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Alien Asteroid Belt Compared
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| Title |
Alien Asteroid Belt Compared to our Own |
| Description |
This artist's concept illustrates what the night sky might look like from a hypothetical alien planet in a star system with an asteroid belt 25 times as massive as the one in our own solar system (alien system above, ours below). NASA's Spitzer Space Telescope found evidence for such a belt around the nearby star called HD 69830, when its infrared eyes spotted dust, presumably from asteroids banging together. The telescope did not find any evidence for a planet in the system, but astronomers speculate one or more may be present. In our solar system, anybody observing the skies on a moonless night far from city lights can see the sunlight that is scattered by dust in our asteroid belt. Called zodiacal light and sometimes the "false dawn," this light appears as a dim band stretching up from the horizon when the Sun is about to rise or set. The light is faint enough that the disk of our Milky Way galaxy remains the most prominent feature in the sky. (The Milky Way disk is shown perpendicular to the zodiacal light in both pictures.) In contrast, the zodiacal light in the HD 69830 system would be 1,000 times brighter than our own, outshining even the Milky Way. |
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Alien Asteroid Belt Compared
…
| Title |
Alien Asteroid Belt Compared to our Own |
| Description |
This artist's concept illustrates what the night sky might look like from a hypothetical alien planet in a star system with an asteroid belt 25 times as massive as the one in our own solar system (alien system above, ours below). NASA's Spitzer Space Telescope found evidence for such a belt around the nearby star called HD 69830, when its infrared eyes spotted dust, presumably from asteroids banging together. The telescope did not find any evidence for a planet in the system, but astronomers speculate one or more may be present. In our solar system, anybody observing the skies on a moonless night far from city lights can see the sunlight that is scattered by dust in our asteroid belt. Called zodiacal light and sometimes the "false dawn," this light appears as a dim band stretching up from the horizon when the Sun is about to rise or set. The light is faint enough that the disk of our Milky Way galaxy remains the most prominent feature in the sky. (The Milky Way disk is shown perpendicular to the zodiacal light in both pictures.) In contrast, the zodiacal light in the HD 69830 system would be 1,000 times brighter than our own, outshining even the Milky Way. |
|
Alien Asteroid Belt Compared
…
| Title |
Alien Asteroid Belt Compared to our Own |
| Description |
This artist's concept illustrates what the night sky might look like from a hypothetical alien planet in a star system with an asteroid belt 25 times as massive as the one in our own solar system (alien system above, ours below). NASA's Spitzer Space Telescope found evidence for such a belt around the nearby star called HD 69830, when its infrared eyes spotted dust, presumably from asteroids banging together. The telescope did not find any evidence for a planet in the system, but astronomers speculate one or more may be present. In our solar system, anybody observing the skies on a moonless night far from city lights can see the sunlight that is scattered by dust in our asteroid belt. Called zodiacal light and sometimes the "false dawn," this light appears as a dim band stretching up from the horizon when the Sun is about to rise or set. The light is faint enough that the disk of our Milky Way galaxy remains the most prominent feature in the sky. (The Milky Way disk is shown perpendicular to the zodiacal light in both pictures.) In contrast, the zodiacal light in the HD 69830 system would be 1,000 times brighter than our own, outshining even the Milky Way. |
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August 2006: View of the Pla
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| Description |
August 2006: View of the Planets |
| Full Description |
Just before the eastern sky brightens with sunrise, three planets and the waning crescent moon join the starry twilight tapestry. Then, as the bright stars of Gemini and Orion fade with oncoming dawn, the planets rise and shine. About 45 minutes before sunrise on Aug. 20 to 22 the planets Venus, Mercury and Saturn dance on the ecliptic -- the plane of Earth's orbit and the imaginary line tracing it in the sky. The sun, moon and planets appear to move along this line. Venus, rising an hour and a half before sunrise, is the easiest to see in the morning sky. Two hundred forty-one million kilometers (150 million miles) distant, Venus is Earth-sized. Mercury, at a distance of 183 million kilometers (114 million miles), is the fastest and smallest of the inner planets and appears brighter than the more distant Saturn. Saturn, 1,517 million kilometers (943 million miles) distant, was at conjunction with the sun just two weeks ago and now rises nearly an hour before sunrise. On Aug. 26 and 27, Saturn pairs with much brighter Venus at dawn. What other planets can we see in late August? Mars sets 45 minutes after sunset by month's end but is lost from view in the twilight, while brilliant Jupiter remains prominent as the only planet visible for a few hours during the late August evenings. Credit: NASA/JPL |
| Date |
August 18, 2006 |
|
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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Hubble Provides the First Im
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| Title |
Hubble Provides the First Images of Saturn's Aurorae |
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Hubble Surveys Dying Stars i
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| Title |
Hubble Surveys Dying Stars in Nearby Galaxy |
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Hubble Images of Asteroids H
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| Title |
Hubble Images of Asteroids Help Astronomers Prepare for Spacecraft Visit |
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Hubble Images of Asteroids H
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| Title |
Hubble Images of Asteroids Help Astronomers Prepare for Spacecraft Visit |
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Hubble Images of Asteroids H
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| Title |
Hubble Images of Asteroids Help Astronomers Prepare for Spacecraft Visit |
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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 |
|
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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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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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
…
| 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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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 ]. |
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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). |
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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 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 ]. |
|
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 |
|
Here Comes Comet Hartley 2!
