|
Stereo Images of Tvashtar Ca
This stereo image illustrate
5/31/00
Date |
5/31/00 |
Description |
This stereo image illustrates the topography of the Tvashtar Catena region on Jupiter's moon Io. It was created by combining two different views of Tvashtar taken by NASA's Galileo spacecraft on November 25, 1999 (shown in red) and February 22, 2000 (shown in blue). A raised plateau surrounds the volcanic depression, or caldera, in the center of the image. To the northeast of the main caldera, the plateau's inner and outer margins are scalloped, which may indicate that a process called sapping is eroding them. Sapping occurs when fluid escapes from the base of a cliff, causing the material above it to collapse. Smaller calderas have formed in the floor of the main caldera. This nesting of calderas is also observed on Earth, at Kilauea in Hawaii. (The two bright red regions toward the upper left of this image, which are roughly triangular in shape, are the areas where the earlier image was overexposed by the brightness of hot lava fountains). Galileo scientists are in the process of generating topographic maps from these images. Such maps will reveal the heights and slopes of different landforms in this region, which will help scientists determine the strength and other properties, of Io's surface materials. They will also be useful in understanding the processes of uplift and erosion on Io. The picture is centered at 59 degrees north latitude and 121 degrees west longitude. North is to the top of the picture and the Sun illuminates the surface from the lower left. The observations used to make the stereo image were made at ranges of 18,000 and 34,500 kilometers (11,400 and 21,600 miles) from Io. The resolution of the stereo image is about 320 meters (350 yards) per picture element. The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is a division of the California Institute of Technology, Pasadena, CA. This image and other images and data received from Galileo are posted on the Galileo mission home page at http://galileo.jpl.nasa.gov . Background information and educational context for the images can be found at http://galileo.jpl.nasa.gov/images/io/ioimages.html . ##### |
|
Colorized View of Zal Region
This image shows one of many
5/31/00
Date |
5/31/00 |
Description |
This image shows one of many intriguing mountains on Jupiter's moon Io. The image was made by combining a recent high- resolution, black and white image with earlier low-resolution color data to provide a high-resolution, color view. NASA's Galileo spacecraft took both images. The 240-kilometer (150-mile) long mountain in the image is south of the volcanic hot spot named Zal. The black and white version of this image was useful for showing the shape of the mountain and the small fans of debris piled against the base of its tall, steep cliffs. However, when colorized the relationship between different types of materials becomes apparent. For example, the bright, red material is believed to contain a compound of sulfur that forms when sulfur is boiled at a high temperature. Active eruptions of molten rock (lava) are the most likely source for the heat. Thus we see red sulfur where lava reaches the surface. Other sulfur compounds cover the yellow areas, and the black areas are fresh silicate lava that has not yet been coated by the yellow sulfurous materials. The green patches are still somewhat mysterious, they appear to form when red sulfur lands on warm lava and the two react in a manner that is still unknown. In this image, it is clear that the red material has blown out of a long crack along the western side of the mountain. Lava has flowed from this crack and filled a depression (caldera). Some of the red sulfur close to the dark caldera appears to have been converted into green material. The fact that lava comes up along the faults that define the sides of the mountains provides important clues to how the mountains form and the state of the interior of Io. Scientists at the University of Arizona speculate that the formation of the mountains on Io may be related to plumes of hot material rising inside the fiery body of Io. North is to the top and the setting sun is shining from the west. The image is centered at about 33 degrees north, 72 degrees west. The high-resolution image was taken on February 22, 2000 by NASA's Galileo spacecraft. The image was taken by the Galileo's onboard camera from a range of 33,500 kilometers (20,800 miles) and has a resolution of 335 meters (1,100 feet) per picture element. The color images were taken on July 3, 1999. They have resolutions of 1.3 kilometers (0.81 miles) per picture element and are illuminated from almost directly behind the spacecraft. They were taken at a distance of about 130,000 kilometers (81,000 miles) from Io. The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC. JPL is a division of the California Institute of Technology, Pasadena, CA. This image and other images and data received from Galileo are posted on the Galileo mission home page at http://galileo.jpl.nasa.gov . Background information and educational context for the images can be found at http://galileo.jpl.nasa.gov/images/io/ioimages.html. ##### |
|
Region of Ganymede with mix
The area of Nicholson Regio
12/16/00
Date |
12/16/00 |
Description |
The area of Nicholson Regio and Arbela Sulcus illustrates many of the diverse terrain types on Jupiter's moon Ganymede, as seen in this image taken by NASA's Galileo spacecraft. The bright terrain of Arbela Sulcus is the youngest terrain here, slicing north-south across the image. It is finely striated, and relatively lightly cratered. To the east (right) is the oldest terrain in this area, rolling and relatively densely cratered Nicholson Regio. To the west (left) is a region of highly deformed grooved terrain, intermediate in relative age. In this area of grooved terrain, stretching and normal faulting of Nicholson Regio has deformed it beyond recognition. North is to the top of the picture and the Sun illuminates the surface from the west. The image, centered at -15 degrees latitude and 347 degrees longitude, covers an area approximately 89 by 26 kilometers (55 by 16 miles). The resolution is 34 meters (112 feet) per picture element. The images were taken on May 20, 2000, at a range of 3,350 kilometers (2,082 miles). This image and other images and data received from Galileo are posted on the Galileo mission home page at http://www.jpl.nasa.gov/galileo . Background information and educational context for the images can be found at http://www.jpl.nasa.gov/galileo/sepo . The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Galileo mission for NASA's Office of Space Science, Washington, D.C. This image was produced by DLR (German Aerospace Center), Berlin, and Brown University, Providence, R.I., http://solarsystem.dlr.de/ and http://www.planetary.brown.edu/ . # # # # # |
|
Regional view of bright and
This view of the Nicholson R
12/16/00
Date |
12/16/00 |
Description |
This view of the Nicholson Regio/Arbela Sulcus region on Jupiter's moon Ganymede, taken by NASA's Galileo spacecraft, shows the stark contrast between the smooth bright terrain and the surrounding highly fractured dark terrain. This observation was designed in part to distinguish between different models for how Arbela Sulcus and other groove lanes on Ganymede were formed. The volcanic model suggests that a relatively clean, water-rich lava filled a tectonic depression, then cooled to create a smooth surface. Tectonic models suggest that focused faulting and deformation of older dark terrain destroyed the pre-existing texture, which was brightened by exposure of underlying, clean ice. Analysis of these photos suggests a third and unexpected possibility: Arbela Sulcus may be similar to some bands on another of Jupiter's moons, Europa, formed by tectonic crustal spreading and renewal. North is to the upper left of the picture and the Sun illuminates the surface from the west. The image, centered at – 14 degrees latitude and 347 degrees longitude, covers an area approximately 258 by 116 kilometers (160 by 72 miles). The resolution is 133 meters (436 feet) per picture element. The images were taken on May 20, 2000, at a range of 13,100 kilometers (8,140 miles). This image and other images and data received from Galileo are posted on the Galileo mission home page at http://www.jpl.nasa.gov/galileo . Background information and educational context for the images can be found at http://www.jpl.nasa.gov/galileo/sepo . The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Galileo mission for NASA's Office of Space Science, Washington, D.C. This image was produced by DLR (German Aerospace Center), Berlin, and Brown University, Providence, R.I., http://solarsystem.dlr.de/ and http://www.planetary.brown.edu/ . # # # # # |
|
Ganymede feature resembling
This frame compares a high-r
12/16/00
Date |
12/16/00 |
Description |
This frame compares a high-resolution view of Arbela Sulcus on Jupiter's moon Ganymede (top) with the gray band Thynia Linea on another Jovian moon, Europa (bottom), shown to the same scale. Both images are from NASA's Galileo spacecraft. Arbela Sulcus is one of the smoothest lanes of bright terrain identified on Ganymede, but subtle striations are apparent here along its length. This section of Arbela contrasts markedly from highly fractured terrain to its west and dark terrain to its east. On Europa, gray bands such as Thynia Linea have formed by tectonic crustal spreading and renewal. Such bands have sliced through and completely separated pre-existing features in the surrounding bright, ridged plains. The younger prominent double ridge Delphi Flexus cuts across Thynia Linea. The scarcity of craters on Europa attests to the relative youth of its surface compared to Ganymede's. Unusual for Ganymede, it is possible that Arbela Sulcus has formed by complete separation of Ganymede's icy crust, like bands on Europa. Tests of this idea come from detailed comparisons of their internal shapes and the relationships to the surrounding structures. In the Ganymede image, north is to the top of the picture and the Sun illuminates the surface from the west. The image, centered at -15 degrees latitude and 347 degrees longitude, covers an area approximately 34 by 26 kilometers (21 by 16 miles). The resolution is 34 meters (112 feet) per picture element. The image was taken on May 20, 2000, at a range of 3,370 kilometers (2,094 miles). In the Europa image, north is to the upper-right of the picture and the Sun illuminates the surface from the northwest. The image, centered at -66 degrees latitude and 161 degrees longitude, covers an area approximately 44 by 46 kilometers (27 by 29 miles). The resolution is 45 meters (147 feet) per picture element. The image was taken on September 26, 1998, at a range of 3,817 kilometers (2,371 miles). This image and other images and data received from Galileo are posted on the Galileo mission home page at http://www.jpl.nasa.gov/galileo . Background information and educational context for the images can be found at http://www.jpl.nasa.gov/galileo/sepo . The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Galileo mission for NASA's Office of Space Science, Washington, D.C. This image was produced by DLR (German Aerospace Center), Berlin, and Brown University, Providence, R.I., http://solarsystem.dlr.de/ and http://www.planetary.brown.edu/ . # # # # # |
|
Comparison of Ganymede and E
This image, taken by NASA's
12/16/00
Date |
12/16/00 |
Description |
