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Search Results: All Fields similar to 'Mercury' and Where equal to 'Goddard Space Flight Center (GSFC)'
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Mercury: Closest Planet to t
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| Title |
Mercury: Closest Planet to the Sun |
| Explanation |
This picture was compiled from images taken by the NASA spacecraft Mariner 10 which flew by the planet three times in 1974. Mercury [ http://seds.lpl.arizona.edu/nineplanets/nineplanets/mercury.html ] is the closest planet to the Sun [ http://antwrp.gsfc.nasa.gov/apod/ap950813.html ], the second hottest planet (Venus gets hotter), and the second smallest planet (Pluto is smaller). Mercury [ http://www.c3.lanl.gov/~cjhamil/SolarSystem/mercury.html ] rotates so slowly that one day there - "day" meaning the normal time it takes from sunset to sunset - lasts 176 days on Earth [ http://antwrp.gsfc.nasa.gov/apod/ap950622.html ]. It is difficult to see Mercury [ http://nssdc.gsfc.nasa.gov/photo_gallery/photogallery-mercury.html ] not because it is dim but because it always appears near the Sun, and is therefore only visible for a short time just after sunset or just before sunrise. Mercury is made of rocky material like Earth. No one knows why Mercury has the magnetic field that it does. Tomorrow's picture: Venus: Earth's Sister Planet |
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Mercury: A Cratered Inferno
| Title |
Mercury: A Cratered Inferno |
| Explanation |
Mercury's surface looks similar to our Moon's. Each is heavily cratered [ http://antwrp.gsfc.nasa.gov/apod/ap960906.html ] and made of rock. Mercury [ http://www.nineplanets.org/mercury.html ]'s diameter is about 4800 km, while the Moon [ http://antwrp.gsfc.nasa.gov/apod/moon.html ]'s is slightly less at about 3500 km (compared with about 12,700 km for the Earth [ http://antwrp.gsfc.nasa.gov/apod/earth.html ]). But Mercury [ http://www.oulu.fi/~spaceweb/textbook/mercury.html ] is unique in many ways. Mercury [ http://www.hawastsoc.org/solar/eng/mercury.htm ] is the closest planet to the Sun [ http://antwrp.gsfc.nasa.gov/apod/ap960518.html ], orbiting at about 1/3 the radius of the Earth's orbit [ http://aa.usno.navy.mil/faq/docs/seasons_orbit.html ]. As Mercury [ http://pds.jpl.nasa.gov/planets/welcome/mercury.htm ] slowly rotates, its surface temperature varies from an unbearably "cold" -180 degrees Celsius [ http://www.athena.ivv.nasa.gov/curric/weather/fahrcels.html ] to an unbearably hot 400 degrees Celsius [ http://www.astro.uu.se/history/Celsius_eng.html ]. The place nearest the Sun [ http://antwrp.gsfc.nasa.gov/apod/ap980830.html ] in Mercury [ http://nssdc.gsfc.nasa.gov/photo_gallery/photogallery-mercury.html ]'s orbit changes slightly each orbit - a fact used by Albert Einstein [ http://antwrp.gsfc.nasa.gov/apod/ap000108.html ] to help verify the correctness of his then newly discovered theory of gravity: General Relativity [ http://www-groups.dcs.st-andrews.ac.uk/~history/HistTopics/General_relativity.html ]. The above picture [ http://nssdc.gsfc.nasa.gov/imgcat/html/object_page/m10_aom_18.html ] was taken by the only spacecraft ever to pass Mercury [ http://antwrp.gsfc.nasa.gov/apod/mercury.html ]: Mariner 10 [ http://www.hawastsoc.org/solar/eng/marin10.htm ] in 1974. |
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Southwest Mercury
| Title |
Southwest Mercury |
| Explanation |
The planet Mercury resembles a moon. Mercury [ http://www.seds.org/nineplanets/nineplanets/mercury.html ]'s old surface is heavily cratered [ http://liftoff.msfc.nasa.gov/Academy/SPACE/SolarSystem/Meteors/Craters.html ] like many moons. Mercury [ http://www.solarviews.com/eng/mercury.htm ] is larger than most moons but smaller than Jupiter [ http://antwrp.gsfc.nasa.gov/apod/ap990806.html ]'s moon Ganymede [ http://antwrp.gsfc.nasa.gov/apod/ap990304.html ] and Saturn [ http://antwrp.gsfc.nasa.gov/apod/ap960717.html ]'s moon Titan [ http://antwrp.gsfc.nasa.gov/apod/ap990207.html ]. Mercury is much denser and more massive than any moon, though, because it is made mostly of iron. In fact, the Earth [ http://antwrp.gsfc.nasa.gov/apod/ap990131.html ] is the only planet more dense. A visitor to Mercury's surface [ http://antwrp.gsfc.nasa.gov/apod/ap960121.html ] would see some strange sights. Because Mercury [ http://www.oulu.fi/~spaceweb/textbook/mercury.html ] rotates exactly three times every two orbits around the Sun [ http://antwrp.gsfc.nasa.gov/apod/ap951004.html ], and because Mercury [ http://nssdc.gsfc.nasa.gov/photo_gallery/photogallery-mercury.html ]'s orbit is so elliptical, a visitor to Mercury [ http://antwrp.gsfc.nasa.gov/apod/ap990102.html ] might see the Sun [ http://antwrp.gsfc.nasa.gov/htmltest/gifcity/interv.html ] rise, stop in the sky, go back toward the rising horizon [ http://antwrp.gsfc.nasa.gov/apod/ap990619.html ], stop again, and then set quickly over the other horizon. From Earth [ http://antwrp.gsfc.nasa.gov/apod/ap980530.html ], Mercury's proximity to the Sun [ http://antwrp.gsfc.nasa.gov/apod/ap981212.html ] cause it to be visible only for a short time just after sunset or just before sunrise. |
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Southwest Mercury
| Title |
Southwest Mercury |
| Explanation |
The planet Mercury resembles a moon. Mercury [ http://www.nineplanets.org/mercury.html ]'s old surface is heavily cratered [ http://liftoff.msfc.nasa.gov/Academy/SPACE/SolarSystem/Meteors/Craters.html ] like many moons. Mercury [ http://antwrp.gsfc.nasa.gov/apod/ap030216.html http://www.solarviews.com/eng/mercury.htm ] is larger than most moons but smaller than Jupiter [ http://antwrp.gsfc.nasa.gov/apod/ap990806.html ]'s moon Ganymede [ http://antwrp.gsfc.nasa.gov/apod/ap000620.html ] and Saturn [ http://antwrp.gsfc.nasa.gov/apod/ap021104.html ]'s moon Titan [ http://antwrp.gsfc.nasa.gov/apod/ap990207.html ]. Mercury is much denser and more massive than any moon, though, because it is made mostly of iron. In fact, the Earth [ http://antwrp.gsfc.nasa.gov/apod/ap010204.html ] is the only planet more dense. A visitor to Mercury's surface [ http://antwrp.gsfc.nasa.gov/apod/ap960121.html ] would see some strange sights. Because Mercury [ http://www.oulu.fi/~spaceweb/textbook/mercury.html ] rotates exactly three times every two orbits around the Sun [ http://antwrp.gsfc.nasa.gov/apod/sun.html ], and because Mercury [ http://nssdc.gsfc.nasa.gov/photo_gallery/photogallery-mercury.html ]'s orbit is so elliptical, a visitor to Mercury [ http://antwrp.gsfc.nasa.gov/apod/ap010819.html ] might see the Sun [ http://antwrp.gsfc.nasa.gov/htmltest/gifcity/interv.html ] rise, stop in the sky, go back toward the rising horizon [ http://antwrp.gsfc.nasa.gov/apod/ap000320.html ], stop again, and then set quickly over the other horizon [ http://antwrp.gsfc.nasa.gov/apod/ap011209.html ]. From Earth, Mercury's proximity to the Sun [ http://antwrp.gsfc.nasa.gov/apod/ap981212.html ] causes it to be visible only for a short time just after sunset or just before sunrise. |
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Mercury: A Cratered Inferno
| Title |
Mercury: A Cratered Inferno |
| Explanation |
