemed to resemble a human face. Nearby buttes and hills were considered by some to represent a "city." The MGS spacecraft flew over the "famous" Cydonia landforms again--for the first time since April 1998--on June 27, 1999, at 10:53 UTC (Greenwich Time Zone). The new MOC images shown here provide the highest resolution view yet obtained of the "Cydonia city" landforms. The picture at the above left (MOC2-142a), shows the regional context. Cydonia constitutes a transition zone between the cratered highlands of Arabia Terra, and the less-cratered lowlands of Acidalia Planitia. This transition zone contains thousands of mesas and buttes--somewhat like the Monument Valley region along the Arizona/Utah border in North America. The white box shows the location of the new high resolution view of the "city" landforms. The image is a red wide angle context frame obtained by MOC at the same time that the high resolution view was acquired. The picture is illuminated from the lower left, and north is toward the upper right. The picture in the center is a processed version of the new MOC narrow angle camera image of this portion of Cydonia. You can view the full-size image Like the context image (above left), the high resolution view (center) is illuminated from the lower left. North is toward the upper right. Boulders can be seen on some of the hill slopes, and the plains between the hills are rough and pitted. To conserve data in order to account for downtrack position uncertainties, only 1/2 of the MOC sensor was used to acquire this picture (allowing the image to be twice the length): it covers an area that is 1.5 km (0.9 mi) wide. The picture at the above right is the unprocessed MOC image. This what the processed image (center) looked like before it was rotated 180° (so that north is toward the top) and corrected for a 1.5 aspect ratio. The pixel size in the unprocessed image is different in the cross-track (left-right) and down-track(top-bottom) directions, thus making the craters look "squished." The cross-track scale is about 1.5 meters (5 feet) per pixel, while the down-track scale is about 2.25 meters (7.4 feet) per pixel. In the unprocessed image, the illumination is coming from the upper right. You can view this image at full-size (use "Save this link as..." and examine (MOC2-142c 100% Size) or see it via your web-browser at half-size (MOC2-142c 50% Size). For a look at the Cydonia images previously obtained by MGS MOC in 1998, CLICKHERE [ http://www.msss.com/mars/global_surveyor/camera/images/MENUS/cydonia_list.html ]. For a pre-MGS discussion of Viking orbiter images of the "Face on Mars,"CLICKHERE [ http://www.msss.com/education/facepage/face.html ]. Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.
New Cydonia Picture
PIA02092
Sol (our sun)
Mars Orbiter Camera
Title New Cydonia Picture
Original Caption Released with Image The Mars Orbiter Camera (MOC) onboard the Mars Global Surveyor (MGS) orbiter, was designed specifically to bridge the gap between what can be seen from orbit in typical Mariner 9 and Viking orbiter images, and what can be seen from the ground by landers such as Viking 1 and Mars Pathfinder. The camera, therefore, takes pictures of extremely high resolution. These images are often comparable to aerial photographs used by geologists when they are exploring Earth. The highest resolution images that can be obtained are in the range of 1.4 to 2.0 meters (4.6 to 6.5 feet) per pixel. Last year, several pictures of a portion of the Cydonia region of Mars were photographed at lower resolution than is now possible in the Mapping Phase of the MGS mission. The Cydonia region is perhaps most "famous" for being the location of a feature that--in Viking Orbiter images--seemed to resemble a human face. Nearby buttes and hills were considered by some to represent a "city." The MGS spacecraft flew over the "famous" Cydonia landforms again--for the first time since April 1998--on June 27, 1999, at 10:53 UTC (Greenwich Time Zone). The new MOC images shown here provide the highest resolution view yet obtained of the "Cydonia city" landforms. The picture at the above left (MOC2-142a), shows the regional context. Cydonia constitutes a transition zone between the cratered highlands of Arabia Terra, and the less-cratered lowlands of Acidalia Planitia. This transition zone contains thousands of mesas and buttes--somewhat like the Monument Valley region along the Arizona/Utah border in North America. The white box shows the location of the new high resolution view of the "city" landforms. The image is a red wide angle context frame obtained by MOC at the same time that the high resolution view was acquired. The picture is illuminated from the lower left, and north is toward the upper right. The picture in the center is a processed version of the new MOC narrow angle camera image of this portion of Cydonia. You can view the full-size image Like the context image (above left), the high resolution view (center) is illuminated from the lower left. North is toward the upper right. Boulders can be seen on some of the hill slopes, and the plains between the hills are rough and pitted. To conserve data in order to account for downtrack position uncertainties, only 1/2 of the MOC sensor was used to acquire this picture (allowing the image to be twice the length): it covers an area that is 1.5 km (0.9 mi) wide. The picture at the above right is the unprocessed MOC image. This what the processed image (center) looked like before it was rotated 180° (so that north is toward the top) and corrected for a 1.5 aspect ratio. The pixel size in the unprocessed image is different in the cross-track (left-right) and down-track(top-bottom) directions, thus making the craters look "squished." The cross-track scale is about 1.5 meters (5 feet) per pixel, while the down-track scale is about 2.25 meters (7.4 feet) per pixel. In the unprocessed image, the illumination is coming from the upper right. You can view this image at full-size (use "Save this link as..." and examine (MOC2-142c 100% Size) or see it via your web-browser at half-size (MOC2-142c 50% Size). For a look at the Cydonia images previously obtained by MGS MOC in 1998, CLICKHERE [ http://www.msss.com/mars/global_surveyor/camera/images/MENUS/cydonia_list.html ]. For a pre-MGS discussion of Viking orbiter images of the "Face on Mars,"CLICKHERE [ http://www.msss.com/education/facepage/face.html ]. Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.
New Cydonia Picture
PIA02092
Sol (our sun)
Mars Orbiter Camera
Title New Cydonia Picture
Original Caption Released with Image The Mars Orbiter Camera (MOC) onboard the Mars Global Surveyor (MGS) orbiter, was designed specifically to bridge the gap between what can be seen from orbit in typical Mariner 9 and Viking orbiter images, and what can be seen from the ground by landers such as Viking 1 and Mars Pathfinder. The camera, therefore, takes pictures of extremely high resolution. These images are often comparable to aerial photographs used by geologists when they are exploring Earth. The highest resolution images that can be obtained are in the range of 1.4 to 2.0 meters (4.6 to 6.5 feet) per pixel. Last year, several pictures of a portion of the Cydonia region of Mars were photographed at lower resolution than is now possible in the Mapping Phase of the MGS mission. The Cydonia region is perhaps most "famous" for being the location of a feature that--in Viking Orbiter images--seemed to resemble a human face. Nearby buttes and hills were considered by some to represent a "city." The MGS spacecraft flew over the "famous" Cydonia landforms again--for the first time since April 1998--on June 27, 1999, at 10:53 UTC (Greenwich Time Zone). The new MOC images shown here provide the highest resolution view yet obtained of the "Cydonia city" landforms. The picture at the above left (MOC2-142a), shows the regional context. Cydonia constitutes a transition zone between the cratered highlands of Arabia Terra, and the less-cratered lowlands of Acidalia Planitia. This transition zone contains thousands of mesas and buttes--somewhat like the Monument Valley region along the Arizona/Utah border in North America. The white box shows the location of the new high resolution view of the "city" landforms. The image is a red wide angle context frame obtained by MOC at the same time that the high resolution view was acquired. The picture is illuminated from the lower left, and north is toward the upper right. The picture in the center is a processed version of the new MOC narrow angle camera image of this portion of Cydonia. You can view the full-size image Like the context image (above left), the high resolution view (center) is illuminated from the lower left. North is toward the upper right. Boulders can be seen on some of the hill slopes, and the plains between the hills are rough and pitted. To conserve data in order to account for downtrack position uncertainties, only 1/2 of the MOC sensor was used to acquire this picture (allowing the image to be twice the length): it covers an area that is 1.5 km (0.9 mi) wide. The picture at the above right is the unprocessed MOC image. This what the processed image (center) looked like before it was rotated 180° (so that north is toward the top) and corrected for a 1.5 aspect ratio. The pixel size in the unprocessed image is different in the cross-track (left-right) and down-track(top-bottom) directions, thus making the craters look "squished." The cross-track scale is about 1.5 meters (5 feet) per pixel, while the down-track scale is about 2.25 meters (7.4 feet) per pixel. In the unprocessed image, the illumination is coming from the upper right. You can view this image at full-size (use "Save this link as..." and examine (MOC2-142c 100% Size) or see it via your web-browser at half-size (MOC2-142c 50% Size). For a look at the Cydonia images previously obtained by MGS MOC in 1998, CLICKHERE [ http://www.msss.com/mars/global_surveyor/camera/images/MENUS/cydonia_list.html ]. For a pre-MGS discussion of Viking orbiter images of the "Face on Mars,"CLICKHERE [ http://www.msss.com/education/facepage/face.html ]. Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.
New Cydonia Picture
PIA02092
Sol (our sun)
Mars Orbiter Camera
Title New Cydonia Picture
Original Caption Released with Image The Mars Orbiter Camera (MOC) onboard the Mars Global Surveyor (MGS) orbiter, was designed specifically to bridge the gap between what can be seen from orbit in typical Mariner 9 and Viking orbiter images, and what can be seen from the ground by landers such as Viking 1 and Mars Pathfinder. The camera, therefore, takes pictures of extremely high resolution. These images are often comparable to aerial photographs used by geologists when they are exploring Earth. The highest resolution images that can be obtained are in the range of 1.4 to 2.0 meters (4.6 to 6.5 feet) per pixel. Last year, several pictures of a portion of the Cydonia region of Mars were photographed at lower resolution than is now possible in the Mapping Phase of the MGS mission. The Cydonia region is perhaps most "famous" for being the location of a feature that--in Viking Orbiter images--seemed to resemble a human face. Nearby buttes and hills were considered by some to represent a "city." The MGS spacecraft flew over the "famous" Cydonia landforms again--for the first time since April 1998--on June 27, 1999, at 10:53 UTC (Greenwich Time Zone). The new MOC images shown here provide the highest resolution view yet obtained of the "Cydonia city" landforms. The picture at the above left (MOC2-142a), shows the regional context. Cydonia constitutes a transition zone between the cratered highlands of Arabia Terra, and the less-cratered lowlands of Acidalia Planitia. This transition zone contains thousands of mesas and buttes--somewhat like the Monument Valley region along the Arizona/Utah border in North America. The white box shows the location of the new high resolution view of the "city" landforms. The image is a red wide angle context frame obtained by MOC at the same time that the high resolution view was acquired. The picture is illuminated from the lower left, and north is toward the upper right. The picture in the center is a processed version of the new MOC narrow angle camera image of this portion of Cydonia. You can view the full-size image Like the context image (above left), the high resolution view (center) is illuminated from the lower left. North is toward the upper right. Boulders can be seen on some of the hill slopes, and the plains between the hills are rough and pitted. To conserve data in order to account for downtrack position uncertainties, only 1/2 of the MOC sensor was used to acquire this picture (allowing the image to be twice the length): it covers an area that is 1.5 km (0.9 mi) wide. The picture at the above right is the unprocessed MOC image. This what the processed image (center) looked like before it was rotated 180° (so that north is toward the top) and corrected for a 1.5 aspect ratio. The pixel size in the unprocessed image is different in the cross-track (left-right) and down-track(top-bottom) directions, thus making the craters look "squished." The cross-track scale is about 1.5 meters (5 feet) per pixel, while the down-track scale is about 2.25 meters (7.4 feet) per pixel. In the unprocessed image, the illumination is coming from the upper right. You can view this image at full-size (use "Save this link as..." and examine (MOC2-142c 100% Size) or see it via your web-browser at half-size (MOC2-142c 50% Size). For a look at the Cydonia images previously obtained by MGS MOC in 1998, CLICKHERE [ http://www.msss.com/mars/global_surveyor/camera/images/MENUS/cydonia_list.html ]. For a pre-MGS discussion of Viking orbiter images of the "Face on Mars,"CLICKHERE [ http://www.msss.com/education/facepage/face.html ]. Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.
New Cydonia Picture
PIA02092
Sol (our sun)
Mars Orbiter Camera
Title New Cydonia Picture
Original Caption Released with Image The Mars Orbiter Camera (MOC) onboard the Mars Global Surveyor (MGS) orbiter, was designed specifically to bridge the gap between what can be seen from orbit in typical Mariner 9 and Viking orbiter images, and what can be seen from the ground by landers such as Viking 1 and Mars Pathfinder. The camera, therefore, takes pictures of extremely high resolution. These images are often comparable to aerial photographs used by geologists when they are exploring Earth. The highest resolution images that can be obtained are in the range of 1.4 to 2.0 meters (4.6 to 6.5 feet) per pixel. Last year, several pictures of a portion of the Cydonia region of Mars were photographed at lower resolution than is now possible in the Mapping Phase of the MGS mission. The Cydonia region is perhaps most "famous" for being the location of a feature that--in Viking Orbiter images--seemed to resemble a human face. Nearby buttes and hills were considered by some to represent a "city." The MGS spacecraft flew over the "famous" Cydonia landforms again--for the first time since April 1998--on June 27, 1999, at 10:53 UTC (Greenwich Time Zone). The new MOC images shown here provide the highest resolution view yet obtained of the "Cydonia city" landforms. The picture at the above left (MOC2-142a), shows the regional context. Cydonia constitutes a transition zone between the cratered highlands of Arabia Terra, and the less-cratered lowlands of Acidalia Planitia. This transition zone contains thousands of mesas and buttes--somewhat like the Monument Valley region along the Arizona/Utah border in North America. The white box shows the location of the new high resolution view of the "city" landforms. The image is a red wide angle context frame obtained by MOC at the same time that the high resolution view was acquired. The picture is illuminated from the lower left, and north is toward the upper right. The picture in the center is a processed version of the new MOC narrow angle camera image of this portion of Cydonia. You can view the full-size image Like the context image (above left), the high resolution view (center) is illuminated from the lower left. North is toward the upper right. Boulders can be seen on some of the hill slopes, and the plains between the hills are rough and pitted. To conserve data in order to account for downtrack position uncertainties, only 1/2 of the MOC sensor was used to acquire this picture (allowing the image to be twice the length): it covers an area that is 1.5 km (0.9 mi) wide. The picture at the above right is the unprocessed MOC image. This what the processed image (center) looked like before it was rotated 180° (so that north is toward the top) and corrected for a 1.5 aspect ratio. The pixel size in the unprocessed image is different in the cross-track (left-right) and down-track(top-bottom) directions, thus making the craters look "squished." The cross-track scale is about 1.5 meters (5 feet) per pixel, while the down-track scale is about 2.25 meters (7.4 feet) per pixel. In the unprocessed image, the illumination is coming from the upper right. You can view this image at full-size (use "Save this link as..." and examine (MOC2-142c 100% Size) or see it via your web-browser at half-size (MOC2-142c 50% Size). For a look at the Cydonia images previously obtained by MGS MOC in 1998, CLICKHERE [ http://www.msss.com/mars/global_surveyor/camera/images/MENUS/cydonia_list.html ]. For a pre-MGS discussion of Viking orbiter images of the "Face on Mars,"CLICKHERE [ http://www.msss.com/education/facepage/face.html ]. Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.
New Cydonia Picture
PIA02092
Sol (our sun)
Mars Orbiter Camera
Title New Cydonia Picture
Original Caption Released with Image The Mars Orbiter Camera (MOC) onboard the Mars Global Surveyor (MGS) orbiter, was designed specifically to bridge the gap between what can be seen from orbit in typical Mariner 9 and Viking orbiter images, and what can be seen from the ground by landers such as Viking 1 and Mars Pathfinder. The camera, therefore, takes pictures of extremely high resolution. These images are often comparable to aerial photographs used by geologists when they are exploring Earth. The highest resolution images that can be obtained are in the range of 1.4 to 2.0 meters (4.6 to 6.5 feet) per pixel. Last year, several pictures of a portion of the Cydonia region of Mars were photographed at lower resolution than is now possible in the Mapping Phase of the MGS mission. The Cydonia region is perhaps most "famous" for being the location of a feature that--in Viking Orbiter images--seemed to resemble a human face. Nearby buttes and hills were considered by some to represent a "city." The MGS spacecraft flew over the "famous" Cydonia landforms again--for the first time since April 1998--on June 27, 1999, at 10:53 UTC (Greenwich Time Zone). The new MOC images shown here provide the highest resolution view yet obtained of the "Cydonia city" landforms. The picture at the above left (MOC2-142a), shows the regional context. Cydonia constitutes a transition zone between the cratered highlands of Arabia Terra, and the less-cratered lowlands of Acidalia Planitia. This transition zone contains thousands of mesas and buttes--somewhat like the Monument Valley region along the Arizona/Utah border in North America. The white box shows the location of the new high resolution view of the "city" landforms. The image is a red wide angle context frame obtained by MOC at the same time that the high resolution view was acquired. The picture is illuminated from the lower left, and north is toward the upper right. The picture in the center is a processed version of the new MOC narrow angle camera image of this portion of Cydonia. You can view the full-size image Like the context image (above left), the high resolution view (center) is illuminated from the lower left. North is toward the upper right. Boulders can be seen on some of the hill slopes, and the plains between the hills are rough and pitted. To conserve data in order to account for downtrack position uncertainties, only 1/2 of the MOC sensor was used to acquire this picture (allowing the image to be twice the length): it covers an area that is 1.5 km (0.9 mi) wide. The picture at the above right is the unprocessed MOC image. This what the processed image (center) looked like before it was rotated 180° (so that north is toward the top) and corrected for a 1.5 aspect ratio. The pixel size in the unprocessed image is different in the cross-track (left-right) and down-track(top-bottom) directions, thus making the craters look "squished." The cross-track scale is about 1.5 meters (5 feet) per pixel, while the down-track scale is about 2.25 meters (7.4 feet) per pixel. In the unprocessed image, the illumination is coming from the upper right. You can view this image at full-size (use "Save this link as..." and examine (MOC2-142c 100% Size) or see it via your web-browser at half-size (MOC2-142c 50% Size). For a look at the Cydonia images previously obtained by MGS MOC in 1998, CLICKHERE [ http://www.msss.com/mars/global_surveyor/camera/images/MENUS/cydonia_list.html ]. For a pre-MGS discussion of Viking orbiter images of the "Face on Mars,"CLICKHERE [ http://www.msss.com/education/facepage/face.html ]. Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.
Mars Shoreline Tests: Contac …
PIA02338
Sol (our sun)
Mars Orbiter Camera
Title Mars Shoreline Tests: Contact between Lycus Sulci and Amazonis Planitia
Original Caption Released with Image If the northern plains of Mars had ever been the site of a vast ocean, then any highlands that protrude above these plains might be expected to exhibit shorelines. The somewhat curved, flat-topped mesa seen in Viking image 026A72 (first image)is bounded by a dark band. Prior to the Mars Global Surveyor (MGS) mission, this mesa was interpreted by some researchers as having been a possible island in an ancient, northern plains ocean. The dark band was interpreted to be a shoreline resulting from the action of waves lapping against the island's coast. A high resolution image of the banded mesa--located on the Acidalia plains around 45°N, 7°W--was acquired by the MGS Mars Orbiter Camera (MOC) in August 1998, over twenty years after the Viking image was taken. A subframe of this image--SPO2-515/06--is shown in the second image. In the MOC image, the dark band resolves into a series of narrower bright and dark bands. Each band has a slightly different texture and brightness. Furthermore, what appeared to be a sunlit escarpment bounding the north side of the mesa in the Viking image appears in the MOC image to be only a shallow slope rather than a scarp or cliff. The origin of the different bands is not known, but the most likely explanation that would be consistent with other MOC observations of Mars is that the mesa consists of layered rock, and that each band is an outcropping of a different layer of this rock. The different textures would result from the differing resistance to erosion of each layer. Both images shown here are illuminated from the left., MRPS 50586 Mars Global Surveyor's (MGS) Mars Orbiter Camera (MOC) took the above picture (second of the two) of some massifs and mesas in the Cydonia region of Mars in early September 1998. The purpose of this image--number SPO2-532/04--was to test the hypothesis that the martian northern plains were once the site of an ocean or large sea. According to this hypothesis, and according to peer-reviewed and published maps, each one of the mesas and massifs in the two pictures above should have shorelines around their margins. The hypothesis holds that these were once islands and that waves would lap--and sometimes crash--against these landforms, rip off huge chunks of rock, and create steep cliffs and stair-stepped terraces in the rock. The first picture above shows the regional context of the MOC high resolution view in Cydonia. The context picture, from Viking orbiter image 227S11, is illuminated from the right. The second picture above is a figure that shows the full SPO2-532/04 MOC image and two expanded views of portions of this image. Mesas are flat-topped uplands, and massifs are the more triangular, massive peaks. If an ocean had been present in this region, terraces that indicate erosion or bathtub rings of salt or carbonate deposits left by the retreat of this ocean as it dried up might be found around each mesa and massif. No such features are found, nor is it at all obvious why these mesas and massifs were portrayed in previously published figures as having shorelines around them. The MOC image is illuminated from the left., MRPS 95319 Lycus Sulci and Amazonis Planitia are shown here separated by a rise that runs diagonally across the scene from near the lower left toward the upper right. This picture is a subframe of MOC image SPO2-428/03, taken in July 1998. The Lycus Sulci uplands here are more roughly-textured than in the previous image, and the flat Amazonis plains appear to be more smooth and lack the small parallel ridges seen in the earlier view. The lack of the small ridges might be real, or they might be present but cannot be seen because this picture has a lower resolution than the previous one. This image, too, shows that the contact between Amazonis and Lycus Sulci is not a cliff, and once again there are no features that can be unambiguously identified as coastal landforms. MRPS 95320 This is the third MOC image obtained during the first year of MGS operations that shows the contact between Lycus Sulci and Amazonis Planitia. This picture, a subframe of SPO2-483/08, was taken in August 1998. The Lycus Sulciup lands at this location dominate the lower half of the picture, while the Amazonis plains cover the upper half. The uplands here exhibit many small buttes (bumps or knobs in lower right of the scene), and the contact zone between the upland and lowland includes a triangular-shaped ridge (center/right). As with the earlier views of the contact between Lycus Sulci and Amazonis, no features of obvious origin by coastal processes (e.g., erosion by waves crashing against ashore) are seen. The scene is illuminated from the right., The first picture above shows the regional context of a Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) high-resolution image that was targeted in August 1998 with the intent to test the hypothesis that the northern plains of Mars were once the site of a vast ocean of liquid water. The second picture shows the resulting MOC image, numbered SPO2-515/05 and located at 40.0°N, 6.0°W in the transition zone between the Cydonia region and Acidalia Planitia, Mars. The context image (first picture) includes several dark lines, some of which are labeled I and some are labeled G. These dark lines were proposed in previous, peer-reviewed scientific papers to be possible ocean shorelines located along the margins of the martian northern plains. Line I was called the Interior Plains Boundary, and line G was called the Gradational Boundary. The MGS MOC high resolution image was targeted such that it would examine the nature of line I, the Interior Plains Boundary. The second figure shows the MOC high resolution view. The picture on the left side of the figure (second image) is the full MOC image and the white box indicates the location of the expanded view to the right. In the expanded view (the center of the figure), the location of line I--the proposed shoreline--is shown by a dashed curve. The dashed curve follows a subtle, shallow trough. None of the types of coastal landforms common on Earth--such as a beach, wave-cut cliff or terrace, or coastal dune fields, are seen at this location. If an ocean had once been present, then the water would have covered the top 2/3 of the expanded view--i.e., water would have lapped up against the rounded mounds in the lower 1/3 of this picture. Instead of coastal landforms, the MOC image exhibits a dark surface in its upper 1/3. The dark surface covers older, rounded hills and has a low, lobate escarpment along its southern margin. This escarpment faces south--that is, it faces toward the once-proposed coastline. In other words, the escarpment faces in a direction opposite of what would be expected for a coastal environment. The context picture uses Viking orbiter image 561a24 as a base., This picture is the first MOC high resolution image that showed the contact between the Lycus Sulci uplands and Amazonis Planitia lowlands. In this subframe of MOC image SPO 1-225/03, Amazonis and Lycus Sulci are separated by a subtle rise that runs diagonally across the scene from near the lower left toward the upper right. The Amazonis plains are toward the top of the picture, the Lycus Sulci uplands are toward the bottom. Both surfaces have been cratered by small meteoroid impacts. The Amazonis plains surface has many small, nearly parallel ridges that may have formed by wind erosion. These ridges are not found on the Lycus Sulci surface. None of the features seen in this image look like typical seashore landforms found on Earth--i.e., there are no beaches, windblown coastal dunes, or even the wave-cut cliff that was thought to exist on the basis of previous Viking images. The picture is illuminated from the lower right and was acquired in April 1998. Lycus Sulci is the name of a region of hills and ridges located north and northwest of the famous giant volcano, Olympus Mons (see inset, above). Viking images of the area where the western margin of the Lycus Sulci meets the smooth Amazonis plains (upper left in the figure above) led some researchers to conclude that the two surfaces were in contact along a cliff. The proposed cliff faces toward the smooth plains, and thus it was suggested that this might be the kind of cliff that forms from erosion by waves in a body of water as they break against a coastline. During the first year that Mars Global Surveyor (MGS) was orbiting the red planet (1997-1998), the Mars Orbiter Camera (MOC) acquired three high-resolution images along the contact between the Lycus Sulci hills and the Amazonis plains. The location of the portion of each image that is illustrated below is shown in this figure by a small, white box identified by the archival image number (e.g., "SPO2-428/03" refers to the 3rd image taken on the 428th orbit during the Science Phasing Orbits 2 phase of the MGS mission). The regional context view shown here is a portion of Viking orbiter image 851A29, its center is near 32°N, 114°W and it is illuminated from the right.