This image, taken by NASA's Galileo spacecraft, shows a same-scale comparison between Arbela Sulcus on Jupiter's moon Ganymede (left) and an unnamed band on another Jovian moon, Europa (right). Arbela Sulcus is one of the smoothest lanes of bright terrain identified on Ganymede, and shows very subtle striations along its length. Arbela contrasts markedly from the surrounding heavily cratered dark terrain. On Europa, dark bands have formed by tectonic crustal spreading and renewal. Bands have sliced through and completely separated pre-existing features in the surrounding bright ridged plains. The scarcity of craters on Europa illustrates the relative youth of its surface compared to Ganymede's. Unusual for Ganymede, it is possible that Arbela Sulcus has formed by complete separation of Ganymede's icy crust, like bands on Europa. Prominent fractures on either side of Arbela appear to have been offset by about 65 kilometers (about 40 miles) along the length of the area of furrows and ridges, suggesting that strike-slip faulting was important in the formation of Arbela Sulcus. In the Ganymede image, north is to the upper left of the picture and the Sun illuminates the surface from the west. The image, centered at -14 degrees latitude and 347 degrees longitude, covers an area approximately 258 by 116 kilometers (160 by 72 miles.) The resolution is 133 meters (436 feet) per picture element. The images were taken on May 20, 2000, at a range of 13,100 kilometers (8,100 miles). In the Europa image, north is to the left of the picture and the Sun illuminates the surface from the east. The image, centered at -7 degrees latitude and 236 degrees longitude, covers an area approximately 275 by 424 kilometers (171 by 263 miles.) The resolution is 220 meters (about 720 feet) per picture element (re-sampled here to 133 meters, or 436 feet). The images were taken on Nov. 6, 1997, at a range of 21,500 kilometers (13,360 miles). The Jet Propulsion Laboratory, Pasadena, Calif., manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is a division of the California Institute of Technology in Pasadena. Images and data received from Galileo are posted on the Galileo mission home page at http://www.jpl.nasa.gov/galileo. Background information and educational context for the images can be found at http://www.jpl.nasa.gov/galileo/sepo . Images were produced by Brown University, Providence, R.I., http://www.planetary.brown.edu/, DLR (German Aerospace Center) Berlin, http://solarsystem.dlr.de , and University of Arizona, Tempe, http://www.lpl.arizona.edu/. # # # # # |
|
Perspective view of Arbela S
This view of Arbela Sulcus,
12/16/00
Date |
12/16/00 |
Description |
This view of Arbela Sulcus, a 24-kilometer-wide (15-mile- wide) region of furrows and ridges on Jupiter's moon Ganymede, shows its relationship to the dark terrain surrounding it. NASA's Galileo spacecraft took these pictures during its May 20, 2000, flyby of Ganymede. Arbela Sulcus lies overall slightly lower than the dark terrain of Nicholson Regio, a 3,700 kilometers (3,300 mile) area in the southern hemisphere. However, along the eastern margin (bottom), a portion of the dark terrain (probably an ancient degraded impact crater) lies even lower than Arbela Sulcus. Scientists did not find bright icy material on Arbela Sulcus, indicating that this ridgy area was not created by watery volcanic activity. Instead, they found fine striations covering the surface, along with a series of broader highs and lows that resemble piano keys. This suggests that the movement of underlying tectonic plates deformed the surface. Combining images from two observations taken from different viewing perspectives provides stereo topographic information, giving valuable clues as to the geologic history of a region. North is to the right of the image. The Sun illuminates the surface from the west. The image, centered at –15 degrees latitude and 347 degrees longitude, covers an area approximately 89 by 26 kilometers (55 by 16 miles). The image resolution is 70 meters (230 feet) per picture element. The images were taken on May 20, 2000, at a range of 3,350 kilometers (2,100 miles). The Jet Propulsion Laboratory, Pasadena, Calif., manages the Galileo mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology in Pasadena. This image and other images and data received from Galileo are posted on the Galileo mission home page at http://www.jpl.nasa.gov/galileo . The images were produced by German Aerospace Center (DLR), http://solarsystem.dlr.de/ Background information and educational context for the images can be found at http://www.jpl.nasa.gov/galileo/sepo . # # # # # |
|
Bright-Dark terrain boundary
The ancient, dark terrain of
12/16/00
Date |
12/16/00 |
Description |
The ancient, dark terrain of Nicholson Regio (left) shows many large impact craters, and zones of fractures oriented generally parallel to the boundary between the dark and bright regions of Jupiter's moon Ganymede. In contrast, the bright terrain of Harpagia Sulcus (right) is less cratered and relatively smooth. The nature of the boundary between ancient, dark terrain and younger, bright terrain, the two principal terrain types on Ganymede, was explored by NASA's Galileo spacecraft on May 20, 2000. Subtle parallel ridges and grooves show that Harpagia Sulcus's land has been smoothed out over the years by tectonic processes. North is to the top of the picture. The Sun illuminates the surface from the left. The image, centered at -14 degrees latitude and 319 degrees longitude, covers an area approximately 213 by 97 kilometers (132 by 60 miles.) The resolution is 121 meters (about 250 feet) per picture element. The images were taken on May 20, 2000, at a range of 11,800 kilometers (about 7,300 miles). The Jet Propulsion Laboratory, Pasadena, Calif., manages the Galileo mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology in Pasadena. This image and other images and data received from Galileo are posted on the Galileo mission home page at http://www.jpl.nasa.gov/galileo . Background information and educational context for the images can be found at http://www.jpl.nasa.gov/galileo/sepo . This image was produced by DLR (German Aerospace Center), Berlin, http://solarsystem.dlr.de/ . ####### |
|
Bright-Dark terrain boundary
The boundary between the bri
12/16/00
Date |
12/16/00 |
Description |
The boundary between the bright terrain of Harpagia Sulcus (right) and dark terrain of Nicholson Regio (left) areas of Jupiter's moon Ganymede springs out when viewed through red/blue 3-D glasses, in this image taken by NASA's Galileo spacecraft as it flew by Ganymede on May 20, 2000. Details of the rough, ancient, heavily cratered dark terrain of Nicholson Regio are in stark contrast to the very smooth, bright, young terrain of Harpagia Sulcus. In the center lies the transition to the boundary between these two regions, providing evidence that extensional faulting marks the boundary. A series of steep slopes deform the dark terrain close to the boundary. In the bright terrain, a deep trough and flanking ridge delimit the boundary. North is to the top of the picture. The Sun illuminates the surface from the left. The imaged region, centered at –14 degrees latitude and 319 degrees longitude, covers an area approximately 25 by 10 kilometers (15.5 by 6 miles.) The resolutions of the two data sets are 20 meters (66 feet) per picture element and 121 meters (397 feet) per picture element. The higher resolution images were taken at a range of 2,000 kilometers (about 1,200 miles). The Jet Propulsion Laboratory, Pasadena, Calif., manages the Galileo mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology in Pasadena. This image and other images and data received from Galileo are posted on the Galileo mission home page at http://www.jpl.nasa.gov/galileo . The image was produced by the German Aerospace Center (DLR), http://solarsystem.dlr.de and Brown University, http://www.planetary.brown.edu/ . Background information and educational context for the images can be found at http://www.jpl.nasa.gov/galileo/sepo . # # # # # |
|
Stair-step scarps in dark te
NASA's Galileo spacecraft to
12/16/00
Date |
12/16/00 |
Description |
NASA's Galileo spacecraft took this image of dark terrain within Nicholson Regio, near the border with Harpagia Sulcus on Jupiter's moon Ganymede. The ancient, heavily cratered dark terrain is faulted by a series of scarps. The faulted blocks form a series of 'stair-steps' like a tilted stack of books. On Earth, similar types of features form when tectonic faulting breaks the crust and the intervening blocks are pulled apart and rotate. This image supports the notion that the boundary between bright and dark terrain is created by that type of extensional faulting. North is to the right of the picture and the Sun illuminates the surface from the west (top). The image is centered at -14 degrees latitude and 320 degrees longitude, and covers an area approximately 16 by 15 kilometers (10 by 9 miles). The resolution is 20 meters (66 feet) per picture element. The image was taken on May 20, 2000, at a range of 2,090 kilometers (1,299 miles). This image and other images and data received from Galileo are posted on the Galileo mission home page at http://www.jpl.nasa.gov/galileo . Background information and educational context for the images can be found at http://www.jpl.nasa.gov/galileo/sepo . The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Galileo mission for NASA's Office of Space Science, Washington, D.C. This image was produced by Brown University, Providence, R.I., http://www.planetary.brown.edu/ . # # # # # |
|
Voyager's Preview of Galileo
Title |
Voyager's Preview of Galileo at Ganymede |
Explanation |
NASA's robot spacecraft Galileo [ http://newproducts.jpl.nasa.gov/galileo/ ] began its long voyage to Jupiter in October of 1989. In December of last year it arrived in the Jovian system, beginning its unprecedented, detailed exploration by dropping a probe [ http://antwrp.gsfc.nasa.gov/apod/ap960123.html ] into the gas giant's atmosphere. By early this morning [ http://newproducts.jpl.nasa.gov/galileo/countdown/g1.html ] it will have accomplished another milestone [ http://nssdc.gsfc.nasa.gov/planetary/galileo_today.html ] in its ambitious mission. Now in orbit around Jupiter [ http://newproducts.jpl.nasa.gov/galileo/tourhilites.html ], Galileo will make its first close flyby of Ganymede, Jupiter's (and the solar system's) largest moon [ http://antwrp.gsfc.nasa.gov/apod/ap950904.html ] at 2:29 a.m. EDT. As planned [ http://antwrp.gsfc.nasa.gov/apod/lib/press1_gal.html ], approaching to within 524 miles, it will make a series of high resolution images of the surface which will reveal features as small as 33 feet across. This close-up color image from the Voyager 2 flyby in 1979 previews sights [ http://newproducts.jpl.nasa.gov/galileo/ganymede/vgrgan.html ] Galileo will see [ http://newproducts.jpl.nasa.gov/galileo/sepo/sepo.html ] in greater detail. Showing features as small as 3 miles across, it reveals a variety of terrain on Ganymede's icy surface, including impact craters with bright rays and long strips of light grooved structures suggesting large scale motions of the frozen crust. Galileo's flyby images will be stored onboard for playback and should be available during the week of July 10. |
|
The Valhalla Multi-ring Stru
PIA01649
Jupiter
Solid-State Imaging
Title |
The Valhalla Multi-ring Structure on Callisto |
Original Caption Released with Image |
These images of Callisto, the outermost of the Galilean satellites of Jupiter, reveal a surface characterized by impact craters. The global view (lower left) is dominated by a large bulls-eye feature, the Valhalla multi-ring structure, consisting of a bright inner region about 600 kilometers (370 miles) across. Valhalla's 4,000 kilometer(2,500 mile) diameter make it one of the largest impact features in the solar system. Callisto is 4,800 kilometers (3,000 miles) in diameter. In this global view, the sun illuminates the surface from near the center, in the same way a full moon is seen from Earth when illuminated by the sun. The image on the right shows part of Valhalla at moderate resolution. At this resolution, the surface is appears to be somewhat smooth, with a lack of numerous small impact craters. Valhalla's outer rings are clearly seen to consist of troughs which could be fractures in the crust which resulted from the impact. The bright central plains possibly were created by the excavation and ejection of "cleaner" ice or liquid water from beneath the surface, with a fluid-like massfilling the crater bowl after impact. North is to the top of the picture. For the moderate resolution view on the right, the sun illuminates the surface from the left and the resolution is approximately 400 meters per picture element. The images were obtained on June 25, 1997 by the solid state imaging (SSI)system on NASA's Galileo spacecraft at a range of about 40,000 kilometers(25,000 miles) from Callisto during Galileo's ninth orbit of Jupiter. The global image on the left is centered at 0.5 degrees south latitude and 56 degrees longitude. The resolution is 14 kilometers per picture element. The images were obtained on November 5, 1997 at a range of 68,400 kilometers(42,400 miles) during Galileo's eleventh orbit of Jupiter. The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URLhttp://galileo.jpl.nasa.gov [ http://galileo.jpl.nasa.gov ]. Background information and educational context for the images can be found at URLhttp://www.jpl.nasa.gov/galileo/sepo [ http://www.jpl.nasa.gov/galileo/sepo ] |
|
Callisto: Pits or Craters?