Mercury's surface looks similar to our Moon's. Each is heavily cratered [ http://antwrp.gsfc.nasa.gov/apod/ap960906.html ] and made of rock. Mercury [ http://seds.lpl.arizona.edu/nineplanets/nineplanets/mercury.html ]'s diameter is about 4800 km, while the Moon [ http://antwrp.gsfc.nasa.gov/apod/ap950707.html ]'s is slightly less at about 3500 km (compared with about 12,700 km for the Earth [ http://antwrp.gsfc.nasa.gov/apod/ap971026.html ]). But Mercury [ http://www.oulu.fi/~spaceweb/textbook/mercury.html ] is unique in many ways. Mercury [ http://bang.lanl.gov/solarsys/mercury.htm ] is the closest planet to the Sun [ http://antwrp.gsfc.nasa.gov/apod/ap960518.html ], orbiting at about 1/3 the radius of the Earth's orbit. As Mercury [ http://pds.jpl.nasa.gov/planets/welcome/mercury.htm ] slowly rotates, its surface temperature varies from an unbearably "cold" -180 degrees Celsius [ http://www.athena.ivv.nasa.gov/curric/weather/fahrcels.html ] to an unbearably hot 400 degrees Celsius [ http://144.26.13.41/phyhist/celsius.htm ]. The place nearest the Sun [ http://antwrp.gsfc.nasa.gov/apod/ap950813.html ] in Mercury [ http://nssdc.gsfc.nasa.gov/photo_gallery/PhotoGallery-Mercury.html ]'s orbit changes slightly each orbit - a fact used by Albert Einstein [ http://antwrp.gsfc.nasa.gov/apod/ap951219.html ] to help verify the correctness of his then newly discovered theory of gravity: General Relativity [ http://rainbow.uchicago.edu/efi/general_relativity.txt.html ]. The above picture [ http://nssdc.gsfc.nasa.gov/imgcat/html/object_page/m10_aom_18.html ] was taken by the only spacecraft ever to pass Mercury [ http://antwrp.gsfc.nasa.gov/apod/lib/mercury.html ]: Mariner 10 [ http://bang.lanl.gov/solarsys/marin10.htm ] in 1974. |
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Mercury: A Cratered Inferno
| Title |
Mercury: A Cratered Inferno |
| Explanation |
Mercury's surface looks similar to our Moon's. Each is heavily cratered [ http://antwrp.gsfc.nasa.gov/apod/ap960906.html ] and made of rock. Mercury [ http://seds.lpl.arizona.edu/nineplanets/nineplanets/mercury.html ]'s diameter is about 4800 km, while the Moon [ http://antwrp.gsfc.nasa.gov/apod/ap950707.html ]'s is slightly less at about 3500 km (compared with about 12,700 km for the Earth [ http://antwrp.gsfc.nasa.gov/apod/ap971026.html ]). But Mercury [ http://www.oulu.fi/~spaceweb/textbook/mercury.html ] is unique in many ways. Mercury [ http://www.hawastsoc.org/solar/eng/mercury.htm ] is the closest planet to the Sun [ http://antwrp.gsfc.nasa.gov/apod/ap960518.html ], orbiting at about 1/3 the radius of the Earth's orbit. As Mercury [ http://pds.jpl.nasa.gov/planets/welcome/mercury.htm ] slowly rotates, its surface temperature varies from an unbearably "cold" -180 degrees Celsius [ http://www.athena.ivv.nasa.gov/curric/weather/fahrcels.html ] to an unbearably hot 400 degrees Celsius [ http://144.26.13.41/phyhist/celsius.htm ]. The place nearest the Sun [ http://antwrp.gsfc.nasa.gov/apod/ap950813.html ] in Mercury [ http://nssdc.gsfc.nasa.gov/photo_gallery/PhotoGallery-Mercury.html ]'s orbit changes slightly each orbit - a fact used by Albert Einstein [ http://antwrp.gsfc.nasa.gov/apod/ap980927.html ] to help verify the correctness of his then newly discovered theory of gravity: General Relativity [ http://rainbow.uchicago.edu/efi/general_relativity.txt.html ]. The above picture [ http://nssdc.gsfc.nasa.gov/imgcat/html/object_page/m10_aom_18.html ] was taken by the only spacecraft ever to pass Mercury [ http://antwrp.gsfc.nasa.gov/apod/lib/mercury.html ]: Mariner 10 [ http://www.hawastsoc.org/solar/eng/marin10.htm ] in 1974. |
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Southwest Mercury
| Title |
Southwest Mercury |
| Explanation |
The planet Mercury resembles a moon. Mercury [ http://seds.lpl.arizona.edu/nineplanets/nineplanets/mercury.html ]'s old surface is heavily cratered [ http://antwrp.gsfc.nasa.gov/apod/ap950924.html ] like many moons. Mercury [ http://bang.lanl.gov/solarsys/mercury.htm ] is larger than most moons but smaller than Jupiter [ http://antwrp.gsfc.nasa.gov/apod/ap951013.html ]'s moon Ganymede [ http://antwrp.gsfc.nasa.gov/apod/ap950904.html ] and Saturn [ http://antwrp.gsfc.nasa.gov/apod/ap960717.html ]'s moon Titan [ http://antwrp.gsfc.nasa.gov/apod/ap950923.html ]. Mercury is much denser and more massive than any moon, though, because it is made mostly of iron. In fact, the Earth [ http://antwrp.gsfc.nasa.gov/apod/ap960819.html ] is the only planet more dense. A visitor to Mercury's surface [ http://antwrp.gsfc.nasa.gov/apod/ap960121.html ] would see some strange sights. Because Mercury [ http://www.oulu.fi/~spaceweb/textbook/mercury.html ]rotates exactly three times every two orbits around the Sun [ http://antwrp.gsfc.nasa.gov/apod/ap951004.html ], and because Mercury [ http://nssdc.gsfc.nasa.gov/photo_gallery/PhotoGallery-Mercury.html ]'s orbit is so elliptical, a visitor to Mercury [ http://antwrp.gsfc.nasa.gov/apod/ap960912.html ] might see the Sun [ http://antwrp.gsfc.nasa.gov/htmltest/gifcity/interv.html ] rise, stop in the sky, go back toward the rising horizon [ http://antwrp.gsfc.nasa.gov/apod/ap951114.html ], stop again, and then set quickly over the other horizon. From Earth [ http://antwrp.gsfc.nasa.gov/apod/ap951118.html ], Mercury's proximity to the Sun [ http://antwrp.gsfc.nasa.gov/apod/ap960727.html ] cause it to be visible only for a short time [ http://www.maths.qmw.ac.uk/~lms/research/skyeye.html#planet ] just after sunset or just before sunrise. |
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3D Mercury Transit
| Title |
3D Mercury Transit |
| Explanation |
Mercury is now [ http://www.astronomy.com/ASY/CS/forums/314872/ ShowPost.aspx ] visible shortly before dawn, the brightest "star" just above the eastern horizon. But almost two weeks ago Mercury [ http://antwrp.gsfc.nasa.gov/apod/ap061114.html ] actually crossed the face of the Sun for the second time in the 21st century. Viewed with red/blue glasses [ http://photojournal.jpl.nasa.gov/Help/VendorList.html ], this stereo anaglyph combines space-based images of the Sun and innermost planet in a just-for-fun 3D [ http://www.sungazer.net/3dtransit.html ] presentation of the Mercury transit [ http://www.transitofvenus.org/mercury.htm ]. The solar disk image is from Hinode [ http://solarb.msfc.nasa.gov/index.html ]. (sounds like "hee-no-day", means sunrise). A sun-staring observatory, Hinode was launched from Uchinoura Space Center and viewed the transit [ http://solar-b.nao.ac.jp/news_e/20061109_e.shtml ] from Earth orbit. Superimposed on Mercury's dark silhouette is a detailed image [ http://antwrp.gsfc.nasa.gov/apod/ap011124.html ] of the planet's rugged surface based on data from the Mariner 10 [ http://nssdc.gsfc.nasa.gov/nmc/tmp/1973-085A.html ] probe that flew by Mercury in 1974 and 1975. |
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Mercury Astronauts and a Red
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| Title |
Mercury Astronauts and a Redstone |
| Explanation |
Space suited project Mercury [ http://www.ksc.nasa.gov/history/mercury/mercury.html ] astronauts John H. Glenn [ http://politicsusa.com/PoliticsUSA/resources/almanac/ohs1.html.cgi ], Virgil I. Grissom [ http://repos.msfc.nasa.gov/history/mm/grisbio.html ], and Alan B. Shepard Jr. [ http://repos.msfc.nasa.gov/history/mm/shepbio.html ] (left to right) are pictured here posing in front of a Redstone rocket [ http://www.redstone.army.mil/history/pioneer.html ] in this 1961 NASA publicity photo. Project Mercury [ http://www.osf.hq.nasa.gov/mercury/ ] was the first U.S. program designed to put humans in space. It resulted in 6 manned flights using one-man capsules and Redstone and Atlas rockets. Shortly after the first U.S. manned flight on May 5, 1961, a suborbital flight piloted by Alan Shepard, President Kennedy announced the goal of a manned lunar landing by 1970. This goal was achieved by NASA's Apollo program [ http://bang.lanl.gov/solarsys/apo14.htm ] and Shepard himself walked on the moon as a member of the Apollo 14 [ http://antwrp.gsfc.nasa.gov/apod/ap951209.html ] mission. |
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Mercury's Caloris Basin
| Title |
Mercury's Caloris Basin |
| Explanation |