Mars Shoreline Tests: Contac …
PIA02338
Sol (our sun)
Mars Orbiter Camera
Title Mars Shoreline Tests: Contact between Lycus Sulci and Amazonis Planitia
Original Caption Released with Image If the northern plains of Mars had ever been the site of a vast ocean, then any highlands that protrude above these plains might be expected to exhibit shorelines. The somewhat curved, flat-topped mesa seen in Viking image 026A72 (first image)is bounded by a dark band. Prior to the Mars Global Surveyor (MGS) mission, this mesa was interpreted by some researchers as having been a possible island in an ancient, northern plains ocean. The dark band was interpreted to be a shoreline resulting from the action of waves lapping against the island's coast. A high resolution image of the banded mesa--located on the Acidalia plains around 45°N, 7°W--was acquired by the MGS Mars Orbiter Camera (MOC) in August 1998, over twenty years after the Viking image was taken. A subframe of this image--SPO2-515/06--is shown in the second image. In the MOC image, the dark band resolves into a series of narrower bright and dark bands. Each band has a slightly different texture and brightness. Furthermore, what appeared to be a sunlit escarpment bounding the north side of the mesa in the Viking image appears in the MOC image to be only a shallow slope rather than a scarp or cliff. The origin of the different bands is not known, but the most likely explanation that would be consistent with other MOC observations of Mars is that the mesa consists of layered rock, and that each band is an outcropping of a different layer of this rock. The different textures would result from the differing resistance to erosion of each layer. Both images shown here are illuminated from the left., MRPS 50586 Mars Global Surveyor's (MGS) Mars Orbiter Camera (MOC) took the above picture (second of the two) of some massifs and mesas in the Cydonia region of Mars in early September 1998. The purpose of this image--number SPO2-532/04--was to test the hypothesis that the martian northern plains were once the site of an ocean or large sea. According to this hypothesis, and according to peer-reviewed and published maps, each one of the mesas and massifs in the two pictures above should have shorelines around their margins. The hypothesis holds that these were once islands and that waves would lap--and sometimes crash--against these landforms, rip off huge chunks of rock, and create steep cliffs and stair-stepped terraces in the rock. The first picture above shows the regional context of the MOC high resolution view in Cydonia. The context picture, from Viking orbiter image 227S11, is illuminated from the right. The second picture above is a figure that shows the full SPO2-532/04 MOC image and two expanded views of portions of this image. Mesas are flat-topped uplands, and massifs are the more triangular, massive peaks. If an ocean had been present in this region, terraces that indicate erosion or bathtub rings of salt or carbonate deposits left by the retreat of this ocean as it dried up might be found around each mesa and massif. No such features are found, nor is it at all obvious why these mesas and massifs were portrayed in previously published figures as having shorelines around them. The MOC image is illuminated from the left., MRPS 95319 Lycus Sulci and Amazonis Planitia are shown here separated by a rise that runs diagonally across the scene from near the lower left toward the upper right. This picture is a subframe of MOC image SPO2-428/03, taken in July 1998. The Lycus Sulci uplands here are more roughly-textured than in the previous image, and the flat Amazonis plains appear to be more smooth and lack the small parallel ridges seen in the earlier view. The lack of the small ridges might be real, or they might be present but cannot be seen because this picture has a lower resolution than the previous one. This image, too, shows that the contact between Amazonis and Lycus Sulci is not a cliff, and once again there are no features that can be unambiguously identified as coastal landforms. MRPS 95320 This is the third MOC image obtained during the first year of MGS operations that shows the contact between Lycus Sulci and Amazonis Planitia. This picture, a subframe of SPO2-483/08, was taken in August 1998. The Lycus Sulciup lands at this location dominate the lower half of the picture, while the Amazonis plains cover the upper half. The uplands here exhibit many small buttes (bumps or knobs in lower right of the scene), and the contact zone between the upland and lowland includes a triangular-shaped ridge (center/right). As with the earlier views of the contact between Lycus Sulci and Amazonis, no features of obvious origin by coastal processes (e.g., erosion by waves crashing against ashore) are seen. The scene is illuminated from the right., The first picture above shows the regional context of a Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) high-resolution image that was targeted in August 1998 with the intent to test the hypothesis that the northern plains of Mars were once the site of a vast ocean of liquid water. The second picture shows the resulting MOC image, numbered SPO2-515/05 and located at 40.0°N, 6.0°W in the transition zone between the Cydonia region and Acidalia Planitia, Mars. The context image (first picture) includes several dark lines, some of which are labeled I and some are labeled G. These dark lines were proposed in previous, peer-reviewed scientific papers to be possible ocean shorelines located along the margins of the martian northern plains. Line I was called the Interior Plains Boundary, and line G was called the Gradational Boundary. The MGS MOC high resolution image was targeted such that it would examine the nature of line I, the Interior Plains Boundary. The second figure shows the MOC high resolution view. The picture on the left side of the figure (second image) is the full MOC image and the white box indicates the location of the expanded view to the right. In the expanded view (the center of the figure), the location of line I--the proposed shoreline--is shown by a dashed curve. The dashed curve follows a subtle, shallow trough. None of the types of coastal landforms common on Earth--such as a beach, wave-cut cliff or terrace, or coastal dune fields, are seen at this location. If an ocean had once been present, then the water would have covered the top 2/3 of the expanded view--i.e., water would have lapped up against the rounded mounds in the lower 1/3 of this picture. Instead of coastal landforms, the MOC image exhibits a dark surface in its upper 1/3. The dark surface covers older, rounded hills and has a low, lobate escarpment along its southern margin. This escarpment faces south--that is, it faces toward the once-proposed coastline. In other words, the escarpment faces in a direction opposite of what would be expected for a coastal environment. The context picture uses Viking orbiter image 561a24 as a base., This picture is the first MOC high resolution image that showed the contact between the Lycus Sulci uplands and Amazonis Planitia lowlands. In this subframe of MOC image SPO 1-225/03, Amazonis and Lycus Sulci are separated by a subtle rise that runs diagonally across the scene from near the lower left toward the upper right. The Amazonis plains are toward the top of the picture, the Lycus Sulci uplands are toward the bottom. Both surfaces have been cratered by small meteoroid impacts. The Amazonis plains surface has many small, nearly parallel ridges that may have formed by wind erosion. These ridges are not found on the Lycus Sulci surface. None of the features seen in this image look like typical seashore landforms found on Earth--i.e., there are no beaches, windblown coastal dunes, or even the wave-cut cliff that was thought to exist on the basis of previous Viking images. The picture is illuminated from the lower right and was acquired in April 1998. Lycus Sulci is the name of a region of hills and ridges located north and northwest of the famous giant volcano, Olympus Mons (see inset, above). Viking images of the area where the western margin of the Lycus Sulci meets the smooth Amazonis plains (upper left in the figure above) led some researchers to conclude that the two surfaces were in contact along a cliff. The proposed cliff faces toward the smooth plains, and thus it was suggested that this might be the kind of cliff that forms from erosion by waves in a body of water as they break against a coastline. During the first year that Mars Global Surveyor (MGS) was orbiting the red planet (1997-1998), the Mars Orbiter Camera (MOC) acquired three high-resolution images along the contact between the Lycus Sulci hills and the Amazonis plains. The location of the portion of each image that is illustrated below is shown in this figure by a small, white box identified by the archival image number (e.g., "SPO2-428/03" refers to the 3rd image taken on the 428th orbit during the Science Phasing Orbits 2 phase of the MGS mission). The regional context view shown here is a portion of Viking orbiter image 851A29, its center is near 32°N, 114°W and it is illuminated from the right.
Mars Shoreline Tests: Contac …
PIA02338
Sol (our sun)
Mars Orbiter Camera
Title Mars Shoreline Tests: Contact between Lycus Sulci and Amazonis Planitia
Original Caption Released with Image If the northern plains of Mars had ever been the site of a vast ocean, then any highlands that protrude above these plains might be expected to exhibit shorelines. The somewhat curved, flat-topped mesa seen in Viking image 026A72 (first image)is bounded by a dark band. Prior to the Mars Global Surveyor (MGS) mission, this mesa was interpreted by some researchers as having been a possible island in an ancient, northern plains ocean. The dark band was interpreted to be a shoreline resulting from the action of waves lapping against the island's coast. A high resolution image of the banded mesa--located on the Acidalia plains around 45°N, 7°W--was acquired by the MGS Mars Orbiter Camera (MOC) in August 1998, over twenty years after the Viking image was taken. A subframe of this image--SPO2-515/06--is shown in the second image. In the MOC image, the dark band resolves into a series of narrower bright and dark bands. Each band has a slightly different texture and brightness. Furthermore, what appeared to be a sunlit escarpment bounding the north side of the mesa in the Viking image appears in the MOC image to be only a shallow slope rather than a scarp or cliff. The origin of the different bands is not known, but the most likely explanation that would be consistent with other MOC observations of Mars is that the mesa consists of layered rock, and that each band is an outcropping of a different layer of this rock. The different textures would result from the differing resistance to erosion of each layer. Both images shown here are illuminated from the left., MRPS 50586 Mars Global Surveyor's (MGS) Mars Orbiter Camera (MOC) took the above picture (second of the two) of some massifs and mesas in the Cydonia region of Mars in early September 1998. The purpose of this image--number SPO2-532/04--was to test the hypothesis that the martian northern plains were once the site of an ocean or large sea. According to this hypothesis, and according to peer-reviewed and published maps, each one of the mesas and massifs in the two pictures above should have shorelines around their margins. The hypothesis holds that these were once islands and that waves would lap--and sometimes crash--against these landforms, rip off huge chunks of rock, and create steep cliffs and stair-stepped terraces in the rock. The first picture above shows the regional context of the MOC high resolution view in Cydonia. The context picture, from Viking orbiter image 227S11, is illuminated from the right. The second picture above is a figure that shows the full SPO2-532/04 MOC image and two expanded views of portions of this image. Mesas are flat-topped uplands, and massifs are the more triangular, massive peaks. If an ocean had been present in this region, terraces that indicate erosion or bathtub rings of salt or carbonate deposits left by the retreat of this ocean as it dried up might be found around each mesa and massif. No such features are found, nor is it at all obvious why these mesas and massifs were portrayed in previously published figures as having shorelines around them. The MOC image is illuminated from the left., MRPS 95319 Lycus Sulci and Amazonis Planitia are shown here separated by a rise that runs diagonally across the scene from near the lower left toward the upper right. This picture is a subframe of MOC image SPO2-428/03, taken in July 1998. The Lycus Sulci uplands here are more roughly-textured than in the previous image, and the flat Amazonis plains appear to be more smooth and lack the small parallel ridges seen in the earlier view. The lack of the small ridges might be real, or they might be present but cannot be seen because this picture has a lower resolution than the previous one. This image, too, shows that the contact between Amazonis and Lycus Sulci is not a cliff, and once again there are no features that can be unambiguously identified as coastal landforms. MRPS 95320 This is the third MOC image obtained during the first year of MGS operations that shows the contact between Lycus Sulci and Amazonis Planitia. This picture, a subframe of SPO2-483/08, was taken in August 1998. The Lycus Sulciup lands at this location dominate the lower half of the picture, while the Amazonis plains cover the upper half. The uplands here exhibit many small buttes (bumps or knobs in lower right of the scene), and the contact zone between the upland and lowland includes a triangular-shaped ridge (center/right). As with the earlier views of the contact between Lycus Sulci and Amazonis, no features of obvious origin by coastal processes (e.g., erosion by waves crashing against ashore) are seen. The scene is illuminated from the right., The first picture above shows the regional context of a Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) high-resolution image that was targeted in August 1998 with the intent to test the hypothesis that the northern plains of Mars were once the site of a vast ocean of liquid water. The second picture shows the resulting MOC image, numbered SPO2-515/05 and located at 40.0°N, 6.0°W in the transition zone between the Cydonia region and Acidalia Planitia, Mars. The context image (first picture) includes several dark lines, some of which are labeled I and some are labeled G. These dark lines were proposed in previous, peer-reviewed scientific papers to be possible ocean shorelines located along the margins of the martian northern plains. Line I was called the Interior Plains Boundary, and line G was called the Gradational Boundary. The MGS MOC high resolution image was targeted such that it would examine the nature of line I, the Interior Plains Boundary. The second figure shows the MOC high resolution view. The picture on the left side of the figure (second image) is the full MOC image and the white box indicates the location of the expanded view to the right. In the expanded view (the center of the figure), the location of line I--the proposed shoreline--is shown by a dashed curve. The dashed curve follows a subtle, shallow trough. None of the types of coastal landforms common on Earth--such as a beach, wave-cut cliff or terrace, or coastal dune fields, are seen at this location. If an ocean had once been present, then the water would have covered the top 2/3 of the expanded view--i.e., water would have lapped up against the rounded mounds in the lower 1/3 of this picture. Instead of coastal landforms, the MOC image exhibits a dark surface in its upper 1/3. The dark surface covers older, rounded hills and has a low, lobate escarpment along its southern margin. This escarpment faces south--that is, it faces toward the once-proposed coastline. In other words, the escarpment faces in a direction opposite of what would be expected for a coastal environment. The context picture uses Viking orbiter image 561a24 as a base., This picture is the first MOC high resolution image that showed the contact between the Lycus Sulci uplands and Amazonis Planitia lowlands. In this subframe of MOC image SPO 1-225/03, Amazonis and Lycus Sulci are separated by a subtle rise that runs diagonally across the scene from near the lower left toward the upper right. The Amazonis plains are toward the top of the picture, the Lycus Sulci uplands are toward the bottom. Both surfaces have been cratered by small meteoroid impacts. The Amazonis plains surface has many small, nearly parallel ridges that may have formed by wind erosion. These ridges are not found on the Lycus Sulci surface. None of the features seen in this image look like typical seashore landforms found on Earth--i.e., there are no beaches, windblown coastal dunes, or even the wave-cut cliff that was thought to exist on the basis of previous Viking images. The picture is illuminated from the lower right and was acquired in April 1998. Lycus Sulci is the name of a region of hills and ridges located north and northwest of the famous giant volcano, Olympus Mons (see inset, above). Viking images of the area where the western margin of the Lycus Sulci meets the smooth Amazonis plains (upper left in the figure above) led some researchers to conclude that the two surfaces were in contact along a cliff. The proposed cliff faces toward the smooth plains, and thus it was suggested that this might be the kind of cliff that forms from erosion by waves in a body of water as they break against a coastline. During the first year that Mars Global Surveyor (MGS) was orbiting the red planet (1997-1998), the Mars Orbiter Camera (MOC) acquired three high-resolution images along the contact between the Lycus Sulci hills and the Amazonis plains. The location of the portion of each image that is illustrated below is shown in this figure by a small, white box identified by the archival image number (e.g., "SPO2-428/03" refers to the 3rd image taken on the 428th orbit during the Science Phasing Orbits 2 phase of the MGS mission). The regional context view shown here is a portion of Viking orbiter image 851A29, its center is near 32°N, 114°W and it is illuminated from the right.
Mars Shoreline Tests: Contac …
PIA02338
Sol (our sun)
Mars Orbiter Camera
Title Mars Shoreline Tests: Contact between Lycus Sulci and Amazonis Planitia
Original Caption Released with Image If the northern plains of Mars had ever been the site of a vast ocean, then any highlands that protrude above these plains might be expected to exhibit shorelines. The somewhat curved, flat-topped mesa seen in Viking image 026A72 (first image)is bounded by a dark band. Prior to the Mars Global Surveyor (MGS) mission, this mesa was interpreted by some researchers as having been a possible island in an ancient, northern plains ocean. The dark band was interpreted to be a shoreline resulting from the action of waves lapping against the island's coast. A high resolution image of the banded mesa--located on the Acidalia plains around 45°N, 7°W--was acquired by the MGS Mars Orbiter Camera (MOC) in August 1998, over twenty years after the Viking image was taken. A subframe of this image--SPO2-515/06--is shown in the second image. In the MOC image, the dark band resolves into a series of narrower bright and dark bands. Each band has a slightly different texture and brightness. Furthermore, what appeared to be a sunlit escarpment bounding the north side of the mesa in the Viking image appears in the MOC image to be only a shallow slope rather than a scarp or cliff. The origin of the different bands is not known, but the most likely explanation that would be consistent with other MOC observations of Mars is that the mesa consists of layered rock, and that each band is an outcropping of a different layer of this rock. The different textures would result from the differing resistance to erosion of each layer. Both images shown here are illuminated from the left., MRPS 50586 Mars Global Surveyor's (MGS) Mars Orbiter Camera (MOC) took the above picture (second of the two) of some massifs and mesas in the Cydonia region of Mars in early September 1998. The purpose of this image--number SPO2-532/04--was to test the hypothesis that the martian northern plains were once the site of an ocean or large sea. According to this hypothesis, and according to peer-reviewed and published maps, each one of the mesas and massifs in the two pictures above should have shorelines around their margins. The hypothesis holds that these were once islands and that waves would lap--and sometimes crash--against these landforms, rip off huge chunks of rock, and create steep cliffs and stair-stepped terraces in the rock. The first picture above shows the regional context of the MOC high resolution view in Cydonia. The context picture, from Viking orbiter image 227S11, is illuminated from the right. The second picture above is a figure that shows the full SPO2-532/04 MOC image and two expanded views of portions of this image. Mesas are flat-topped uplands, and massifs are the more triangular, massive peaks. If an ocean had been present in this region, terraces that indicate erosion or bathtub rings of salt or carbonate deposits left by the retreat of this ocean as it dried up might be found around each mesa and massif. No such features are found, nor is it at all obvious why these mesas and massifs were portrayed in previously published figures as having shorelines around them. The MOC image is illuminated from the left., MRPS 95319 Lycus Sulci and Amazonis Planitia are shown here separated by a rise that runs diagonally across the scene from near the lower left toward the upper right. This picture is a subframe of MOC image SPO2-428/03, taken in July 1998. The Lycus Sulci uplands here are more roughly-textured than in the previous image, and the flat Amazonis plains appear to be more smooth and lack the small parallel ridges seen in the earlier view. The lack of the small ridges might be real, or they might be present but cannot be seen because this picture has a lower resolution than the previous one. This image, too, shows that the contact between Amazonis and Lycus Sulci is not a cliff, and once again there are no features that can be unambiguously identified as coastal landforms. MRPS 95320 This is the third MOC image obtained during the first year of MGS operations that shows the contact between Lycus Sulci and Amazonis Planitia. This picture, a subframe of SPO2-483/08, was taken in August 1998. The Lycus Sulciup lands at this location dominate the lower half of the picture, while the Amazonis plains cover the upper half. The uplands here exhibit many small buttes (bumps or knobs in lower right of the scene), and the contact zone between the upland and lowland includes a triangular-shaped ridge (center/right). As with the earlier views of the contact between Lycus Sulci and Amazonis, no features of obvious origin by coastal processes (e.g., erosion by waves crashing against ashore) are seen. The scene is illuminated from the right., The first picture above shows the regional context of a Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) high-resolution image that was targeted in August 1998 with the intent to test the hypothesis that the northern plains of Mars were once the site of a vast ocean of liquid water. The second picture shows the resulting MOC image, numbered SPO2-515/05 and located at 40.0°N, 6.0°W in the transition zone between the Cydonia region and Acidalia Planitia, Mars. The context image (first picture) includes several dark lines, some of which are labeled I and some are labeled G. These dark lines were proposed in previous, peer-reviewed scientific papers to be possible ocean shorelines located along the margins of the martian northern plains. Line I was called the Interior Plains Boundary, and line G was called the Gradational Boundary. The MGS MOC high resolution image was targeted such that it would examine the nature of line I, the Interior Plains Boundary. The second figure shows the MOC high resolution view. The picture on the left side of the figure (second image) is the full MOC image and the white box indicates the location of the expanded view to the right. In the expanded view (the center of the figure), the location of line I--the proposed shoreline--is shown by a dashed curve. The dashed curve follows a subtle, shallow trough. None of the types of coastal landforms common on Earth--such as a beach, wave-cut cliff or terrace, or coastal dune fields, are seen at this location. If an ocean had once been present, then the water would have covered the top 2/3 of the expanded view--i.e., water would have lapped up against the rounded mounds in the lower 1/3 of this picture. Instead of coastal landforms, the MOC image exhibits a dark surface in its upper 1/3. The dark surface covers older, rounded hills and has a low, lobate escarpment along its southern margin. This escarpment faces south--that is, it faces toward the once-proposed coastline. In other words, the escarpment faces in a direction opposite of what would be expected for a coastal environment. The context picture uses Viking orbiter image 561a24 as a base., This picture is the first MOC high resolution image that showed the contact between the Lycus Sulci uplands and Amazonis Planitia lowlands. In this subframe of MOC image SPO 1-225/03, Amazonis and Lycus Sulci are separated by a subtle rise that runs diagonally across the scene from near the lower left toward the upper right. The Amazonis plains are toward the top of the picture, the Lycus Sulci uplands are toward the bottom. Both surfaces have been cratered by small meteoroid impacts. The Amazonis plains surface has many small, nearly parallel ridges that may have formed by wind erosion. These ridges are not found on the Lycus Sulci surface. None of the features seen in this image look like typical seashore landforms found on Earth--i.e., there are no beaches, windblown coastal dunes, or even the wave-cut cliff that was thought to exist on the basis of previous Viking images. The picture is illuminated from the lower right and was acquired in April 1998. Lycus Sulci is the name of a region of hills and ridges located north and northwest of the famous giant volcano, Olympus Mons (see inset, above). Viking images of the area where the western margin of the Lycus Sulci meets the smooth Amazonis plains (upper left in the figure above) led some researchers to conclude that the two surfaces were in contact along a cliff. The proposed cliff faces toward the smooth plains, and thus it was suggested that this might be the kind of cliff that forms from erosion by waves in a body of water as they break against a coastline. During the first year that Mars Global Surveyor (MGS) was orbiting the red planet (1997-1998), the Mars Orbiter Camera (MOC) acquired three high-resolution images along the contact between the Lycus Sulci hills and the Amazonis plains. The location of the portion of each image that is illustrated below is shown in this figure by a small, white box identified by the archival image number (e.g., "SPO2-428/03" refers to the 3rd image taken on the 428th orbit during the Science Phasing Orbits 2 phase of the MGS mission). The regional context view shown here is a portion of Viking orbiter image 851A29, its center is near 32°N, 114°W and it is illuminated from the right.