PIA01630
Jupiter
Solid-State Imaging
Title |
Callisto: Pits or Craters? |
Original Caption Released with Image |
This image of Jupiter's second largest moon, Callisto, presents one of the mysteries discovered by NASA's Galileo spacecraft. In the upper left corner of the image, what appear to be very small craters are visible (See enlargement.) on the floors of some larger craters as well as in the area immediately adjacent to the larger craters. Some these smaller craters are not entirely circular. They are very similar to a population of unclassified "pits" seen in one Callisto mosaic [ http://photojournal.jpl.nasa.gov/catalog/PIA00745 ] from Galileo's ninth orbit. One possible explanation for the pits is that they represent a class of previously unseen endogenic (formed by some surface or subsurface process, rather than an impact) features. Another explanation is that they are partially eroded secondary craters. Secondary craters are formed when an initial large impact ejects large enough pieces of the surface that the pieces themselves create small craters. By studying the orientation of the pits and clusters of small craters relative to larger impacts, as well as carefully examining the physical appearance of the two groups, scientists hope to discover the origin of the pits, and the possible relationship they may have with small craters. North is to the top of the picture, and the sun illuminates the surface from the right. The full image, centered at 20.5 degrees north latitude and 142.2 degrees west longitude, covers an area approximately 72 kilometers (45 miles) by 55 kilometers (34) miles. The resolution is about 90 meters (295 feet) per picture element. The image was taken on September 17th, 1997 at a range of 8800 kilometers (5460 miles) by the Solid State Imaging (SSI) system on NASA's Galileo spacecraft during its tenth orbit of Jupiter. The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov [ http://galileo.jpl.nasa.gov ] . Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo [ http://www.jpl.nasa.gov/galileo/sepo ] |
|
Impact Craters on Icy Callis
PIA01648
Jupiter
Solid-State Imaging
Title |
Impact Craters on Icy Callisto: Doh crater and Asgard |
Original Caption Released with Image |
This composite of Jupiter's icy moon Callisto combines data from two orbits showing several types of impact craters. North is to the top of the picture, the sun illuminates the surface from the east. The global image on the right shows one of the largest impact structures on Callisto, the Asgard multi-ring structure located near 30 degrees north latitude, 142 degrees west longitude. The Asgard structure is approximately 1700 kilometers (1,054 miles) across and consists of a bright central zone surrounded by discontinuous rings. The rings include degraded ridges near the central zone and troughs at the outer margin, which resulted from deformation of the icy crust following impact. Smaller impacts have smashed into Callisto after the formation of Asgard. The young, bright-rayed crater Burr located on the northern part of Asgardis about 75 kilometers (46 miles) across. Galileo images show a third type of impact crater in this image, a dome crater named Doh, located in the bright central plains of Asgard. Doh (left image) is about 55 kilometers (34 miles)in diameter, while the dome is about 25 kilometers (15 miles) across. Dome craters contain a central mound instead of a bowl shaped depression or central mountain (peak) typically seen in larger impact craters. This type of crater could represent penetration into a slushy zone beneath the surface of the Asgard impact. The global image on the right was taken on November 4, 1996, at a distance of 111,900 kilometers (69,400 miles) by the solid state imaging (SSI) camera onboard NASA's Galileo spacecraft during its third orbit around Jupiter. The image on the left was obtained at a resolution of 90 meters (295 feet)per picture element on September 16, 1997 during Galileo's tenth orbit when the spacecraft was less than 9,500 kilometers (6,000 miles) from Callisto. The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URLhttp://galileo.jpl.nasa.gov [ http://galileo.jpl.nasa.gov ]. Background information and educational context for the images can be found at URLhttp://www.jpl.nasa.gov/galileo/sepo [ http://www.jpl.nasa.gov/galileo/sepo ] |
|
The Asgard Hemisphere of Cal
PIA01100
Jupiter
Solid-State Imaging
Title |
The Asgard Hemisphere of Callisto |
Original Caption Released with Image |
False color view of a portion of the leading hemisphere of Jupiter's moon Callisto as seen through the infrared filters of the Solid State Imaging (CCD) system aboard NASA's Galileo spacecraft. North is to the top of the picture and the sun illuminates the surface from the east. More recent impacts have excavated bright, relatively clean ice from beneath Callisto's battered surface. Callisto's dark mottled appearance may be due to contamination by non-ice components contributed by impactors or concentrated in a residue as ice is removed. This color composite image is centered on longitude 139 West and encompasses an area about 1000 miles (1600 kilometers) by 2470 miles (4000 kilometers). The images were obtained on November 3rd, 1996. The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo |
|
Ganymede Global
PIA00706
Jupiter
Solid-State Imaging
Title |
Ganymede Global |
Original Caption Released with Image |
View of Ganymede from the Galileo spacecraft during its first encounter with the Satellite. North is to the top of the picture and the sun illuminates the surface from the right. The finest details that can be discerned in this picture are about 6.7 kilometers across. The Universal Time is 8:45:09 UT on June 26, 1996. The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo |
|
Ganymede Color Global
PIA00716
Jupiter
Solid-State Imaging
Title |
Ganymede Color Global |
Original Caption Released with Image |
Natural color view of Ganymede from the Galileo spacecraft during its first encounter with the satellite. North is to the top of the picture and the sun illuminates the surface from the right. The dark areas are the older, more heavily cratered regions and the light areas are younger, tectonically deformed regions. The brownish-gray color is due to mixtures of rocky materials and ice. Bright spots are geologically recent impact craters and their ejecta. The finest details that can be discerned in this picture are about 13.4 kilometers across. The images which combine for this color image were taken beginning at Universal Time 8:46:04 UT on June 26, 1996. The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo |
|
Mosaic of Io
PIA01108
Jupiter
Solid-State Imaging
Title |
Mosaic of Io |
Original Caption Released with Image |
Mosaic of images of Io acquired during orbit C3, showing more than half of Io's surface. These are the best images available to show topographic features over most of this region. The map projection is called Simple Cylindrical, and the grid lines mark 10 degree intervals of latitude and longitude. The mosaic covers an area of about 8 million square kilometers, and the finest details that can discerned are about 2.5 kilometers in size. North is to the top of the picture and the sun illuminates the surface from the left. The images which form this mosaic were obtained through the clear filter of the Solid State Imaging (CCD) system aboard NASA's Galileo spacecraft on Nov. 6, 1996 (Universal Time) at a range which varied from 245,719 kilometers to 403,100 kilometers. The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo |
|
Jupiter's Ring System
PIA01621
Jupiter
Solid-State Imaging
Title |
Jupiter's Ring System |
Original Caption Released with Image |
This mosaic of Jupiter's ring system was acquired by NASA's Galileo spacecraft when the Sun was behind the planet, and the spacecraft was in Jupiter's shadow peering back toward the Sun. [ http://photojournal.jpl.nasa.gov/figures/occultation.html ] Galileo's November 1996 trajectory In such a configuration, very small dust-sized particles are accentuated so both the ring particles and the smallest particles in the upper atmosphere of Jupiter are highlighted. Such small particles are believed to have human-scale lifetimes, i.e., very brief compared to the solar system's age. Jupiter's ring system is composed of three parts: a flat main ring, a toroidal halo interior to the main ring, and the gossamer ring, which lies exterior to the main ring. Only the main ring and a hint of the surrounding halo can be seen in this mosaic. In order to see the less dense components (the outer halo and gossamer ring) the images must be overexposed with respect to the main ring. This composite of two mosaics was taken through the clear filter (610 nanometers) of the solid state imaging (CCD) system on November 9, 1996, during Galileo's third orbit of Jupiter. The ring was approximately 2,300,000 kilometers away. The resolution is approximately 46 kilometers per picture element from right to left, however, because the spacecraft was only about 0.5 degrees above the ring plane, the image is highly foreshortened in the vertical direction. The vertical bright arcs in the middle of the ring mosaics show the edges of Jupiter and are composed of images obtained by NASA's Voyager spacecraft in 1979. The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov [ http://galileo.jpl.nasa.gov ]. Background information and educational context for the images can be found at URLhttp://www.jpl.nasa.gov/galileo/sepo [ http://www.jpl.nasa.gov/galileo/sepo ] |
|
Io imaging during Galileo's
PIA01605
Jupiter
Title |
Io imaging during Galileo's 24th orbit |
Original Caption Released with Image |
During its 14th orbit of Jupiter in March 29, 1998, NASA's Galileo spacecraft captured an image of Jupiter's moon, Io, that has the same lighting geometry that will exist during Io's close Io flyby on October 11, 1999 (the 24th orbit). The spacecraft groundtrack on Io is shown, with two-minute intervals marked by X's. The large X marks the location of closest approach, when Galileo will be just 500 kilometers (about 300 miles) above Io's surface. The curved boundary on the left marks the "terminator" or boundary between the lit day side and dark night side. Although the Pele volcano will be on the night side during the flyby, the hot lavas will be seen glowing in the dark. Other targets of interest that will be visible near closest approach are Pillan Patera, the site of dramatic surface changes [ http://photojournal.jpl.nasa.gov/catalog/PIA00744 ], Reiden Patera, Marduk, the bright plains of Colchis regio, and the rugged Dorian Montes mountains. Active volcanic plumes and high-temperature hot spots have been seen at Pele, Pillan, and Marduk. North is to the top of this image, which has a resolution of 2.6 kilometers (1.6 miles) per picture element. The image was taken at a range of 256,948 kilometers (about 160,000 miles) by the solid state imaging camera system on NASA's Galileo spacecraft. The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, D.C. This image and other images and data received from Galileo are posted on the World Wide Web on the Galileo mission home page at URL http://galileo.jpl.nasa.gov [ http://galileo.jpl.nasa.gov ] . Background information and educational context for the images can be found at http://www.jpl.nasa.gov/galileo/sepo [ http://www.jpl.nasa.gov/galileo/sepo ] . |