Mercury [ http://antwrp.gsfc.nasa.gov/apod/ap950814.html ], the closest planet to the Sun [ http://antwrp.gsfc.nasa.gov/apod/ap950813.html ], has a surface with so many craters it resembles the Earth [ http://antwrp.gsfc.nasa.gov/apod/ap950622.html ]'s Moon [ http://antwrp.gsfc.nasa.gov/apod/ap950707.html ]. The largest surface feature on Mercury [ http://seds.lpl.arizona.edu/nineplanets/nineplanets/mercury.html ] is the Caloris Basin, which resulted from a collision with an asteroid [ http://antwrp.gsfc.nasa.gov/apod/ap951020.html ]. The basin, which is more that 1000 kilometers across, is visible as the large circular feature at the bottom of the above photograph. Similar features, such as the Mare Orientale [ http://antwrp.gsfc.nasa.gov/apod/ap960112.html ], are seen on the Moon. The Caloris Basin gets very hot because it is near the "sub-solar point" - the point on Mercury [ http://bang.lanl.gov/solarsys/mercury.htm ]'s surface that is directly under the Sun [ http://antwrp.gsfc.nasa.gov/apod/ap951004.html ] when Mercury [ http://stardust.jpl.nasa.gov/planets/welcome/mercury.htm ] is closest to the Sun [ http://antwrp.gsfc.nasa.gov/apod/ap951024.html ]. |
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Mercury And The Sun
| Title |
Mercury And The Sun |
| Explanation |
Just days before the peak of the Leonid meteor shower [ http://www.arm.ac.uk/leonid/latest.html ], skywatchers were offered another astronomical treat as planet Mercury [ http://pds.jpl.nasa.gov/planets/welcome/mercury.htm ] crossed the face of the Sun on November 15. Viewed from [ http://space.jpl.nasa.gov/ ] planet Earth, a transit of Mercury [ http://sunearth.gsfc.nasa.gov/eclipse/OH/transit99.html ] is not all that rare. The last [ http://antwrp.gsfc.nasa.gov/apod/ap991106.html ] occurred in 1993 and the next will happen in 2003. Enjoying a mercurial transit does require an appropriately filtered telescope, still the event can be dramatic as the diminutive well-done [ http://antwrp.gsfc.nasa.gov/apod/ap991111.html ] world drifts past [ http://www2.astronomy.com/astro/Magazine/Astindex/1999/99Nov/ Transit.html ] the dominating solar disk. This slow loading gif animation [ http://lambic.physics.montana.edu/~handy/trace/mercury/ ] is based on images recorded by the earth-orbiting TRACE [ http://antwrp.gsfc.nasa.gov/apod/ap980515.html ] satellite. The false-color TRACE images [ http://canopy.lmsal.com/schryver/Public/mercury.html ] were made in ultraviolet light and tend to show the hot gas just above the Sun's visible surface. Mercury's disk is silhouetted [ http://chippewa.nascom.nasa.gov/~dcm/transit/transit.html ] against the seething plasma as it follows a trajectory near the edge of the Sun. |
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MESSENGER Passes Mercury
| Title |
MESSENGER Passes Mercury |
| Explanation |
Two days ago, the MESSENGER spacecraft became only the second spacecraft in human history to swoop past Mercury. The last spacecraft to visit the Sun's closest planet was Mariner 10 [ http://en.wikipedia.org/wiki/Mariner_10 ] over 35 years ago. Mariner 10 was not able to photograph Mercury [ http://antwrp.gsfc.nasa.gov/apod/ap040912.html ]'s entire surface [ http://antwrp.gsfc.nasa.gov/apod/ap030216.html ], and the images it did send back [ http://nssdc.gsfc.nasa.gov/photo_gallery/photogallery-mercury.html ] raised many questions. Therefore, much about planet Mercury [ http://en.wikipedia.org/wiki/Mercury_%28planet%29 ] remains unknown. This week's flyby of MESSENGER [ http://en.wikipedia.org/wiki/MESSENGER ] was only the first of three flybys. Over the next few years MESSENGER will swing past [ http://messenger.jhuapl.edu/the_mission/MESSENGERTimeline/TimeLine_content.html ] twice more and finally enter Mercury's orbit in 2011. MESSENGER is currently moving too fast to enter orbit around Mercury now. The above image [ http://messenger.jhuapl.edu/gallery/sciencePhotos/image.php?gallery_id=2&image_id=117 ] was taken two days ago during MESSENGER's flyby and shows part of Mercury's surface that has never been imaged [ http://www.planetary.org/blog/article/00001299/ ] in detail before. Many more detailed images of Mercury [ http://messenger.jhuapl.edu/gallery/sciencePhotos/index.php ] are expected to be sent back over the next few days. The data acquired by MESSENGER [ http://www.nasa.gov/mission_pages/messenger/main/index.html ] will hopefully help scientists better understand [ http://www.nasa.gov/mission_pages/messenger/main/Land_of_Confusion_f.html ] how Mercury's surface was formed, and why it is so dense. |
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Mercury transit of the Sun
| Title |
Mercury transit of the Sun |
| Completed |
2003-05-07 |
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Mercury transit of the Sun
| Title |
Mercury transit of the Sun |
| Completed |
2003-05-07 |
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Mercury's Transit: An Unusua
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| Title |
Mercury's Transit: An Unusual Spot on the Sun |
| Explanation |
What's that dot on the Sun? [ http://www.davidcortner.com/astro/mtransit/ ] If you look closely, it is almost perfectly round. The dot is the result of an unusual type of solar eclipse [ http://antwrp.gsfc.nasa.gov/apod/ap060404.html ] that occurred last week. Usually it is the Earth's Moon [ http://www.windows.ucar.edu/tour/link=/earth/ moons_and_rings.html ] that eclipses the Sun. Last week, for the first time in over three years, the planet Mercury [ http://en.wikipedia.org/wiki/Mercury_%28mythology%29 ] took a turn. Like the approach to New Moon before a solar eclipse [ http://antwrp.gsfc.nasa.gov/apod/ap040926.html ], the phase of Mercury became a continually thinner crescent [ http://antwrp.gsfc.nasa.gov/apod/ap061030.html ] as the planet progressed toward an alignment with the Sun. Eventually the phase of Mercury dropped [ http://antwrp.gsfc.nasa.gov/apod/ap040606.html ] to zero and the dark spot of Mercury crossed our parent star. The situation could technically be labeled a Mercurian annular eclipse [ http://www.mreclipse.com/Special/SEprimer.html ] with an extraordinarily large ring of fire [ http://antwrp.gsfc.nasa.gov/apod/ap020610.html ]. From above the cratered planes [ http://antwrp.gsfc.nasa.gov/apod/ap040912.html ] of the night side of Mercury, the Earth appeared in its fullest phase. Hours later, as Mercury continued in its orbit, a slight crescent phase appeared again. The next Mercurian solar eclipse [ http://en.wikipedia.org/wiki/ Transit_of_Mercury_from_Earth ] will occur in 2016. |
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Mercury on the Horizon
| Title |
Mercury on the Horizon |
| Explanation |
Have you ever seen the planet Mercury? Because Mercury [ http://www.seds.org/nineplanets/nineplanets/ mercury.html ] orbits so close to the Sun, it never wanders far from the Sun in Earth's sky [ http://antwrp.gsfc.nasa.gov/apod/ap020509.html ]. If trailing the Sun, Mercury [ http://antwrp.gsfc.nasa.gov/apod/mercury.html ] will be visible low on the horizon for only a short while after sunset [ http://antwrp.gsfc.nasa.gov/apod/ap020510.html ]. If leading the Sun, Mercury will be visible only shortly before sunrise. So at certain times of the year an informed skygazer [ http://skyandtelescope.com/observing/ataglance/ article_110_1.asp ] with a little determination can usually pick Mercury out from a site with an unobscured horizon. Above, a lot of determination has been combined with a little digital trickery [ http://www.astropix.com/HTML/J_DIGIT/ ETHICS.HTM ] to show Mercury's successive positions during March of 2000. Each picture was taken from the same location in Spain when the Sun itself was 10 degrees below the horizon [ http://antwrp.gsfc.nasa.gov/apod/ap970909.html ] and superposed on the single most photogenic sunset [ http://antwrp.gsfc.nasa.gov/apod/ap980526.html ]. By the middle of this month, Mercury will again be well placed for viewing above the western horizon at sunset, but by the end of April it will have faded and dropped into the twilight. On May 7th, Mercury will cross [ http://sunearth.gsfc.nasa.gov/eclipse/OH/transit03.html ] the Sun's disk. |
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Mercury on the Horizon
| Title |
Mercury on the Horizon |
| Explanation |