Mars Shoreline Tests: Contac …
PIA02338
Sol (our sun)
Mars Orbiter Camera
Title Mars Shoreline Tests: Contact between Lycus Sulci and Amazonis Planitia
Original Caption Released with Image If the northern plains of Mars had ever been the site of a vast ocean, then any highlands that protrude above these plains might be expected to exhibit shorelines. The somewhat curved, flat-topped mesa seen in Viking image 026A72 (first image)is bounded by a dark band. Prior to the Mars Global Surveyor (MGS) mission, this mesa was interpreted by some researchers as having been a possible island in an ancient, northern plains ocean. The dark band was interpreted to be a shoreline resulting from the action of waves lapping against the island's coast. A high resolution image of the banded mesa--located on the Acidalia plains around 45°N, 7°W--was acquired by the MGS Mars Orbiter Camera (MOC) in August 1998, over twenty years after the Viking image was taken. A subframe of this image--SPO2-515/06--is shown in the second image. In the MOC image, the dark band resolves into a series of narrower bright and dark bands. Each band has a slightly different texture and brightness. Furthermore, what appeared to be a sunlit escarpment bounding the north side of the mesa in the Viking image appears in the MOC image to be only a shallow slope rather than a scarp or cliff. The origin of the different bands is not known, but the most likely explanation that would be consistent with other MOC observations of Mars is that the mesa consists of layered rock, and that each band is an outcropping of a different layer of this rock. The different textures would result from the differing resistance to erosion of each layer. Both images shown here are illuminated from the left., MRPS 50586 Mars Global Surveyor's (MGS) Mars Orbiter Camera (MOC) took the above picture (second of the two) of some massifs and mesas in the Cydonia region of Mars in early September 1998. The purpose of this image--number SPO2-532/04--was to test the hypothesis that the martian northern plains were once the site of an ocean or large sea. According to this hypothesis, and according to peer-reviewed and published maps, each one of the mesas and massifs in the two pictures above should have shorelines around their margins. The hypothesis holds that these were once islands and that waves would lap--and sometimes crash--against these landforms, rip off huge chunks of rock, and create steep cliffs and stair-stepped terraces in the rock. The first picture above shows the regional context of the MOC high resolution view in Cydonia. The context picture, from Viking orbiter image 227S11, is illuminated from the right. The second picture above is a figure that shows the full SPO2-532/04 MOC image and two expanded views of portions of this image. Mesas are flat-topped uplands, and massifs are the more triangular, massive peaks. If an ocean had been present in this region, terraces that indicate erosion or bathtub rings of salt or carbonate deposits left by the retreat of this ocean as it dried up might be found around each mesa and massif. No such features are found, nor is it at all obvious why these mesas and massifs were portrayed in previously published figures as having shorelines around them. The MOC image is illuminated from the left., MRPS 95319 Lycus Sulci and Amazonis Planitia are shown here separated by a rise that runs diagonally across the scene from near the lower left toward the upper right. This picture is a subframe of MOC image SPO2-428/03, taken in July 1998. The Lycus Sulci uplands here are more roughly-textured than in the previous image, and the flat Amazonis plains appear to be more smooth and lack the small parallel ridges seen in the earlier view. The lack of the small ridges might be real, or they might be present but cannot be seen because this picture has a lower resolution than the previous one. This image, too, shows that the contact between Amazonis and Lycus Sulci is not a cliff, and once again there are no features that can be unambiguously identified as coastal landforms. MRPS 95320 This is the third MOC image obtained during the first year of MGS operations that shows the contact between Lycus Sulci and Amazonis Planitia. This picture, a subframe of SPO2-483/08, was taken in August 1998. The Lycus Sulciup lands at this location dominate the lower half of the picture, while the Amazonis plains cover the upper half. The uplands here exhibit many small buttes (bumps or knobs in lower right of the scene), and the contact zone between the upland and lowland includes a triangular-shaped ridge (center/right). As with the earlier views of the contact between Lycus Sulci and Amazonis, no features of obvious origin by coastal processes (e.g., erosion by waves crashing against ashore) are seen. The scene is illuminated from the right., The first picture above shows the regional context of a Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) high-resolution image that was targeted in August 1998 with the intent to test the hypothesis that the northern plains of Mars were once the site of a vast ocean of liquid water. The second picture shows the resulting MOC image, numbered SPO2-515/05 and located at 40.0°N, 6.0°W in the transition zone between the Cydonia region and Acidalia Planitia, Mars. The context image (first picture) includes several dark lines, some of which are labeled I and some are labeled G. These dark lines were proposed in previous, peer-reviewed scientific papers to be possible ocean shorelines located along the margins of the martian northern plains. Line I was called the Interior Plains Boundary, and line G was called the Gradational Boundary. The MGS MOC high resolution image was targeted such that it would examine the nature of line I, the Interior Plains Boundary. The second figure shows the MOC high resolution view. The picture on the left side of the figure (second image) is the full MOC image and the white box indicates the location of the expanded view to the right. In the expanded view (the center of the figure), the location of line I--the proposed shoreline--is shown by a dashed curve. The dashed curve follows a subtle, shallow trough. None of the types of coastal landforms common on Earth--such as a beach, wave-cut cliff or terrace, or coastal dune fields, are seen at this location. If an ocean had once been present, then the water would have covered the top 2/3 of the expanded view--i.e., water would have lapped up against the rounded mounds in the lower 1/3 of this picture. Instead of coastal landforms, the MOC image exhibits a dark surface in its upper 1/3. The dark surface covers older, rounded hills and has a low, lobate escarpment along its southern margin. This escarpment faces south--that is, it faces toward the once-proposed coastline. In other words, the escarpment faces in a direction opposite of what would be expected for a coastal environment. The context picture uses Viking orbiter image 561a24 as a base., This picture is the first MOC high resolution image that showed the contact between the Lycus Sulci uplands and Amazonis Planitia lowlands. In this subframe of MOC image SPO 1-225/03, Amazonis and Lycus Sulci are separated by a subtle rise that runs diagonally across the scene from near the lower left toward the upper right. The Amazonis plains are toward the top of the picture, the Lycus Sulci uplands are toward the bottom. Both surfaces have been cratered by small meteoroid impacts. The Amazonis plains surface has many small, nearly parallel ridges that may have formed by wind erosion. These ridges are not found on the Lycus Sulci surface. None of the features seen in this image look like typical seashore landforms found on Earth--i.e., there are no beaches, windblown coastal dunes, or even the wave-cut cliff that was thought to exist on the basis of previous Viking images. The picture is illuminated from the lower right and was acquired in April 1998. Lycus Sulci is the name of a region of hills and ridges located north and northwest of the famous giant volcano, Olympus Mons (see inset, above). Viking images of the area where the western margin of the Lycus Sulci meets the smooth Amazonis plains (upper left in the figure above) led some researchers to conclude that the two surfaces were in contact along a cliff. The proposed cliff faces toward the smooth plains, and thus it was suggested that this might be the kind of cliff that forms from erosion by waves in a body of water as they break against a coastline. During the first year that Mars Global Surveyor (MGS) was orbiting the red planet (1997-1998), the Mars Orbiter Camera (MOC) acquired three high-resolution images along the contact between the Lycus Sulci hills and the Amazonis plains. The location of the portion of each image that is illustrated below is shown in this figure by a small, white box identified by the archival image number (e.g., "SPO2-428/03" refers to the 3rd image taken on the 428th orbit during the Science Phasing Orbits 2 phase of the MGS mission). The regional context view shown here is a portion of Viking orbiter image 851A29, its center is near 32°N, 114°W and it is illuminated from the right.
Mars Shoreline Tests: Contac …
PIA02338
Sol (our sun)
Mars Orbiter Camera
Title Mars Shoreline Tests: Contact between Lycus Sulci and Amazonis Planitia
Original Caption Released with Image If the northern plains of Mars had ever been the site of a vast ocean, then any highlands that protrude above these plains might be expected to exhibit shorelines. The somewhat curved, flat-topped mesa seen in Viking image 026A72 (first image)is bounded by a dark band. Prior to the Mars Global Surveyor (MGS) mission, this mesa was interpreted by some researchers as having been a possible island in an ancient, northern plains ocean. The dark band was interpreted to be a shoreline resulting from the action of waves lapping against the island's coast. A high resolution image of the banded mesa--located on the Acidalia plains around 45°N, 7°W--was acquired by the MGS Mars Orbiter Camera (MOC) in August 1998, over twenty years after the Viking image was taken. A subframe of this image--SPO2-515/06--is shown in the second image. In the MOC image, the dark band resolves into a series of narrower bright and dark bands. Each band has a slightly different texture and brightness. Furthermore, what appeared to be a sunlit escarpment bounding the north side of the mesa in the Viking image appears in the MOC image to be only a shallow slope rather than a scarp or cliff. The origin of the different bands is not known, but the most likely explanation that would be consistent with other MOC observations of Mars is that the mesa consists of layered rock, and that each band is an outcropping of a different layer of this rock. The different textures would result from the differing resistance to erosion of each layer. Both images shown here are illuminated from the left., MRPS 50586 Mars Global Surveyor's (MGS) Mars Orbiter Camera (MOC) took the above picture (second of the two) of some massifs and mesas in the Cydonia region of Mars in early September 1998. The purpose of this image--number SPO2-532/04--was to test the hypothesis that the martian northern plains were once the site of an ocean or large sea. According to this hypothesis, and according to peer-reviewed and published maps, each one of the mesas and massifs in the two pictures above should have shorelines around their margins. The hypothesis holds that these were once islands and that waves would lap--and sometimes crash--against these landforms, rip off huge chunks of rock, and create steep cliffs and stair-stepped terraces in the rock. The first picture above shows the regional context of the MOC high resolution view in Cydonia. The context picture, from Viking orbiter image 227S11, is illuminated from the right. The second picture above is a figure that shows the full SPO2-532/04 MOC image and two expanded views of portions of this image. Mesas are flat-topped uplands, and massifs are the more triangular, massive peaks. If an ocean had been present in this region, terraces that indicate erosion or bathtub rings of salt or carbonate deposits left by the retreat of this ocean as it dried up might be found around each mesa and massif. No such features are found, nor is it at all obvious why these mesas and massifs were portrayed in previously published figures as having shorelines around them. The MOC image is illuminated from the left., MRPS 95319 Lycus Sulci and Amazonis Planitia are shown here separated by a rise that runs diagonally across the scene from near the lower left toward the upper right. This picture is a subframe of MOC image SPO2-428/03, taken in July 1998. The Lycus Sulci uplands here are more roughly-textured than in the previous image, and the flat Amazonis plains appear to be more smooth and lack the small parallel ridges seen in the earlier view. The lack of the small ridges might be real, or they might be present but cannot be seen because this picture has a lower resolution than the previous one. This image, too, shows that the contact between Amazonis and Lycus Sulci is not a cliff, and once again there are no features that can be unambiguously identified as coastal landforms. MRPS 95320 This is the third MOC image obtained during the first year of MGS operations that shows the contact between Lycus Sulci and Amazonis Planitia. This picture, a subframe of SPO2-483/08, was taken in August 1998. The Lycus Sulciup lands at this location dominate the lower half of the picture, while the Amazonis plains cover the upper half. The uplands here exhibit many small buttes (bumps or knobs in lower right of the scene), and the contact zone between the upland and lowland includes a triangular-shaped ridge (center/right). As with the earlier views of the contact between Lycus Sulci and Amazonis, no features of obvious origin by coastal processes (e.g., erosion by waves crashing against ashore) are seen. The scene is illuminated from the right., The first picture above shows the regional context of a Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) high-resolution image that was targeted in August 1998 with the intent to test the hypothesis that the northern plains of Mars were once the site of a vast ocean of liquid water. The second picture shows the resulting MOC image, numbered SPO2-515/05 and located at 40.0°N, 6.0°W in the transition zone between the Cydonia region and Acidalia Planitia, Mars. The context image (first picture) includes several dark lines, some of which are labeled I and some are labeled G. These dark lines were proposed in previous, peer-reviewed scientific papers to be possible ocean shorelines located along the margins of the martian northern plains. Line I was called the Interior Plains Boundary, and line G was called the Gradational Boundary. The MGS MOC high resolution image was targeted such that it would examine the nature of line I, the Interior Plains Boundary. The second figure shows the MOC high resolution view. The picture on the left side of the figure (second image) is the full MOC image and the white box indicates the location of the expanded view to the right. In the expanded view (the center of the figure), the location of line I--the proposed shoreline--is shown by a dashed curve. The dashed curve follows a subtle, shallow trough. None of the types of coastal landforms common on Earth--such as a beach, wave-cut cliff or terrace, or coastal dune fields, are seen at this location. If an ocean had once been present, then the water would have covered the top 2/3 of the expanded view--i.e., water would have lapped up against the rounded mounds in the lower 1/3 of this picture. Instead of coastal landforms, the MOC image exhibits a dark surface in its upper 1/3. The dark surface covers older, rounded hills and has a low, lobate escarpment along its southern margin. This escarpment faces south--that is, it faces toward the once-proposed coastline. In other words, the escarpment faces in a direction opposite of what would be expected for a coastal environment. The context picture uses Viking orbiter image 561a24 as a base., This picture is the first MOC high resolution image that showed the contact between the Lycus Sulci uplands and Amazonis Planitia lowlands. In this subframe of MOC image SPO 1-225/03, Amazonis and Lycus Sulci are separated by a subtle rise that runs diagonally across the scene from near the lower left toward the upper right. The Amazonis plains are toward the top of the picture, the Lycus Sulci uplands are toward the bottom. Both surfaces have been cratered by small meteoroid impacts. The Amazonis plains surface has many small, nearly parallel ridges that may have formed by wind erosion. These ridges are not found on the Lycus Sulci surface. None of the features seen in this image look like typical seashore landforms found on Earth--i.e., there are no beaches, windblown coastal dunes, or even the wave-cut cliff that was thought to exist on the basis of previous Viking images. The picture is illuminated from the lower right and was acquired in April 1998. Lycus Sulci is the name of a region of hills and ridges located north and northwest of the famous giant volcano, Olympus Mons (see inset, above). Viking images of the area where the western margin of the Lycus Sulci meets the smooth Amazonis plains (upper left in the figure above) led some researchers to conclude that the two surfaces were in contact along a cliff. The proposed cliff faces toward the smooth plains, and thus it was suggested that this might be the kind of cliff that forms from erosion by waves in a body of water as they break against a coastline. During the first year that Mars Global Surveyor (MGS) was orbiting the red planet (1997-1998), the Mars Orbiter Camera (MOC) acquired three high-resolution images along the contact between the Lycus Sulci hills and the Amazonis plains. The location of the portion of each image that is illustrated below is shown in this figure by a small, white box identified by the archival image number (e.g., "SPO2-428/03" refers to the 3rd image taken on the 428th orbit during the Science Phasing Orbits 2 phase of the MGS mission). The regional context view shown here is a portion of Viking orbiter image 851A29, its center is near 32°N, 114°W and it is illuminated from the right.
Mars Shoreline Tests: Contac …
PIA02338
Sol (our sun)
Mars Orbiter Camera
Title Mars Shoreline Tests: Contact between Lycus Sulci and Amazonis Planitia
Original Caption Released with Image If the northern plains of Mars had ever been the site of a vast ocean, then any highlands that protrude above these plains might be expected to exhibit shorelines. The somewhat curved, flat-topped mesa seen in Viking image 026A72 (first image)is bounded by a dark band. Prior to the Mars Global Surveyor (MGS) mission, this mesa was interpreted by some researchers as having been a possible island in an ancient, northern plains ocean. The dark band was interpreted to be a shoreline resulting from the action of waves lapping against the island's coast. A high resolution image of the banded mesa--located on the Acidalia plains around 45°N, 7°W--was acquired by the MGS Mars Orbiter Camera (MOC) in August 1998, over twenty years after the Viking image was taken. A subframe of this image--SPO2-515/06--is shown in the second image. In the MOC image, the dark band resolves into a series of narrower bright and dark bands. Each band has a slightly different texture and brightness. Furthermore, what appeared to be a sunlit escarpment bounding the north side of the mesa in the Viking image appears in the MOC image to be only a shallow slope rather than a scarp or cliff. The origin of the different bands is not known, but the most likely explanation that would be consistent with other MOC observations of Mars is that the mesa consists of layered rock, and that each band is an outcropping of a different layer of this rock. The different textures would result from the differing resistance to erosion of each layer. Both images shown here are illuminated from the left., MRPS 50586 Mars Global Surveyor's (MGS) Mars Orbiter Camera (MOC) took the above picture (second of the two) of some massifs and mesas in the Cydonia region of Mars in early September 1998. The purpose of this image--number SPO2-532/04--was to test the hypothesis that the martian northern plains were once the site of an ocean or large sea. According to this hypothesis, and according to peer-reviewed and published maps, each one of the mesas and massifs in the two pictures above should have shorelines around their margins. The hypothesis holds that these were once islands and that waves would lap--and sometimes crash--against these landforms, rip off huge chunks of rock, and create steep cliffs and stair-stepped terraces in the rock. The first picture above shows the regional context of the MOC high resolution view in Cydonia. The context picture, from Viking orbiter image 227S11, is illuminated from the right. The second picture above is a figure that shows the full SPO2-532/04 MOC image and two expanded views of portions of this image. Mesas are flat-topped uplands, and massifs are the more triangular, massive peaks. If an ocean had been present in this region, terraces that indicate erosion or bathtub rings of salt or carbonate deposits left by the retreat of this ocean as it dried up might be found around each mesa and massif. No such features are found, nor is it at all obvious why these mesas and massifs were portrayed in previously published figures as having shorelines around them. The MOC image is illuminated from the left., MRPS 95319 Lycus Sulci and Amazonis Planitia are shown here separated by a rise that runs diagonally across the scene from near the lower left toward the upper right. This picture is a subframe of MOC image SPO2-428/03, taken in July 1998. The Lycus Sulci uplands here are more roughly-textured than in the previous image, and the flat Amazonis plains appear to be more smooth and lack the small parallel ridges seen in the earlier view. The lack of the small ridges might be real, or they might be present but cannot be seen because this picture has a lower resolution than the previous one. This image, too, shows that the contact between Amazonis and Lycus Sulci is not a cliff, and once again there are no features that can be unambiguously identified as coastal landforms. MRPS 95320 This is the third MOC image obtained during the first year of MGS operations that shows the contact between Lycus Sulci and Amazonis Planitia. This picture, a subframe of SPO2-483/08, was taken in August 1998. The Lycus Sulciup lands at this location dominate the lower half of the picture, while the Amazonis plains cover the upper half. The uplands here exhibit many small buttes (bumps or knobs in lower right of the scene), and the contact zone between the upland and lowland includes a triangular-shaped ridge (center/right). As with the earlier views of the contact between Lycus Sulci and Amazonis, no features of obvious origin by coastal processes (e.g., erosion by waves crashing against ashore) are seen. The scene is illuminated from the right., The first picture above shows the regional context of a Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) high-resolution image that was targeted in August 1998 with the intent to test the hypothesis that the northern plains of Mars were once the site of a vast ocean of liquid water. The second picture shows the resulting MOC image, numbered SPO2-515/05 and located at 40.0°N, 6.0°W in the transition zone between the Cydonia region and Acidalia Planitia, Mars. The context image (first picture) includes several dark lines, some of which are labeled I and some are labeled G. These dark lines were proposed in previous, peer-reviewed scientific papers to be possible ocean shorelines located along the margins of the martian northern plains. Line I was called the Interior Plains Boundary, and line G was called the Gradational Boundary. The MGS MOC high resolution image was targeted such that it would examine the nature of line I, the Interior Plains Boundary. The second figure shows the MOC high resolution view. The picture on the left side of the figure (second image) is the full MOC image and the white box indicates the location of the expanded view to the right. In the expanded view (the center of the figure), the location of line I--the proposed shoreline--is shown by a dashed curve. The dashed curve follows a subtle, shallow trough. None of the types of coastal landforms common on Earth--such as a beach, wave-cut cliff or terrace, or coastal dune fields, are seen at this location. If an ocean had once been present, then the water would have covered the top 2/3 of the expanded view--i.e., water would have lapped up against the rounded mounds in the lower 1/3 of this picture. Instead of coastal landforms, the MOC image exhibits a dark surface in its upper 1/3. The dark surface covers older, rounded hills and has a low, lobate escarpment along its southern margin. This escarpment faces south--that is, it faces toward the once-proposed coastline. In other words, the escarpment faces in a direction opposite of what would be expected for a coastal environment. The context picture uses Viking orbiter image 561a24 as a base., This picture is the first MOC high resolution image that showed the contact between the Lycus Sulci uplands and Amazonis Planitia lowlands. In this subframe of MOC image SPO 1-225/03, Amazonis and Lycus Sulci are separated by a subtle rise that runs diagonally across the scene from near the lower left toward the upper right. The Amazonis plains are toward the top of the picture, the Lycus Sulci uplands are toward the bottom. Both surfaces have been cratered by small meteoroid impacts. The Amazonis plains surface has many small, nearly parallel ridges that may have formed by wind erosion. These ridges are not found on the Lycus Sulci surface. None of the features seen in this image look like typical seashore landforms found on Earth--i.e., there are no beaches, windblown coastal dunes, or even the wave-cut cliff that was thought to exist on the basis of previous Viking images. The picture is illuminated from the lower right and was acquired in April 1998. Lycus Sulci is the name of a region of hills and ridges located north and northwest of the famous giant volcano, Olympus Mons (see inset, above). Viking images of the area where the western margin of the Lycus Sulci meets the smooth Amazonis plains (upper left in the figure above) led some researchers to conclude that the two surfaces were in contact along a cliff. The proposed cliff faces toward the smooth plains, and thus it was suggested that this might be the kind of cliff that forms from erosion by waves in a body of water as they break against a coastline. During the first year that Mars Global Surveyor (MGS) was orbiting the red planet (1997-1998), the Mars Orbiter Camera (MOC) acquired three high-resolution images along the contact between the Lycus Sulci hills and the Amazonis plains. The location of the portion of each image that is illustrated below is shown in this figure by a small, white box identified by the archival image number (e.g., "SPO2-428/03" refers to the 3rd image taken on the 428th orbit during the Science Phasing Orbits 2 phase of the MGS mission). The regional context view shown here is a portion of Viking orbiter image 851A29, its center is near 32°N, 114°W and it is illuminated from the right.