|
Topography on Europa....the
PIA01101
Jupiter
Solid-State Imaging
Title |
Topography on Europa....the Shadow knows |
Original Caption Released with Image |
This image of Europa was taken by the Galileo spacecraft under "low-sun" illumination--the equivalent of taking a picture from a high altitude at sunrise or sunset. Note that in this image the topography of the terrain is emphasized. Planetary geologists use information from images acquired under a variety of lighting conditions to identify different types of structures and interpret how they formed. For example, the length of the shadow cast by a feature (e.g. a ridge or knob) is indicative of that feature's height. In this recent image, ridges and irregularly shaped knobs ranging in size from 5 kilometers across down to the limit of resolution (0.44 kilometers/pixel) can be seen. Measurements from shadow lengths indicate that features in this image range from tens of meters up to approximately one hundred meters in height. The Galileo spacecraft acquired this image of Europa's surface during its third orbit around Jupiter. The image covers an area approximately 40 kilometers (25 miles) by 75 kilometers (45 miles), centered near 10S, 190W. The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. |
|
Calderas" on Ganymede?
PIA01614
Jupiter
Solid-State Imaging
Title |
Calderas" on Ganymede? |
Original Caption Released with Image |
NASA's Galileo imaging camera targeted an area in Sippar Sulcus on Jupiter's moon, Ganymede. Images obtained in 1979 by NASA's Voyager spacecraft showed that the area contained curvilinear and arcuate scarps or cliffs. These features appeared to be depressions which were candidate sources for some of the water ice volcanism thought to form the bright grooved terrain on Ganymede. The high resolution Galileo images seen here reveal that one of these structures contains a lobate, flow-like feature that is the best candidate yet seen for an icy volcanic lava flow on Ganymede. The prominent depression with scalloped walls and internal terraces is about 55 kilometers (km) in length and 17 to 20 km wide. On the floor of the inner depression is a lobate flow-like deposit 7 to 10 km wide with ridges that are curved outward (and apparently downslope) toward a cross-cutting lane of grooved terrain. The morphology of this structure suggests the possibility of volcanic eruptions creating a channel and flow, and cutting down into the surface. North is to the bottom of the picture and the sun illuminates the surface from the left. The mosaic, centered at 31 degrees south latitude and 189 degrees longitude, covers an area approximately 91 by 62 kilometers. The resolution is 172 meters per picture element. The images were taken on May 7, 1997 at 15 hours, 18 minutes, 35 seconds Universal Time at a range of 17,489 kilometers by the Solid State Imaging(SSI) system on NASA's Galileo spacecraft. The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov [ http://galileo.jpl.nasa.gov ] . Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo [ http://www.jpl.nasa.gov/galileo/sepo ] |
|
Recent Eruption at Gish Bar
PIA03884
Jupiter
Solid-State Imaging
Title |
Recent Eruption at Gish Bar Patera on Io |
Original Caption Released with Image |
This image taken by NASA's Galileo spacecraft reveals fresh lava in a wide pit named Gish Bar Patera on Jupiter's moon Io. The patera, or depression, is quite large: 106.3 kilometers (66 miles) by 115.0 kilometers (71 miles). Galileo has detected volcanic activity at this site in the past, particularly in late 1996. Galileo took this image on Oct. 16, 2001, during its 32nd orbit of Jupiter. Effects of a new eruption at Gish Bar can be seen in a comparison with images from 1999 (see figure below). The new eruption was first detected in infrared imaging by Galileo's near-infrared mapping spectrometer in August 2001. This visible-light image shows a pair of new lava flows. The largest runs to the western boundary and extends to the central and northern portions of the patera. The other flow corresponds to a secondary depression in the southeastern portion of the patera. Based on changes seen at this depression between July and October 1999, this is thought to be the site of an outburst seen by Earth-based observers in August 1999. Gish Bar Patera lies at the base of an 11-kilometer (36,000-foot) mountain at 15.6 degrees north latitude, 89.1 degrees west longitude on Io. This image was taken from a distance of 25,000 kilometers (15,500 miles) and has a resolution of 250 meters (820 feet) per pixel. The Sun is straight behind the observer, an illumination angle that minimizes shadows and emphasizes inherent brightness variations rather than topography. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Galileo mission for NASA's Office of Space Science, Washington, D.C. Additional information about Galileo and its discoveries is available on the Galileo mission home page at http://galileo.jpl.nasa.gov [ http://galileo.jpl.nasa.gov ]. Background information and educational context for the images can be found at http://galileo.jpl.nasa.gov/gallery/io.cfm [ http://galileo.jpl.nasa.gov/gallery/io.cfm ]. |
|
Recent Eruption at Gish Bar
PIA03884
Jupiter
Solid-State Imaging
Title |
Recent Eruption at Gish Bar Patera on Io |
Original Caption Released with Image |
This image taken by NASA's Galileo spacecraft reveals fresh lava in a wide pit named Gish Bar Patera on Jupiter's moon Io. The patera, or depression, is quite large: 106.3 kilometers (66 miles) by 115.0 kilometers (71 miles). Galileo has detected volcanic activity at this site in the past, particularly in late 1996. Galileo took this image on Oct. 16, 2001, during its 32nd orbit of Jupiter. Effects of a new eruption at Gish Bar can be seen in a comparison with images from 1999 (see figure below). The new eruption was first detected in infrared imaging by Galileo's near-infrared mapping spectrometer in August 2001. This visible-light image shows a pair of new lava flows. The largest runs to the western boundary and extends to the central and northern portions of the patera. The other flow corresponds to a secondary depression in the southeastern portion of the patera. Based on changes seen at this depression between July and October 1999, this is thought to be the site of an outburst seen by Earth-based observers in August 1999. Gish Bar Patera lies at the base of an 11-kilometer (36,000-foot) mountain at 15.6 degrees north latitude, 89.1 degrees west longitude on Io. This image was taken from a distance of 25,000 kilometers (15,500 miles) and has a resolution of 250 meters (820 feet) per pixel. The Sun is straight behind the observer, an illumination angle that minimizes shadows and emphasizes inherent brightness variations rather than topography. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Galileo mission for NASA's Office of Space Science, Washington, D.C. Additional information about Galileo and its discoveries is available on the Galileo mission home page at http://galileo.jpl.nasa.gov [ http://galileo.jpl.nasa.gov ]. Background information and educational context for the images can be found at http://galileo.jpl.nasa.gov/gallery/io.cfm [ http://galileo.jpl.nasa.gov/gallery/io.cfm ]. |
|
Regional View of Ganymede
PIA01618
Jupiter
Solid-State Imaging
Title |
Regional View of Ganymede |
Original Caption Released with Image |
View of the Marius Regio and Nippur Sulcus area of Jupiter's moon, Ganymede showing the dark and bright grooved terrain which is typical of this satellite. This regional scale view was imaged near the terminator (the line between day and night) and provides geologic context for small areas that were imaged at much higher resolution earlier in the tour of NASA's Galileo spacecraft through the Jovian system. The older, more heavily cratered dark terrain of Marius Regio is rutted with furrows, shallow troughs perhaps formed as a result of ancient giant impacts. Bright grooved terrain is younger and is formed through tectonism probably combined with icy volcanism. The lane of grooved terrain in the lower left, Byblus Sulcus [ http://photojournal.jpl.nasa.gov/catalog/PIA01088 ], was imaged during the spacecraft's second orbit, as were Philus Sulcus and Nippur Sulcus [ http://photojournal.jpl.nasa.gov/catalog/PIA00497 ], seen here in the upper left. Placing the small higher resolution targets of Galileo's second orbit into the context of more distant, lower resolution views of the areas surrounding and connecting them, and imaging them along Ganymede's terminator, allows for an integrated understanding of Ganymede' s geology. North is to the top left of the picture and the sun illuminates the surface from the lower right. The image, centered at 43 degrees latitude and 194 degrees longitude, covers an area approximately 664 by 518 kilometers. The resolution is 940 meters per picture element. The image was taken on May 7, 1997 at 12 hours, 50 minutes, 11 seconds Universal Time at a range of 92,402 kilometers by the Solid State Imaging (SSI) system on NASA's Galileo spacecraft. The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov [ http://galileo.jpl.nasa.gov ] . Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo [ http://www.jpl.nasa.gov/galileo/sepo ] |
|
Mosaic of Jupiter's Great Re
PIA00832
Sol (our sun)
Solid-State Imaging
Title |
Mosaic of Jupiter's Great Red Spot (727 nm) |
Original Caption Released with Image |
The Great Red Spot of Jupiter as seen through a "Methane" filter (727 nm) of the Galileo imaging system. The image is a mosaic of six images that have been map-projected to a uniform grid of latitude and longitude. North is at the top. The mosaic was taken over a 76 second interval beginning at universal time 14 hours, 31 minutes, 52 seconds on June 26, 1996. The Red Spot is 20,000 km long and has been followed by observers on Earth since the telescope was invented 300 years ago. It is a huge storm made visible by variations in the composition of the cloud particles. The Red Spot is not unique, but is simply the largest of a class of long-lived vortices, some of which are visible in the lower part of the image. The range is 1.46 million kilometers. The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo |
|
Dome shaped features on Euro
PIA00852
Jupiter
Solid-State Imaging
Title |
Dome shaped features on Europa's surface |
Original Caption Released with Image |
The Solid State Imaging system aboard the spacecraft Galileo took this image of the surface of Europa on February 20, 1997 during its sixth orbit around Jupiter. The image is located near 16 North, 268 West, illumination is from the lower-right. The area covered is approximately 48 miles (80 kilometers) by 56 miles (95 kilometers) across. North is toward the top of the image. This image reveals that the icy surface of Europa has been disrupted by ridges and faults numerous times during its past. These ridges have themselves been disrupted by the localized formation of domes and other features that may be indicative of thermal upwelling of water from beneath the crust. These features provide strong evidence for the presence of subsurface liquid during Europa's recent past. The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo |
|
Thera and Thrace on Europa
PIA02099
Jupiter
Solid-State Imaging
Title |
Thera and Thrace on Europa |
Original Caption Released with Image |
Thera and Thrace are two dark, reddish regions of enigmatic terrain that disrupt the older icy ridged plains on Jupiter's moon Europa. North is toward the top of the mosaic obtained by NASA's Galileo spacecraft. Thera (left) is about 70 kilometers wide by 85 kilometers high (43 by 53 miles) and appears to lie slightly below the level of the surrounding plains. Some bright icy plates which are observed inside appear to be dislodged from the edges of the chaos region. The curved fractures along its boundaries suggest that collapse may have been involved in Thera's formation. In contrast, Thrace (right) is longer, shows a hummocky texture, and appears to stand at or slightly above the older surrounding bright plains. Thrace abuts the gray band Libya Linea to the south and appears to darken Libya. One model for the formation of these and other chaos regions on Europa is complete melt-through of Europa's icy shell from an ocean below. Another model is that warm ice welled up from below and caused partial melting and disruption of the surface. To produce this image, two regional images obtained at a resolution of 220 meters (240 yards) per picture element during Galileo's 17th orbit of Jupiter were colorized with lower resolution (1.4 kilometers or 1526 yards per picture element) images of the region obtained during the 14th orbit. The color image is generated from the violet, green, and near-infrared (968 nanometers) filters of the Galileo Solid State Imaging system and exaggerates the subtle color differences of Europa's surface. The mosaic, centered at about 50 degrees south latitude and 180 degrees longitude, covers an area approximately 525 by 300 kilometers (325 by 186 miles). The images from the 17th orbit were acquired at Universal Time 02 hours, 51 minutes, 56 seconds on September 26, 1998 when the sun illuminated the region from the northeast. The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov [ http://galileo.jpl.nasa.gov ]. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo [ http://www.jpl.nasa.gov/galileo/sepo ]. |
|
Detailed View of Mountain an
PIA03527
Jupiter
Solid-State Imaging
Title |
Detailed View of Mountain and Craters at Tohil, Io |
Original Caption Released with Image |
Scientists pointed NASA's Galileo spacecraft camera at the Tohil region of Jupiter's moon Io to investigate the curious relationship between Io's mountains and its volcanoes. This mosaic of Galileo images taken Oct. 16, 2001, shows details of the mountain called Tohil Mons (lower left), a small dark-floored volcanic crater, or "patera," bordered by mountain walls (middle), and intricate patterns of dark lava flows intertwined with bright material on the floor of a larger crater, Tohil Patera (upper right). An earlier stereoobservation [ http://photojournal.jpl.nasa.gov/catalog/PIA02586 ] by Galileo revealed that Tohil Mons rises up to 6 kilometers (19,700 feet) above the surrounding plains. In contrast, shadows in the new images indicate the two paterae are only about 100 meters (330 feet) deep. The new images were taken soon after sunrise at Tohil, with a resolution of 50 meters (160 feet) per picture element to reveal details never seen before. Another view showing the entire mountain at lower resolution [ http://photojournal.jpl.nasa.gov/catalog/PIA03600 ]was also acquired. Despite Io's extremely high rate of volcanic activity, its mountains do not resemble volcanoes seen elsewhere in the solar system. Instead, the mountains appear to be formed by the uplift of large blocks of Io's crust. This image shows evidence of numerous landslides from the mountain (bottom left). However, one of the most surprising revelations from this observation is that despite the closeness of the small, dark-floored patera to the mountain walls, the patera floor is not covered with any landslide debris. This indicates that the patera floor has been resurfaced with lava more recently than any landslides have occurred. Another possibility is that this patera, like others on Io [ http://photojournal.jpl.nasa.gov/catalog/PIA02596 ] is actually a lava lake and completely consumes debris that falls into it from the mountain. Galileo's infrared-mapping instrument has detected heat from the patera, indicating an active or very recent eruption. North is to the top of the picture and the Sun illuminates the surface from the right. The mosaic is centered at 27.5 degrees south latitude and 160 degrees west longitude and covers 280 kilometers (170 miles) from upper right to lower left. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Galileo mission for NASA's Office of Space Science, Washington, D.C. Additional information about Galileo and its discoveries is available on the Galileo mission home page athttp://galileo.jpl.nasa.gov [ http://galileo.jpl.nasa.gov ]. Background information and educationalcontext for the images can be found at http://galileo.jpl.nasa.gov/gallery/io.cfm [ http://galileo.jpl.nasa.gov/gallery/io.cfm ]. |
|
New plume vent near Zamama,
PIA03531
Jupiter
Solid-State Imaging
Title |
New plume vent near Zamama, Io |
Original Caption Released with Image |
The source area of what had been a towering volcanic plume two months earlier lies in the far-right frame of this mosaic of images taken of Jupiter's moon Io by NASA's Galileo spacecraft on Oct. 16, 2001. The region in the images includes the Zamama lava flow in Jupiter's northern hemisphere. The Zamama flow field emanates from the northernmost of two small volcanoes in the far left frame. These lava flows were not present in Voyager images of Io, so they formed some time between the Voyager 1 flyby in 1979 and the first Galileo observations of Io in 1996. Galileo also observed Zamama during Io encounters in 1999 [ http://photojournal.jpl.nasa.gov/catalog/PIA02504 ], and scientists identified narrow, long, dark lava flows thought to be similar to lava flows in Hawaii. Moving northeast, the second and third frames of this mosaic contain lava flow fields and several unnamed volcanic depressions, called "paterae." It is unclear whether the broad, shield-like features or plateaus on which the paterae rest were created by eruptions from the paterae, or if they were preexisting features. Some fractures and dark lines suggest that the crust here is breaking up, creating cracks that magma can use to rise to the surface. The far-right frame of this mosaic shows dark lava flows and bright spots. The bright spots are probably sulfur-bearing plume deposits, which are thought to be associated with the source of a plume eruption [ http://photojournal.jpl.nasa.gov/catalog/PIA02592 ] 500 kilometers (310 miles) high that was observed by the Galileo spacecraft in August, 2001. It was the largest plume eruption ever observed on Io. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Galileo mission for NASA's Office of Space Science, Washington, D.C. Additional information about Galileo and its discoveries is available on the Galileo mission home page at http://galileo.jpl.nasa.gov [ http://galileo.jpl.nasa.gov ]. Background information and educational context for the images can be found at http://galileo.jpl.nasa.gov/gallery/io.cfm [ http://galileo.jpl.nasa.gov/gallery/io.cfm ]. |
|
Pwyll Crater on Europa
PIA00586
Jupiter
Solid-State Imaging
Title |
Pwyll Crater on Europa |
Original Caption Released with Image |
Pwyll crater on Jupiter's moon, Europa, was photographed by the Solid State Imaging system on the Galileo spacecraft during its sixth orbit around Jupiter. This impact crater is located at 26 degrees south latitude, 271 degrees west longitude, and is about 26 kilometers (16 miles) in diameter. Lower resolution pictures of Pwyll Crater taken earlier in the mission show that material ejected by the impact can be traced for hundreds of miles across the icy surface of Europa. The dark zone seen here in and around the crater is material excavated from several kilometers (a few miles) below the surface. Also visible in this picture are complex ridges. The two images comprising this mosaic were taken on February 20, 1997 from a distance of 12,000 kilometers (7,500 miles) by the Galileo spacecraft. The area shown is about 120 kilometers by 100 kilometers (75 miles by 60 miles). The Jet Propulsion Laboratory, Pasadena, CA, manages the mission for NASA's Office of Space Science, Washington D.C. This image and other images and data received from Galileo are posted on the World Wide Web Galileo mission home page at http://galileo.jpl.nasa.gov. |
|
Ridges and Fractures on Euro
PIA00849
Jupiter
Solid-State Imaging
Title |
Ridges and Fractures on Europa |
Original Caption Released with Image |
This high resolution image of the icy crust of Europa, one of Jupiter's moons, reveals a surface criss-crossed by multiple sets of ridges and fractures. The area covered by this image is approximately 9 miles (15 kilometers) by 7 miles (12 kilometers), located near 15 North, 273 West. North is to the top, and the sun is illuminating the terrain from the right. The large ridge in the lower right corner of the image is approximately 1.5 miles (2.5 kilometers) across, and is one of the youngest features in this image, as it cuts across many of the other features. Note that one ridge has been sheared by a right-lateral fault. This image was taken by the Galileo spacecraft on February 20, 1997 from a distance of 1240 miles (2000 kilometers). The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo |
|
High Spatial Resolution Euro
PIA00855
Jupiter
Near Infrared Mapping Spectr
Title |
High Spatial Resolution Europa Coverage by the Galileo Near Infrared Mapping Spectrometer (NIMS) |