Have you ever seen the planet Mercury? Because Mercury [ http://www.seds.org/nineplanets/nineplanets/mercury.html ] orbits so close to the Sun, it is never seen far from the Sun, and so is only visible near sunrise [ http://antwrp.gsfc.nasa.gov/apod/ap990817.html ] or sunset [ http://antwrp.gsfc.nasa.gov/apod/ap990619.html ]. If trailing the Sun, Mercury [ http://antwrp.gsfc.nasa.gov/apod/mercury.html ] will be visible for several minutes before it follows the Sun [ http://antwrp.gsfc.nasa.gov/apod/sun.html ] behind the Earth [ http://antwrp.gsfc.nasa.gov/apod/earth.html ]. If leading the Sun, Mercury [ http://www.solarviews.com/eng/mercury.htm ] will be visible [ http://www.skypub.com/sights/northern/0003skyn.html ] for only several minutes before the Sun [ http://www.seds.org/nineplanets/nineplanets/sol.html ] rises and hides it with increasing glare. An informed skygazer [ http://www.skypub.com/sights/northern/0003skyn.html ] can usually pick Mercury out of a dark horizon glow [ http://antwrp.gsfc.nasa.gov/apod/ap991110.html ] with little more than determination. Above, a lot of determination has been combined with a little digital trickery [ http://www.astropix.com/HTML/J_DIGIT/ETHICS.HTM ] to show [ http://www.galeon.com/eclipses/indexi.htm ] Mercury's successive positions during the middle of last month. Each picture was taken from the same location in Spain when the Sun was 10 degrees below the horizon [ http://antwrp.gsfc.nasa.gov/apod/ap970909.html ] and superposed on the single most photogenic sunset [ http://antwrp.gsfc.nasa.gov/apod/ap980526.html ]. |
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Mercury on the Horizon
| Title |
Mercury on the Horizon |
| Explanation |
Have you ever seen the planet Mercury? Because Mercury [ http://www.seds.org/nineplanets/nineplanets/ mercury.html ] orbits so close to the Sun, it never wanders far from the Sun in Earth's sky [ http://antwrp.gsfc.nasa.gov/apod/ap020509.html ]. If trailing the Sun, Mercury [ http://antwrp.gsfc.nasa.gov/apod/mercury.html ] will be visible low on the horizon for only a short while after sunset [ http://antwrp.gsfc.nasa.gov/apod/ap020510.html ]. If leading the Sun, Mercury will be visible only shortly before sunrise. So at certain times of the year an informed skygazer [ http://skyandtelescope.com/observing/ataglance/ article_110_1.asp ] with a little determination can usually pick Mercury out from a site with an unobscured horizon. Above, a lot of determination has been combined with a little digital trickery [ http://www.astropix.com/HTML/J_DIGIT/ ETHICS.HTM ] to show Mercury's successive positions during March of 2000. Each picture was taken from the same location in Spain when the Sun itself was 10 degrees below the horizon [ http://antwrp.gsfc.nasa.gov/apod/ap970909.html ] and superposed on the single most photogenic sunset [ http://antwrp.gsfc.nasa.gov/apod/ap980526.html ]. Mercury is currently visible in the western sky [ http://starfieldobservatory.com/coming.htm ] after sunset, but will disappear in the Sun's glare after a few days. |
|
Mercury's Horizon from MESSE
…
| Title |
Mercury's Horizon from MESSENGER |
| Explanation |
What would it look like to fly past Mercury? Just such an adventure was experienced last week by the MESSENGER spacecraft during its first flyby [ http://messenger.jhuapl.edu/the_mission/mercury_rendezvous.html ] of the strange moon [ http://antwrp.gsfc.nasa.gov/apod/ap030312.html ]-like world nearest the Sun. Pictured above [ http://messenger.jhuapl.edu/gallery/sciencePhotos/image.php?page=1&gallery_id=2&image_id=122 ] is the limb of Mercury [ http://en.wikipedia.org/wiki/Mercury_%28planet%29 ] seen by MESSENGER [ http://en.wikipedia.org/wiki/MESSENGER ] upon approach, from about 1 1/2 Earth [ http://antwrp.gsfc.nasa.gov/apod/ap070514.html ] diameters away. Visible on the hot and barren planet are many craters [ http://liftoff.msfc.nasa.gov/academy/space/solarsystem/meteors/Craters.html ], many appeared to be more shallow than similarly sized craters on the Moon. The comparatively high gravity [ http://www.exploratorium.edu/ronh/weight/ ] of Mercury helps flatten [ http://www.planetary.org/blog/article/00001301/ ] tall structures like high crater walls. MESSENGER [ http://messenger.jhuapl.edu/why_mercury/index.html ] was able to take over 1,000 images of Mercury which will be beamed back to Earth for planetary geologists [ http://en.wikipedia.org/wiki/Planetary_geology ] to study. The robotic MESSENGER spacecraft is scheduled [ http://www.nasa.gov/mission_pages/messenger/timeline/index.html ] to fly past Mercury twice more before firing its thrusters to enter orbit in 2011. |
|
Outbound from Mercury
| Title |
Outbound from Mercury |
| Explanation |
After just passing Mercury, the robot spacecraft Mariner 10 looked back. The above picture [ http://antwrp.gsfc.nasa.gov/apod/ap020716.html http://photojournal.jpl.nasa.gov/cgi-bin/PIAGenCatalogPage.pl?PIA03104 ] is what it saw. Mercury [ http://www.nineplanets.org/mercury.html ], the closest planet to the Sun [ http://antwrp.gsfc.nasa.gov/apod/sun.html ], is heavily cratered much like Earth's Moon [ http://antwrp.gsfc.nasa.gov/apod/ap010428.html ]. As Mercury slowly rotates, its surface temperature [ http://www.unidata.ucar.edu/staff/blynds/tmp.html ] varies from an unbearably cold -180 degrees Celsius [ http://www.astro.uu.se/history/Celsius_eng.html ] in the half facing away from the Sun, to an unbearably hot 400 degrees Celsius [ http://www.santesson.com/engtemp.html ] in the half facing toward the Sun. Mercury [ http://solarviews.com/eng/mercury.htm ] is slightly larger than Earth's Moon [ http://antwrp.gsfc.nasa.gov/apod/ap010218.html ] and much denser [ http://scienceworld.wolfram.com/physics/Density.html ]. The Mariner 10 spacecraft [ http://nssdc.gsfc.nasa.gov/nmc/tmp/1973-085A.html ] swooped by Mercury [ http://pds.jpl.nasa.gov/planets/welcome/mercury.htm ] three times in its journey around the inner Solar System [ http://www.nineplanets.org/overview.html ] in the mid-1970s. This outbound view [ http://photojournal.jpl.nasa.gov/cgi-bin/PIAGenCatalogPage.pl?PIA03104 ] has similarities to the inbound view [ http://antwrp.gsfc.nasa.gov/apod/ap010819.html ]. Nearly half of Mercury's surface [ http://antwrp.gsfc.nasa.gov/apod/ap011124.html ] has yet to be photographed in detail. |
|
Hot Shot
| title |
Hot Shot |
| description |
The black dot in this picture of the Sun is Mercury. The planet made a rare pass in front of the Sun on May 7, 2003. The SOHO and TRACE spacecraft were watching with all instruments. The spacecraft websites are among many with Mercury transit galleries. *Image Credit*: NASA Goddard Space Flight Center |
|
Mercury Over Leeds
| Title |
Mercury Over Leeds |
| Explanation |
Have you ever seen the planet Mercury? This week might be a good time. Because Mercury [ http://www.nineplanets.org/mercury.html ] orbits so close to the Sun, it never wanders far from the Sun in Earth's sky. If trailing the Sun, Mercury will be visible [ http://www.space.com/spacewatch/sky_calendar.html ] low on the horizon for only a short while after sunset [ http://antwrp.gsfc.nasa.gov/apod/ap031021.html ]. If leading the Sun, Mercury will be visible [ http://www.almanac.com/astronomy/moon/index.php ] only shortly before sunrise [ http://antwrp.gsfc.nasa.gov/apod/ap030320.html ]. So at certain times of the year an informed skygazer [ http://antwrp.gsfc.nasa.gov/apod/ap040808.html ] with a little determination can usually pick Mercury out [ http://stardate.org/nightsky/almanac/ ] from a site with an clear horizon. Above, a lot of determination has been combined with a little digital trickery to show Mercury's successive positions [ http://antwrp.gsfc.nasa.gov/apod/ap030412.html ] during March of 2004. Each picture was taken from the same location in Leeds, England [ http://www.cia.gov/cia/publications/factbook/geos/uk.html ] exactly 33 minutes after sunset. Over the next two weeks, Mercury [ http://antwrp.gsfc.nasa.gov/apod/ap040606.html ] will again be well placed for viewing [ http://www.jb.man.ac.uk/public/nightsky.html ] above the western horizon at sunset, but by the third week in March it will have faded and dropped into the twilight [ http://antwrp.gsfc.nasa.gov/apod/ap040501.html ]. |