Mars Shoreline Tests: Contac …
PIA02338
Sol (our sun)
Mars Orbiter Camera
Title Mars Shoreline Tests: Contact between Lycus Sulci and Amazonis Planitia
Original Caption Released with Image If the northern plains of Mars had ever been the site of a vast ocean, then any highlands that protrude above these plains might be expected to exhibit shorelines. The somewhat curved, flat-topped mesa seen in Viking image 026A72 (first image)is bounded by a dark band. Prior to the Mars Global Surveyor (MGS) mission, this mesa was interpreted by some researchers as having been a possible island in an ancient, northern plains ocean. The dark band was interpreted to be a shoreline resulting from the action of waves lapping against the island's coast. A high resolution image of the banded mesa--located on the Acidalia plains around 45°N, 7°W--was acquired by the MGS Mars Orbiter Camera (MOC) in August 1998, over twenty years after the Viking image was taken. A subframe of this image--SPO2-515/06--is shown in the second image. In the MOC image, the dark band resolves into a series of narrower bright and dark bands. Each band has a slightly different texture and brightness. Furthermore, what appeared to be a sunlit escarpment bounding the north side of the mesa in the Viking image appears in the MOC image to be only a shallow slope rather than a scarp or cliff. The origin of the different bands is not known, but the most likely explanation that would be consistent with other MOC observations of Mars is that the mesa consists of layered rock, and that each band is an outcropping of a different layer of this rock. The different textures would result from the differing resistance to erosion of each layer. Both images shown here are illuminated from the left., MRPS 50586 Mars Global Surveyor's (MGS) Mars Orbiter Camera (MOC) took the above picture (second of the two) of some massifs and mesas in the Cydonia region of Mars in early September 1998. The purpose of this image--number SPO2-532/04--was to test the hypothesis that the martian northern plains were once the site of an ocean or large sea. According to this hypothesis, and according to peer-reviewed and published maps, each one of the mesas and massifs in the two pictures above should have shorelines around their margins. The hypothesis holds that these were once islands and that waves would lap--and sometimes crash--against these landforms, rip off huge chunks of rock, and create steep cliffs and stair-stepped terraces in the rock. The first picture above shows the regional context of the MOC high resolution view in Cydonia. The context picture, from Viking orbiter image 227S11, is illuminated from the right. The second picture above is a figure that shows the full SPO2-532/04 MOC image and two expanded views of portions of this image. Mesas are flat-topped uplands, and massifs are the more triangular, massive peaks. If an ocean had been present in this region, terraces that indicate erosion or bathtub rings of salt or carbonate deposits left by the retreat of this ocean as it dried up might be found around each mesa and massif. No such features are found, nor is it at all obvious why these mesas and massifs were portrayed in previously published figures as having shorelines around them. The MOC image is illuminated from the left., MRPS 95319 Lycus Sulci and Amazonis Planitia are shown here separated by a rise that runs diagonally across the scene from near the lower left toward the upper right. This picture is a subframe of MOC image SPO2-428/03, taken in July 1998. The Lycus Sulci uplands here are more roughly-textured than in the previous image, and the flat Amazonis plains appear to be more smooth and lack the small parallel ridges seen in the earlier view. The lack of the small ridges might be real, or they might be present but cannot be seen because this picture has a lower resolution than the previous one. This image, too, shows that the contact between Amazonis and Lycus Sulci is not a cliff, and once again there are no features that can be unambiguously identified as coastal landforms. MRPS 95320 This is the third MOC image obtained during the first year of MGS operations that shows the contact between Lycus Sulci and Amazonis Planitia. This picture, a subframe of SPO2-483/08, was taken in August 1998. The Lycus Sulciup lands at this location dominate the lower half of the picture, while the Amazonis plains cover the upper half. The uplands here exhibit many small buttes (bumps or knobs in lower right of the scene), and the contact zone between the upland and lowland includes a triangular-shaped ridge (center/right). As with the earlier views of the contact between Lycus Sulci and Amazonis, no features of obvious origin by coastal processes (e.g., erosion by waves crashing against ashore) are seen. The scene is illuminated from the right., The first picture above shows the regional context of a Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) high-resolution image that was targeted in August 1998 with the intent to test the hypothesis that the northern plains of Mars were once the site of a vast ocean of liquid water. The second picture shows the resulting MOC image, numbered SPO2-515/05 and located at 40.0°N, 6.0°W in the transition zone between the Cydonia region and Acidalia Planitia, Mars. The context image (first picture) includes several dark lines, some of which are labeled I and some are labeled G. These dark lines were proposed in previous, peer-reviewed scientific papers to be possible ocean shorelines located along the margins of the martian northern plains. Line I was called the Interior Plains Boundary, and line G was called the Gradational Boundary. The MGS MOC high resolution image was targeted such that it would examine the nature of line I, the Interior Plains Boundary. The second figure shows the MOC high resolution view. The picture on the left side of the figure (second image) is the full MOC image and the white box indicates the location of the expanded view to the right. In the expanded view (the center of the figure), the location of line I--the proposed shoreline--is shown by a dashed curve. The dashed curve follows a subtle, shallow trough. None of the types of coastal landforms common on Earth--such as a beach, wave-cut cliff or terrace, or coastal dune fields, are seen at this location. If an ocean had once been present, then the water would have covered the top 2/3 of the expanded view--i.e., water would have lapped up against the rounded mounds in the lower 1/3 of this picture. Instead of coastal landforms, the MOC image exhibits a dark surface in its upper 1/3. The dark surface covers older, rounded hills and has a low, lobate escarpment along its southern margin. This escarpment faces south--that is, it faces toward the once-proposed coastline. In other words, the escarpment faces in a direction opposite of what would be expected for a coastal environment. The context picture uses Viking orbiter image 561a24 as a base., This picture is the first MOC high resolution image that showed the contact between the Lycus Sulci uplands and Amazonis Planitia lowlands. In this subframe of MOC image SPO 1-225/03, Amazonis and Lycus Sulci are separated by a subtle rise that runs diagonally across the scene from near the lower left toward the upper right. The Amazonis plains are toward the top of the picture, the Lycus Sulci uplands are toward the bottom. Both surfaces have been cratered by small meteoroid impacts. The Amazonis plains surface has many small, nearly parallel ridges that may have formed by wind erosion. These ridges are not found on the Lycus Sulci surface. None of the features seen in this image look like typical seashore landforms found on Earth--i.e., there are no beaches, windblown coastal dunes, or even the wave-cut cliff that was thought to exist on the basis of previous Viking images. The picture is illuminated from the lower right and was acquired in April 1998. Lycus Sulci is the name of a region of hills and ridges located north and northwest of the famous giant volcano, Olympus Mons (see inset, above). Viking images of the area where the western margin of the Lycus Sulci meets the smooth Amazonis plains (upper left in the figure above) led some researchers to conclude that the two surfaces were in contact along a cliff. The proposed cliff faces toward the smooth plains, and thus it was suggested that this might be the kind of cliff that forms from erosion by waves in a body of water as they break against a coastline. During the first year that Mars Global Surveyor (MGS) was orbiting the red planet (1997-1998), the Mars Orbiter Camera (MOC) acquired three high-resolution images along the contact between the Lycus Sulci hills and the Amazonis plains. The location of the portion of each image that is illustrated below is shown in this figure by a small, white box identified by the archival image number (e.g., "SPO2-428/03" refers to the 3rd image taken on the 428th orbit during the Science Phasing Orbits 2 phase of the MGS mission). The regional context view shown here is a portion of Viking orbiter image 851A29, its center is near 32°N, 114°W and it is illuminated from the right.
Mars Shoreline Tests: Contac …
PIA02338
Sol (our sun)
Mars Orbiter Camera
Title Mars Shoreline Tests: Contact between Lycus Sulci and Amazonis Planitia
Original Caption Released with Image If the northern plains of Mars had ever been the site of a vast ocean, then any highlands that protrude above these plains might be expected to exhibit shorelines. The somewhat curved, flat-topped mesa seen in Viking image 026A72 (first image)is bounded by a dark band. Prior to the Mars Global Surveyor (MGS) mission, this mesa was interpreted by some researchers as having been a possible island in an ancient, northern plains ocean. The dark band was interpreted to be a shoreline resulting from the action of waves lapping against the island's coast. A high resolution image of the banded mesa--located on the Acidalia plains around 45°N, 7°W--was acquired by the MGS Mars Orbiter Camera (MOC) in August 1998, over twenty years after the Viking image was taken. A subframe of this image--SPO2-515/06--is shown in the second image. In the MOC image, the dark band resolves into a series of narrower bright and dark bands. Each band has a slightly different texture and brightness. Furthermore, what appeared to be a sunlit escarpment bounding the north side of the mesa in the Viking image appears in the MOC image to be only a shallow slope rather than a scarp or cliff. The origin of the different bands is not known, but the most likely explanation that would be consistent with other MOC observations of Mars is that the mesa consists of layered rock, and that each band is an outcropping of a different layer of this rock. The different textures would result from the differing resistance to erosion of each layer. Both images shown here are illuminated from the left., MRPS 50586 Mars Global Surveyor's (MGS) Mars Orbiter Camera (MOC) took the above picture (second of the two) of some massifs and mesas in the Cydonia region of Mars in early September 1998. The purpose of this image--number SPO2-532/04--was to test the hypothesis that the martian northern plains were once the site of an ocean or large sea. According to this hypothesis, and according to peer-reviewed and published maps, each one of the mesas and massifs in the two pictures above should have shorelines around their margins. The hypothesis holds that these were once islands and that waves would lap--and sometimes crash--against these landforms, rip off huge chunks of rock, and create steep cliffs and stair-stepped terraces in the rock. The first picture above shows the regional context of the MOC high resolution view in Cydonia. The context picture, from Viking orbiter image 227S11, is illuminated from the right. The second picture above is a figure that shows the full SPO2-532/04 MOC image and two expanded views of portions of this image. Mesas are flat-topped uplands, and massifs are the more triangular, massive peaks. If an ocean had been present in this region, terraces that indicate erosion or bathtub rings of salt or carbonate deposits left by the retreat of this ocean as it dried up might be found around each mesa and massif. No such features are found, nor is it at all obvious why these mesas and massifs were portrayed in previously published figures as having shorelines around them. The MOC image is illuminated from the left., MRPS 95319 Lycus Sulci and Amazonis Planitia are shown here separated by a rise that runs diagonally across the scene from near the lower left toward the upper right. This picture is a subframe of MOC image SPO2-428/03, taken in July 1998. The Lycus Sulci uplands here are more roughly-textured than in the previous image, and the flat Amazonis plains appear to be more smooth and lack the small parallel ridges seen in the earlier view. The lack of the small ridges might be real, or they might be present but cannot be seen because this picture has a lower resolution than the previous one. This image, too, shows that the contact between Amazonis and Lycus Sulci is not a cliff, and once again there are no features that can be unambiguously identified as coastal landforms. MRPS 95320 This is the third MOC image obtained during the first year of MGS operations that shows the contact between Lycus Sulci and Amazonis Planitia. This picture, a subframe of SPO2-483/08, was taken in August 1998. The Lycus Sulciup lands at this location dominate the lower half of the picture, while the Amazonis plains cover the upper half. The uplands here exhibit many small buttes (bumps or knobs in lower right of the scene), and the contact zone between the upland and lowland includes a triangular-shaped ridge (center/right). As with the earlier views of the contact between Lycus Sulci and Amazonis, no features of obvious origin by coastal processes (e.g., erosion by waves crashing against ashore) are seen. The scene is illuminated from the right., The first picture above shows the regional context of a Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) high-resolution image that was targeted in August 1998 with the intent to test the hypothesis that the northern plains of Mars were once the site of a vast ocean of liquid water. The second picture shows the resulting MOC image, numbered SPO2-515/05 and located at 40.0°N, 6.0°W in the transition zone between the Cydonia region and Acidalia Planitia, Mars. The context image (first picture) includes several dark lines, some of which are labeled I and some are labeled G. These dark lines were proposed in previous, peer-reviewed scientific papers to be possible ocean shorelines located along the margins of the martian northern plains. Line I was called the Interior Plains Boundary, and line G was called the Gradational Boundary. The MGS MOC high resolution image was targeted such that it would examine the nature of line I, the Interior Plains Boundary. The second figure shows the MOC high resolution view. The picture on the left side of the figure (second image) is the full MOC image and the white box indicates the location of the expanded view to the right. In the expanded view (the center of the figure), the location of line I--the proposed shoreline--is shown by a dashed curve. The dashed curve follows a subtle, shallow trough. None of the types of coastal landforms common on Earth--such as a beach, wave-cut cliff or terrace, or coastal dune fields, are seen at this location. If an ocean had once been present, then the water would have covered the top 2/3 of the expanded view--i.e., water would have lapped up against the rounded mounds in the lower 1/3 of this picture. Instead of coastal landforms, the MOC image exhibits a dark surface in its upper 1/3. The dark surface covers older, rounded hills and has a low, lobate escarpment along its southern margin. This escarpment faces south--that is, it faces toward the once-proposed coastline. In other words, the escarpment faces in a direction opposite of what would be expected for a coastal environment. The context picture uses Viking orbiter image 561a24 as a base., This picture is the first MOC high resolution image that showed the contact between the Lycus Sulci uplands and Amazonis Planitia lowlands. In this subframe of MOC image SPO 1-225/03, Amazonis and Lycus Sulci are separated by a subtle rise that runs diagonally across the scene from near the lower left toward the upper right. The Amazonis plains are toward the top of the picture, the Lycus Sulci uplands are toward the bottom. Both surfaces have been cratered by small meteoroid impacts. The Amazonis plains surface has many small, nearly parallel ridges that may have formed by wind erosion. These ridges are not found on the Lycus Sulci surface. None of the features seen in this image look like typical seashore landforms found on Earth--i.e., there are no beaches, windblown coastal dunes, or even the wave-cut cliff that was thought to exist on the basis of previous Viking images. The picture is illuminated from the lower right and was acquired in April 1998. Lycus Sulci is the name of a region of hills and ridges located north and northwest of the famous giant volcano, Olympus Mons (see inset, above). Viking images of the area where the western margin of the Lycus Sulci meets the smooth Amazonis plains (upper left in the figure above) led some researchers to conclude that the two surfaces were in contact along a cliff. The proposed cliff faces toward the smooth plains, and thus it was suggested that this might be the kind of cliff that forms from erosion by waves in a body of water as they break against a coastline. During the first year that Mars Global Surveyor (MGS) was orbiting the red planet (1997-1998), the Mars Orbiter Camera (MOC) acquired three high-resolution images along the contact between the Lycus Sulci hills and the Amazonis plains. The location of the portion of each image that is illustrated below is shown in this figure by a small, white box identified by the archival image number (e.g., "SPO2-428/03" refers to the 3rd image taken on the 428th orbit during the Science Phasing Orbits 2 phase of the MGS mission). The regional context view shown here is a portion of Viking orbiter image 851A29, its center is near 32°N, 114°W and it is illuminated from the right.
Mars Shoreline Tests: Contac …
PIA02338
Sol (our sun)
Mars Orbiter Camera
Title Mars Shoreline Tests: Contact between Lycus Sulci and Amazonis Planitia
Original Caption Released with Image If the northern plains of Mars had ever been the site of a vast ocean, then any highlands that protrude above these plains might be expected to exhibit shorelines. The somewhat curved, flat-topped mesa seen in Viking image 026A72 (first image)is bounded by a dark band. Prior to the Mars Global Surveyor (MGS) mission, this mesa was interpreted by some researchers as having been a possible island in an ancient, northern plains ocean. The dark band was interpreted to be a shoreline resulting from the action of waves lapping against the island's coast. A high resolution image of the banded mesa--located on the Acidalia plains around 45°N, 7°W--was acquired by the MGS Mars Orbiter Camera (MOC) in August 1998, over twenty years after the Viking image was taken. A subframe of this image--SPO2-515/06--is shown in the second image. In the MOC image, the dark band resolves into a series of narrower bright and dark bands. Each band has a slightly different texture and brightness. Furthermore, what appeared to be a sunlit escarpment bounding the north side of the mesa in the Viking image appears in the MOC image to be only a shallow slope rather than a scarp or cliff. The origin of the different bands is not known, but the most likely explanation that would be consistent with other MOC observations of Mars is that the mesa consists of layered rock, and that each band is an outcropping of a different layer of this rock. The different textures would result from the differing resistance to erosion of each layer. Both images shown here are illuminated from the left., MRPS 50586 Mars Global Surveyor's (MGS) Mars Orbiter Camera (MOC) took the above picture (second of the two) of some massifs and mesas in the Cydonia region of Mars in early September 1998. The purpose of this image--number SPO2-532/04--was to test the hypothesis that the martian northern plains were once the site of an ocean or large sea. According to this hypothesis, and according to peer-reviewed and published maps, each one of the mesas and massifs in the two pictures above should have shorelines around their margins. The hypothesis holds that these were once islands and that waves would lap--and sometimes crash--against these landforms, rip off huge chunks of rock, and create steep cliffs and stair-stepped terraces in the rock. The first picture above shows the regional context of the MOC high resolution view in Cydonia. The context picture, from Viking orbiter image 227S11, is illuminated from the right. The second picture above is a figure that shows the full SPO2-532/04 MOC image and two expanded views of portions of this image. Mesas are flat-topped uplands, and massifs are the more triangular, massive peaks. If an ocean had been present in this region, terraces that indicate erosion or bathtub rings of salt or carbonate deposits left by the retreat of this ocean as it dried up might be found around each mesa and massif. No such features are found, nor is it at all obvious why these mesas and massifs were portrayed in previously published figures as having shorelines around them. The MOC image is illuminated from the left., MRPS 95319 Lycus Sulci and Amazonis Planitia are shown here separated by a rise that runs diagonally across the scene from near the lower left toward the upper right. This picture is a subframe of MOC image SPO2-428/03, taken in July 1998. The Lycus Sulci uplands here are more roughly-textured than in the previous image, and the flat Amazonis plains appear to be more smooth and lack the small parallel ridges seen in the earlier view. The lack of the small ridges might be real, or they might be present but cannot be seen because this picture has a lower resolution than the previous one. This image, too, shows that the contact between Amazonis and Lycus Sulci is not a cliff, and once again there are no features that can be unambiguously identified as coastal landforms. MRPS 95320 This is the third MOC image obtained during the first year of MGS operations that shows the contact between Lycus Sulci and Amazonis Planitia. This picture, a subframe of SPO2-483/08, was taken in August 1998. The Lycus Sulciup lands at this location dominate the lower half of the picture, while the Amazonis plains cover the upper half. The uplands here exhibit many small buttes (bumps or knobs in lower right of the scene), and the contact zone between the upland and lowland includes a triangular-shaped ridge (center/right). As with the earlier views of the contact between Lycus Sulci and Amazonis, no features of obvious origin by coastal processes (e.g., erosion by waves crashing against ashore) are seen. The scene is illuminated from the right., The first picture above shows the regional context of a Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) high-resolution image that was targeted in August 1998 with the intent to test the hypothesis that the northern plains of Mars were once the site of a vast ocean of liquid water. The second picture shows the resulting MOC image, numbered SPO2-515/05 and located at 40.0°N, 6.0°W in the transition zone between the Cydonia region and Acidalia Planitia, Mars. The context image (first picture) includes several dark lines, some of which are labeled I and some are labeled G. These dark lines were proposed in previous, peer-reviewed scientific papers to be possible ocean shorelines located along the margins of the martian northern plains. Line I was called the Interior Plains Boundary, and line G was called the Gradational Boundary. The MGS MOC high resolution image was targeted such that it would examine the nature of line I, the Interior Plains Boundary. The second figure shows the MOC high resolution view. The picture on the left side of the figure (second image) is the full MOC image and the white box indicates the location of the expanded view to the right. In the expanded view (the center of the figure), the location of line I--the proposed shoreline--is shown by a dashed curve. The dashed curve follows a subtle, shallow trough. None of the types of coastal landforms common on Earth--such as a beach, wave-cut cliff or terrace, or coastal dune fields, are seen at this location. If an ocean had once been present, then the water would have covered the top 2/3 of the expanded view--i.e., water would have lapped up against the rounded mounds in the lower 1/3 of this picture. Instead of coastal landforms, the MOC image exhibits a dark surface in its upper 1/3. The dark surface covers older, rounded hills and has a low, lobate escarpment along its southern margin. This escarpment faces south--that is, it faces toward the once-proposed coastline. In other words, the escarpment faces in a direction opposite of what would be expected for a coastal environment. The context picture uses Viking orbiter image 561a24 as a base., This picture is the first MOC high resolution image that showed the contact between the Lycus Sulci uplands and Amazonis Planitia lowlands. In this subframe of MOC image SPO 1-225/03, Amazonis and Lycus Sulci are separated by a subtle rise that runs diagonally across the scene from near the lower left toward the upper right. The Amazonis plains are toward the top of the picture, the Lycus Sulci uplands are toward the bottom. Both surfaces have been cratered by small meteoroid impacts. The Amazonis plains surface has many small, nearly parallel ridges that may have formed by wind erosion. These ridges are not found on the Lycus Sulci surface. None of the features seen in this image look like typical seashore landforms found on Earth--i.e., there are no beaches, windblown coastal dunes, or even the wave-cut cliff that was thought to exist on the basis of previous Viking images. The picture is illuminated from the lower right and was acquired in April 1998. Lycus Sulci is the name of a region of hills and ridges located north and northwest of the famous giant volcano, Olympus Mons (see inset, above). Viking images of the area where the western margin of the Lycus Sulci meets the smooth Amazonis plains (upper left in the figure above) led some researchers to conclude that the two surfaces were in contact along a cliff. The proposed cliff faces toward the smooth plains, and thus it was suggested that this might be the kind of cliff that forms from erosion by waves in a body of water as they break against a coastline. During the first year that Mars Global Surveyor (MGS) was orbiting the red planet (1997-1998), the Mars Orbiter Camera (MOC) acquired three high-resolution images along the contact between the Lycus Sulci hills and the Amazonis plains. The location of the portion of each image that is illustrated below is shown in this figure by a small, white box identified by the archival image number (e.g., "SPO2-428/03" refers to the 3rd image taken on the 428th orbit during the Science Phasing Orbits 2 phase of the MGS mission). The regional context view shown here is a portion of Viking orbiter image 851A29, its center is near 32°N, 114°W and it is illuminated from the right.