Original Caption Released with Image |
The NIMS instrument on the Galileo spacecraft, which is being used to map the mineral and ice properties over the surfaces of the Jovian moons, produces global spectral images at modest spatial resolution and high resolution spectral images for small selected regions on the satellites. This map illustrates the high resolution coverage of Europa obtained by NIMS through the April 1997 G7 orbit. The areas covered are displayed on a Voyager-derived map. A good sampling of the dark trailing-side material (180 to 360 degrees) has been obtained, with less coverage of Europa's leading side. The false-color composites use red, green and blue to represent the infrared brightnesses at 0.7, 1.51 and 1.82 microns respectively. Considerable variations are evident and are related to the composition and sizes of the surface grains. The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC. The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. |
|
Agenor Linea at High Resolut
PIA01646
Jupiter
Solid-State Imaging
Title |
Agenor Linea at High Resolution |
Original Caption Released with Image |
Agenor Linea is an unusual feature on Jupiter's icy moon Europa since it is brighter than its surroundings while most of Europa's ridges and bands are relatively dark. During the Galileo spacecraft's 17th orbit of Jupiter, high resolution images were obtained of Agenor Linea near Europa's day/night boundary so as to emphasize fine surface details. This mosaic shows high resolution images embedded in slightly lower resolution images which were also acquired during the 17th orbit. The Galileo images show that Agenoris not a ridge, but is relatively flat. Its interior consists of several long bands, just one of which is the very bright feature known as Agenor. Each long band shows fine striations along its length. A few very small craters pockmark Agenor Linea and its surroundings. Agenor is cut by some narrow fractures, and by some small subcircular features called lenticulae. Rough chaotic terrain is visible at the top and bottom of this photo, and appears to be "eating away" at the edges of Agenor. Though previously it was suspected that Agenor Linea might be one of the youngest features on Europa, this new view shows that it is probably not. North is to the upper right of the picture and the sun illuminates the surface from the east. The image, centered at 44 degrees south latitude and 219 degrees west longitude, covers an area approximately 130 by 95 kilometers (80 by 60 miles). The highest resolution images were obtained at a resolution of about 50 meters (165 feet) per picture element and are shown here in context at about 220 meters per picture element. The images were taken on September 26th, 1998 at ranges as close as 5000 kilometers (3100 miles) by the Solid State Imaging (SSI) system on NASA's Galileo spacecraft. The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URLhttp://galileo.jpl.nasa.gov [ http://galileo.jpl.nasa.gov ]. Background information and educational context for the images can be found at URLhttp://www.jpl.nasa.gov/galileo/sepo [ http://www.jpl.nasa.gov/galileo/sepo ] |
|
Europa's Leading Hemisphere
PIA00874
Jupiter
Solid-State Imaging
Title |
Europa's Leading Hemisphere |
Original Caption Released with Image |
This image of Europa's leading hemisphere was obtained by the solid state imaging (CCD) system on board NASA's Galileo spacecraft during its seventh orbit of Jupiter. In the upper left part of the image is Tyre, a multi-ringed structure that may have formed as a result of an ancient impact. Also visible are numerous lineaments that extend for over 1000 kilometers. The limb, or edge, of Europa in this image can be used by scientists to constrain the radius and shape of the satellite. North is to the top of the picture and the sun illuminates the surface from the right. The image, centered at -40 latitude and 180 longitude, covers an area approximately 2000 by 1300 kilometers. The finest details that can be discerned in this picture are about 6.6 kilometers across. The images were taken on April 3, 1997 at 17 hours, 42 minutes, 19 seconds Universal Time when the spacecraft was at a range of 31,8628 kilometers. The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo |
|
Cross-cutting Relationships
PIA00851
Jupiter
Solid-State Imaging
Title |
Cross-cutting Relationships of Surface Features on Europa |
Original Caption Released with Image |
This image of Jupiter's moon Europa shows a very complex terrain of ridges and fractures. The absence of large craters and the low number of small craters indicates that this surface is geologically young. The relative ages of the ridges can be determined by using the principle of cross-cutting relationships, i.e. older features are cross-cut by younger features. Using this principle, planetary geologists are able to unravel the sequence of events in this seemingly chaotic terrain to unfold Europa's unique geologic history. The spacecraft Galileo obtained this image on February 20, 1997. The area covered in this image is approximately 11 miles (18 kilometers) by 8.5 miles (14 kilometers) across, near 15 North, 273 West. North is toward the top of the image, with the sun illuminating from the right. The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo |
|
Prominent Doublet Ridges on
PIA00542
Jupiter
Solid-State Imaging
Title |
Prominent Doublet Ridges on Europa |
Original Caption Released with Image |
This image of Jupiter's satellite Europa was obtained from a range of 7364 miles (11851 km) by the Galileo spacecraft during its fourth orbit around Jupiter and its first close pass of Europa. The image spans 30 miles by 57 miles (48 km x 91 km) and shows features as small as 800 feet (240 meters) across, a resolution more than 150 times better than the best Voyager coverage of this area. The sun illuminates the scene from the right. The large circular feature in the upper left of the image could be the scar of a large meteorite impact. Clusters of small craters seen in the right of the image may mark sites where debris thrown from this impact fell back to the surface. Prominent doublet ridges over a mile (1.6 km) wide cross the plains in the right part of the image, younger ridges overlap older ones, allowing the sequence of formation to be determined. Gaps in ridges indicate areas where emplacement of new surface material has obliterated pre-existing terrain. The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the Galileo mission home page on the World Wide Web at http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo |
|
Io's Pele Hemisphere After P
PIA01667
Jupiter
Solid-State Imaging
Title |
Io's Pele Hemisphere After Pillan Changes |
Original Caption Released with Image |
This global view of Jupiter's moon, Io, was obtained during the tenth orbit of Jupiter by NASA's Galileo spacecraft. Io, which is slightly larger than Earth's moon, is the most volcanically active body in the solar system. In this enhanced color composite, deposits of sulfur dioxide frost appear in white and grey hues while yellowish and brownish hues are probably due to other sulfurous materials. Bright red materials, such as the prominent ring surrounding Pele, and "black" spots with low brightness mark areas of recent volcanic activity and are usually associated with high temperatures and surface changes. One of the most dramatic changes [ http://photojournal.jpl.nasa.gov/catalog/PIA00744 ] is the appearance of a new dark spot (upper right edge of Pele), 400 kilometers (250 miles)in diameter which surrounds a volcanic center named Pillan Patera. The dark spot did not exist in images obtained 5 months earlier, but Galileo imaged a 120 kilometer (75 mile) high plume erupting from this location during its ninth orbit. North is to the top of the picture which was taken on September 19, 1997 at a range of more than 500,000 kilometers (310,000 miles)by the Solid State Imaging (SSI) system on NASA's Galileo spacecraft. The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URLhttp://galileo.jpl.nasa.gov [ http://galileo.jpl.nasa.gov ]. Background information and educational context for the images can be found at URLhttp://www.jpl.nasa.gov/galileo/sepo [ http://www.jpl.nasa.gov/galileo/sepo ]. |
|
Jupiter's Gossamer Ring
PIA00659
Jupiter
Solid-State Imaging
Title |
Jupiter's Gossamer Ring |
Original Caption Released with Image |
Jupiter's ring system is composed of three parts: a flat main ring, a toroidal halo interior to the main ring, and the gossamer ring, which lies exterior to the main ring. The gossamer ring is the extremely diffuse and uniform band that stretches across the center of this mosaic, starting from the main ring and halo on the right-hand side. The gossamer ring had been seen previously only in the single Voyager image in which it was discovered at a very low brightness level, there its brightness appeared to drop from about one-tenth the main ring's value until the ring totally vanished at a distance of about three Jovian radii. The gossamer ring is clearly visible in this Galileo view, the left side of the image corresponds to a radial distance of about 2.2 Jovian radii. The outer edge of the gossamer ring is beyond the edge of this mosaic. [ http://photojournal.jpl.nasa.gov/figures/gossamer.html ] Jupiter's gossamer ring To accentuate the very faint, gossamer ring, the images were overexposed with respect to the main ring and the halo (both seen on the far right of the mosaic). In these long exposures, some stars are visible, other specks in the mosaic were caused by cosmic ray hits to the CCD. All parts of the Jovian rings scatter sunlight very efficiently in the forward direction, indicating that the particles are micrometers or less in diameter, small than the thickness of tissue paper. Such small particles are believed to have human-scale lifetimes, i.e., very brief compared to the solar system's age. These images were taken through the clear filter (610 nanometers) of the solid state imaging (CCD) system aboard NASA's Galileo spacecraft on November 9, 1996. The resolution is approximately 46 kilometers per picture element from right to left, however, because the spacecraft was only about 0.5 degrees above the ring plane, the image is highly foreshortened in the vertical direction. The images were obtained when Galileo was in Jupiter's shadow, peering back toward the Sun, the ring was approximately 2.3 million kilometers (1.4 million miles) away. Jupiter lies about a full frame off the right edge. The view of Earth's moon included in the explanatory graphics was created from imagery returned by the BMDO/NASA Clementine lunar orbiter which was launched in early 1994. (BMDO is Ballistic Missile Defense Organization.) The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov [ http://galileo.jpl.nasa.gov ] . Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo [ http://www.jpl.nasa.gov/galileo/sepo ] |