|
Mercury's Faults
| Title |
Mercury's Faults |
| Explanation |
The surface [ http://antwrp.gsfc.nasa.gov/apod/ap960120.html ] of the planet Mercury [ http://antwrp.gsfc.nasa.gov/apod/ap950814.html ] is not without fault. In this case, however, "fault" refers to unusual surface features that are the topic of much speculation. The above fault line is called Santa Maria Rupes, and runs through many prominent craters. The meandering feature is thought to be the result of huge forces of compression on Mercury [ http://seds.lpl.arizona.edu/nineplanets/nineplanets/mercury.html ]'s surface. Such rupes probably originate from large impacts [ http://antwrp.gsfc.nasa.gov/apod/ap950924.html ] and a general shrinking of Mercury [ http://bang.lanl.gov/solarsys/mercury.htm ]'s crust, which in turn causes parts of the crust to push above other parts. |
|
Tomorrow's picture: Mariner'
…
| Title |
Tomorrow's picture: Mariner's Mercury [ http://antwrp.gsfc.nasa.gov/apod/ap961217.html ] |
|
Tomorrow's picture: Mercury'
…
| Title |
Tomorrow's picture: Mercury's Craters Within Craters [ http://antwrp.gsfc.nasa.gov/apod/ap970112.html ] (in Stereo ...) |
|
Mercury transit of the Sun
| Title |
Mercury transit of the Sun |
| Completed |
2003-05-07 |
|
Mercury transit of the Sun
| Title |
Mercury transit of the Sun |
| Completed |
2003-05-07 |
|
Mercury transit of the Sun
| Title |
Mercury transit of the Sun |
| Completed |
2003-05-07 |
|
Mercury Chases the Sunset
| Title |
Mercury Chases the Sunset |
| Explanation |
This colorful view of the western sky at sunset features last Wednesday's slender crescent Moon. Of course, when the Moon is in its crescent phase [ http://antwrp.gsfc.nasa.gov/apod/ap050513.html ] it can never be far from the Sun in the sky. Also always close to the Sun in Earth's sky is innermost planet Mercury [ http://www.seds.org/nineplanets/nineplanets/mercury.html ], seen here below and right of center against the bright orange glow along the horizon. Mercury is usually difficult to glimpse [ http://www.fourmilab.ch/images/3planets/elongation.html ] because of overwhelming sunlight, but increasingly better views of the small planet after sunset will be possible as it wanders [ http://antwrp.gsfc.nasa.gov/apod/ap030412.html ] farther east of the Sun in the coming days. On January 14th, NASA's MESSENGER [ http://antwrp.gsfc.nasa.gov/apod/ap040814.html ] spacecraft will have a good view [ http://messenger.jhuapl.edu/gallery/sciencePhotos/ image.php?gallery_id=2&image_id=111 ] too, as it makes its first Mercury flyby [ http://messenger.jhuapl.edu/ ]. |
|
Messenger Launch
| Title |
Messenger Launch |
| Explanation |
Streaking [ http://www.jhuapl.edu/newscenter/pressreleases/2004/ 040803.htm ] into the early morning sky on August 3rd, a Delta II rocket [ http://www.boeing.com/defense-space/space/delta/delta2/ delta2.htm ] launches NASA's Messenger spacecraft [ http://messenger.jhuapl.edu/index.html ] on an interplanetary voyage to Mercury [ http://www.nineplanets.org/mercury.html ]. Scheduled to become the first probe to orbit Mercury, Messenger will begin by looping through [ http://messenger.jhuapl.edu/the_mission/ mission_design.html ] the inner Solar System in a series of close flybys of planet Earth and Venus. The flybys are designed as trajectory changing gravity assist [ http://www2.jpl.nasa.gov/basics/grav/primer.html ] encounters to ultimately achieve the goal of orbiting Mercury in 2011. Prior to entering orbit, Messenger will also flyby Mercury in 2008 and 2009 as the first spacecraft to visit the Solar System's innermost planet since Mariner 10 [ http://antwrp.gsfc.nasa.gov/apod/ap011124.html ] in the mid 1970s. This dramatic view [ http://www.geocities.com/ovpathfinder/ MESSENGER.html ] of the Messenger launch was recorded from a pier in Jetty Park at the north end of Cocoa Beach about 2.5 miles from the Cape Canaveral [ http://www.astronautix.com/sites/capveral.htm ] launch site. So what's that erratic blue streak on the right? It's the reflection from a camera blurred in the time exposure. |
|
Spot The Planet
| Title |
Spot The Planet |
| Explanation |
OK, it's a picture of the Sun (duh!), but can you spot the planet [ http://members.home.com/rmscott/space_sky01/mercury_transit.html ]? Of course, most of the spots you've spotted are sunspots, as large or larger than planet Earth itself. The sunspots are [ http://antwrp.gsfc.nasa.gov/apod/ap991021.html ] regions of strong surface magnetic fields which are dark in this picture only because they are relatively cool compared to their surroundings. Over the past few years, the number of sunspots [ http://www.sunspotcycle.com/ ] has been steadily increasing as the Sun approaches the maximum in its 11 year activity cycle. But also [ http://pages.prodigy.net/pam.orman/JoeHome.html ] visible [ http://members.home.com/rmscott/index.html ] in this photograph [ http://pages.prodigy.net/pam.orman/joesun/Sun991115.html ] from November 15, is planet Mercury. At just over 1/3 Earth's size, Mercury is passing in front of the Sun, its silhouette briefly creating a diminutive dark spot drifting across [ http://www2.astronomy.com/astro/Magazine/Astindex/ 1999/99Nov/Transit.html ] an enormous solar disk. While "transits" of Mercury [ http://antwrp.gsfc.nasa.gov/apod/ap991119.html ] do occur 13 times a century, this one was additionally a very rare grazing transit of our Solar System's innermost planet [ http://nssdc.gsfc.nasa.gov/planetary/factsheet/mercuryfact.html ]. Spotted Mercury yet? Click on the picture for a hint. |
|
Mariner's Mercury
| Title |
Mariner's Mercury |
| Explanation |
Mercury [ http://www.seds.org/nineplanets/nineplanets/ mercury.html ], the closest planet to the Sun, remains the most mysterious [ http://wwwflag.wr.usgs.gov/USGSFlag/Space/wall/ mercury.html ] of the Solar System's inner planets. Hiding in the Sun's glare [ http://antwrp.gsfc.nasa.gov/apod/ap991119.html ] it is a difficult target [ http://www.bu.edu/csp/imaging_science/planetary/mercury/ ] for Earth bound observers. The only spacecraft to explore Mercury [ http://www.psrd.hawaii.edu/Jan97/ MercuryUnveiled.html ] close-up was Mariner 10 [ http://sse.jpl.nasa.gov/missions/merc_missns/ merc-m10.html ] which executed three flybys of [ http://nssdc.gsfc.nasa.gov/nmc/tmp/ 1973-085A-traj.html ] Mercury in 1974 and 1975, surveying approximately 45 percent of its surface. Mariner 10 [ http://nssdc.gsfc.nasa.gov/nmc/tmp/1973-085A.html ] deftly manuevered to photograph part of the sunlit hemisphere during each approach, passed behind the planet, and continued to image the sun-facing side as the spacecraft receded. Its highest resolution photographs [ http://nssdc.gsfc.nasa.gov/imgcat/html/mission_page/ MC_Mariner_10_page1.html ] recorded features approximately a mile across. A reprocessing of the Mariner 10 data [ http://www.earth.nwu.edu/people/robinson/merc.html ] has resulted in this dramatic mosaic. Like the Earth's Moon, Mercury's surface [ http://antwrp.gsfc.nasa.gov/apod/ap010819.html ] shows the scars of impact [ http://antwrp.gsfc.nasa.gov/apod/ap990326.html ] cratering - the smooth vertical band and patches visible above represent regions where no image information is available. |
|
A Spider Shaped Crater on Me
…
| Title |
A Spider Shaped Crater on Mercury |
| Explanation |
