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Dawn and Sun of Goddard Space Flight Center (GSFC)
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Phoebe Temperature Maps
| Description |
Phoebe Temperature Maps |
| Full Description |
A montage of maps of Saturn's moon Phoebe shows surface temperatures at various times of day as determined by the composite infrared spectrometer onboard Cassini during the June 11, 2004, Phoebe flyby. The asterisk on each map shows the location of the subsolar point, where the Sun is directly overhead. This point moves across the surface as Phoebe rotates. It is morning in regions to the left of the subsolar point, and afternoon in regions to the right. Like a newspaper weather map, different colors indicate different temperatures, though Phoebe's temperatures are distinctly cooler than even the coldest January day on Earth. Equatorial temperatures peak in the early afternoon near 112 Kelvin (-257 Fahrenheit), plunging to 78 Kelvin (-319 Fahrenheit) before dawn, and are even colder at higher latitudes. The large day/night temperature contrasts imply that Phoebe's surface is covered in loose dust or ice particles that store little heat and thus cool off rapidly at night. Regions of Phoebe's surface that were not observed are shown in black. Most of the maps show the effect on surface temperatures of the large crater-like depression seen in Cassini's visible-wavelength images of Phoebe, which is located just left of center in these maps. Crater walls that are shadowed and cold in the early morning in the first map are sunlit and warm in the late afternoon in the final map. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Office of Space Science, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md. For more information about the Cassini-Huygens mission, visit http://saturn.jpl.nasa.gov and the Cassini composite infrared spectrometer home page at http://cirs.gsfc.nasa.gov/ . Image Credit: NASA/JPL/Goddard Space Flight Center |
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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 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 transit of the Sun
| Title |
Mercury transit of the Sun |
| Completed |
2003-05-07 |
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Mount St. Helens
| Title |
Mount St. Helens |
| Description |
Hot lava had broken through the surface of the growing lava dome on Mount St. Helens when the MASTER sensor took this image in the early morning hours of October 13, 2004. MASTER, which stands for MODIS/ASTER Airborne Simulator, is an aircraft- mounted remote sensing device built to simulate the Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov/ ]) and Advanced Spaceborne Thermal Emission and Reflection Radiometer [ http://asterweb.jpl.nasa.gov/ ] (ASTER) instruments on NASA's Terra [ http://terra.nasa.gov/ ] satellite. The top image was made from MASTER's thermal sensitive bands, and shows the heat in the volcano's crater. A brilliant white spot on the southwest side of the crater is hot lava bubbling to the surface. Smaller, less intense hot spots around the crater have formed where magma near the surface has heated the rock above it. The dark area around the lava dome is the crater. Shielded from the sun and covered with snow, the dark crater floor is cooler than the surrounding landscape, which appears red. A plume of steam rising from the lava dome (colored purple) drifts southeast in this image. The plume and crater floor are more visible in the lower, true color image. Acquired just after dawn, the image has few shadows and low contrast. An image composed of thermal infrared and visible light wavelengths reveals more details around the mountain. The volcanic plume is bright cyan, the cool crater is purple, and snow is light blue. To the north of the volcano, two bright red lines extend from south to north. These are warm-water streams, possibly heated by the active volcano. NASA images courtesy Jeff Myers, MASTER [ http://masterweb.jpl.nasa.gov/ ] instrument team, NASA Ames Research Center |
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Mount St. Helens
| Title |
Mount St. Helens |
| Description |
Hot lava had broken through the surface of the growing lava dome on Mount St. Helens when the MASTER sensor took this image in the early morning hours of October 13, 2004. MASTER, which stands for MODIS/ASTER Airborne Simulator, is an aircraft- mounted remote sensing device built to simulate the Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov/ ]) and Advanced Spaceborne Thermal Emission and Reflection Radiometer [ http://asterweb.jpl.nasa.gov/ ] (ASTER) instruments on NASA's Terra [ http://terra.nasa.gov/ ] satellite. The top image was made from MASTER's thermal sensitive bands, and shows the heat in the volcano's crater. A brilliant white spot on the southwest side of the crater is hot lava bubbling to the surface. Smaller, less intense hot spots around the crater have formed where magma near the surface has heated the rock above it. The dark area around the lava dome is the crater. Shielded from the sun and covered with snow, the dark crater floor is cooler than the surrounding landscape, which appears red. A plume of steam rising from the lava dome (colored purple) drifts southeast in this image. The plume and crater floor are more visible in the lower, true color image. Acquired just after dawn, the image has few shadows and low contrast. An image composed of thermal infrared and visible light wavelengths reveals more details around the mountain. The volcanic plume is bright cyan, the cool crater is purple, and snow is light blue. To the north of the volcano, two bright red lines extend from south to north. These are warm-water streams, possibly heated by the active volcano. NASA images courtesy Jeff Myers, MASTER [ http://masterweb.jpl.nasa.gov/ ] instrument team, NASA Ames Research Center |