|
Europa In Color
PIA00275
Jupiter
Solid-State Imaging
Title |
Europa In Color |
Original Caption Released with Image |
False color has been used here to enhance the visibility of certain features in this composite of three images of the Minos Linea region on Jupiter's moon Europa taken on 28 June 1996 Universal Time by the solid state imaging camera on NASA's Galileo spacecraft. Triple bands, lineae and mottled terrains appear in brown and reddish hues, indicating the presence of contaminants in the ice. The icy plains, shown here in bluish hues, subdivide into units with different albedos at infrared wavelengths probably because of differences in the grain size of the ice. The composite was produced using images with effective wavelengths at 989, 757, and 559 nanometers. The spatial resolution in the individual images ranges from 1.6 to 3.3 kilometers (1 to 2 miles) per pixel. The area covered, centered at 45N, 221 W, is about 1,260 km (about 780 miles) across. The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo |
|
PPR Great Red Spot Temperatu
PIA01234
Sol (our sun)
Photopolarimeter-Radiometer
Title |
PPR Great Red Spot Temperature Map |
Original Caption Released with Image |
This map shows temperature for the region around Jupiter's Great Red Spot and an area to the northwest. It corresponds to a level in Jupiter's atmosphere where the pressure is 1/2 of the of the Earth's at sea level (500 millibars), the same as it is near 6000 meters (20,000 feet) above sea level on Earth. The center of Great Red Spot appears colder than the surrounding areas, where air from below is being brought up. The "panhandle" to the northwest is warmer and drier, and the gases there are descending, so it is much clearer of clouds. Compare this map to one released earlier at a higher place in the atmosphere (250 millibars or 12000 meters). The center of the Great Red Spot is warmer lower in the atmosphere, and a white "hot spot" appears in this image that is not present at the higher place. This map was made from data taken by the Photopolarimeter/Radiometer (PPR) instrument on June 26, 1996. Launched in October 1989, Galileo entered orbit around Jupiter on December 7, 1995. The spacecraft's mission is to conduct detailed studies of the giant planet, its largest moons and the Jovian magnetic environment. JPL manages the Galileo mission for NASA's Office of Space Science, Washington, D.C. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. |
|
Zal Patera, Io, in color
PIA02527
Jupiter
Solid-State Imaging
Title |
Zal Patera, Io, in color |
Original Caption Released with Image |
The Zal Patera region of Jupiter's volcanic moon Io is shown in this combination of high-resolution black and white images taken by NASA's Galileo spacecraft on November 25, 1999 and lower resolution color images taken by Galileo on July 3, 1999. By combining both types of images, Galileo scientists can better understand the relationships between the different surface materials and the underlying geologic structures. For example, in the center toward the top of the picture, the edge of the caldera, or volcanic crater, is marked by the black flows, and it coincides with the edge of a plateau. Also, the red material(just above and to the right of the center of the image) is typically associated with regions where lava is erupting onto the surface. Here the red material follows the base of a mountain, which may indicate that sulfurous gases are escaping along a fault associated with the formation of the mountain. Scientists can use the lengths of the shadows cast to estimate the height of the mountains. They estimate that the northernmost plateau, which bounds the western edge of Zal Patera, rises up to approximately 2 kilometers (6,600 feet) high. The mountain to the south of the caldera has peaks up to approximately 4.6 kilometers (15,000 feet) high, while the small peak at the bottom of the picture is approximately 4.2 kilometers (14,000 feet) high. North is to the top of the image, which is centered at 33.7 degrees north latitude and 81.9 degrees west longitude. The higher resolution images have a sharpness of about 260 meters (or yards) per picture element, and they are illuminated from the left. These images were taken on November 25, 1999 at a range of 26,000 kilometers (16,000 miles). The color images are illuminated from almost directly behind the Galileo spacecraft. The resolution of the color images is 1.3 kilometers (0.8 miles) per picture element. They were taken on July 3, 1999 at a distance of about 130,000 kilometers (81,000 miles). The Jet Propulsion Laboratory, Pasadena, CA manages Galileo for NASA's Office of Space Science, Washington, DC. JPL is a division of the California Institute of Technology, Pasadena, CA. This image and other images and data received from Galileo are posted on the Galileo mission home page at http://galileo.jpl.nasa.gov [ http://galileo.jpl.nasa.gov ]. Background information and educational context for the images can be found at http://galileo.jpl.nasa.gov/gallery/io.cfm [ http://galileo.jpl.nasa.gov/gallery/io.cfm ]. |
|
Galileo's Near-Infrared Mapp
PIA02509
Jupiter
Near Infrared Mapping Spectr
Title |
Galileo's Near-Infrared Mapping Spectrometer Detects Active Lava Flows at Prometheus Volcano, Io |
Original Caption Released with Image |
The active volcano Prometheus on Jupiter's moon Io was imaged by the near-infrared mapping spectrometer instrument onboard NASA's Galileo spacecraft during the close flyby of Io on October 10, 1999. The images were taken at a distance of about 15,000 kilometers (9,400 miles). The spectrometer can detect active volcanoes on Io by measuring their heat in the near-infrared wavelengths (just beyond the red end of human vision). It can also obtain information on the composition of materials on Io¹s surface using the same wavelengths. The image on the left, taken at an infrared wavelength, shows the different compositions of materials on the volcano. The dark material is thought to be silicate lava, and the white material is sulfur dioxide frost. Sulfur dioxide erupts out of this volcano as a plume and condenses into snow by the time it reaches the ground, forming a distinctive white ring around the volcano. The image on the right was taken at a longer infrared wavelength that shows heat coming out of the volcano. The hottest areas appear white and the coolest appear black. From this image, it is clear that there are two major "hot spots" (high-temperature areas) on this volcano. The hottest area (white spot on the left) corresponds to a location where images taken by Galileo's camera show a complex lava flow field. The cooler "hot spot" (green spot on the right) is located near where camera images show a newly-discovered volcanic caldera [ http://photojournal.jpl.nasa.gov/catalog/PIA02508 ]. The high temperatures at both hot spots are probably due to active lava flowing on the surface. Previous observations of the Prometheus region by the spectrometer, taken when the spacecraft was at much greater distances from Io, showed Prometheus to be a persistently active volcano. Temperatures calculated from spectrometer data areas high as about 800 degrees Celsius or 1,500 Fahrenheit), similar to those of cooling lava flows in Hawaii. The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at http://galileo.jpl.nasa.gov/ [ http://galileo.jpl.nasa.gov/ ] Background information and educational context for the images can be found athttp://galileo.jpl.nasa.gov/images/images.html [ http://galileo.jpl.nasa.gov/images/images.html ] |
|
Mountains on Io
PIA02520
Jupiter
Solid-State Imaging
Title |
Mountains on Io |
Original Caption Released with Image |
This image taken by NASA's Galileo spacecraft during its close flyby of Jupiter's moon Io on November 25, 1999 shows some of the curious mountains found there. The Sun is illuminating the scene from the left, and because it is setting, the Sun exaggerates the shadows cast by the mountains. By measuring the lengths of these shadows, Galileo scientists can estimate the height of the mountains. The mountain just left of the middle of the picture is 4 kilometers (13,000 feet) high and the small peak to the lower left is 1.6 kilometers (5,000 feet) high. These mountains, like others imaged during a previous Galileo flyby of Io in October [ http://photojournal.jpl.nasa.gov/catalog/PIA02513 ], seem to be in the process of collapsing. Huge landslides have left piles of debris at the bases of the mountains. The ridges that parallel their margins are also indicative of material moving down the mountainsides due to gravity. North is to the upper left of the picture. The image, centered at -8.1degrees latitude and 78.7 degrees longitude, covers an area approximately 210-by-110 kilometers (130-by-70 miles). The resolution is 267 meters (880 feet) per picture element. The image was taken at a range of 25,000 kilometers (16,000 miles) by Galileo's onboard camera. The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is a division of the California Institute of Technology, Pasadena, CA. This image and other images and data received from Galileo are posted on the Galileo mission home page at http://galileo.jpl.nasa.gov [ http://galileo.jpl.nasa.gov ]. Background information and educational context for the images can be found at http://galileo.jpl.nasa.gov/gallery/io.cfm [ http://galileo.jpl.nasa.gov/gallery/io.cfm ]. |
|
Earth-based images of the Fa
PIA02523
Jupiter
Title |
Earth-based images of the Fall 1999 Loki Eruption |
Original Caption Released with Image |
These false-color images of Io and Jupiter were taken with the NASA Infrared Telescope Facility at Mauna Kea, Hawaii, as part of a campaign to support closeup Io observations by NASA's Galileo spacecraft. These and other Earth-based observations show that Io's most powerful volcano, Loki, began one of its periodic major eruptions about a month before Galileo's October Io flyby, and that the eruption was continuing during the Galileo flyby. These infrared images (taken at a wavelength of 3.8 microns) show Sunlight reflected from the edge of Jupiter's disk on the left-hand side, and the heat from several glowing volcanoes on Io on the right. Io is in Jupiter's shadow, so no Sunlight falls on it -- the volcanoes are all we see. On August 9, 1999 (left), several volcanoes glowed faintly with roughly equal brightness. However, on October 10, 1999, roughly 20 hours before Galileo flew past, a single volcano, Loki, dominated the image. Loki brightened by a factor of ten in the period between these images. Other observations from the NASA Infrared Telescope and from Wyoming Infrared Telescope near Laramie operated by the University of Wyoming show that most of this brightening occurred during September. Earth-based observations since the 1980s have shown that these periodic bright eruptions are typical behavior for Loki. They occur about once per year and last several months. Galileo has given us our first chance to see one of these eruptions up close. The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is a division of the California Institute of Technology, Pasadena, CA. This image and other images and data received from Galileo are posted on the Galileo mission home page at http://galileo.jpl.nasa.gov [ http://galileo.jpl.nasa.gov ]. Background information and educational context for the images can be found at http://galileo.jpl.nasa.gov/gallery/io.cfm [ http://galileo.jpl.nasa.gov/gallery/io.cfm ]. |