Why does this crater on Mercury look like a spider? When the robotic MESSENGER spacecraft [ http://en.wikipedia.org/wiki/MESSENGER ] glided by the planet Mercury [ http://www.nineplanets.org/mercury.html ] last month, it was able to image portions of the Sun's closest planet that had never been seen before. When imaging the center of Mercury's extremely large Caloris Basin [ http://antwrp.gsfc.nasa.gov/apod/ap960120.html ], MESSENGER found a crater, pictured above [ http://messenger.jhuapl.edu/gallery/sciencePhotos/image.php?page=1&gallery_id=2&image_id=144 ], with a set of unusual rays [ http://antwrp.gsfc.nasa.gov/apod/ap050305.html ] emanating out from its center. A crater with such troughs has never been seen before anywhere in our Solar System [ http://solarsystem.nasa.gov/planets/index.cfm ]. What isn't clear is the relation [ http://www.planetary.org/news/2008/0130_MESSENGERs_First_Mercury_Flyby_Reveals.html ] of the crater to the radial troughs. Perhaps the crater created the radial rays [ http://www.badastronomy.com/bablog/2008/01/30/spiders-on-mercury/ ], or perhaps the two features appear only by a chance superposition -- the topic is sure to be one of future research. MESSENGER is scheduled [ http://www.nasa.gov/mission_pages/messenger/timeline/index.html ] to fly past Mercury twice more before firing its thrusters [ http://www.youtube.com/watch?v=hKoB0MHVBvM ] to enter orbit in 2011. digg_url = 'http://apod.nasa.gov/apod/ap080204.html', digg_skin = 'compact'; |
|
Mercury and the Chromosphere
| Title |
Mercury and the Chromosphere |
| Explanation |
Enjoying [ http://www.spaceweather.com/eclipses/ gallery_08nov06.htm ] Wednesday's transit of Mercury [ http://sohowww.nascom.nasa.gov/hotshots/2006_11_06/ ] from Dallas, Texas, astronomer Phil Jones recorded this detailed image [ http://www.visualuniverse.org/ solar_mercury_transit.shtml ] of the Sun. Along with a silhouette of the innermost planet, a network of cells and dark filaments [ http://solar.physics.montana.edu/YPOP/Program/ hfilament.html ] can be seen against a bright solar disk with spicules and prominences [ http://antwrp.gsfc.nasa.gov/apod/ap030418.html ] along the Sun's edge. The composited image was taken through a telescope equiped with an H-alpha filter that narrowly transmits only the red light from hydrogen atoms. Such images emphasize the solar chromosphere [ http://solar.physics.montana.edu/YPOP/Program/ chromosphere.html ], the region of the Sun's atmosphere immediately above its photosphere or normally visible surface. Left of center, the tiny disk of Mercury seems to be imitating a small sunspot that looks a little too round. But in H-alpha pictures [ http://www.spaceweathercenter.org/living_with_a_star/01/ solarvision.html ], sunspot regions are usually dominated by bright splotches (called plages [ http://csep10.phys.utk.edu/astr162/lect/sun/ prominences.html ]) on the solar chromosphere. |
|
Moon, Mercury, Monaco
| Title |
Moon, Mercury, Monaco |
| Explanation |
Low on the western horizon after sunset, a slender crescent [ http://antwrp.gsfc.nasa.gov/apod/ap031225.html ] Moon and wandering planet [ http://antwrp.gsfc.nasa.gov/apod/ap050307.html ] Mercury join the lights of Menton and Monaco along the French Riviera. Astronomer [ http://vjac.free.fr/ ] Vincent Jacques took advantage of this gorgeous photo opportunity a week ago on March 11, when the Moon and Mercury were separated in the sky by just three degrees. Of course, the Moon in a slender crescent phase is always [ http://www.astro.wisc.edu/~dolan/java/MoonPhase.html ] seen near the horizon, as is Mercury - a bright planet which can be otherwise difficult to glimpse as it never strays far from the Sun [ http://www.fourmilab.ch/images/3planets/ elongation.html ] in Earth's sky. In the coming days [ http://stardate.org/nightsky/almanac/ ] good views of Mercury will indeed be fleeting as the solar system's innermost planet [ http://www.nineplanets.org/mercury.html ] is rapidly dropping closer to the glare of the setting Sun. But tonight a waxing Moon will join another bright planet wandering overhead [ http://skyandtelescope.com/observing/ highlights/article_1472_1.asp ] through the evening sky, Saturn [ http://soc.jpl.nasa.gov/viewing.cfm ]. |
|
A Mercury Transit Sequence
| Title |
A Mercury Transit Sequence |
| Explanation |
Earlier this month, the planet Mercury [ http://www.nineplanets.org/mercury.html ] crossed the face [ http://antwrp.gsfc.nasa.gov/apod/ap010528.html ] of the Sun [ http://antwrp.gsfc.nasa.gov/apod/sun.html ], as seen from Earth. Because the plane [ http://mathworld.wolfram.com/PlaneGeometry.html ] of Mercury's orbit [ http://phyun5.ucr.edu/~wudka/Physics7/Notes_www/node98.html ] is not exactly coincident with the plane of Earth's orbit [ http://antwrp.gsfc.nasa.gov/apod/ap001014.html ], Mercury usually appears [ http://www.eso.org/outreach/eduoff/vt-2004/mt-2003/mt-display.html ] to pass over or under the Sun. The above time-lapse sequence [ http://users.pandora.be/create/mercury.htm ], superimposed on a single frame, was taken from a balcony in Belgium [ http://www.cia.gov/cia/publications/factbook/geos/be.html ] on May 7 and shows the entire transit [ http://antwrp.gsfc.nasa.gov/apod/ap030508.html ]. The solar crossing [ http://antwrp.gsfc.nasa.gov/apod/ap030513.html ] lasted over five hours, so that the above 23 images were taken roughly 15 minutes apart. The north pole [ http://antwrp.gsfc.nasa.gov/apod/ap020818.html ] of the Sun, the Earth [ http://antwrp.gsfc.nasa.gov/apod/ap001020.html ], Mercury's orbit, although all different, all occur in directions slightly above the left of the image. Near the center and on the far right, sunspot [ http://antwrp.gsfc.nasa.gov/apod/ap000223.html ]s are visible. |
|
X-ray Transit Of Mercury
| Title |
X-ray Transit Of Mercury |
| Explanation |
This sequence of [ http://www.solar.isas.ac.jp/sxt_co/980626.html ] false color X-ray images captures a rare event - the passage [ http://www.arrakis.es/~xgarciaf/paso.htm ] or transit of [ http://www.dsellers.demon.co.uk/venus/ven_ch4.htm ] planet Mercury in front of the Sun. Mercury's small disk [ http://www.seds.org/nineplanets/nineplanets/mercury.html ] is silhouetted against the bright background of X-rays from the hot Solar Corona [ http://antwrp.gsfc.nasa.gov/apod/ap970217.html ]. It appears just to the right of center in the top frame and moves farther right as the sequence progresses toward the bottom. The dark notch is a coronal hole near the Solar South Pole [ http://ulysses.jpl.nasa.gov/ ], while a flaring coronal bright point can be seen to the left of the notch in the top frames. The frames were recorded [ http://www.lmsal.com/SXT/html2/Mercury_Transit_of_Solar_Corona.html ] on November 6, 1993 by the Soft X-ray Telescope [ http://www.lmsal.com/SXT/homepage.html ] on board the orbiting Yohkoh satellite [ http://www.lmsal.com/cgi-bin/yopos ]. Transits of Mercury (and Venus) were historically used to discover the geometry of the solar system [ http://beast.as.arizona.edu/textbook/text/CH03.html ] and to map planet Earth [ http://pacific.vita.org/pacific/cook/ ] itself. |
|
A Superior Conjunction Of Me
…
| Title |
A Superior Conjunction Of Mercury |
| Explanation |
In astronomical parlance [ http://www.treasure-troves.com/astro/astro0.html ], an interior planet is at superior conjunction [ http://www.treasure-troves.com/astro/SuperiorConjunction.html ] when it is located on the opposite side of the Sun from Earth. Mercury [ http://www.seds.org/nineplanets/nineplanets/mercury.html ], the solar system's innermost planet, zips past this point in its orbit today. In fact, this recent picture [ http://sohowww.nascom.nasa.gov/data/realtime-images.html ] from a solar coronagraph on board the the space-based SOHO observatory [ http://sohowww.nascom.nasa.gov/descriptions/mission/ english/page1.html ] shows Mercury [ http://nssdc.gsfc.nasa.gov/planetary/factsheet/mercuryfact.html ] positioned very close to the Sun as seen from a near Earth vantage point. The coronagraph [ http://lasco-www.nrl.navy.mil/about_lasco.html ] uses an internal occulting disk to block the intense solar glare which otherwise hides this sight from ground-based observers. The shadow of the occulting disk is at the center with the Sun's size and position indicated by the white circle. Mercury is the bright dot with a horizontal line (a digital artifact), while faint dots scattered throughout the field are stars [ http://antwrp.gsfc.nasa.gov/apod/ap970304.html ]. Bright regions of the sun's outer atmosphere [ http://www.lmsal.com/YPOP/Spotlight/Tour/tour05.html ] are also visible. As Mercury continues [ http://eclipse.span.ch/transit.htm ] in its orbit, on November 15 [ http://sunearth.gsfc.nasa.gov/eclipse/OH/transit99.html ] it will actually appear to cross the disk [ http://antwrp.gsfc.nasa.gov/apod/ap980702.html ] of the Sun as viewed from Earth [ http://nssdc.gsfc.nasa.gov/cgi-bin/database/www-nmc?MESSNGR ]. |