Mars Shoreline Tests: Contac …
PIA02338
Sol (our sun)
Mars Orbiter Camera
Title Mars Shoreline Tests: Contact between Lycus Sulci and Amazonis Planitia
Original Caption Released with Image If the northern plains of Mars had ever been the site of a vast ocean, then any highlands that protrude above these plains might be expected to exhibit shorelines. The somewhat curved, flat-topped mesa seen in Viking image 026A72 (first image)is bounded by a dark band. Prior to the Mars Global Surveyor (MGS) mission, this mesa was interpreted by some researchers as having been a possible island in an ancient, northern plains ocean. The dark band was interpreted to be a shoreline resulting from the action of waves lapping against the island's coast. A high resolution image of the banded mesa--located on the Acidalia plains around 45°N, 7°W--was acquired by the MGS Mars Orbiter Camera (MOC) in August 1998, over twenty years after the Viking image was taken. A subframe of this image--SPO2-515/06--is shown in the second image. In the MOC image, the dark band resolves into a series of narrower bright and dark bands. Each band has a slightly different texture and brightness. Furthermore, what appeared to be a sunlit escarpment bounding the north side of the mesa in the Viking image appears in the MOC image to be only a shallow slope rather than a scarp or cliff. The origin of the different bands is not known, but the most likely explanation that would be consistent with other MOC observations of Mars is that the mesa consists of layered rock, and that each band is an outcropping of a different layer of this rock. The different textures would result from the differing resistance to erosion of each layer. Both images shown here are illuminated from the left., MRPS 50586 Mars Global Surveyor's (MGS) Mars Orbiter Camera (MOC) took the above picture (second of the two) of some massifs and mesas in the Cydonia region of Mars in early September 1998. The purpose of this image--number SPO2-532/04--was to test the hypothesis that the martian northern plains were once the site of an ocean or large sea. According to this hypothesis, and according to peer-reviewed and published maps, each one of the mesas and massifs in the two pictures above should have shorelines around their margins. The hypothesis holds that these were once islands and that waves would lap--and sometimes crash--against these landforms, rip off huge chunks of rock, and create steep cliffs and stair-stepped terraces in the rock. The first picture above shows the regional context of the MOC high resolution view in Cydonia. The context picture, from Viking orbiter image 227S11, is illuminated from the right. The second picture above is a figure that shows the full SPO2-532/04 MOC image and two expanded views of portions of this image. Mesas are flat-topped uplands, and massifs are the more triangular, massive peaks. If an ocean had been present in this region, terraces that indicate erosion or bathtub rings of salt or carbonate deposits left by the retreat of this ocean as it dried up might be found around each mesa and massif. No such features are found, nor is it at all obvious why these mesas and massifs were portrayed in previously published figures as having shorelines around them. The MOC image is illuminated from the left., MRPS 95319 Lycus Sulci and Amazonis Planitia are shown here separated by a rise that runs diagonally across the scene from near the lower left toward the upper right. This picture is a subframe of MOC image SPO2-428/03, taken in July 1998. The Lycus Sulci uplands here are more roughly-textured than in the previous image, and the flat Amazonis plains appear to be more smooth and lack the small parallel ridges seen in the earlier view. The lack of the small ridges might be real, or they might be present but cannot be seen because this picture has a lower resolution than the previous one. This image, too, shows that the contact between Amazonis and Lycus Sulci is not a cliff, and once again there are no features that can be unambiguously identified as coastal landforms. MRPS 95320 This is the third MOC image obtained during the first year of MGS operations that shows the contact between Lycus Sulci and Amazonis Planitia. This picture, a subframe of SPO2-483/08, was taken in August 1998. The Lycus Sulciup lands at this location dominate the lower half of the picture, while the Amazonis plains cover the upper half. The uplands here exhibit many small buttes (bumps or knobs in lower right of the scene), and the contact zone between the upland and lowland includes a triangular-shaped ridge (center/right). As with the earlier views of the contact between Lycus Sulci and Amazonis, no features of obvious origin by coastal processes (e.g., erosion by waves crashing against ashore) are seen. The scene is illuminated from the right., The first picture above shows the regional context of a Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) high-resolution image that was targeted in August 1998 with the intent to test the hypothesis that the northern plains of Mars were once the site of a vast ocean of liquid water. The second picture shows the resulting MOC image, numbered SPO2-515/05 and located at 40.0°N, 6.0°W in the transition zone between the Cydonia region and Acidalia Planitia, Mars. The context image (first picture) includes several dark lines, some of which are labeled I and some are labeled G. These dark lines were proposed in previous, peer-reviewed scientific papers to be possible ocean shorelines located along the margins of the martian northern plains. Line I was called the Interior Plains Boundary, and line G was called the Gradational Boundary. The MGS MOC high resolution image was targeted such that it would examine the nature of line I, the Interior Plains Boundary. The second figure shows the MOC high resolution view. The picture on the left side of the figure (second image) is the full MOC image and the white box indicates the location of the expanded view to the right. In the expanded view (the center of the figure), the location of line I--the proposed shoreline--is shown by a dashed curve. The dashed curve follows a subtle, shallow trough. None of the types of coastal landforms common on Earth--such as a beach, wave-cut cliff or terrace, or coastal dune fields, are seen at this location. If an ocean had once been present, then the water would have covered the top 2/3 of the expanded view--i.e., water would have lapped up against the rounded mounds in the lower 1/3 of this picture. Instead of coastal landforms, the MOC image exhibits a dark surface in its upper 1/3. The dark surface covers older, rounded hills and has a low, lobate escarpment along its southern margin. This escarpment faces south--that is, it faces toward the once-proposed coastline. In other words, the escarpment faces in a direction opposite of what would be expected for a coastal environment. The context picture uses Viking orbiter image 561a24 as a base., This picture is the first MOC high resolution image that showed the contact between the Lycus Sulci uplands and Amazonis Planitia lowlands. In this subframe of MOC image SPO 1-225/03, Amazonis and Lycus Sulci are separated by a subtle rise that runs diagonally across the scene from near the lower left toward the upper right. The Amazonis plains are toward the top of the picture, the Lycus Sulci uplands are toward the bottom. Both surfaces have been cratered by small meteoroid impacts. The Amazonis plains surface has many small, nearly parallel ridges that may have formed by wind erosion. These ridges are not found on the Lycus Sulci surface. None of the features seen in this image look like typical seashore landforms found on Earth--i.e., there are no beaches, windblown coastal dunes, or even the wave-cut cliff that was thought to exist on the basis of previous Viking images. The picture is illuminated from the lower right and was acquired in April 1998. Lycus Sulci is the name of a region of hills and ridges located north and northwest of the famous giant volcano, Olympus Mons (see inset, above). Viking images of the area where the western margin of the Lycus Sulci meets the smooth Amazonis plains (upper left in the figure above) led some researchers to conclude that the two surfaces were in contact along a cliff. The proposed cliff faces toward the smooth plains, and thus it was suggested that this might be the kind of cliff that forms from erosion by waves in a body of water as they break against a coastline. During the first year that Mars Global Surveyor (MGS) was orbiting the red planet (1997-1998), the Mars Orbiter Camera (MOC) acquired three high-resolution images along the contact between the Lycus Sulci hills and the Amazonis plains. The location of the portion of each image that is illustrated below is shown in this figure by a small, white box identified by the archival image number (e.g., "SPO2-428/03" refers to the 3rd image taken on the 428th orbit during the Science Phasing Orbits 2 phase of the MGS mission). The regional context view shown here is a portion of Viking orbiter image 851A29, its center is near 32°N, 114°W and it is illuminated from the right.
Mars Shoreline Tests: Contac …
PIA02338
Sol (our sun)
Mars Orbiter Camera
Title Mars Shoreline Tests: Contact between Lycus Sulci and Amazonis Planitia
Original Caption Released with Image If the northern plains of Mars had ever been the site of a vast ocean, then any highlands that protrude above these plains might be expected to exhibit shorelines. The somewhat curved, flat-topped mesa seen in Viking image 026A72 (first image)is bounded by a dark band. Prior to the Mars Global Surveyor (MGS) mission, this mesa was interpreted by some researchers as having been a possible island in an ancient, northern plains ocean. The dark band was interpreted to be a shoreline resulting from the action of waves lapping against the island's coast. A high resolution image of the banded mesa--located on the Acidalia plains around 45°N, 7°W--was acquired by the MGS Mars Orbiter Camera (MOC) in August 1998, over twenty years after the Viking image was taken. A subframe of this image--SPO2-515/06--is shown in the second image. In the MOC image, the dark band resolves into a series of narrower bright and dark bands. Each band has a slightly different texture and brightness. Furthermore, what appeared to be a sunlit escarpment bounding the north side of the mesa in the Viking image appears in the MOC image to be only a shallow slope rather than a scarp or cliff. The origin of the different bands is not known, but the most likely explanation that would be consistent with other MOC observations of Mars is that the mesa consists of layered rock, and that each band is an outcropping of a different layer of this rock. The different textures would result from the differing resistance to erosion of each layer. Both images shown here are illuminated from the left., MRPS 50586 Mars Global Surveyor's (MGS) Mars Orbiter Camera (MOC) took the above picture (second of the two) of some massifs and mesas in the Cydonia region of Mars in early September 1998. The purpose of this image--number SPO2-532/04--was to test the hypothesis that the martian northern plains were once the site of an ocean or large sea. According to this hypothesis, and according to peer-reviewed and published maps, each one of the mesas and massifs in the two pictures above should have shorelines around their margins. The hypothesis holds that these were once islands and that waves would lap--and sometimes crash--against these landforms, rip off huge chunks of rock, and create steep cliffs and stair-stepped terraces in the rock. The first picture above shows the regional context of the MOC high resolution view in Cydonia. The context picture, from Viking orbiter image 227S11, is illuminated from the right. The second picture above is a figure that shows the full SPO2-532/04 MOC image and two expanded views of portions of this image. Mesas are flat-topped uplands, and massifs are the more triangular, massive peaks. If an ocean had been present in this region, terraces that indicate erosion or bathtub rings of salt or carbonate deposits left by the retreat of this ocean as it dried up might be found around each mesa and massif. No such features are found, nor is it at all obvious why these mesas and massifs were portrayed in previously published figures as having shorelines around them. The MOC image is illuminated from the left., MRPS 95319 Lycus Sulci and Amazonis Planitia are shown here separated by a rise that runs diagonally across the scene from near the lower left toward the upper right. This picture is a subframe of MOC image SPO2-428/03, taken in July 1998. The Lycus Sulci uplands here are more roughly-textured than in the previous image, and the flat Amazonis plains appear to be more smooth and lack the small parallel ridges seen in the earlier view. The lack of the small ridges might be real, or they might be present but cannot be seen because this picture has a lower resolution than the previous one. This image, too, shows that the contact between Amazonis and Lycus Sulci is not a cliff, and once again there are no features that can be unambiguously identified as coastal landforms. MRPS 95320 This is the third MOC image obtained during the first year of MGS operations that shows the contact between Lycus Sulci and Amazonis Planitia. This picture, a subframe of SPO2-483/08, was taken in August 1998. The Lycus Sulciup lands at this location dominate the lower half of the picture, while the Amazonis plains cover the upper half. The uplands here exhibit many small buttes (bumps or knobs in lower right of the scene), and the contact zone between the upland and lowland includes a triangular-shaped ridge (center/right). As with the earlier views of the contact between Lycus Sulci and Amazonis, no features of obvious origin by coastal processes (e.g., erosion by waves crashing against ashore) are seen. The scene is illuminated from the right., The first picture above shows the regional context of a Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) high-resolution image that was targeted in August 1998 with the intent to test the hypothesis that the northern plains of Mars were once the site of a vast ocean of liquid water. The second picture shows the resulting MOC image, numbered SPO2-515/05 and located at 40.0°N, 6.0°W in the transition zone between the Cydonia region and Acidalia Planitia, Mars. The context image (first picture) includes several dark lines, some of which are labeled I and some are labeled G. These dark lines were proposed in previous, peer-reviewed scientific papers to be possible ocean shorelines located along the margins of the martian northern plains. Line I was called the Interior Plains Boundary, and line G was called the Gradational Boundary. The MGS MOC high resolution image was targeted such that it would examine the nature of line I, the Interior Plains Boundary. The second figure shows the MOC high resolution view. The picture on the left side of the figure (second image) is the full MOC image and the white box indicates the location of the expanded view to the right. In the expanded view (the center of the figure), the location of line I--the proposed shoreline--is shown by a dashed curve. The dashed curve follows a subtle, shallow trough. None of the types of coastal landforms common on Earth--such as a beach, wave-cut cliff or terrace, or coastal dune fields, are seen at this location. If an ocean had once been present, then the water would have covered the top 2/3 of the expanded view--i.e., water would have lapped up against the rounded mounds in the lower 1/3 of this picture. Instead of coastal landforms, the MOC image exhibits a dark surface in its upper 1/3. The dark surface covers older, rounded hills and has a low, lobate escarpment along its southern margin. This escarpment faces south--that is, it faces toward the once-proposed coastline. In other words, the escarpment faces in a direction opposite of what would be expected for a coastal environment. The context picture uses Viking orbiter image 561a24 as a base., This picture is the first MOC high resolution image that showed the contact between the Lycus Sulci uplands and Amazonis Planitia lowlands. In this subframe of MOC image SPO 1-225/03, Amazonis and Lycus Sulci are separated by a subtle rise that runs diagonally across the scene from near the lower left toward the upper right. The Amazonis plains are toward the top of the picture, the Lycus Sulci uplands are toward the bottom. Both surfaces have been cratered by small meteoroid impacts. The Amazonis plains surface has many small, nearly parallel ridges that may have formed by wind erosion. These ridges are not found on the Lycus Sulci surface. None of the features seen in this image look like typical seashore landforms found on Earth--i.e., there are no beaches, windblown coastal dunes, or even the wave-cut cliff that was thought to exist on the basis of previous Viking images. The picture is illuminated from the lower right and was acquired in April 1998. Lycus Sulci is the name of a region of hills and ridges located north and northwest of the famous giant volcano, Olympus Mons (see inset, above). Viking images of the area where the western margin of the Lycus Sulci meets the smooth Amazonis plains (upper left in the figure above) led some researchers to conclude that the two surfaces were in contact along a cliff. The proposed cliff faces toward the smooth plains, and thus it was suggested that this might be the kind of cliff that forms from erosion by waves in a body of water as they break against a coastline. During the first year that Mars Global Surveyor (MGS) was orbiting the red planet (1997-1998), the Mars Orbiter Camera (MOC) acquired three high-resolution images along the contact between the Lycus Sulci hills and the Amazonis plains. The location of the portion of each image that is illustrated below is shown in this figure by a small, white box identified by the archival image number (e.g., "SPO2-428/03" refers to the 3rd image taken on the 428th orbit during the Science Phasing Orbits 2 phase of the MGS mission). The regional context view shown here is a portion of Viking orbiter image 851A29, its center is near 32°N, 114°W and it is illuminated from the right.
Mars Shoreline Tests: Contac …
PIA02338
Sol (our sun)
Mars Orbiter Camera
Title Mars Shoreline Tests: Contact between Lycus Sulci and Amazonis Planitia
Original Caption Released with Image If the northern plains of Mars had ever been the site of a vast ocean, then any highlands that protrude above these plains might be expected to exhibit shorelines. The somewhat curved, flat-topped mesa seen in Viking image 026A72 (first image)is bounded by a dark band. Prior to the Mars Global Surveyor (MGS) mission, this mesa was interpreted by some researchers as having been a possible island in an ancient, northern plains ocean. The dark band was interpreted to be a shoreline resulting from the action of waves lapping against the island's coast. A high resolution image of the banded mesa--located on the Acidalia plains around 45°N, 7°W--was acquired by the MGS Mars Orbiter Camera (MOC) in August 1998, over twenty years after the Viking image was taken. A subframe of this image--SPO2-515/06--is shown in the second image. In the MOC image, the dark band resolves into a series of narrower bright and dark bands. Each band has a slightly different texture and brightness. Furthermore, what appeared to be a sunlit escarpment bounding the north side of the mesa in the Viking image appears in the MOC image to be only a shallow slope rather than a scarp or cliff. The origin of the different bands is not known, but the most likely explanation that would be consistent with other MOC observations of Mars is that the mesa consists of layered rock, and that each band is an outcropping of a different layer of this rock. The different textures would result from the differing resistance to erosion of each layer. Both images shown here are illuminated from the left., MRPS 50586 Mars Global Surveyor's (MGS) Mars Orbiter Camera (MOC) took the above picture (second of the two) of some massifs and mesas in the Cydonia region of Mars in early September 1998. The purpose of this image--number SPO2-532/04--was to test the hypothesis that the martian northern plains were once the site of an ocean or large sea. According to this hypothesis, and according to peer-reviewed and published maps, each one of the mesas and massifs in the two pictures above should have shorelines around their margins. The hypothesis holds that these were once islands and that waves would lap--and sometimes crash--against these landforms, rip off huge chunks of rock, and create steep cliffs and stair-stepped terraces in the rock. The first picture above shows the regional context of the MOC high resolution view in Cydonia. The context picture, from Viking orbiter image 227S11, is illuminated from the right. The second picture above is a figure that shows the full SPO2-532/04 MOC image and two expanded views of portions of this image. Mesas are flat-topped uplands, and massifs are the more triangular, massive peaks. If an ocean had been present in this region, terraces that indicate erosion or bathtub rings of salt or carbonate deposits left by the retreat of this ocean as it dried up might be found around each mesa and massif. No such features are found, nor is it at all obvious why these mesas and massifs were portrayed in previously published figures as having shorelines around them. The MOC image is illuminated from the left., MRPS 95319 Lycus Sulci and Amazonis Planitia are shown here separated by a rise that runs diagonally across the scene from near the lower left toward the upper right. This picture is a subframe of MOC image SPO2-428/03, taken in July 1998. The Lycus Sulci uplands here are more roughly-textured than in the previous image, and the flat Amazonis plains appear to be more smooth and lack the small parallel ridges seen in the earlier view. The lack of the small ridges might be real, or they might be present but cannot be seen because this picture has a lower resolution than the previous one. This image, too, shows that the contact between Amazonis and Lycus Sulci is not a cliff, and once again there are no features that can be unambiguously identified as coastal landforms. MRPS 95320 This is the third MOC image obtained during the first year of MGS operations that shows the contact between Lycus Sulci and Amazonis Planitia. This picture, a subframe of SPO2-483/08, was taken in August 1998. The Lycus Sulciup lands at this location dominate the lower half of the picture, while the Amazonis plains cover the upper half. The uplands here exhibit many small buttes (bumps or knobs in lower right of the scene), and the contact zone between the upland and lowland includes a triangular-shaped ridge (center/right). As with the earlier views of the contact between Lycus Sulci and Amazonis, no features of obvious origin by coastal processes (e.g., erosion by waves crashing against ashore) are seen. The scene is illuminated from the right., The first picture above shows the regional context of a Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) high-resolution image that was targeted in August 1998 with the intent to test the hypothesis that the northern plains of Mars were once the site of a vast ocean of liquid water. The second picture shows the resulting MOC image, numbered SPO2-515/05 and located at 40.0°N, 6.0°W in the transition zone between the Cydonia region and Acidalia Planitia, Mars. The context image (first picture) includes several dark lines, some of which are labeled I and some are labeled G. These dark lines were proposed in previous, peer-reviewed scientific papers to be possible ocean shorelines located along the margins of the martian northern plains. Line I was called the Interior Plains Boundary, and line G was called the Gradational Boundary. The MGS MOC high resolution image was targeted such that it would examine the nature of line I, the Interior Plains Boundary. The second figure shows the MOC high resolution view. The picture on the left side of the figure (second image) is the full MOC image and the white box indicates the location of the expanded view to the right. In the expanded view (the center of the figure), the location of line I--the proposed shoreline--is shown by a dashed curve. The dashed curve follows a subtle, shallow trough. None of the types of coastal landforms common on Earth--such as a beach, wave-cut cliff or terrace, or coastal dune fields, are seen at this location. If an ocean had once been present, then the water would have covered the top 2/3 of the expanded view--i.e., water would have lapped up against the rounded mounds in the lower 1/3 of this picture. Instead of coastal landforms, the MOC image exhibits a dark surface in its upper 1/3. The dark surface covers older, rounded hills and has a low, lobate escarpment along its southern margin. This escarpment faces south--that is, it faces toward the once-proposed coastline. In other words, the escarpment faces in a direction opposite of what would be expected for a coastal environment. The context picture uses Viking orbiter image 561a24 as a base., This picture is the first MOC high resolution image that showed the contact between the Lycus Sulci uplands and Amazonis Planitia lowlands. In this subframe of MOC image SPO 1-225/03, Amazonis and Lycus Sulci are separated by a subtle rise that runs diagonally across the scene from near the lower left toward the upper right. The Amazonis plains are toward the top of the picture, the Lycus Sulci uplands are toward the bottom. Both surfaces have been cratered by small meteoroid impacts. The Amazonis plains surface has many small, nearly parallel ridges that may have formed by wind erosion. These ridges are not found on the Lycus Sulci surface. None of the features seen in this image look like typical seashore landforms found on Earth--i.e., there are no beaches, windblown coastal dunes, or even the wave-cut cliff that was thought to exist on the basis of previous Viking images. The picture is illuminated from the lower right and was acquired in April 1998. Lycus Sulci is the name of a region of hills and ridges located north and northwest of the famous giant volcano, Olympus Mons (see inset, above). Viking images of the area where the western margin of the Lycus Sulci meets the smooth Amazonis plains (upper left in the figure above) led some researchers to conclude that the two surfaces were in contact along a cliff. The proposed cliff faces toward the smooth plains, and thus it was suggested that this might be the kind of cliff that forms from erosion by waves in a body of water as they break against a coastline. During the first year that Mars Global Surveyor (MGS) was orbiting the red planet (1997-1998), the Mars Orbiter Camera (MOC) acquired three high-resolution images along the contact between the Lycus Sulci hills and the Amazonis plains. The location of the portion of each image that is illustrated below is shown in this figure by a small, white box identified by the archival image number (e.g., "SPO2-428/03" refers to the 3rd image taken on the 428th orbit during the Science Phasing Orbits 2 phase of the MGS mission). The regional context view shown here is a portion of Viking orbiter image 851A29, its center is near 32°N, 114°W and it is illuminated from the right.