|
Sources of Volcanic Plumes N
PIA02565
Jupiter
Solid-State Imaging
Title |
Sources of Volcanic Plumes Near Prometheus |
Original Caption Released with Image |
Prometheus is the "Old Faithful" of the many active volcanoes on Jupiter's moon Io. A broad, umbrella-shaped plume of gas and dust has been spotted above Prometheus by NASA's Voyager and Galileo spacecraft every time the viewing conditions have been favorable. The volcano is surrounded by a prominent circular ring of bright sulfur dioxide apparently deposited by the plume. However, the origin of Prometheus' plume is a long-standing mystery: Where is the vent that is the source of all the gas and dust? Some clues are offered by this false-color picture with a resolution of 170 meters (186 yards) per picture element, which was taken by Galileo on February 22, 2000. To the right is a dark, semi-circular, lava-filled caldera. South of it lies a fissure from which dark lava has flowed toward the west (left). The lava flow extends 90 kilometers (54 miles) from the source. Bright patches probably composed of sulfur dioxide can be seen in several places along the flow's margins. Two of these patches (near the top left edge of the dark lava, at the farthest reaches of the flow) display faint blue hazes, apparently produced by airborne dust entrained within plumes. Both of these spots are locations of newly erupted lava that has encroached on the surrounding plains since Galileo last imaged the region in October 1999. Galileo scientists are now studying whether heating of the volatile, sulfur dioxide-rich plains by encroaching hot lava might account for the persistent plume activity observed near Prometheus. The Jet Propulsion Laboratory, Pasadena, Calif. manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is a division of the California Institute of Technology in Pasadena. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at http://galileo.jpl.nasa.gov [ http://galileo.jpl.nasa.gov ]. Background information and educational context for the images can be found at http://galileo.jpl.nasa.gov/gallery/io.cfm [ http://galileo.jpl.nasa.gov/gallery/io.cfm ]. |
|
Ganymede dark terrain at hig
PIA02571
Jupiter
Solid-State Imaging
Title |
Ganymede dark terrain at high resolution |
Original Caption Released with Image |
Impact craters dominate the surface down to the smallest features visible on the dark terrain of the Nicholson Regio region of Jupiter's moon Ganymede in this image taken by NASA's Galileo spacecraft. It is the highest resolution view ever obtained of Ganymede's dark terrain. Both the regional-scale image at the bottom and high-resolution image at the top were taken by Galileo during its May 20, 2000, flyby of Ganymede. The latter are the highest resolution images ever obtained of Ganymede's dark terrain, which makes up about one third of Ganymede's surface. Impact cratering is clearly the dominant mechanism of surface modification in this relatively ancient terrain, which is analogous to the cratered highlands of Earth's Moon. Small-scale craters seem to mimic larger-scale craters, as is apparent in the similarities between the high and medium resolution scenes. The bright spots are probably fresh ice-rich ejecta excavated by the most recent impact events. North is to the top of the images and the Sun illuminates the surface from the west. The medium-resolution image, centered at ?15 degrees latitude and 337 degrees longitude, covers an area approximately 237 by 130 kilometers (147 by 81 miles) at a resolution of 125 meters (410 feet) per picture element. The high-resolution image is at 28 meters (92 feet) per picture element. This image and other images and data received from Galileo are posted on the Galileo mission home page at http://www.jpl.nasa.gov/galileo [ http://www.jpl.nasa.gov/galileo ]. Background information and educational context for the images can be found at http://www.jpl.nasa.gov/galileo/sepo [ http://www.jpl.nasa.gov/galileo/sepo ]. The Jet Propulsion Laboratory, a division of the California Institute of Technology, in Pasadena, manages the Galileo mission for NASA's Office of Space Science, Washington, D.C. The images were produced by Arizona State University, Tempe, and Brown University, Providence, R.I. Their websites are athttp://europa.la.asu.edu/index.html [ http://europa.la.asu.edu/index.html ] and http://www.planetary.brown.edu/ [ http://www.planetary.brown.edu/ ]. |
|
Not-so-smooth bright terrain
PIA02581
Jupiter
Solid-State Imaging
Title |
Not-so-smooth bright terrain of Harpagia Sulcus |
Original Caption Released with Image |
The highest-resolution images ever obtained of Jupiter's moon Ganymede show that even smooth-looking terrain has been deformed at a fine scale. The high-resolution image taken of the bright Harpagia Sulcus area by NASA's Galileo spacecraft during a May 20, 2000, flyby of Ganymede shows features as small as 16 meters (52 feet). This area was selected for a closer look because, in images taken by NASA's Voyager spacecraft about 20 years earlier, it looked as flat as a hockey rink. It appears smooth even in a medium-resolution Galileo image (at 116 meters or 380 feet per pixel) that is superimposed over a Voyager image in the top portion of this frame. But the closeup shot revealed that, instead of a hockey rink, the area has ups and downs that would be challenging for across-country skier. North is to the top of the picture and the Sun illuminates the surface from the left. The medium-resolution image mosaic is centered at -16degrees latitude and 310 degrees longitude, and covers an area approximately 282 by 144 kilometers (175 by 89 miles). This image and other images and data received from Galileo are posted on the Galileo mission home page at http://www.jpl.nasa.gov/galileo [ http://www.jpl.nasa.gov/galileo ]. Background information and educational context for the images can be found at http://www.jpl.nasa.gov/galileo/sepo [ http://www.jpl.nasa.gov/galileo/sepo ]. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Galileo mission for NASA's Office of Space Science, Washington, D.C. This image was produced by DLR (German Aerospace Center), Berlin, and Brown University, Providence, R.I., http://solarsystem.dlr.de/ [ http://solarsystem.dlr.de/ ]andhttp://www.planetary.brown.edu/ [ http://www.planetary.brown.edu/ ]. |
|
Colorful Tupan Patera, Io
PIA02599
Jupiter
Solid-State Imaging
Title |
Colorful Tupan Patera, Io |
Original Caption Released with Image |
Wonderful colors in a volcanic crater named Tupan Patera on Jupiter's moon Io, as seen in this image from NASA's Galileo spacecraft, show varied results of lava interacting with sulfur-rich materials. The colorfulness of the image is only slightly enhanced from what the human eye would see on the scene. The red in the image includes a small amount of infrared energy. Tupan Patera, named after a Brazilian thunder god, was seen as an active hot spot in earlier Galileo observations, but those low-resolution views [ http://photojournal.jpl.nasa.gov/catalog/PIA02319 ] did not show details of volcanic activity. This image taken in October 2001 at a resolution of 135 meters (443 feet) per picture element reveals the complex nature of the crater. Tupan is now clearly shown to be a volcanic depression, about 75 kilometers (47 miles) across, surrounded by cliffs about 900 meters (3000 feet) tall. In the center is a large area that must be higher than the rest of the crater floor because it has not been covered by the dark lavas. Much of the area is coated with a diffuse red deposit that Galileo scientists believe has condensed from sulfur gas escaping from volcanic vents. The floor of Tupan is covered with a surreal pattern of dark black, green, red, and yellow materials. The black material is recent, still-warm lava. The yellow is presumed to be a mix of sulfurous compounds, and the green appears to form where red sulfur has interacted with the dark lavas. While Galileo scientists have found previous evidence for both molten sulfur and molten rock on Io, this image shows the best evidence to date of chemical reactions taking place between the two. The intermingled patches of sulfur and lava are difficult to explain. The yellowish sulfur may be melting from within the crater walls over solidified but warm lava. The sulfur may boil away from the areas too hot for liquid sulfur to sit on, leaving patches where the dark lava is still visible. North is to the top of the image and the Sun illuminates the surface from the upper right. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Galileo mission for NASA's Office of Space Science, Washington, D.C. Additional information about Galileo and its discoveries is available on the Galileo mission home page at http://galileo.jpl.nasa.gov [ http://galileo.jpl.nasa.gov ]. Background information and educational context for the images can be found at http://galileo.jpl.nasa.gov/gallery/io.cfm [ http://galileo.jpl.nasa.gov/gallery/io.cfm ]. |
|
Mosaic of Jupiter's Great Re
PIA00831
Sol (our sun)
Solid-State Imaging
Title |
Mosaic of Jupiter's Great Red Spot (Violet Filter) |
Original Caption Released with Image |
Great Red Spot of Jupiter as seen through the violet (404 nm) filter of the Galileo imaging system. The image is a mosaic of six images that have been map-projected to a uniform grid of latitude and longitude. North is at the top. The mosaic was taken over a 75 second interval beginning at universal time 4 hours, 18 minutes, 8 seconds on June 26, 1996. The Red Spot is 20,000 km long and has been followed by observers on Earth since the telescope was invented 300 years ago. It is a huge storm made visible by variations in the composition of the cloud particles. The Red Spot is not unique, but is simply the largest of a class of long-lived vortices, some of which are visible in the lower part of the image. The range is 1.76 million kilometers. The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo |
|
|