|
Tomorrow's picture: Degas Ra
…
| Title |
Tomorrow's picture: Degas Ray Crater on Mercury [ http://antwrp.gsfc.nasa.gov/apod/ap961208.html ] |
|
Tomorrow's picture: Mercury
…
| Title |
Tomorrow's picture: Mercury Astronauts and a Redstone [ http://antwrp.gsfc.nasa.gov/apod/ap970406.html ] |
|
Simulated Transit of Mercury
| Title |
Simulated Transit of Mercury |
| Explanation |
Mercury, the solar system's innermost planet, will spend about five hours crossing in front of the Sun today [ http://science.nasa.gov/headlines/y2006/ 20oct_transitofmercury.htm ] - beginning at 1912 UT [ http://aa.usno.navy.mil/faq/docs/UT.html ] (2:12pm EST), November 8. Specially equipped telescopes are highly recommended to safely spot the planet's [ http://antwrp.gsfc.nasa.gov/apod/ap991210.html ] diminutive silhouette however, as Mercury should appear about 200 times smaller than the enormous solar disk. This simulated view [ http://www.sungazer.net/transitsim.html ] is based on a filtered solar image recorded on November 3rd. It shows active regions and the Mercury transit [ http://sunearth.gsfc.nasa.gov/eclipse/OH/transit06.html ] across the Sun at six positions from lower left to middle right [ http://www.sungazer.net/transit110806a.html ]. Depending on your location [ http://sunearth.gsfc.nasa.gov/eclipse/OH/ image1/TM2006Nov08-Fig2.GIF ], the Sun may not be above the horizon during the entire transit, but webcasts of the event [ http://www.exploratorium.edu/transit/ ] are planned - including one using images from the sun-staring SOHO [ http://sohowww.nascom.nasa.gov/hotshots/ 2006_11_06/ ] spacecraft. This is the second of 14 transits of Mercury during the 21st century. The next similar event will be a transit of Venus in June of 2012. |
|
Shepard Flies Freedom 7
| Title |
Shepard Flies Freedom 7 |
| Explanation |
Forty years ago today (May 5, 1961 [ http://www.thespaceplace.com/history/mercury/ mercury03.html ]), at the dawn of the space age [ http://www.hq.nasa.gov/office/pao/History/sputnik/ index.html ], NASA controllers "lit the candle" and sent Alan Shepard arcing into space atop a Redstone rocket [ http://antwrp.gsfc.nasa.gov/apod/ap980404.html ]. The picture shows the pressure-suited Shepard before launch in his cramped space capsule [ http://www.hq.nasa.gov/office/pao/History/diagrams/ mercury.html ] dubbed "Freedom 7" [ http://images.jsc.nasa.gov/images/pao/MR3/ 10073523.htm ]. Broadcast live to a global television audience, the flight of Freedom 7 [ http://www.nasm.edu/galleries/attm/nojs/rm.ey.f7.1.html ] - the first space flight by an American - followed less than a month after the first human venture into space by Soviet Cosmonaut Yuri Gagarin [ http://antwrp.gsfc.nasa.gov/apod/ap010414.html ]. Freedom 7's historic flight [ http://www.hq.nasa.gov/office/pao/History/40thmerc7/ intro.htm ] was suborbital, lasting only about 15 minutes, but during it Shepard demonstrated manual control of his capsule. Naval aviator [ http://www.hq.nasa.gov/office/pao/History/40thmerc7/ shepard.htm ] Shepard was chosen as one of the original seven Mercury Program [ http://www.hq.nasa.gov/office/pao/History/SP-4201/ toc.htm ] astronauts. He considered this first flight [ http://www.hq.nasa.gov/office/pao/History/SP-4201/ch11-4.htm ] the greatest challenge and actively sought the assignment. Shepard's career as an astronaut spanned a remarkable period in human achievement and in 1971 he walked on the moon [ http://www.hq.nasa.gov/office/pao/History/alsj/a14/ a14.crew.html ] as commander of the Apollo 14 mission. A true pioneer and intrepid explorer, Alan Shepard died in 1998 [ http://www.nasa.gov/shepard.html ] at age 74. |
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Mercury Spotting
| Title |
Mercury Spotting |
| Explanation |
Can you spot [ http://antwrp.gsfc.nasa.gov/apod/ap991210.html ] the planet? The diminutive disk of Mercury, the solar system's innermost [ http://www.seds.org/nineplanets/nineplanets/ mercury.html ] planet, spent about five hours crossing in front of the enormous solar disk yesterday (Wednesday, May 7th), as viewed from [ http://www.xs4all.nl/~carlkop/mercurius/transit.html ] the general vicinity of planet Earth. The Sun was above the horizon during the entire transit [ http://www.eso.org/outreach/eduoff/vt-2004/mt-2003/ mt-display.html ] for observers in Europe, Africa, Asia, or Australia, and the horizon was certainly no problem [ http://sohowww.nascom.nasa.gov/hotshots/2003_05_07/ ] for the sun-staring SOHO spacecraft. Seen as a dark spot [ http://www.solarphysics.kva.se/ Mercurytransit7May2003/ ], Mercury progresses from left to right (top panel to bottom) in these four images from SOHO's extreme ultraviolet camera. The panels' false-colors correspond to different wavelengths in the extreme ultraviolet which highlight regions above the Sun's visible surface. This is the first [ http://sunearth.gsfc.nasa.gov/eclipse/OH/transit03.html ] of 14 transits of Mercury which will occur during the 21st century [ http://sunearth.gsfc.nasa.gov/eclipse/transit/catalog/ MercuryCatalog.html ], but the next similar event will be a transit of Venus [ http://www.eso.org/outreach/eduoff/vt-2004/index.html ] in June of 2004. Need help spotting Mercury? Just click on the picture. |
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Mercury Transits the Sun
| Title |
Mercury Transits the Sun |
| Explanation |
How big is the Sun? The Sun [ http://www.nineplanets.org/sol.html ] is not only larger than any planet, it is larger than all of the planets [ http://pds.jpl.nasa.gov/planets/welcome.htm ] put together. The Sun [ http://antwrp.gsfc.nasa.gov/apod/sun.html ] accounts for about 99.9 percent of all the mass in its Solar System [ http://www.nineplanets.org/overview.html ]. Merely stating the Sun's diameter is about 1,400,000 kilometers [ http://www.bms.abdn.ac.uk/undergraduate/guidetosiunits.htm#history ] does not do it justice. Last week a chance to gain visual size perspective occurred when planet Mercury [ http://www.solarviews.com/eng/mercury.htm ] made a rare crossing [ http://sunearth.gsfc.nasa.gov/eclipse/transit/catalog/MercuryCatalog.html ] in front to Sun. Mercury [ http://antwrp.gsfc.nasa.gov/apod/ap991119.html ], a planet over a third of the diameter of our Earth, is the dark dot on the upper right. In comparison to the Sun, Mercury is so small it is initially hard to spot [ http://antwrp.gsfc.nasa.gov/apod/ap030508.html ]. Also visible on the Sun are dark circular sunspots [ http://es.rice.edu/ES/humsoc/Galileo/Things/sunspots.html ], bright plages [ http://csep10.phys.utk.edu/astr162/lect/sun/prominences.html ], and dark elongated prominences [ http://antwrp.gsfc.nasa.gov/apod/ap970127.html ] -- many of which are larger than Mercury. The above contrast-enhanced picture was captured [ http://antwrp.gsfc.nasa.gov/apod/ap010129.html ] last week from France [ http://www.cia.gov/cia/publications/factbook/geos/fr.html ]. |
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Mercury And The Moon
| Title |
Mercury And The Moon |
| Explanation |