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Total solar eclipse over Ant
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| Title |
Total solar eclipse over Antarctica |
| Description |
The moon cast a long shadow over Antarctica on November 23, 2003, in a total solar eclipse. The sun typically hangs low on the horizon during the southernmost continent's almost-summer months, so when the Moon moved between the Sun and the Earth, its shadow fell in a roughly 500-kilometer long oval like the long shadows of a early summer dawn. At the time this image was taken, the sun was at approximately 15 degrees above the horizon. The shadow's long circular shape is the same pattern a flashlight casts an the floor when held at a similar angle. The moon's shadow has two parts: the fuzzy outer shadow, the penumbra, and the dark inner shadow, the umbra. Within the umbra, the sun is completely blocked. A person standing on the ground sees a glowing black disk in front of the sun?the disk is the moon, and the glow is the sun's corona. In the penumbra, the ground observer sees the moon covering part of the sun. Both the penumbra and the umbra are visible in this true-color image. The Moderate Resolution Imaging Spectroradiometer [ http://modis.gsfc.nasa.gov ] (MODIS) on the Aqua [ http://aqua.nasa.gov/ ] satellite captured this image of the eclipse between 23:15 and 23:20 UTC. The Terra [ http://terra.nasa.gov/ ] satellite captured a similar image [ http://rapidfire.sci.gsfc.nasa.gov/gallery/?2003327-1123/Antarctica.A2003327.2255 ] of the eclipse. The eclipse started at 22:08 UTC, and the shadow passed from the surface of the earth a little over an hour later at 23:20 UTC. The sun's light was completely blocked at 22:49 for one minute and 55 seconds. At the time this image was taken, the sun was just rising over Antarctica, tinting the mountains a delicate pink, even within the shadow of the eclipse. Beyond the dark upper left corner, the sun has not yet driven away night's darkness. The bluish tones of the snow reveal how Antarctica appears from space without atmospheric correction. The shadow covers Queen Maud Land, Antarctica, with its tip pointing towards Africa. The South Pole is just beyond the right corner of the image. The moon is not the only thing throwing shadows across the landscape in this image. On the top left, the Pensacola Mountains make long horizontal shadows on the ice. Patches of low cloud along the left side of the umbra are also leaving a dark smudge on the surface. This image is available in multiple resolutions [ http://rapidfire.sci.gsfc.nasa.gov/gallery/?2003327-1123/Antarctica2.A2003327.2320 ]. Image courtesy Jacques Descloitres, MODIS Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov ] at NASA GSFC |
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Total solar eclipse over Ant
…
| Title |
Total solar eclipse over Antarctica |
| Description |
The moon cast a long shadow over Antarctica on November 23, 2003, in a total solar eclipse. The sun typically hangs low on the horizon during the southernmost continent's almost-summer months, so when the Moon moved between the Sun and the Earth, its shadow fell in a roughly 500-kilometer long oval like the long shadows of a early summer dawn. At the time this image was taken, the sun was at approximately 15 degrees above the horizon. The shadow's long circular shape is the same pattern a flashlight casts an the floor when held at a similar angle. The moon's shadow has two parts: the fuzzy outer shadow, the penumbra, and the dark inner shadow, the umbra. Within the umbra, the sun is completely blocked. A person standing on the ground sees a glowing black disk in front of the sun?the disk is the moon, and the glow is the sun's corona. In the penumbra, the ground observer sees the moon covering part of the sun. Both the penumbra and the umbra are visible in this true-color image. The Moderate Resolution Imaging Spectroradiometer [ http://modis.gsfc.nasa.gov ] (MODIS) on the Aqua [ http://aqua.nasa.gov/ ] satellite captured this image of the eclipse between 23:15 and 23:20 UTC. The Terra [ http://terra.nasa.gov/ ] satellite captured a similar image [ http://rapidfire.sci.gsfc.nasa.gov/gallery/?2003327-1123/Antarctica.A2003327.2255 ] of the eclipse. The eclipse started at 22:08 UTC, and the shadow passed from the surface of the earth a little over an hour later at 23:20 UTC. The sun's light was completely blocked at 22:49 for one minute and 55 seconds. At the time this image was taken, the sun was just rising over Antarctica, tinting the mountains a delicate pink, even within the shadow of the eclipse. Beyond the dark upper left corner, the sun has not yet driven away night's darkness. The bluish tones of the snow reveal how Antarctica appears from space without atmospheric correction. The shadow covers Queen Maud Land, Antarctica, with its tip pointing towards Africa. The South Pole is just beyond the right corner of the image. The moon is not the only thing throwing shadows across the landscape in this image. On the top left, the Pensacola Mountains make long horizontal shadows on the ice. Patches of low cloud along the left side of the umbra are also leaving a dark smudge on the surface. This image is available in multiple resolutions [ http://rapidfire.sci.gsfc.nasa.gov/gallery/?2003327-1123/Antarctica2.A2003327.2320 ]. Image courtesy Jacques Descloitres, MODIS Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov ] at NASA GSFC |