Mars Shoreline Tests: Contac …
PIA02338
Sol (our sun)
Mars Orbiter Camera
Title Mars Shoreline Tests: Contact between Lycus Sulci and Amazonis Planitia
Original Caption Released with Image If the northern plains of Mars had ever been the site of a vast ocean, then any highlands that protrude above these plains might be expected to exhibit shorelines. The somewhat curved, flat-topped mesa seen in Viking image 026A72 (first image)is bounded by a dark band. Prior to the Mars Global Surveyor (MGS) mission, this mesa was interpreted by some researchers as having been a possible island in an ancient, northern plains ocean. The dark band was interpreted to be a shoreline resulting from the action of waves lapping against the island's coast. A high resolution image of the banded mesa--located on the Acidalia plains around 45°N, 7°W--was acquired by the MGS Mars Orbiter Camera (MOC) in August 1998, over twenty years after the Viking image was taken. A subframe of this image--SPO2-515/06--is shown in the second image. In the MOC image, the dark band resolves into a series of narrower bright and dark bands. Each band has a slightly different texture and brightness. Furthermore, what appeared to be a sunlit escarpment bounding the north side of the mesa in the Viking image appears in the MOC image to be only a shallow slope rather than a scarp or cliff. The origin of the different bands is not known, but the most likely explanation that would be consistent with other MOC observations of Mars is that the mesa consists of layered rock, and that each band is an outcropping of a different layer of this rock. The different textures would result from the differing resistance to erosion of each layer. Both images shown here are illuminated from the left., MRPS 50586 Mars Global Surveyor's (MGS) Mars Orbiter Camera (MOC) took the above picture (second of the two) of some massifs and mesas in the Cydonia region of Mars in early September 1998. The purpose of this image--number SPO2-532/04--was to test the hypothesis that the martian northern plains were once the site of an ocean or large sea. According to this hypothesis, and according to peer-reviewed and published maps, each one of the mesas and massifs in the two pictures above should have shorelines around their margins. The hypothesis holds that these were once islands and that waves would lap--and sometimes crash--against these landforms, rip off huge chunks of rock, and create steep cliffs and stair-stepped terraces in the rock. The first picture above shows the regional context of the MOC high resolution view in Cydonia. The context picture, from Viking orbiter image 227S11, is illuminated from the right. The second picture above is a figure that shows the full SPO2-532/04 MOC image and two expanded views of portions of this image. Mesas are flat-topped uplands, and massifs are the more triangular, massive peaks. If an ocean had been present in this region, terraces that indicate erosion or bathtub rings of salt or carbonate deposits left by the retreat of this ocean as it dried up might be found around each mesa and massif. No such features are found, nor is it at all obvious why these mesas and massifs were portrayed in previously published figures as having shorelines around them. The MOC image is illuminated from the left., MRPS 95319 Lycus Sulci and Amazonis Planitia are shown here separated by a rise that runs diagonally across the scene from near the lower left toward the upper right. This picture is a subframe of MOC image SPO2-428/03, taken in July 1998. The Lycus Sulci uplands here are more roughly-textured than in the previous image, and the flat Amazonis plains appear to be more smooth and lack the small parallel ridges seen in the earlier view. The lack of the small ridges might be real, or they might be present but cannot be seen because this picture has a lower resolution than the previous one. This image, too, shows that the contact between Amazonis and Lycus Sulci is not a cliff, and once again there are no features that can be unambiguously identified as coastal landforms. MRPS 95320 This is the third MOC image obtained during the first year of MGS operations that shows the contact between Lycus Sulci and Amazonis Planitia. This picture, a subframe of SPO2-483/08, was taken in August 1998. The Lycus Sulciup lands at this location dominate the lower half of the picture, while the Amazonis plains cover the upper half. The uplands here exhibit many small buttes (bumps or knobs in lower right of the scene), and the contact zone between the upland and lowland includes a triangular-shaped ridge (center/right). As with the earlier views of the contact between Lycus Sulci and Amazonis, no features of obvious origin by coastal processes (e.g., erosion by waves crashing against ashore) are seen. The scene is illuminated from the right., The first picture above shows the regional context of a Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) high-resolution image that was targeted in August 1998 with the intent to test the hypothesis that the northern plains of Mars were once the site of a vast ocean of liquid water. The second picture shows the resulting MOC image, numbered SPO2-515/05 and located at 40.0°N, 6.0°W in the transition zone between the Cydonia region and Acidalia Planitia, Mars. The context image (first picture) includes several dark lines, some of which are labeled I and some are labeled G. These dark lines were proposed in previous, peer-reviewed scientific papers to be possible ocean shorelines located along the margins of the martian northern plains. Line I was called the Interior Plains Boundary, and line G was called the Gradational Boundary. The MGS MOC high resolution image was targeted such that it would examine the nature of line I, the Interior Plains Boundary. The second figure shows the MOC high resolution view. The picture on the left side of the figure (second image) is the full MOC image and the white box indicates the location of the expanded view to the right. In the expanded view (the center of the figure), the location of line I--the proposed shoreline--is shown by a dashed curve. The dashed curve follows a subtle, shallow trough. None of the types of coastal landforms common on Earth--such as a beach, wave-cut cliff or terrace, or coastal dune fields, are seen at this location. If an ocean had once been present, then the water would have covered the top 2/3 of the expanded view--i.e., water would have lapped up against the rounded mounds in the lower 1/3 of this picture. Instead of coastal landforms, the MOC image exhibits a dark surface in its upper 1/3. The dark surface covers older, rounded hills and has a low, lobate escarpment along its southern margin. This escarpment faces south--that is, it faces toward the once-proposed coastline. In other words, the escarpment faces in a direction opposite of what would be expected for a coastal environment. The context picture uses Viking orbiter image 561a24 as a base., This picture is the first MOC high resolution image that showed the contact between the Lycus Sulci uplands and Amazonis Planitia lowlands. In this subframe of MOC image SPO 1-225/03, Amazonis and Lycus Sulci are separated by a subtle rise that runs diagonally across the scene from near the lower left toward the upper right. The Amazonis plains are toward the top of the picture, the Lycus Sulci uplands are toward the bottom. Both surfaces have been cratered by small meteoroid impacts. The Amazonis plains surface has many small, nearly parallel ridges that may have formed by wind erosion. These ridges are not found on the Lycus Sulci surface. None of the features seen in this image look like typical seashore landforms found on Earth--i.e., there are no beaches, windblown coastal dunes, or even the wave-cut cliff that was thought to exist on the basis of previous Viking images. The picture is illuminated from the lower right and was acquired in April 1998. Lycus Sulci is the name of a region of hills and ridges located north and northwest of the famous giant volcano, Olympus Mons (see inset, above). Viking images of the area where the western margin of the Lycus Sulci meets the smooth Amazonis plains (upper left in the figure above) led some researchers to conclude that the two surfaces were in contact along a cliff. The proposed cliff faces toward the smooth plains, and thus it was suggested that this might be the kind of cliff that forms from erosion by waves in a body of water as they break against a coastline. During the first year that Mars Global Surveyor (MGS) was orbiting the red planet (1997-1998), the Mars Orbiter Camera (MOC) acquired three high-resolution images along the contact between the Lycus Sulci hills and the Amazonis plains. The location of the portion of each image that is illustrated below is shown in this figure by a small, white box identified by the archival image number (e.g., "SPO2-428/03" refers to the 3rd image taken on the 428th orbit during the Science Phasing Orbits 2 phase of the MGS mission). The regional context view shown here is a portion of Viking orbiter image 851A29, its center is near 32°N, 114°W and it is illuminated from the right.
Mars Shoreline Tests: Contac …
PIA02338
Sol (our sun)
Mars Orbiter Camera
Title Mars Shoreline Tests: Contact between Lycus Sulci and Amazonis Planitia
Original Caption Released with Image If the northern plains of Mars had ever been the site of a vast ocean, then any highlands that protrude above these plains might be expected to exhibit shorelines. The somewhat curved, flat-topped mesa seen in Viking image 026A72 (first image)is bounded by a dark band. Prior to the Mars Global Surveyor (MGS) mission, this mesa was interpreted by some researchers as having been a possible island in an ancient, northern plains ocean. The dark band was interpreted to be a shoreline resulting from the action of waves lapping against the island's coast. A high resolution image of the banded mesa--located on the Acidalia plains around 45°N, 7°W--was acquired by the MGS Mars Orbiter Camera (MOC) in August 1998, over twenty years after the Viking image was taken. A subframe of this image--SPO2-515/06--is shown in the second image. In the MOC image, the dark band resolves into a series of narrower bright and dark bands. Each band has a slightly different texture and brightness. Furthermore, what appeared to be a sunlit escarpment bounding the north side of the mesa in the Viking image appears in the MOC image to be only a shallow slope rather than a scarp or cliff. The origin of the different bands is not known, but the most likely explanation that would be consistent with other MOC observations of Mars is that the mesa consists of layered rock, and that each band is an outcropping of a different layer of this rock. The different textures would result from the differing resistance to erosion of each layer. Both images shown here are illuminated from the left., MRPS 50586 Mars Global Surveyor's (MGS) Mars Orbiter Camera (MOC) took the above picture (second of the two) of some massifs and mesas in the Cydonia region of Mars in early September 1998. The purpose of this image--number SPO2-532/04--was to test the hypothesis that the martian northern plains were once the site of an ocean or large sea. According to this hypothesis, and according to peer-reviewed and published maps, each one of the mesas and massifs in the two pictures above should have shorelines around their margins. The hypothesis holds that these were once islands and that waves would lap--and sometimes crash--against these landforms, rip off huge chunks of rock, and create steep cliffs and stair-stepped terraces in the rock. The first picture above shows the regional context of the MOC high resolution view in Cydonia. The context picture, from Viking orbiter image 227S11, is illuminated from the right. The second picture above is a figure that shows the full SPO2-532/04 MOC image and two expanded views of portions of this image. Mesas are flat-topped uplands, and massifs are the more triangular, massive peaks. If an ocean had been present in this region, terraces that indicate erosion or bathtub rings of salt or carbonate deposits left by the retreat of this ocean as it dried up might be found around each mesa and massif. No such features are found, nor is it at all obvious why these mesas and massifs were portrayed in previously published figures as having shorelines around them. The MOC image is illuminated from the left., MRPS 95319 Lycus Sulci and Amazonis Planitia are shown here separated by a rise that runs diagonally across the scene from near the lower left toward the upper right. This picture is a subframe of MOC image SPO2-428/03, taken in July 1998. The Lycus Sulci uplands here are more roughly-textured than in the previous image, and the flat Amazonis plains appear to be more smooth and lack the small parallel ridges seen in the earlier view. The lack of the small ridges might be real, or they might be present but cannot be seen because this picture has a lower resolution than the previous one. This image, too, shows that the contact between Amazonis and Lycus Sulci is not a cliff, and once again there are no features that can be unambiguously identified as coastal landforms. MRPS 95320 This is the third MOC image obtained during the first year of MGS operations that shows the contact between Lycus Sulci and Amazonis Planitia. This picture, a subframe of SPO2-483/08, was taken in August 1998. The Lycus Sulciup lands at this location dominate the lower half of the picture, while the Amazonis plains cover the upper half. The uplands here exhibit many small buttes (bumps or knobs in lower right of the scene), and the contact zone between the upland and lowland includes a triangular-shaped ridge (center/right). As with the earlier views of the contact between Lycus Sulci and Amazonis, no features of obvious origin by coastal processes (e.g., erosion by waves crashing against ashore) are seen. The scene is illuminated from the right., The first picture above shows the regional context of a Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) high-resolution image that was targeted in August 1998 with the intent to test the hypothesis that the northern plains of Mars were once the site of a vast ocean of liquid water. The second picture shows the resulting MOC image, numbered SPO2-515/05 and located at 40.0°N, 6.0°W in the transition zone between the Cydonia region and Acidalia Planitia, Mars. The context image (first picture) includes several dark lines, some of which are labeled I and some are labeled G. These dark lines were proposed in previous, peer-reviewed scientific papers to be possible ocean shorelines located along the margins of the martian northern plains. Line I was called the Interior Plains Boundary, and line G was called the Gradational Boundary. The MGS MOC high resolution image was targeted such that it would examine the nature of line I, the Interior Plains Boundary. The second figure shows the MOC high resolution view. The picture on the left side of the figure (second image) is the full MOC image and the white box indicates the location of the expanded view to the right. In the expanded view (the center of the figure), the location of line I--the proposed shoreline--is shown by a dashed curve. The dashed curve follows a subtle, shallow trough. None of the types of coastal landforms common on Earth--such as a beach, wave-cut cliff or terrace, or coastal dune fields, are seen at this location. If an ocean had once been present, then the water would have covered the top 2/3 of the expanded view--i.e., water would have lapped up against the rounded mounds in the lower 1/3 of this picture. Instead of coastal landforms, the MOC image exhibits a dark surface in its upper 1/3. The dark surface covers older, rounded hills and has a low, lobate escarpment along its southern margin. This escarpment faces south--that is, it faces toward the once-proposed coastline. In other words, the escarpment faces in a direction opposite of what would be expected for a coastal environment. The context picture uses Viking orbiter image 561a24 as a base., This picture is the first MOC high resolution image that showed the contact between the Lycus Sulci uplands and Amazonis Planitia lowlands. In this subframe of MOC image SPO 1-225/03, Amazonis and Lycus Sulci are separated by a subtle rise that runs diagonally across the scene from near the lower left toward the upper right. The Amazonis plains are toward the top of the picture, the Lycus Sulci uplands are toward the bottom. Both surfaces have been cratered by small meteoroid impacts. The Amazonis plains surface has many small, nearly parallel ridges that may have formed by wind erosion. These ridges are not found on the Lycus Sulci surface. None of the features seen in this image look like typical seashore landforms found on Earth--i.e., there are no beaches, windblown coastal dunes, or even the wave-cut cliff that was thought to exist on the basis of previous Viking images. The picture is illuminated from the lower right and was acquired in April 1998. Lycus Sulci is the name of a region of hills and ridges located north and northwest of the famous giant volcano, Olympus Mons (see inset, above). Viking images of the area where the western margin of the Lycus Sulci meets the smooth Amazonis plains (upper left in the figure above) led some researchers to conclude that the two surfaces were in contact along a cliff. The proposed cliff faces toward the smooth plains, and thus it was suggested that this might be the kind of cliff that forms from erosion by waves in a body of water as they break against a coastline. During the first year that Mars Global Surveyor (MGS) was orbiting the red planet (1997-1998), the Mars Orbiter Camera (MOC) acquired three high-resolution images along the contact between the Lycus Sulci hills and the Amazonis plains. The location of the portion of each image that is illustrated below is shown in this figure by a small, white box identified by the archival image number (e.g., "SPO2-428/03" refers to the 3rd image taken on the 428th orbit during the Science Phasing Orbits 2 phase of the MGS mission). The regional context view shown here is a portion of Viking orbiter image 851A29, its center is near 32°N, 114°W and it is illuminated from the right.
Mars Shoreline Tests: Contac …
PIA02338
Sol (our sun)
Mars Orbiter Camera
Title Mars Shoreline Tests: Contact between Lycus Sulci and Amazonis Planitia
Original Caption Released with Image If the northern plains of Mars had ever been the site of a vast ocean, then any highlands that protrude above these plains might be expected to exhibit shorelines. The somewhat curved, flat-topped mesa seen in Viking image 026A72 (first image)is bounded by a dark band. Prior to the Mars Global Surveyor (MGS) mission, this mesa was interpreted by some researchers as having been a possible island in an ancient, northern plains ocean. The dark band was interpreted to be a shoreline resulting from the action of waves lapping against the island's coast. A high resolution image of the banded mesa--located on the Acidalia plains around 45°N, 7°W--was acquired by the MGS Mars Orbiter Camera (MOC) in August 1998, over twenty years after the Viking image was taken. A subframe of this image--SPO2-515/06--is shown in the second image. In the MOC image, the dark band resolves into a series of narrower bright and dark bands. Each band has a slightly different texture and brightness. Furthermore, what appeared to be a sunlit escarpment bounding the north side of the mesa in the Viking image appears in the MOC image to be only a shallow slope rather than a scarp or cliff. The origin of the different bands is not known, but the most likely explanation that would be consistent with other MOC observations of Mars is that the mesa consists of layered rock, and that each band is an outcropping of a different layer of this rock. The different textures would result from the differing resistance to erosion of each layer. Both images shown here are illuminated from the left., MRPS 50586 Mars Global Surveyor's (MGS) Mars Orbiter Camera (MOC) took the above picture (second of the two) of some massifs and mesas in the Cydonia region of Mars in early September 1998. The purpose of this image--number SPO2-532/04--was to test the hypothesis that the martian northern plains were once the site of an ocean or large sea. According to this hypothesis, and according to peer-reviewed and published maps, each one of the mesas and massifs in the two pictures above should have shorelines around their margins. The hypothesis holds that these were once islands and that waves would lap--and sometimes crash--against these landforms, rip off huge chunks of rock, and create steep cliffs and stair-stepped terraces in the rock. The first picture above shows the regional context of the MOC high resolution view in Cydonia. The context picture, from Viking orbiter image 227S11, is illuminated from the right. The second picture above is a figure that shows the full SPO2-532/04 MOC image and two expanded views of portions of this image. Mesas are flat-topped uplands, and massifs are the more triangular, massive peaks. If an ocean had been present in this region, terraces that indicate erosion or bathtub rings of salt or carbonate deposits left by the retreat of this ocean as it dried up might be found around each mesa and massif. No such features are found, nor is it at all obvious why these mesas and massifs were portrayed in previously published figures as having shorelines around them. The MOC image is illuminated from the left., MRPS 95319 Lycus Sulci and Amazonis Planitia are shown here separated by a rise that runs diagonally across the scene from near the lower left toward the upper right. This picture is a subframe of MOC image SPO2-428/03, taken in July 1998. The Lycus Sulci uplands here are more roughly-textured than in the previous image, and the flat Amazonis plains appear to be more smooth and lack the small parallel ridges seen in the earlier view. The lack of the small ridges might be real, or they might be present but cannot be seen because this picture has a lower resolution than the previous one. This image, too, shows that the contact between Amazonis and Lycus Sulci is not a cliff, and once again there are no features that can be unambiguously identified as coastal landforms. MRPS 95320 This is the third MOC image obtained during the first year of MGS operations that shows the contact between Lycus Sulci and Amazonis Planitia. This picture, a subframe of SPO2-483/08, was taken in August 1998. The Lycus Sulciup lands at this location dominate the lower half of the picture, while the Amazonis plains cover the upper half. The uplands here exhibit many small buttes (bumps or knobs in lower right of the scene), and the contact zone between the upland and lowland includes a triangular-shaped ridge (center/right). As with the earlier views of the contact between Lycus Sulci and Amazonis, no features of obvious origin by coastal processes (e.g., erosion by waves crashing against ashore) are seen. The scene is illuminated from the right., The first picture above shows the regional context of a Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) high-resolution image that was targeted in August 1998 with the intent to test the hypothesis that the northern plains of Mars were once the site of a vast ocean of liquid water. The second picture shows the resulting MOC image, numbered SPO2-515/05 and located at 40.0°N, 6.0°W in the transition zone between the Cydonia region and Acidalia Planitia, Mars. The context image (first picture) includes several dark lines, some of which are labeled I and some are labeled G. These dark lines were proposed in previous, peer-reviewed scientific papers to be possible ocean shorelines located along the margins of the martian northern plains. Line I was called the Interior Plains Boundary, and line G was called the Gradational Boundary. The MGS MOC high resolution image was targeted such that it would examine the nature of line I, the Interior Plains Boundary. The second figure shows the MOC high resolution view. The picture on the left side of the figure (second image) is the full MOC image and the white box indicates the location of the expanded view to the right. In the expanded view (the center of the figure), the location of line I--the proposed shoreline--is shown by a dashed curve. The dashed curve follows a subtle, shallow trough. None of the types of coastal landforms common on Earth--such as a beach, wave-cut cliff or terrace, or coastal dune fields, are seen at this location. If an ocean had once been present, then the water would have covered the top 2/3 of the expanded view--i.e., water would have lapped up against the rounded mounds in the lower 1/3 of this picture. Instead of coastal landforms, the MOC image exhibits a dark surface in its upper 1/3. The dark surface covers older, rounded hills and has a low, lobate escarpment along its southern margin. This escarpment faces south--that is, it faces toward the once-proposed coastline. In other words, the escarpment faces in a direction opposite of what would be expected for a coastal environment. The context picture uses Viking orbiter image 561a24 as a base., This picture is the first MOC high resolution image that showed the contact between the Lycus Sulci uplands and Amazonis Planitia lowlands. In this subframe of MOC image SPO 1-225/03, Amazonis and Lycus Sulci are separated by a subtle rise that runs diagonally across the scene from near the lower left toward the upper right. The Amazonis plains are toward the top of the picture, the Lycus Sulci uplands are toward the bottom. Both surfaces have been cratered by small meteoroid impacts. The Amazonis plains surface has many small, nearly parallel ridges that may have formed by wind erosion. These ridges are not found on the Lycus Sulci surface. None of the features seen in this image look like typical seashore landforms found on Earth--i.e., there are no beaches, windblown coastal dunes, or even the wave-cut cliff that was thought to exist on the basis of previous Viking images. The picture is illuminated from the lower right and was acquired in April 1998. Lycus Sulci is the name of a region of hills and ridges located north and northwest of the famous giant volcano, Olympus Mons (see inset, above). Viking images of the area where the western margin of the Lycus Sulci meets the smooth Amazonis plains (upper left in the figure above) led some researchers to conclude that the two surfaces were in contact along a cliff. The proposed cliff faces toward the smooth plains, and thus it was suggested that this might be the kind of cliff that forms from erosion by waves in a body of water as they break against a coastline. During the first year that Mars Global Surveyor (MGS) was orbiting the red planet (1997-1998), the Mars Orbiter Camera (MOC) acquired three high-resolution images along the contact between the Lycus Sulci hills and the Amazonis plains. The location of the portion of each image that is illustrated below is shown in this figure by a small, white box identified by the archival image number (e.g., "SPO2-428/03" refers to the 3rd image taken on the 428th orbit during the Science Phasing Orbits 2 phase of the MGS mission). The regional context view shown here is a portion of Viking orbiter image 851A29, its center is near 32°N, 114°W and it is illuminated from the right.