Mercury is [ http://nssdc.gsfc.nasa.gov/planetary/factsheet/mercuryfact.html ] the closest planet to the Sun and never moves far from our parent star in Earth's sky [ http://space.jpl.nasa.gov/ ]. Racing around its tight orbit, this well-done world is a little over 1/3 the diameter of Earth and is often lost to our view [ http://www.seds.org/nineplanets/nineplanets/see.html ] in the solar glare. But, just one day before the August 11 total solar eclipse [ http://www.exploratorium.edu/eclipse/personal_accounts.html ], astronomer Tunc Tezel captured this fleeting view of a close conjunction of Mercury and the soon to be silhouetted Moon [ http://antwrp.gsfc.nasa.gov/apod/ap990818.html ] as seen from Turkey. Mercury at [ http://antwrp.gsfc.nasa.gov/apod/ap980906.html ] the lower right shines brightly in reflected sunlight while only a thin crescent of the almost new Moon is [ http://www.inconstantmoon.com/index.htm ] directly illuminated. The rest of the lunar nearside is faintly visible though, illuminated by light [ http://www.gi.alaska.edu/ScienceForum/ASF11/1191.html ] from an almost full Earth [ http://space.jpl.nasa.gov/cgi-bin/wspace?tbody=3&vbody=103&month=8&day=10¢ury=19&decade=9&year=9&hour=00&minute=0&rfov=30&fovmul=-1&bfov=30 ]. On Monday, November 15th, Mercury will [ http://sunearth.gsfc.nasa.gov/eclipse/OH/transit99.html ] actually be seen to transit or pass across the disk of the Sun for well placed observers in the pacific hemisphere. |
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Crescent Mercury in Color
| Title |
Crescent Mercury in Color |
| Explanation |
Hard to spot against the twilight glow [ http://antwrp.gsfc.nasa.gov/apod/ap080112.html ] near planet Earth's horizon, a crescent Mercury was imaged close up by the MESSENGER [ http://messenger.jhuapl.edu/mer_flyby1.html ] spacecraft early last week. Colors in this remarkable picture [ http://messenger.jhuapl.edu/gallery/sciencePhotos/ image.php?gallery_id=2&image_id=132 ] were created using data recorded through infrared, red, and violet filters. The combination enhances color differences otherwise not visible to the eye across the innermost planet's cratered surface [ http://messenger.jhuapl.edu/gallery/sciencePhotos/ image.php?gallery_id=2&image_id=136 ]. In this view, light bluish [ http://www.planetary.org/blog/article/00001304/ ] material seems to surround relatively new craters, contrasting [ http://antwrp.gsfc.nasa.gov/apod/ap001216.html ] with the mostly drab, brown terrain. Mercury itself is 4,880 kilometers in diameter. The full resolution image shows features as small as 10 kilometers across. |
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Alan B. Shepard Jr. 1923-199
…
| Title |
Alan B. Shepard Jr. 1923-1998 |
| Explanation |
On another Friday (May 5, 1961), at the dawn of the space age [ http://www.hq.nasa.gov/office/pao/History/sputnik/index.html ], NASA controllers "lit the candle" and sent Alan B. Shepard Jr. arcing into space atop a Redstone rocket [ http://antwrp.gsfc.nasa.gov/apod/ap980404.html ]. The picture shows the pressure-suited Shepard before the launch in his cramped space capsule [ http://images.jsc.nasa.gov/images/pao/MERC_OV/10073402.htm ] dubbed "Freedom 7" [ http://images.jsc.nasa.gov/images/pao/MR3/10073523.htm ]. This historic flight [ http://www.ksc.nasa.gov/history/mercury/mr-3/mr-3.html ] - the first spaceflight by an American - made Shepard a national hero [ http://www.nasm.edu/GALLERIES/GAL114/SpaceRace/ ]. Born in East Derry, New Hampshire on November 18, 1923, Shepard graduated from the United States Naval Academy in 1944 and went on to train and serve as a Naval Aviator. Chosen as one of the original seven Mercury Program [ http://www.hq.nasa.gov/office/pao/History/SP-4201/toc.htm ] astronauts, he considered this first flight [ http://www.hq.nasa.gov/office/pao/History/SP-4201/ch11-4.htm ] the greatest challenge and actively sought the assignment. Shepard's accomplishments in his career as an astronaut spanned a remarkable period in human achievement and in 1972 he walked on the moon [ http://www.hq.nasa.gov/office/pao/History/alsj/ ] as commander of the Apollo 14 mission. A true pioneer and intrepid explorer, Alan Shepard died Tuesday [ http://www.nasa.gov/shepard.html ] at age 74 after a lengthy illness. |
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Sky and Planets
| Title |
Sky and Planets |
| Explanation |
On February 10th, an evocative [ http://www.jps.net/ssumner/ ] evening sky above Rocklin, California, USA inspired astrophotographer Steve Sumner to record this remarkable sight - five planets and the Moon. Near its first quarter phase, the bright Moon [ http://lunar.arc.nasa.gov/ ] was intentionally overexposed but Saturn [ http://www.jpl.nasa.gov/cassini/ ], Jupiter [ http://galileo.jpl.nasa.gov/ ], Mars [ http://mars.jpl.nasa.gov/ ], and Mercury [ http://sd-www.jhuapl.edu/MESSENGER/ ] (and, of course, planet Earth's [ http://www.earth.nasa.gov/ ] horizon) are all clearly visible in the deepening twilight. Notably absent in this grouping of naked-eye planets is Venus [ http://antwrp.gsfc.nasa.gov/apod/ap990903.html ] which is still putting in an early appearance as the morning star [ http://ispec.scibernet.com/station/morn_star.html ]. This month, Mercury has joined Venus in the dawn twilight while Saturn, Jupiter, and Mars still shine brightly in the western sky at nightfall [ http://www.skypub.com/sights/sights.shtml ] making another gorgeous close grouping with the crescent Moon [ http://www.inconstantmoon.com/ ]. |
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Three Planets in Dawn Skies
| Title |
Three Planets in Dawn Skies |
| Explanation |
Three children of the Sun [ http://antwrp.gsfc.nasa.gov/apod/ap061116.html ] rise in the east in this peaceful dawn skyview recorded December 7th near Bolu, Turkey. Inner planet Mercury [ http://kids.nineplanets.org/mercury.htm ], fresh from its second transit [ http://antwrp.gsfc.nasa.gov/apod/ap061114.html ] of the 21st century, stands highest in the bright sky at the top right. Gas giant Jupiter [ http://nssdc.gsfc.nasa.gov/planetary/factsheet/ jupiterfact.html ] lies below the cloud bank near picture center. A newsworthy Mars [ http://www.nasa.gov/mission_pages/mars/news/ mgs-20061206.html ] is also visible, right of Jupiter and just above the dark cloud bank. On Sunday, these planets will form a much tighter grouping [ http://skytonight.com/observing/ataglance ] before sunrise [ http://niteskys.com/mercury_mars_jupiter_120806.html ], while in the coming days the western sky after sunset will be ruled by brilliant planet Venus [ http://www.esa.int/SPECIALS/Venus_Express/ ], also known as the evening star. |
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Liberty Bell 7
| Title |
Liberty Bell 7 |
| Explanation |
Today, the space capsule Liberty Bell 7 rests [ http://www.discovery.com/exp/libertybell7/libertybell7.html ] about 3 miles below the surface of the Atlantic Ocean. But on July 21, 1961 [ http://www.ksc.nasa.gov/history/mercury/mr-4/mr-4.html ], astronaut Virgil I. "Gus" Grissom [ http://www.hq.nasa.gov/office/pao/History/Apollo204/zorn/grissom.htm ] rode this tiny craft 118 miles above the Earth to become the second American in space [ http://www.nasm.edu/GALLERIES/GAL114/SpaceRace/ ]. Grissom's flight was suborbital [ http://www.hq.nasa.gov/office/pao/History/SP-4201/ch11-8.htm ] - like fellow Mercury astronaut Alan Shepard's [ http://antwrp.gsfc.nasa.gov/apod/ap980724.html ] first flight - however his capsule was different, with a window, a new manual spacecraft control system, and an explosive hatch. Unfortunately, after Grissom brought Liberty Bell 7 to a successful splash down in the planned area, the hatch blew prematurely and rough seas began to flood the capsule. While Grissom was able to get out, the military recovery helicopter could not lift the waterlogged spacecraft. This dramatic picture [ http://www.ksc.nasa.gov/mirrors/images/images/pao/MR4/10073570.htm ] was taken from the helicopter shortly before Liberty Bell 7 was released and sank. |
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