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Moon And Venus Share The Sky
| Title |
Moon And Venus Share The Sky |
| Explanation |
July is drawing to a close and in the past few days, some early morning risers [ http://antwrp.gsfc.nasa.gov/apod/ap990714.html ] could have looked east and seen a crescent Moon sharing the pre-dawn [ http://science.nasa.gov/headlines/y2000/ast25jul_1m.htm ] skies with planets Jupiter and Saturn. Planet Mercury will also pass about 2 degrees from the thin waning crescent Moon [ http://aa.usno.navy.mil/AA/faq/docs/moon_phases.html ] just before sunrise near the eastern horizon on Saturday, July 29. And finally, on the evening of July 31st, Venus will take its turn near the crescent Moon [ http://antwrp.gsfc.nasa.gov/apod/ap991108.html ]. But this time it will be a day-old crescent Moon near the western horizon, shortly after sunset [ http://antwrp.gsfc.nasa.gov/apod/ap000507.html ]. In fact [ http://pages.prodigy.net/pam.orman/JoeAlmanac2000.html ], on July 31 (August 1 Universal Time) the Moon will occult [ http://www.skypub.com/sights/occultations/lunar/ 0001lunarocc.html ] (pass in front of) Venus for northwestern observers [ http://www.skypub.com/sights/images2000/ 0008moonvenus_big.jpg ] in North America. This telescopic picture taken on 31 December 1997, shows a lovely young crescent Moon and brilliant crescent Venus in [ http://antwrp.gsfc.nasa.gov/apod/ap990903.html ] the early evening sky near Bursa, Turkey [ http://www.mersina.com/Turkey/Marmara/Bursa/index.html ]. And what about the Sun? On Sunday, July 30, a partial eclipse of the Sun [ http://sunearth.gsfc.nasa.gov/eclipse/extra/ PSE2000Jul31.html ] will be visible from some locations [ http://sunearth.gsfc.nasa.gov/eclipse/OH/ PSE2000Jul.gif ] in North America. |
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Comet SWAN Brightens
| Title |
Comet SWAN Brightens |
| Explanation |
A newly discovered comet has brightened enough to be visible this week with binoculars. The picturesque comet [ http://antwrp.gsfc.nasa.gov/apod/ap050904.html ] is already becoming a favored target for northern sky imagers. Pictured above [ http://www.astrostudio.at/Astrofotos/astrofotos.php?k_id=69 ] just last week, Comet SWAN showed a bright blue-green coma and an impressive tail. Comet C/2006 M4 (SWAN) [ http://cometography.com/lcomets/2006m4.html ] was discovered in June in public images from the Solar Wind Anisotropies [ http://www.fmi.fi/research_space/space_7.html ] (SWAN) instrument of NASA and ESA [ http://en.wikipedia.org/wiki/ESA ]'s Sun-orbiting SOHO [ http://sohowww.nascom.nasa.gov/ ] spacecraft. Comet [ http://en.wikipedia.org/wiki/Comet ] SWAN, near magnitude six, will be visible with binoculars in the northeastern sky not far from the Big Dipper over the next few days before dawn. The comet [ http://www.aerith.net/comet/catalog/2006M4/2006M4.html ] is expected to reach its peak brightness this week. Passing its closest to the Sun two days ago, Comet SWAN [ http://ssd.jpl.nasa.gov/sbdb.cgi?ID=dK06M040;orb=1;cov=0#orb ] and will be at its closest to the Earth toward the end of this month. Comet SWAN's unusual orbit [ http://cfa-www.harvard.edu/cfa/ps/mpec/K06/K06S89.html ] appears to be hyperbolic [ http://adsabs.harvard.edu/abs/1992A&A...259..692K ], meaning that it will likely go off into interstellar space [ http://antwrp.gsfc.nasa.gov/apod/ap020210.html ], never to return. |
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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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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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Comet McNaught Heads for the
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| Title |
Comet McNaught Heads for the Sun |
| Explanation |
Early morning risers with a clear and unobstructed eastern horizon can enjoy the sight of Comet McNaught (C/2006 P1) in dawn skies over the next few days. Discovered in August by R. H. McNaught (Siding Spring Survey [ http://www.mso.anu.edu.au/~rmn/ ]) the comet has grown bright enough to see with the unaided eye but will soon be lost in the glare of the Sun. Still, by January 11 sun-staring spacecraft SOHO should be able to offer web-based views [ http://sohowww.nascom.nasa.gov/data/realtime/c3/ 512/ ] as the comet heads toward [ http://neo.jpl.nasa.gov/cgi-bin/db_shm?name=c/2006+P1 ] a perihelion [ http://www.windows.ucar.edu/tour/ link=/physical_science/physics/mechanics/orbit/ perihelion_aphelion.html&edu=high ] passage inside the orbit of Mercury. This image captures [ http://www.astrostudio.at/Astrofotos/astrofotos.php?k_id=71 ] the new naked-eye comet [ http://www.nasa.gov/worldbook/comet_worldbook.html ] at about 2nd magnitude [ http://en.wikipedia.org/wiki/Apparent_magnitude ] in twilight skies near sunset on January 3rd. After rounding the Sun [ http://www.shadowandsubstance.com/ ] and emerging from the solar glare later this month, Comet McNaught [ http://www.aerith.net/comet/catalog/2006P1/2006P1.html ] could be even brighter. |
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Jupiter, Vesta, and the Milk
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| Title |
Jupiter, Vesta, and the Milky Way |
| Explanation |