Mars Shoreline Tests: Contac …
PIA02338
Sol (our sun)
Mars Orbiter Camera
Title Mars Shoreline Tests: Contact between Lycus Sulci and Amazonis Planitia
Original Caption Released with Image If the northern plains of Mars had ever been the site of a vast ocean, then any highlands that protrude above these plains might be expected to exhibit shorelines. The somewhat curved, flat-topped mesa seen in Viking image 026A72 (first image)is bounded by a dark band. Prior to the Mars Global Surveyor (MGS) mission, this mesa was interpreted by some researchers as having been a possible island in an ancient, northern plains ocean. The dark band was interpreted to be a shoreline resulting from the action of waves lapping against the island's coast. A high resolution image of the banded mesa--located on the Acidalia plains around 45°N, 7°W--was acquired by the MGS Mars Orbiter Camera (MOC) in August 1998, over twenty years after the Viking image was taken. A subframe of this image--SPO2-515/06--is shown in the second image. In the MOC image, the dark band resolves into a series of narrower bright and dark bands. Each band has a slightly different texture and brightness. Furthermore, what appeared to be a sunlit escarpment bounding the north side of the mesa in the Viking image appears in the MOC image to be only a shallow slope rather than a scarp or cliff. The origin of the different bands is not known, but the most likely explanation that would be consistent with other MOC observations of Mars is that the mesa consists of layered rock, and that each band is an outcropping of a different layer of this rock. The different textures would result from the differing resistance to erosion of each layer. Both images shown here are illuminated from the left., MRPS 50586 Mars Global Surveyor's (MGS) Mars Orbiter Camera (MOC) took the above picture (second of the two) of some massifs and mesas in the Cydonia region of Mars in early September 1998. The purpose of this image--number SPO2-532/04--was to test the hypothesis that the martian northern plains were once the site of an ocean or large sea. According to this hypothesis, and according to peer-reviewed and published maps, each one of the mesas and massifs in the two pictures above should have shorelines around their margins. The hypothesis holds that these were once islands and that waves would lap--and sometimes crash--against these landforms, rip off huge chunks of rock, and create steep cliffs and stair-stepped terraces in the rock. The first picture above shows the regional context of the MOC high resolution view in Cydonia. The context picture, from Viking orbiter image 227S11, is illuminated from the right. The second picture above is a figure that shows the full SPO2-532/04 MOC image and two expanded views of portions of this image. Mesas are flat-topped uplands, and massifs are the more triangular, massive peaks. If an ocean had been present in this region, terraces that indicate erosion or bathtub rings of salt or carbonate deposits left by the retreat of this ocean as it dried up might be found around each mesa and massif. No such features are found, nor is it at all obvious why these mesas and massifs were portrayed in previously published figures as having shorelines around them. The MOC image is illuminated from the left., MRPS 95319 Lycus Sulci and Amazonis Planitia are shown here separated by a rise that runs diagonally across the scene from near the lower left toward the upper right. This picture is a subframe of MOC image SPO2-428/03, taken in July 1998. The Lycus Sulci uplands here are more roughly-textured than in the previous image, and the flat Amazonis plains appear to be more smooth and lack the small parallel ridges seen in the earlier view. The lack of the small ridges might be real, or they might be present but cannot be seen because this picture has a lower resolution than the previous one. This image, too, shows that the contact between Amazonis and Lycus Sulci is not a cliff, and once again there are no features that can be unambiguously identified as coastal landforms. MRPS 95320 This is the third MOC image obtained during the first year of MGS operations that shows the contact between Lycus Sulci and Amazonis Planitia. This picture, a subframe of SPO2-483/08, was taken in August 1998. The Lycus Sulciup lands at this location dominate the lower half of the picture, while the Amazonis plains cover the upper half. The uplands here exhibit many small buttes (bumps or knobs in lower right of the scene), and the contact zone between the upland and lowland includes a triangular-shaped ridge (center/right). As with the earlier views of the contact between Lycus Sulci and Amazonis, no features of obvious origin by coastal processes (e.g., erosion by waves crashing against ashore) are seen. The scene is illuminated from the right., The first picture above shows the regional context of a Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) high-resolution image that was targeted in August 1998 with the intent to test the hypothesis that the northern plains of Mars were once the site of a vast ocean of liquid water. The second picture shows the resulting MOC image, numbered SPO2-515/05 and located at 40.0°N, 6.0°W in the transition zone between the Cydonia region and Acidalia Planitia, Mars. The context image (first picture) includes several dark lines, some of which are labeled I and some are labeled G. These dark lines were proposed in previous, peer-reviewed scientific papers to be possible ocean shorelines located along the margins of the martian northern plains. Line I was called the Interior Plains Boundary, and line G was called the Gradational Boundary. The MGS MOC high resolution image was targeted such that it would examine the nature of line I, the Interior Plains Boundary. The second figure shows the MOC high resolution view. The picture on the left side of the figure (second image) is the full MOC image and the white box indicates the location of the expanded view to the right. In the expanded view (the center of the figure), the location of line I--the proposed shoreline--is shown by a dashed curve. The dashed curve follows a subtle, shallow trough. None of the types of coastal landforms common on Earth--such as a beach, wave-cut cliff or terrace, or coastal dune fields, are seen at this location. If an ocean had once been present, then the water would have covered the top 2/3 of the expanded view--i.e., water would have lapped up against the rounded mounds in the lower 1/3 of this picture. Instead of coastal landforms, the MOC image exhibits a dark surface in its upper 1/3. The dark surface covers older, rounded hills and has a low, lobate escarpment along its southern margin. This escarpment faces south--that is, it faces toward the once-proposed coastline. In other words, the escarpment faces in a direction opposite of what would be expected for a coastal environment. The context picture uses Viking orbiter image 561a24 as a base., This picture is the first MOC high resolution image that showed the contact between the Lycus Sulci uplands and Amazonis Planitia lowlands. In this subframe of MOC image SPO 1-225/03, Amazonis and Lycus Sulci are separated by a subtle rise that runs diagonally across the scene from near the lower left toward the upper right. The Amazonis plains are toward the top of the picture, the Lycus Sulci uplands are toward the bottom. Both surfaces have been cratered by small meteoroid impacts. The Amazonis plains surface has many small, nearly parallel ridges that may have formed by wind erosion. These ridges are not found on the Lycus Sulci surface. None of the features seen in this image look like typical seashore landforms found on Earth--i.e., there are no beaches, windblown coastal dunes, or even the wave-cut cliff that was thought to exist on the basis of previous Viking images. The picture is illuminated from the lower right and was acquired in April 1998. Lycus Sulci is the name of a region of hills and ridges located north and northwest of the famous giant volcano, Olympus Mons (see inset, above). Viking images of the area where the western margin of the Lycus Sulci meets the smooth Amazonis plains (upper left in the figure above) led some researchers to conclude that the two surfaces were in contact along a cliff. The proposed cliff faces toward the smooth plains, and thus it was suggested that this might be the kind of cliff that forms from erosion by waves in a body of water as they break against a coastline. During the first year that Mars Global Surveyor (MGS) was orbiting the red planet (1997-1998), the Mars Orbiter Camera (MOC) acquired three high-resolution images along the contact between the Lycus Sulci hills and the Amazonis plains. The location of the portion of each image that is illustrated below is shown in this figure by a small, white box identified by the archival image number (e.g., "SPO2-428/03" refers to the 3rd image taken on the 428th orbit during the Science Phasing Orbits 2 phase of the MGS mission). The regional context view shown here is a portion of Viking orbiter image 851A29, its center is near 32°N, 114°W and it is illuminated from the right.
Mars Shoreline Tests: Contac …
PIA02338
Sol (our sun)
Mars Orbiter Camera
Title Mars Shoreline Tests: Contact between Lycus Sulci and Amazonis Planitia
Original Caption Released with Image If the northern plains of Mars had ever been the site of a vast ocean, then any highlands that protrude above these plains might be expected to exhibit shorelines. The somewhat curved, flat-topped mesa seen in Viking image 026A72 (first image)is bounded by a dark band. Prior to the Mars Global Surveyor (MGS) mission, this mesa was interpreted by some researchers as having been a possible island in an ancient, northern plains ocean. The dark band was interpreted to be a shoreline resulting from the action of waves lapping against the island's coast. A high resolution image of the banded mesa--located on the Acidalia plains around 45°N, 7°W--was acquired by the MGS Mars Orbiter Camera (MOC) in August 1998, over twenty years after the Viking image was taken. A subframe of this image--SPO2-515/06--is shown in the second image. In the MOC image, the dark band resolves into a series of narrower bright and dark bands. Each band has a slightly different texture and brightness. Furthermore, what appeared to be a sunlit escarpment bounding the north side of the mesa in the Viking image appears in the MOC image to be only a shallow slope rather than a scarp or cliff. The origin of the different bands is not known, but the most likely explanation that would be consistent with other MOC observations of Mars is that the mesa consists of layered rock, and that each band is an outcropping of a different layer of this rock. The different textures would result from the differing resistance to erosion of each layer. Both images shown here are illuminated from the left., MRPS 50586 Mars Global Surveyor's (MGS) Mars Orbiter Camera (MOC) took the above picture (second of the two) of some massifs and mesas in the Cydonia region of Mars in early September 1998. The purpose of this image--number SPO2-532/04--was to test the hypothesis that the martian northern plains were once the site of an ocean or large sea. According to this hypothesis, and according to peer-reviewed and published maps, each one of the mesas and massifs in the two pictures above should have shorelines around their margins. The hypothesis holds that these were once islands and that waves would lap--and sometimes crash--against these landforms, rip off huge chunks of rock, and create steep cliffs and stair-stepped terraces in the rock. The first picture above shows the regional context of the MOC high resolution view in Cydonia. The context picture, from Viking orbiter image 227S11, is illuminated from the right. The second picture above is a figure that shows the full SPO2-532/04 MOC image and two expanded views of portions of this image. Mesas are flat-topped uplands, and massifs are the more triangular, massive peaks. If an ocean had been present in this region, terraces that indicate erosion or bathtub rings of salt or carbonate deposits left by the retreat of this ocean as it dried up might be found around each mesa and massif. No such features are found, nor is it at all obvious why these mesas and massifs were portrayed in previously published figures as having shorelines around them. The MOC image is illuminated from the left., MRPS 95319 Lycus Sulci and Amazonis Planitia are shown here separated by a rise that runs diagonally across the scene from near the lower left toward the upper right. This picture is a subframe of MOC image SPO2-428/03, taken in July 1998. The Lycus Sulci uplands here are more roughly-textured than in the previous image, and the flat Amazonis plains appear to be more smooth and lack the small parallel ridges seen in the earlier view. The lack of the small ridges might be real, or they might be present but cannot be seen because this picture has a lower resolution than the previous one. This image, too, shows that the contact between Amazonis and Lycus Sulci is not a cliff, and once again there are no features that can be unambiguously identified as coastal landforms. MRPS 95320 This is the third MOC image obtained during the first year of MGS operations that shows the contact between Lycus Sulci and Amazonis Planitia. This picture, a subframe of SPO2-483/08, was taken in August 1998. The Lycus Sulciup lands at this location dominate the lower half of the picture, while the Amazonis plains cover the upper half. The uplands here exhibit many small buttes (bumps or knobs in lower right of the scene), and the contact zone between the upland and lowland includes a triangular-shaped ridge (center/right). As with the earlier views of the contact between Lycus Sulci and Amazonis, no features of obvious origin by coastal processes (e.g., erosion by waves crashing against ashore) are seen. The scene is illuminated from the right., The first picture above shows the regional context of a Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) high-resolution image that was targeted in August 1998 with the intent to test the hypothesis that the northern plains of Mars were once the site of a vast ocean of liquid water. The second picture shows the resulting MOC image, numbered SPO2-515/05 and located at 40.0°N, 6.0°W in the transition zone between the Cydonia region and Acidalia Planitia, Mars. The context image (first picture) includes several dark lines, some of which are labeled I and some are labeled G. These dark lines were proposed in previous, peer-reviewed scientific papers to be possible ocean shorelines located along the margins of the martian northern plains. Line I was called the Interior Plains Boundary, and line G was called the Gradational Boundary. The MGS MOC high resolution image was targeted such that it would examine the nature of line I, the Interior Plains Boundary. The second figure shows the MOC high resolution view. The picture on the left side of the figure (second image) is the full MOC image and the white box indicates the location of the expanded view to the right. In the expanded view (the center of the figure), the location of line I--the proposed shoreline--is shown by a dashed curve. The dashed curve follows a subtle, shallow trough. None of the types of coastal landforms common on Earth--such as a beach, wave-cut cliff or terrace, or coastal dune fields, are seen at this location. If an ocean had once been present, then the water would have covered the top 2/3 of the expanded view--i.e., water would have lapped up against the rounded mounds in the lower 1/3 of this picture. Instead of coastal landforms, the MOC image exhibits a dark surface in its upper 1/3. The dark surface covers older, rounded hills and has a low, lobate escarpment along its southern margin. This escarpment faces south--that is, it faces toward the once-proposed coastline. In other words, the escarpment faces in a direction opposite of what would be expected for a coastal environment. The context picture uses Viking orbiter image 561a24 as a base., This picture is the first MOC high resolution image that showed the contact between the Lycus Sulci uplands and Amazonis Planitia lowlands. In this subframe of MOC image SPO 1-225/03, Amazonis and Lycus Sulci are separated by a subtle rise that runs diagonally across the scene from near the lower left toward the upper right. The Amazonis plains are toward the top of the picture, the Lycus Sulci uplands are toward the bottom. Both surfaces have been cratered by small meteoroid impacts. The Amazonis plains surface has many small, nearly parallel ridges that may have formed by wind erosion. These ridges are not found on the Lycus Sulci surface. None of the features seen in this image look like typical seashore landforms found on Earth--i.e., there are no beaches, windblown coastal dunes, or even the wave-cut cliff that was thought to exist on the basis of previous Viking images. The picture is illuminated from the lower right and was acquired in April 1998. Lycus Sulci is the name of a region of hills and ridges located north and northwest of the famous giant volcano, Olympus Mons (see inset, above). Viking images of the area where the western margin of the Lycus Sulci meets the smooth Amazonis plains (upper left in the figure above) led some researchers to conclude that the two surfaces were in contact along a cliff. The proposed cliff faces toward the smooth plains, and thus it was suggested that this might be the kind of cliff that forms from erosion by waves in a body of water as they break against a coastline. During the first year that Mars Global Surveyor (MGS) was orbiting the red planet (1997-1998), the Mars Orbiter Camera (MOC) acquired three high-resolution images along the contact between the Lycus Sulci hills and the Amazonis plains. The location of the portion of each image that is illustrated below is shown in this figure by a small, white box identified by the archival image number (e.g., "SPO2-428/03" refers to the 3rd image taken on the 428th orbit during the Science Phasing Orbits 2 phase of the MGS mission). The regional context view shown here is a portion of Viking orbiter image 851A29, its center is near 32°N, 114°W and it is illuminated from the right.
Mars Shoreline Tests: Contac …
PIA02338
Sol (our sun)
Mars Orbiter Camera
Title Mars Shoreline Tests: Contact between Lycus Sulci and Amazonis Planitia
Original Caption Released with Image If the northern plains of Mars had ever been the site of a vast ocean, then any highlands that protrude above these plains might be expected to exhibit shorelines. The somewhat curved, flat-topped mesa seen in Viking image 026A72 (first image)is bounded by a dark band. Prior to the Mars Global Surveyor (MGS) mission, this mesa was interpreted by some researchers as having been a possible island in an ancient, northern plains ocean. The dark band was interpreted to be a shoreline resulting from the action of waves lapping against the island's coast. A high resolution image of the banded mesa--located on the Acidalia plains around 45°N, 7°W--was acquired by the MGS Mars Orbiter Camera (MOC) in August 1998, over twenty years after the Viking image was taken. A subframe of this image--SPO2-515/06--is shown in the second image. In the MOC image, the dark band resolves into a series of narrower bright and dark bands. Each band has a slightly different texture and brightness. Furthermore, what appeared to be a sunlit escarpment bounding the north side of the mesa in the Viking image appears in the MOC image to be only a shallow slope rather than a scarp or cliff. The origin of the different bands is not known, but the most likely explanation that would be consistent with other MOC observations of Mars is that the mesa consists of layered rock, and that each band is an outcropping of a different layer of this rock. The different textures would result from the differing resistance to erosion of each layer. Both images shown here are illuminated from the left., MRPS 50586 Mars Global Surveyor's (MGS) Mars Orbiter Camera (MOC) took the above picture (second of the two) of some massifs and mesas in the Cydonia region of Mars in early September 1998. The purpose of this image--number SPO2-532/04--was to test the hypothesis that the martian northern plains were once the site of an ocean or large sea. According to this hypothesis, and according to peer-reviewed and published maps, each one of the mesas and massifs in the two pictures above should have shorelines around their margins. The hypothesis holds that these were once islands and that waves would lap--and sometimes crash--against these landforms, rip off huge chunks of rock, and create steep cliffs and stair-stepped terraces in the rock. The first picture above shows the regional context of the MOC high resolution view in Cydonia. The context picture, from Viking orbiter image 227S11, is illuminated from the right. The second picture above is a figure that shows the full SPO2-532/04 MOC image and two expanded views of portions of this image. Mesas are flat-topped uplands, and massifs are the more triangular, massive peaks. If an ocean had been present in this region, terraces that indicate erosion or bathtub rings of salt or carbonate deposits left by the retreat of this ocean as it dried up might be found around each mesa and massif. No such features are found, nor is it at all obvious why these mesas and massifs were portrayed in previously published figures as having shorelines around them. The MOC image is illuminated from the left., MRPS 95319 Lycus Sulci and Amazonis Planitia are shown here separated by a rise that runs diagonally across the scene from near the lower left toward the upper right. This picture is a subframe of MOC image SPO2-428/03, taken in July 1998. The Lycus Sulci uplands here are more roughly-textured than in the previous image, and the flat Amazonis plains appear to be more smooth and lack the small parallel ridges seen in the earlier view. The lack of the small ridges might be real, or they might be present but cannot be seen because this picture has a lower resolution than the previous one. This image, too, shows that the contact between Amazonis and Lycus Sulci is not a cliff, and once again there are no features that can be unambiguously identified as coastal landforms. MRPS 95320 This is the third MOC image obtained during the first year of MGS operations that shows the contact between Lycus Sulci and Amazonis Planitia. This picture, a subframe of SPO2-483/08, was taken in August 1998. The Lycus Sulciup lands at this location dominate the lower half of the picture, while the Amazonis plains cover the upper half. The uplands here exhibit many small buttes (bumps or knobs in lower right of the scene), and the contact zone between the upland and lowland includes a triangular-shaped ridge (center/right). As with the earlier views of the contact between Lycus Sulci and Amazonis, no features of obvious origin by coastal processes (e.g., erosion by waves crashing against ashore) are seen. The scene is illuminated from the right., The first picture above shows the regional context of a Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) high-resolution image that was targeted in August 1998 with the intent to test the hypothesis that the northern plains of Mars were once the site of a vast ocean of liquid water. The second picture shows the resulting MOC image, numbered SPO2-515/05 and located at 40.0°N, 6.0°W in the transition zone between the Cydonia region and Acidalia Planitia, Mars. The context image (first picture) includes several dark lines, some of which are labeled I and some are labeled G. These dark lines were proposed in previous, peer-reviewed scientific papers to be possible ocean shorelines located along the margins of the martian northern plains. Line I was called the Interior Plains Boundary, and line G was called the Gradational Boundary. The MGS MOC high resolution image was targeted such that it would examine the nature of line I, the Interior Plains Boundary. The second figure shows the MOC high resolution view. The picture on the left side of the figure (second image) is the full MOC image and the white box indicates the location of the expanded view to the right. In the expanded view (the center of the figure), the location of line I--the proposed shoreline--is shown by a dashed curve. The dashed curve follows a subtle, shallow trough. None of the types of coastal landforms common on Earth--such as a beach, wave-cut cliff or terrace, or coastal dune fields, are seen at this location. If an ocean had once been present, then the water would have covered the top 2/3 of the expanded view--i.e., water would have lapped up against the rounded mounds in the lower 1/3 of this picture. Instead of coastal landforms, the MOC image exhibits a dark surface in its upper 1/3. The dark surface covers older, rounded hills and has a low, lobate escarpment along its southern margin. This escarpment faces south--that is, it faces toward the once-proposed coastline. In other words, the escarpment faces in a direction opposite of what would be expected for a coastal environment. The context picture uses Viking orbiter image 561a24 as a base., This picture is the first MOC high resolution image that showed the contact between the Lycus Sulci uplands and Amazonis Planitia lowlands. In this subframe of MOC image SPO 1-225/03, Amazonis and Lycus Sulci are separated by a subtle rise that runs diagonally across the scene from near the lower left toward the upper right. The Amazonis plains are toward the top of the picture, the Lycus Sulci uplands are toward the bottom. Both surfaces have been cratered by small meteoroid impacts. The Amazonis plains surface has many small, nearly parallel ridges that may have formed by wind erosion. These ridges are not found on the Lycus Sulci surface. None of the features seen in this image look like typical seashore landforms found on Earth--i.e., there are no beaches, windblown coastal dunes, or even the wave-cut cliff that was thought to exist on the basis of previous Viking images. The picture is illuminated from the lower right and was acquired in April 1998. Lycus Sulci is the name of a region of hills and ridges located north and northwest of the famous giant volcano, Olympus Mons (see inset, above). Viking images of the area where the western margin of the Lycus Sulci meets the smooth Amazonis plains (upper left in the figure above) led some researchers to conclude that the two surfaces were in contact along a cliff. The proposed cliff faces toward the smooth plains, and thus it was suggested that this might be the kind of cliff that forms from erosion by waves in a body of water as they break against a coastline. During the first year that Mars Global Surveyor (MGS) was orbiting the red planet (1997-1998), the Mars Orbiter Camera (MOC) acquired three high-resolution images along the contact between the Lycus Sulci hills and the Amazonis plains. The location of the portion of each image that is illustrated below is shown in this figure by a small, white box identified by the archival image number (e.g., "SPO2-428/03" refers to the 3rd image taken on the 428th orbit during the Science Phasing Orbits 2 phase of the MGS mission). The regional context view shown here is a portion of Viking orbiter image 851A29, its center is near 32°N, 114°W and it is illuminated from the right.