In this gorgeous skyscape, gas giant Jupiter [ http://antwrp.gsfc.nasa.gov/apod/ap070329.html ] along with the stars and cosmic dust clouds of the Milky Way [ http://antwrp.gsfc.nasa.gov/apod/ap070330.html ] hang over the southern horizon in the early morning hours as seen from Stagecoach, Colorado, USA. Recorded on Thursday, Jupiter is the brightest object near picture center. Along with the stunning Milky Way, Jupiter is hard to miss, but a careful inspection of the view also reveals main belt [ http://www.solstation.com/stars/asteroid.htm ] asteroid Vesta [ http://antwrp.gsfc.nasa.gov/apod/ap060820.html ]. Of all the asteroids [ http://www.nineplanets.org/asteroids.html ] Vesta is the brightest and is now just bright enough to be visible to the naked eye from locations with very dark, clear skies. Vesta (as well as Jupiter) appears relatively bright now because it is near opposition, literally [ http://www.heavens-above.com/ gloss.asp?term=opposition ] opposite the Sun in planet Earth's sky and closest to Earth in its orbit. For Vesta [ http://dawn.jpl.nasa.gov/feature_stories/ Vesta_chart_descrip.asp ], this opposition offers the best viewing in many years. The year 2007 also coincides [ http://adsabs.harvard.edu/abs/1907Obs....30..103L ] with the 200th anniversary of the asteroid's discovery [ http://dawn.jpl.nasa.gov/DawnCommunity/ flashbacks/fb_06.asp ]. Starting late next month, NASA plans to launch the Dawn mission [ http://dawn.jpl.nasa.gov/index.asp ] intended to explore Vesta (and Ceres) and the main asteroid belt. |
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Venus' Evening Loop
| Title |
Venus' Evening Loop |
| Explanation |
From September 2000 through March 2001, astronomer Tunc Tezel patiently photographed the planet Venus on 25 different dates as it wandered [ http://zebu.uoregon.edu/~js/ast221/lectures/ lec06.html ] through the evening twilight. The pictures were taken from the same spot on the campus of the Middle East Technical University near Ankara, Turkey, and timed so that for each photo the Sun was [ http://aa.usno.navy.mil/data/docs/RS_OneYear.html ] 7 degrees below the horizon. Carefully registering and combining the pictures, he produced this composite image -- a stunning demonstration of Venus' grand [ http://stoner.eps.mcgill.ca/~bud/craters/ FaceOfVenus.html ] looping sky motion [ http://sunra.colorado.edu/david/ch1.html ] during its recent stint as planet Earth's evening star [ http://www.library.utoronto.ca/utel/rp/poems/ longfe10.html ]. As indicated, the first picture, taken September 28, 2000, finds Venus [ http://www.windows.ucar.edu/cgi-bin/tour_def/venus/ morning_star.html ] close to the western horizon [ http://antwrp.gsfc.nasa.gov/apod/ap990619.html ] and drifting south (left) with the passing days. By December however, Venus [ http://nssdc.gsfc.nasa.gov/planetary/planets/ venuspage.html ] was climbing well above the horizon after sunset and in January 2001 it reached its maximum apparent distance (elongation [ http://astrosun.tn.cornell.edu/courses/astro201/ planet_view.htm ]) from the Sun. March found Venus [ http://antwrp.gsfc.nasa.gov/apod/ap010308.html ] falling from the evening sky while moving rapidly north, finally appearing (far right) as a faint dot against the sunset glow on March 24. This month, Venus rises before dawn as the brilliant morning star [ http://stardate.utexas.edu/resources/ faqs/049.html ]. |
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Zodiacal Light and the False
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| Title |
Zodiacal Light and the False Dawn |
| Explanation |
An unusual triangle of light will be particularly bright near the eastern horizon before sunrise during the next two months for observers in Earth's northern hemisphere. Once considered a false dawn [ http://en.wikipedia.org/wiki/Zodiacal_light ], this triangle of light is actually Zodiacal Light [ http://home.wanadoo.nl/marco.langbroek/zodiac.html ], light reflected from interplanetary dust particles [ http://antwrp.gsfc.nasa.gov/apod/ap010813.html ]. The triangle is clearly visible toward the left of the frame taken from the Paranal Observatory [ http://en.wikipedia.org/wiki/Paranal_Observatory ] in Chile [ http://en.wikipedia.org/wiki/Chile ] in July. Zodiacal dust [ http://coolcosmos.ipac.caltech.edu/cosmic_classroom/ cosmic_reference/zodydust.html ] orbits the Sun [ http://www.nineplanets.org/sol.html ] predominantly in the same plane as the planets: the ecliptic [ http://antwrp.gsfc.nasa.gov/apod/ap001014.html ]. Zodiacal light [ http://www.as.wvu.edu/~jel/skywatch/skw9810h.html ] is so bright this time of year because the dust band [ http://antwrp.gsfc.nasa.gov/apod/ap000517.html ] is oriented nearly vertical at sunrise, so that the thick air near the horizon does not block out relatively bright reflecting dust [ http://antwrp.gsfc.nasa.gov/apod/ap970825.html ]. Zodiacal light [ http://antwrp.gsfc.nasa.gov/apod/ap020915.html ] is also bright for people in Earth's northern hemisphere in March and April just after sunset. APOD editor to review best space pictures in Philadelphia tomorrow (Wednesday) night [ http://www.rittenhouseastronomicalsociety.org/ ] |
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Zodiacal Light and the False
…
| Title |
Zodiacal Light and the False Dawn |
| Explanation |
An unusual triangle of light will be particularly bright near the eastern horizon before sunrise during the next two months for observers in Earth's northern hemisphere. Once considered a false dawn [ http://www.odysseymagazine.com/pages/Stargazer.html ], this triangle of light is actually Zodiacal Light [ http://home.wanadoo.nl/marco.langbroek/zodiac.html ], light reflected from interplanetary dust particles [ http://antwrp.gsfc.nasa.gov/apod/ap010813.html ]. The triangle is clearly visible on the left of the above frame taken from Mauna Kea [ http://www.ifa.hawaii.edu/mko/ ] in Hawaii [ http://www.state.hi.us/ ] on August 30 by one of the developing global network of fisheye nighttime web cameras [ http://concam.net/ ] called CONCAMs [ http://concam.net/about.html ]. Zodiacal dust [ http://stardust.wustl.edu/IDPIntro.html ] orbits the Sun [ http://www.nineplanets.org/sol.html ] predominantly in the same plane as the planets: the ecliptic [ http://antwrp.gsfc.nasa.gov/apod/ap001014.html ]. Indeed, the triangle points to bright spots Jupiter and Saturn [ http://antwrp.gsfc.nasa.gov/apod/ap010807.html ], with Saturn [ http://antwrp.gsfc.nasa.gov/apod/ap010702.html ] nearer the center. Zodiacal light [ http://www.as.wvu.edu/~jel/skywatch/skw9810h.html ] is so bright this time of year because the dust band [ http://antwrp.gsfc.nasa.gov/apod/ap000517.html ] is oriented nearly vertical at sunrise, so that the thick air near the horizon does not block [ http://www.earthsky.com/2000/es000327.html ] out relatively bright reflecting [ http://sirtf.jpl.nasa.gov/SciUser/C_PropKit/bgdoc_release/node3.html ] dust. Zodiacal light [ http://antwrp.gsfc.nasa.gov/apod/ap990613.html ] is also bright for people in Earth's northern hemisphere in March and April just after sunset. |
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Zodiacal Light and the False
…
| Title |
Zodiacal Light and the False Dawn |
| Explanation |
An unusual triangle of light will be particularly bright near the eastern horizon before sunrise during the next two months for observers in Earth's northern hemisphere. Once considered a false dawn [ http://www.odysseymagazine.com/pages/Stargazer.html ], this triangle of light is actually Zodiacal Light [ http://home.wanadoo.nl/marco.langbroek/zodiac.html ], light reflected from interplanetary dust particles [ http://antwrp.gsfc.nasa.gov/apod/ap010813.html ]. The triangle is clearly visible on the left of the above frame taken from Mauna Kea [ http://www.ifa.hawaii.edu/mko/ ] in Hawaii [ http://www.state.hi.us/ ] on September 8 by one of the developing global network of fisheye nighttime web cameras, called CONCAMs [ http://concam.net/about.html ], of the Night Sky Live Project [ http://concam.net/ ]. Zodiacal dust [ http://stardust.wustl.edu/IDPIntro.html ] orbits the Sun [ http://www.nineplanets.org/sol.html ] predominantly in the same plane as the planets: the ecliptic [ http://antwrp.gsfc.nasa.gov/apod/ap001014.html ]. Zodiacal light [ http://www.as.wvu.edu/~jel/skywatch/skw9810h.html ] is so bright this time of year because the dust band [ http://antwrp.gsfc.nasa.gov/apod/ap000517.html ] is oriented nearly vertical at sunrise, so that the thick air near the horizon does not block [ http://www.earthsky.com/2000/es000327.html ] out relatively bright reflecting dust [ http://antwrp.gsfc.nasa.gov/apod/ap970825.html ]. Zodiacal light [ http://antwrp.gsfc.nasa.gov/apod/ap990613.html ] is also bright for people in Earth's northern hemisphere in March and April just after sunset. |
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Moon, Mars, Venus, and Spica
| Title |
Moon, Mars, Venus, and Spica |
| Explanation |
Gliding toward today's total eclipse [ http://sunearth.gsfc.nasa.gov/ eclipse/TSE2002/TSE2002.html ] of the Sun, the crescent Moon has been rising early, just before dawn. And as a prelude to its close solar alignment [ http://www.mreclipse.com/ Special/SEprimer.html ], the Moon also completed a lovely celestial triangle, closing with bright planets Mars and Venus [ http://antwrp.gsfc.nasa.gov/apod/ap020524.html ] on the morning of December 1. While [ http://antwrp.gsfc.nasa.gov/apod/ap021203.html ] the total solar eclipse can only [ http://profjohn.com/el/el2002/index.html ] be seen [ http://www.csiro.au/helix/eclipse/ ] from a [ http://astronomy.swin.edu.au/solar_eclipse_2002/ ] narrow corridor, skygazers around the globe could appreciate this [ http://www.spaceweather.com/planets/ gallery_01dec02.html ] lunar-planetary conjunction. This view is from near Nashville Tennessee, USA, and finds brilliant Venus at the lowest corner of the triangle with a much fainter Mars immediately to the right of the Moon. The Moon's sunlit crescent is overexposed, but details of the lunar night side are revealed by earthshine [ http://antwrp.gsfc.nasa.gov/apod/ap020419.html ]. Above and to the right of the trio is Spica [ http://www.astro.wisc.edu/~dolan/constellations/ hr/5056.html ], brightest star in the constellation Virgo. |
|
A Magellanic Starfield
| Title |
A Magellanic Starfield |
| Explanation |
Stars of many types and colors are visible in this Hubble Space Telescope [ http://heritage.stsci.edu/1999/44/index.html ] close-up of a starfield in the Large Magellanic Cloud [ http://antwrp.gsfc.nasa.gov/apod/ap980203.html ] (LMC). Over 10,000 stars are visible [ http://heritage.stsci.edu/1999/44/ supplemental.html ] -- the brightest of which are giant stars [ http://antwrp.gsfc.nasa.gov/apod/ap990605.html ]. Were our Sun [ http://www.seds.org/nineplanets/nineplanets/sol.html ] at the distance of these stars [ http://sciastro.astronomy.net/sci.astro.7.FAQ ], about 170,000 light-years, it would hardly be discernable. By contrast, only a few thousand individual stars [ http://antwrp.gsfc.nasa.gov/htmltest/gifcity/ msblues.html ] can be seen in the night sky with the unaided eye, and many of these lie within only a few hundred light-years. So typically, the light we see from nearby stars [ http://antwrp.gsfc.nasa.gov/apod/ap981025.html ] left during the age of our great-grand-parents, while light from LMC stars [ http://antwrp.gsfc.nasa.gov/apod/ap990221.html ] started its journey well before the dawn [ http://www.ucmp.berkeley.edu/ quaternary/ple.html ] of recorded human history. |