Hematite Abundance on Martia …
PIA01339
Sol (our sun)
Thermal Emission Spectromete …
Title Hematite Abundance on Martian Surface
Original Caption Released with Image This figure shows the concentration of hematite measured by the Mars Global Surveyor Thermal Emission Spectrometer (TES) instrument. The abundance of hematite is shown in red, with increasing brightness indicating increasing hematite abundance. The location and size of the individual TES observations on the surface are indicated by the individual squares. Black squares indicate observations with no detectable hematite. Data from 11 separate orbits acquired between Nov. 22, 1997 and April 25, 1998 are shown in this image. The TES data are superimposed on a Viking photomosaic for context. The image extends from 10 S to 10 N latitude and 350 W to 15 W longitude, covering an area 1500 km (940 miles) in longitude by 1200 km (750 miles) in latitude. The TES instrument was built by Santa Barbara Remote Sensing and is operated by Philip R. Christensen, of Arizona State University, Tempe, AZ. The MGS mission is managed for NASA by the Jet Propulsion Laboratory, Pasadena CA.
MGS Approach Image - Chryse …
PIA00911
Sol (our sun)
Mars Orbiter Camera
Title MGS Approach Image - Chryse Planitia
Original Caption Released with Image The Mars Orbiter Camera (MOC) took this image on August 20, 1997, when the Mars Global Surveyor (MGS) was 5.67 million kilometers (3.52 million miles) and 22 days from entering orbit. At this distance, the MOC's resolution is about 21.2 km per picture element, and the 6800 km (4200 mile) diameter planet is about 327 pixels across. North is at the top of the image. The MGS spacecraft pointed the camera at the center of the planet (near the dark, morning sunrise line, or terminator) at 23.6° N, 82.1° W. At this distance from Mars, only bright and dark markings resulting from variations in the amount and thickness of dust and sand are visible. The large dark marking stretching from the right center northward is Acidalia Planitia, a region of rock and sand with less dust on it than the area immediately to the south, Chryse Planitia. Both Viking Lander 1 and Pathfinder landed in the latter, bright area. In this low resolution image, some of the dark features resemble the "canals" seen prominently in maps created by astronomers of the 19th and early 20th century. Mariner 9 and Viking images show that most of these dark lines are associated with sand deposits that are trapped in rough areas. Mars Global Surveyor was launched on November 7, 1996 and will enter Mars orbit on Thursday, September 11 around 6:30 PM PDT. The spacecraft will use atmospheric drag to reduce the size of its orbit. Mapping operations will begin in March 1998. The MOC on MGS is a spare camera originally developed for the ill-fated Mars Observer mission. Malin Space Science Systems and the California Institute of Technology were responsible for development of both cameras. MSSS operates the MOC from its facilities in San Diego, CA, under contract to the Jet Propulsion Laboratory.
Giant "Polygon" Troughs, Ely …
PIA01469
Sol (our sun)
Mars Orbiter Camera
Title Giant "Polygon" Troughs, Elysium Planitia
Original Caption Released with Image ). Similar drifts can also be seen in and encroaching upon the surrounding, small impact craters. These drifts attest to the movement of sediment on the surface, and their brightness and shape suggests that they have not been active recently. MOC image 52706 was taken at about 11:36 p.m. (PDT) on August 31, 1998, during the 526th orbit of Mars Global Surveyor as the spacecraft was nearing its 527th "periapsis" (closest point to the planet during the orbit). Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO., Mars Global Surveyor's Mars Orbiter Camera (MOC) continued to obtain images of the red planet during August and into September 1998. MOC has seen many features that address old questions and ideas about the geologic history of Mars. Among the geological features examined by MOC in recent weeks--the enigmatic "Giant Polygons" on the martian northern plains. In the 1970s the Viking Orbiters saw huge cracks , some more than 1 kilometer (0.62 miles) wide, arranged in a polygonal pattern that outlined flat-lying areas sometimes 5 to 20 kilometers (3 to 12 miles) across. Giant polygons are most common in parts of Utopia Planitia and Acidalia Planitia, but there is also a cluster of them in the lowlands west of the Elysium volcanoes, on Elysium Planitia. The exact origin of the giant polygons has never been determined. At first glance, they appear to resemble mud cracks that one might see on the surface of a dried-up puddle, pond, or lake. However, mud cracks and the polygonal patterns they create are small features--like the size of a human hand. The giant polygons on Mars are big enough to hold the entire downtown area of a moderate-sized city. Mud cracks form by "dessication"-- "i.e.," the removal of water by evaporation (drying). Many ideas about the polygons on Mars have centered on the idea that they are somehow related to the dessication of thick layers of wet sediment-- perhaps deposited by some of the giant floods that Mars is known to have had. However, there has been considerable debate about whether the polygons formed in lava instead of sediment. Cooling lava might also crack and give the polygon texture, some have argued. Two observations have been made--using Viking images--that constrain the types of origins that can be proposed: (1) most of the "cracks" appear to be "graben"- -down-dropped blocks caused by faulting, and (2) some of the "cracks" appear to indicate the outlines of buried craters. These observations suggest that whatever caused the polygons, the process appears to be confined to material that has buried older terrain. The new MOC image confirms the impression--from Viking images--that the polygon cracks-- troughs--are graben formed by faults. Unfortunately, the image does not provide ample information to distinguish between the various models for the origin of the polygons or the material in which they occur. The images, however, do show features of interest. The floors of the polygon troughs have bright, almost evenly spaced, windblown ripples or drifts(see also detailed sub-areas [ http://photojournal.jpl.nasa.gov/catalog/PIA01470 ]
Giant "Polygon" Troughs, Ely …
PIA01469
Sol (our sun)
Mars Orbiter Camera
Title Giant "Polygon" Troughs, Elysium Planitia
Original Caption Released with Image ). Similar drifts can also be seen in and encroaching upon the surrounding, small impact craters. These drifts attest to the movement of sediment on the surface, and their brightness and shape suggests that they have not been active recently. MOC image 52706 was taken at about 11:36 p.m. (PDT) on August 31, 1998, during the 526th orbit of Mars Global Surveyor as the spacecraft was nearing its 527th "periapsis" (closest point to the planet during the orbit). Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO., Mars Global Surveyor's Mars Orbiter Camera (MOC) continued to obtain images of the red planet during August and into September 1998. MOC has seen many features that address old questions and ideas about the geologic history of Mars. Among the geological features examined by MOC in recent weeks--the enigmatic "Giant Polygons" on the martian northern plains. In the 1970s the Viking Orbiters saw huge cracks , some more than 1 kilometer (0.62 miles) wide, arranged in a polygonal pattern that outlined flat-lying areas sometimes 5 to 20 kilometers (3 to 12 miles) across. Giant polygons are most common in parts of Utopia Planitia and Acidalia Planitia, but there is also a cluster of them in the lowlands west of the Elysium volcanoes, on Elysium Planitia. The exact origin of the giant polygons has never been determined. At first glance, they appear to resemble mud cracks that one might see on the surface of a dried-up puddle, pond, or lake. However, mud cracks and the polygonal patterns they create are small features--like the size of a human hand. The giant polygons on Mars are big enough to hold the entire downtown area of a moderate-sized city. Mud cracks form by "dessication"-- "i.e.," the removal of water by evaporation (drying). Many ideas about the polygons on Mars have centered on the idea that they are somehow related to the dessication of thick layers of wet sediment-- perhaps deposited by some of the giant floods that Mars is known to have had. However, there has been considerable debate about whether the polygons formed in lava instead of sediment. Cooling lava might also crack and give the polygon texture, some have argued. Two observations have been made--using Viking images--that constrain the types of origins that can be proposed: (1) most of the "cracks" appear to be "graben"- -down-dropped blocks caused by faulting, and (2) some of the "cracks" appear to indicate the outlines of buried craters. These observations suggest that whatever caused the polygons, the process appears to be confined to material that has buried older terrain. The new MOC image confirms the impression--from Viking images--that the polygon cracks-- troughs--are graben formed by faults. Unfortunately, the image does not provide ample information to distinguish between the various models for the origin of the polygons or the material in which they occur. The images, however, do show features of interest. The floors of the polygon troughs have bright, almost evenly spaced, windblown ripples or drifts(see also detailed sub-areas [ http://photojournal.jpl.nasa.gov/catalog/PIA01470 ]
Giant "Polygon" Troughs, Ely …
PIA01470
Sol (our sun)
Mars Orbiter Camera
Title Giant "Polygon" Troughs, Elysium Planitia at Full Resolution
Original Caption Released with Image ). Similar drifts can also be seen in and encroaching upon the surrounding, small impact craters. These drifts attest to the movement of sediment on the surface, and their brightness and shape suggests that they have not been active recently. MOC image 52706 was taken at about 11:36 p.m. (PDT) on August 31, 1998, during the 526th orbit of Mars Global Surveyor as the spacecraft was nearing its 527th "periapsis" (closest point to the planet during the orbit). Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO., Mars Global Surveyor's Mars Orbiter Camera (MOC) continued to obtain images of the red planet during August and into September 1998. MOC has seen many features that address old questions and ideas about the geologic history of Mars. Among the geological features examined by MOC in recent weeks--the enigmatic "Giant Polygons" on the martian northern plains. In the 1970s the Viking Orbiters saw huge cracks , some more than 1 kilometer (0.62 miles) wide, arranged in a polygonal pattern that outlined flat-lying areas sometimes 5 to 20 kilometers (3 to 12 miles) across. Giant polygons are most common in parts of Utopia Planitia and Acidalia Planitia, but there is also a cluster of them in the lowlands west of the Elysium volcanoes, on Elysium Planitia. The exact origin of the giant polygons has never been determined. At first glance, they appear to resemble mud cracks that one might see on the surface of a dried-up puddle, pond, or lake. However, mud cracks and the polygonal patterns they create are small features--like the size of a human hand. The giant polygons on Mars are big enough to hold the entire downtown area of a moderate-sized city. Mud cracks form by "dessication"--"i.e.," the removal of water by evaporation (drying). Many ideas about the polygons on Mars have centered on the idea that they are somehow related to the dessication of thick layers of wet sediment--perhaps deposited by some of the giant floods that Mars is known to have had. However, there has been considerable debate about whether the polygons formed in lava instead of sediment. Cooling lava might also crack and give the polygon texture, some have argued. Two observations have been made--using Viking images--that constrain the types of origins that can be proposed: (1) most of the "cracks" appear to be "graben"--down-dropped blocks caused by faulting, and (2) some of the "cracks" appear to indicate the outlines of buried craters. These observations suggest that whatever caused the polygons, the process appears to be confined to material that has buried older terrain. The new MOC image confirms the impression--from Viking images--that the polygon cracks--troughs--are graben formed by faults. Unfortunately, the image does not provide ample information to distinguish between the various models for the origin of the polygons or the material in which they occur. The images, however, do show features of interest. The floors of the polygon troughs, highlighted in these sub-areas of the MOC image (locations on MOC image) have bright, almost evenly spaced, windblown ripples or drifts(see also detailed sub-areas [ http://photojournal.jpl.nasa.gov/catalog/PIA01469 ]
Giant "Polygon" Troughs, Ely …
PIA01470
Sol (our sun)
Mars Orbiter Camera
Title Giant "Polygon" Troughs, Elysium Planitia at Full Resolution
Original Caption Released with Image ). Similar drifts can also be seen in and encroaching upon the surrounding, small impact craters. These drifts attest to the movement of sediment on the surface, and their brightness and shape suggests that they have not been active recently. MOC image 52706 was taken at about 11:36 p.m. (PDT) on August 31, 1998, during the 526th orbit of Mars Global Surveyor as the spacecraft was nearing its 527th "periapsis" (closest point to the planet during the orbit). Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO., Mars Global Surveyor's Mars Orbiter Camera (MOC) continued to obtain images of the red planet during August and into September 1998. MOC has seen many features that address old questions and ideas about the geologic history of Mars. Among the geological features examined by MOC in recent weeks--the enigmatic "Giant Polygons" on the martian northern plains. In the 1970s the Viking Orbiters saw huge cracks , some more than 1 kilometer (0.62 miles) wide, arranged in a polygonal pattern that outlined flat-lying areas sometimes 5 to 20 kilometers (3 to 12 miles) across. Giant polygons are most common in parts of Utopia Planitia and Acidalia Planitia, but there is also a cluster of them in the lowlands west of the Elysium volcanoes, on Elysium Planitia. The exact origin of the giant polygons has never been determined. At first glance, they appear to resemble mud cracks that one might see on the surface of a dried-up puddle, pond, or lake. However, mud cracks and the polygonal patterns they create are small features--like the size of a human hand. The giant polygons on Mars are big enough to hold the entire downtown area of a moderate-sized city. Mud cracks form by "dessication"--"i.e.," the removal of water by evaporation (drying). Many ideas about the polygons on Mars have centered on the idea that they are somehow related to the dessication of thick layers of wet sediment--perhaps deposited by some of the giant floods that Mars is known to have had. However, there has been considerable debate about whether the polygons formed in lava instead of sediment. Cooling lava might also crack and give the polygon texture, some have argued. Two observations have been made--using Viking images--that constrain the types of origins that can be proposed: (1) most of the "cracks" appear to be "graben"--down-dropped blocks caused by faulting, and (2) some of the "cracks" appear to indicate the outlines of buried craters. These observations suggest that whatever caused the polygons, the process appears to be confined to material that has buried older terrain. The new MOC image confirms the impression--from Viking images--that the polygon cracks--troughs--are graben formed by faults. Unfortunately, the image does not provide ample information to distinguish between the various models for the origin of the polygons or the material in which they occur. The images, however, do show features of interest. The floors of the polygon troughs, highlighted in these sub-areas of the MOC image (locations on MOC image) have bright, almost evenly spaced, windblown ripples or drifts(see also detailed sub-areas [ http://photojournal.jpl.nasa.gov/catalog/PIA01469 ]
Mars Global Surveyor Celebra …
title Mars Global Surveyor Celebrates Discovery of Deimos
Description , University of Western Ontario (London, Ontario, Canada) for his input on the geography of Deimos and the locations of Swift and Voltaire. Credit: NASA/JPL/Malin Space Science Systems, One might say that today is Deimos' birthday. To celebrate, we present here the first and only Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image of this tiny moon. Deimos was discovered 129 years ago on 11 August 1877 (U.S. time, it was 12 August UTC), by U.S. astronomer Asaph Hall. It was the first of two major discoveries that he made that month, less than a week later, he found the other, inner martian satellite, Phobos. About a month before the 129th anniversary of its discovery, on 10 July 2006, Mars Global Surveyor was pointed away from the martian surface, out toward distant Deimos. Imaging the smaller of the two martian moons was the result of a combined effort between MGS engineers at Lockheed Martin Astronautics and MOC operations engineers at Malin Space Science Systems. When the picture was acquired, Deimos was about 22,985 kilometers (14,285 miles) from MGS. This results in an image of approximately 95 meters (about 312 feet) per pixel. Higher resolution images were obtained by the Viking orbiters in the 1970s - some of those pictures were so good that boulders could be resolved on the moon's surface. While the MOC image is at a lower resolution than the Viking data, acquiring an image of Deimos helps refine the understanding of the tiny moon's orbit and geography. The two craters, Voltaire and Swift, are presently the only craters with names on all of Deimos. Author Jonathan Swift, in his 1726 "Gulliver's Travels," had coincidentally surmised that Mars has two moons. Sunlight illuminates the scene from the upper right. MGS previously imaged the inner, larger moon, Phobos, on several occasions in 1998 and 2003. In 1998, MGS was in an elliptical orbit that permitted the spacecraft to actually fly past the moon, this was not done for Deimos because MGS hasn't been out past the orbit of Deimos since it arrived at the red planet in 1997. To review the MOC images of Phobos, visit: * Moons of Mars [ http://www.msss.com/mars_images/moc/themes/MOONS.html ] * 1998 First Phobos Encounter [ http://www.msss.com/moc_gallery/ab1_m04/images/SP247603.html ] * 1998 Second Phobos Encounter [ http://www.msss.com/moc_gallery/ab1_m04/images/SP250103.html ] * 1998 Third Phobos Encounter, first view [ http://www.msss.com/moc_gallery/ab1_m04/images/SP252603.html ] * 1998 Third Phobos Encounter, second view [ http://www.msss.com/moc_gallery/ab1_m04/images/SP252604.html ] * 1998 Fourth Phobos Encounter [ http://www.msss.com/moc_gallery/ab1_m04/images/SP255103.html ] * 2003 view of Phobos [ http://www.msss.com/moc_gallery/r03_r09/images/R06/R0600044.html ] The MGS MOC team thanks Philip J. Stooke [ http://www.ssc.uwo.ca/geography/spacemap/index.htm ]
Seeing Mars' Northern Plains …
PIA01467
Sol (our sun)
Mars Orbiter Camera
Title Seeing Mars' Northern Plains Through Springtime Haze
Original Caption Released with Image "Vastitas Borealis"--the Northern Vastness--is the name given to the enigmatic northern plains of Mars. In August 1998, the ground track of Mars Global Surveyor's Mars Orbiter Camera (MOC) has evolved such that most of the terrain visible to the imager occurs in the northern lowland plains. Photographing these plains at high spatial resolution has proven to be quite a challenge, however, because the change in available ground track corresponded to a change in martian seasons--from northern winter to northern spring. Springtime at the middle and high latitudes on Mars means clouds. The clouds form as the seasonal ("i.e.," winter) polar cap frosts and snows sublime and carbon dioxide and water vapor are returned to the atmosphere. In early August 1998, clouds and hazes were especially prevalent over the northern plains of Mars, mainly between about 50°N and 75°N latitude. As has been the case throughout the Science Phasing Orbit period, the challenge for the MOC team has been to try to guess, about 3 days in advance, which areas within the accessible latitude band will be relatively cloud-free for high resolution imaging. Often this is not possible, but as the season has progressed, the clouds have thinned. Thus, despite the clouds, a few pictures of the northern plains have shown some surface detail. Most of these pictures still appear "murky" because of the thin haze still present in the atmosphere. This is the best example of MOC imaging of the Vastitas Borealis plains obtained as of mid-August 1998. MOC image 48107 covers an area approximately 4.6 kilometers (2.9 miles) wide and 12.9 kilometers (8.0 miles) long, centered at 64.54°N, 155.71°W, and is shown here at full spatial resolution (~5.5 m/pixel, ~18 feet/pixel). The context maps, identified below show that the MOC image is located north of Arcadia Planitia and several thousand kilometers northwest of the famous Olympus Mons volcano. Context maps: * Martian Landmarks. Digital shaded relief map showing location of MOC 48107 relative to familiar Martian landmarks. * Regional Context. This Viking Orbiter photomosaic is at a scale of 64 pixels per degree of latitude. The large white box represents the area covered in the local context image. The small white box indicates the location of MOC image 48107. * Local Context., This Viking Orbiter photomosaic is at a scale of 256 pixels per degree of latitude/longitude. The small white box in the center represents the location of the MOC image. The area containing the white box is also shown as a 2x enlargement in the lower right corner. The orange circle outlines a subtle crater that is seen as a bright mound (rather than as a crater) in the MOC image. This circular feature was targeted by the MOC team to provide a link between the MOC image and the lower-resolution Viking images of this location. The northern plains of Mars have puzzled planetary scientists ever since they were recognized in images from the Mariner 9 orbiter in 1972. The northern plains of Mars are lower than most of the cratered terrains in the martian southern hemisphere, and these plains are considerably lower than the volcanic rises of Tharsis and Elysium. The northern plains have been generally assumed to consist of both volcanic surfaces--"e.g.," flood basalts--and windblown sediments. An alternative model--that the northern plains are blanketed by sediment from an ocean which might have once covered these lowlands--has gained some popularity recently. High resolution images of the northern plains are rare. A few taken by the Viking Orbiters in the late 1970s (with resolutions 8-20 meters-- 26-66 feet--per pixel) revealed an eroded, layered landscape. The northern plains show a complex arrangement of old, eroded impact craters, partly buried craters, polygonal cracks that range in scales from tens of meters to tens of kilometers, and vast areas that appear relatively flat and featureless. The MOC image shows a relatively featureless terrain with some circular depressions that are probably buried or partly buried impact craters. The "hummocky" (hilly) surface appears to be eroded--probably by wind-- but no windblown dunes or drifts are present. There are no obvious lava flow features in the image, although the area covered is so small that the likelihood of seeing such features is very small. The style of erosion suggests that the surficial material was not hard rock, lending some support for the idea that the surface material is a sedimentary deposit. Nothing in this picture, however, provides an adequate test of the competing models for the nature and origin of the northern plains surfaces ("e.g.," volcanic "vs." oceanic "vs.", windblown materials). The MOC image was taken during the 381st orbit of Mars Global Surveyor at 4:41 p.m. (PDT) on August 9, 1998. The local time (on Mars) was very early in the morning--the Sun had only risen 8.9° above the horizon--equivalent to about 5:20 a.m. Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.
1 2 3
1-50 of 139