|
Eclipse in the Mist
| Title |
Eclipse in the Mist |
| Explanation |
The Sun and Moon [ http://antwrp.gsfc.nasa.gov/apod/ap010907.html ] rose together over much of Europe on the morning of May 31st [ http://www.xs4all.nl/~carlkop/zoneclips/eclipse.html ] with the first solar eclipse of 2003 already in progress. And while sightings of the full annular phase of the eclipse were restricted to far northern [ http://eclipse.span.ch/2003ase.htm ] regions, early morning risers were still treated to inspiring views [ http://astrosurf.com/avex/eclipse.html ] of two celestial bodies which are most important to life [ http://www.astronomytoday.com/astronomy/ earthmoon.html ] on planet Earth. Following the dawn's spectacle from Charneux, Belgium, astrophotographer Olivier Meeckers recorded this evocative image of the partially eclipsed Sun rising above a primeval apparition of mists and trees [ http://antwrp.gsfc.nasa.gov/apod/ap021122.html ]. Last month was indeed a rewarding one for eclipse watchers [ http://www.eurospacecenter.be/eclipses2003.htm ] as May's full Moon and (second) new Moon lined up for their respective lunar [ http://www.spaceweather.com/eclipses/ gallery_15may03.html ] and solar [ http://www.spaceweather.com/eclipses/ gallery_31may03.html ] eclipses. November 2003 [ http://sunearth.gsfc.nasa.gov/eclipse/OH/ OH2003.html ] will also host both a total lunar and total solar eclipse [ http://www.earthview.com/tutorial/causes.htm ]. |
|
Comet C/2002 T7 (LINEAR)
| Title |
Comet C/2002 T7 (LINEAR) |
| Explanation |
Discovered by the the Lincoln Near Earth Asteroid Research (LINEAR) project in October of 2002, comet C/2002 T7 [ http://antwrp.gsfc.nasa.gov/apod/ap040209.html ] is now visiting the inner solar system, making its closest approach (see animation by L. Koehn [ mailto:zeromagnitude@aol.com ]) to the Sun tomorrow, April 23rd. Emerging from the solar glare, the comet is [ http://www.nineplanets.org/comets.html ] now just visible to the unaided eye in the constellation Pisces, near the eastern horizon in morning twilight. In this gorgeous telescopic view [ http://www.noao.edu/outreach/aop/observers/ c-2002t7.html ] recorded before dawn yesterday, the clearly active comet has developed an extensive, complex tail extending [ http://antwrp.gsfc.nasa.gov/apod/ap000413.html ] over 2 degrees in the anti-sunward direction, and a pronounced anti-tail [ http://encke.jpl.nasa.gov/define.html ] or anomalous tail. Later next month this comet should appear brighter, making its closest approach to planet Earth on May 19th. In fact, it could share southern skies [ http://skyandtelescope.com/observing/objects/comets/ article_1037_1.asp ] with another naked-eye comet, also anticipated to brighten in May, designated C/2001 Q4 (NEAT). |
|
Zodiacal Light and the False
…
| Title |
Zodiacal Light and the False Dawn |
| Explanation |
An unusual triangle of light will be particularly bright near the eastern horizon before sunrise during the next two months for observers in Earth's northern hemisphere. Once considered a false dawn [ http://www.odysseymagazine.com/pages/Stargazer.html ], this triangle of light is actually Zodiacal Light [ http://home.wanadoo.nl/marco.langbroek/zodiac.html ], light reflected from interplanetary dust particles [ http://antwrp.gsfc.nasa.gov/apod/ap010813.html ]. The triangle is clearly visible in the left frame taken in Namibia [ http://www.cia.gov/cia/publications/factbook/geos/wa.html ] in May. Rolling the cursor [ http://www.ox.compsoc.net/~swhite/history/ ] over the image will bring up labels. Bright zodiacal light [ http://nightskylive.net/asterisk/viewtopic.php?p=170 ] can be seen nearly every clear moonless morning over the next few months on images taken by the Mauna Kea [ http://www.ifa.hawaii.edu/mko/ ], Hawaii [ http://www.state.hi.us/ ] fisheye CONCAM [ http://nightskylive.net/about.html ] of the Night Sky Live [ http://nightskylive.net/ ] project. Zodiacal dust [ http://coolcosmos.ipac.caltech.edu/cosmic_classroom/cosmic_reference/zodydust.html ] orbits the Sun [ http://www.nineplanets.org/sol.html ] predominantly in the same plane as the planets: the ecliptic [ http://antwrp.gsfc.nasa.gov/apod/ap001014.html ]. Zodiacal light [ http://www.as.wvu.edu/~jel/skywatch/skw9810h.html ] is so bright this time of year because the dust band [ http://antwrp.gsfc.nasa.gov/apod/ap000517.html ] is oriented nearly vertical at sunrise, so that the thick air near the horizon does not block [ http://www.earthsky.com/shows/shows.php?t=20040324 ] out relatively bright reflecting dust [ http://antwrp.gsfc.nasa.gov/apod/ap970825.html ]. Zodiacal light [ http://antwrp.gsfc.nasa.gov/apod/ap020915.html ] is also bright for people in Earth's northern hemisphere in March and April just after sunset. |
|
Shadow Set
| Title |
Shadow Set |
| Explanation |
A nearly full Moon [ http://www.inconstantmoon.com/ ] and planet Earth's [ http://antwrp.gsfc.nasa.gov/apod/ap030424.html ] shadow set together in this scene captured Monday from snowy Mt. Jelm, home of the Wyoming Infrared Observatory [ http://faraday.uwyo.edu/observatories/wiro/ ]. For early morning risers (and late to bed astronomers [ http://antwrp.gsfc.nasa.gov/apod/ap030313.html ]), shadow set in the western sky is a daily apparition [ http://webexhibits.org/causesofcolor/14E.html ] whose subtle beauty is often overlooked in favor of the more colorful eastern horizon. Extending through [ http://www.sundog.clara.co.uk/atoptics/ earshad.htm ] the dense atmosphere, Earth's setting shadow is seen [ http://antwrp.gsfc.nasa.gov/apod/ap030822.html ] in this picture as a dark blue band along the distant horizon, bounded above by a pinkish glow or antitwilight [ http://amsglossary.allenpress.com/ glossary/search?id=antitwilight-arch1 ] arch. Also known as the Belt of Venus, the arch's lovely color [ http://pages.prodigy.net/pam.orman/joemoon/ MoonPlanets_040206_34.html ] is due to backscattering of reddened light from the rising Sun. The setting Moon's light is also reddened [ http://www.exploratorium.edu/snacks/ blue_sky.html ] by the long sight-line through the atmosphere and echoes the dawn sky's yellow-orange hues [ http://webexhibits.org/ causesofcolor/14B.html ]. |
|
A Magellanic Starfield
| Title |
A Magellanic Starfield |
| Explanation |
Stars of many types and colors are visible in this Hubble Space Telescope vista [ http://heritage.stsci.edu/public/99dec2/lmcstarlinklist.html ] of the Large Magellanic Cloud [ http://antwrp.gsfc.nasa.gov/apod/ap980203.html ] (LMC). Over 10,000 stars [ http://www2.stx.com/cafe/qadir/astarsg.html ] are visible -- the brightest of which are giant stars [ http://antwrp.gsfc.nasa.gov/apod/ap990605.html ]. Were our Sun [ http://www.seds.org/nineplanets/nineplanets/sol.html ] 170,000 light-years distant and among these stars [ http://sciastro.astronomy.net/sci.astro.7.FAQ ], it would hardly be discernable [ http://heritage.stsci.edu/public/99dec2/lmcstarphil.html ]. By contrast, only a few thousand stars [ http://antwrp.gsfc.nasa.gov/htmltest/gifcity/msblues.html ] are individually visible at night with the unaided eye, and many of these lie within only a few hundred light-years. Typically, the light we see from nearby stars [ http://antwrp.gsfc.nasa.gov/apod/ap981025.html ] left during the age of our great-grand-parents, while light from LMC stars [ http://antwrp.gsfc.nasa.gov/apod/ap990221.html ] started its journey before the dawn of recorded [ http://news.bbc.co.uk/hi/english/sci/tech/newsid_334000/334517.stm ] human history. |
|
Total solar eclipse over Ant
…
nasa, nasanaturalhazards
The moon cast a long shadow
…
Eclipse2.AMO2003327
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2003-11-23 |
| creator |
NASA -- NASA Image Of The Day |
| identifier |
Eclipse2.AMO2003327 |
|
Total solar eclipse over Ant
…
nasa, nasanaturalhazards
The moon cast a long shadow
…
Eclipse2.AMO2003327
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2003-11-23 |
| creator |
NASA -- NASA Image Of The Day |
| identifier |
Eclipse2.AMO2003327 |
|
Phoebe Temperature Maps
PIA06403
Saturn
Composite Infrared Spectrome
…
| Title |
Phoebe Temperature Maps |
| Original Caption Released with Image |
A montage of maps of Saturn's moon Phoebe shows surface temperatures at various times of day as determined by the composite infrared spectrometer onboard Cassini during the June 11, 2004, Phoebe flyby. The asterisk on each map shows the location of the subsolar point, where the Sun is directly overhead. This point moves across the surface as Phoebe rotates. It is morning in regions to the left of the subsolar point, and afternoon in regions to the right. Like a newspaper weather map, different colors indicate different temperatures, though Phoebe's temperatures are distinctly cooler than even the coldest January day on Earth. Equatorial temperatures peak in the early afternoon near 112 Kelvin (-257 Fahrenheit), plunging to 78 Kelvin (-319 Fahrenheit) before dawn, and are even colder at higher latitudes. The large day/night temperature contrasts imply that Phoebe's surface is covered in loose dust or ice particles that store little heat and thus cool off rapidly at night. Regions of Phoebe's surface that were not observed are shown in black. Most of the maps show the effect on surface temperatures of the large crater-like depression seen in Cassini's visible-wavelength images of Phoebe, which is located just left of center in these maps. Crater walls that are shadowed and cold in the early morning in the first map are sunlit and warm in the late afternoon in the final map. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Office of Space Science, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md. For more information, about the Cassini-Huygens mission visit, http://saturn.jpl.nasa.gov [ http://saturn.jpl.nasa.gov/ ] and the Cassini imaging team home page, http//cirs.gsfc.nasa.gov/ [ http://cirs.gsfc.nasa.gov/ ]. |
|
MGS MOC Coverage of Mars Pol
…
PIA02310
Sol (our sun)
Mars Orbiter Camera
| Title |
MGS MOC Coverage of Mars Polar Lander Region |
| Original Caption Released with Image |
. The selection criteria were to find a place that was relatively flat and relatively smooth, but which displayed characteristics of the south polar layered materials. The inset (upper left) shows the location of the landing zone with respect to the south polar residual (year-round) ice cap. The base map used here is a mosaic of Viking Orbiter images from the U.S. Geological Survey. Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO., High-resolution views of the Mars Polar Lander [ http://www.marspolarlander.com/ ] landing zone were essential to the selection of a safe place for the December 3, 1999, landing to occur. The Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) took its first pictures of the landing zone in December 1997 [ http://www.msss.com/mars_images/3_9_98_release/7200/index.html ] and January 1998 [ http://www.msss.com/mars_images/3_9_98_release/9500/index.html ]. After that time, the south polar region was not accessible to the camera until June 1999, when the south polar winter was ending and the sun began to dawn on this region once again. Since the beginning of June 1999, an intense period of imaging has been conducted over the landing zone so that a safe site could be found. The final site has now been identified, and the pictures shown here give some idea of what the Mars Polar Lander will encounter a little more than three months from now. This figure shows the zone originally proposed by the Mars Volatiles and Climate Surveyor (MVACS) [ http://mvacs.ess.ucla.edu/ ] science team for the Mars Polar Lander mission, which spanned the region from 72° to 78°S latitude and 170° to 230°W longitude. The thin white boxes and lines crossing the proposed zone outline MOC images taken between the first week in June 1999 and the first week in August 1999. The longest images were taken at 12 by 18 meters (39 by 59 feet) per pixel, there are three sets of long images, each taken during a given week in June as the terminator (the line separating "night" from "day") moved south across the landing zone. Smaller swaths represent images at higher resolution. The best resolution so far achieved is about 4 meters (13 ft) per pixel, better images will be taken in September and October as the sun rises farther and the surface becomes better illuminated. This figure shows the location of the primary (blue) and secondary (white) landing ellipses, which were selected on the basis of interpretation of the MGS data, in particular data from the Mars Orbiter Laser Altimeter [ http://ltpwww.gsfc.nasa.gov/tharsis/98lander.html ] and the Mars Orbiter Camera [ http://www.msss.com/mars_images/index.html ] |
|
Martian Sunrise at Utopia Pl
…
PIA00576
Sol (our sun)
Camera 2
| Title |
Martian Sunrise at Utopia Planitia |
| Original Caption Released with Image |
A Martian sunrise was captured in this Viking 2 Lander picture taken June 14, 1978, at the spacecraft's Utopia Planitia landing site. The data composing this image were acquired just as the Sun peaked over the horizon on the Lander's 631st sol (Martian solar day). Pictures taken at dawn (or dusk) are quite dark except where the sky is brightened above the Sun's position. The glow in the sky results as light from the Sun is scattered and preferentially absorbed by tiny particles of dust and ice in the atmosphere. When the Viking cameras are calibrated for darker scenes, the "sky glow" tends to saturate their sensitivity and produce the bright regions seen here. The "banding" and color separation effects are also artifacts, rather than real features, and are introduced because the cameras are not able to record continuous gradations of light. The cameras must represent such gradations in steps (bands) of brightness and color, and the process sometimes produces some "false" colors within the bands. The scattering of light closest to the Sun's position tends to enhance blue wavelengths. The narrowing sky glow nearer the horizon above the Sun's position occurs as a result of light extinction. At that elevation, the optical path of sunlight through the atmosphere is at its longest penetration angle, and a substantial portion of the light is simply prevented from reaching the cameras by the dust, ice particles and other material in its way. NASA's Langley Research Center was the primary and extended mission manager, JPL assumed management for continued mission operations. |
|
KENNEDY SPACE CENTER, FLA. -
…
| Description |
KENNEDY SPACE CENTER, FLA. - Against a pre-dawn sky on Launch Pad 17-B at Cape Canaveral Air Force Station, the STEREO spacecraft is lifted alongside the mobile service tower. In the tower, STEREO will be mated with its launch vehicle, a Boeing Delta II rocket. STEREO stands for Solar Terrestrial Relations Observatory and comprises two spacecraft. The STEREO mission is the first to take measurements of the sun and solar wind in 3-dimension. This new view will improve our understanding of space weather and its impact on the Earth. The STEREO mission is managed by Goddard Space Flight Center. The Applied Physics Laboratory designed and built the spacecraft. The laboratory will maintain command and control of the observatories throughout the mission, while NASA tracks and receives the data, determines the orbit of the satellites, and coordinates the science results. STEREO is expected to lift off Oct. 25. Photo credit: NASA/George Shelton |
| Release Date |
10/11/2006 |
|
KENNEDY SPACE CENTER, FLA. -
…
| Description |
KENNEDY SPACE CENTER, FLA. - Against a pre-dawn sky on Launch Pad 17-B at Cape Canaveral Air Force Station, the STEREO spacecraft is lifted up toward the platform on the mobile service tower. In the tower, STEREO will be mated with its launch vehicle, a Boeing Delta II rocket. STEREO stands for Solar Terrestrial Relations Observatory and comprises two spacecraft. The STEREO mission is the first to take measurements of the sun and solar wind in 3-dimension. This new view will improve our understanding of space weather and its impact on the Earth. The STEREO mission is managed by Goddard Space Flight Center. The Applied Physics Laboratory designed and built the spacecraft. The laboratory will maintain command and control of the observatories throughout the mission, while NASA tracks and receives the data, determines the orbit of the satellites, and coordinates the science results. STEREO is expected to lift off Oct. 25. Photo credit: NASA/George Shelton |
| Release Date |
10/11/2006 |
|
|