nasa, solarsystemcollection
A pale green interloper amon
…
484976main_hartley2_sept2010
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2010-09-29 |
| creator |
NASA |
| identifier |
484976main_hartley2_sept2010 |
|
Solar Eclipse over Antarctic
…
nasa, nasaimageofthedaygalle
…
The moon cast a long shadow
…
Eclipse_Amo2003327
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2003-11-23 |
| creator |
NASA -- Image courtesy Jacques Descloitres, rapidfire.sci.gsfc.nasa.gov MODIS Rapid Response Team at NASA GSFC |
| identifier |
Eclipse_Amo2003327 |
|
The Dawn of a New Solar Cycl
…
nasa, nasaimageofthedaygalle
…
* eoimages.gsfc.nasa.gov/ima
…
sunspot_10891
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2008-01-04 |
| creator |
NASA -- NASA Image Of The Day |
| identifier |
sunspot_10891 |
|
Asymetric Aurora: Image of t
…
nasa, nasaimageofthedaygalle
…
All day long, a steady strea
…
aurora_2002296
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2002-10-23 |
| creator |
NASA -- Images courtesy Timothy J. Stubbs, NASA GSFC ssed.gsfc.nasa.gov/ Solar System Exploration Division |
| identifier |
aurora_2002296 |
|
Pre-Dawn Temperatures on Gan
…
PIA01145
Jupiter
Photopolarimeter-Radiometer
| Title |
Pre-Dawn Temperatures on Ganymede |
| Original Caption Released with Image |
This infrared image of Jupiter's moon Ganymede, showing heat radiation from its surface at a wavelength of 27 microns (millionths of a meter), provides the best view yet of pre-dawn temperatures on Ganymede. Temperatures, derived from the brightness of the infrared radiation, can be determined from the colors by reference to the scale at the bottom of the image. The image, taken by NASA's Galileo spacecraft, shows half of Ganymede's disk as seen by the approaching spacecraft. Longitudes covered range from 340 on the right of the image, through longitude zero (the direction facing Jupiter) to longitude 60 near Ganymede's limb on the left. The morning terminator, near longitude 15, curves through the middle of the image, separating areas experiencing the last hours of the long (3.5 Earth day) Ganymede night, on the left, from areas that are warming up in the morning sunshine, on the right. Ganymede's north pole is in the upper right corner of the image, and the south pole is in the lower right. Ganymede rotates from left to right. Nighttime temperatures, shown in blue and purple colors, are in the range 85 - 100 Kelvin (-306 to -279 F). The surface cools steadily during the night, so the warmest nighttime temperatures are on the left side of the disk, and temperatures drop towards the dawn terminator on the right, before warming rapidly once the sun rises (the red, yellow and white areas on the far right). Study of the rate of nighttime cooling and the rate of post-sunrise warming, will provide information about Ganymede's surface properties. The image was taken with Galileo's PPR (Photopolarimeter-Radiometer) instrument on the spacecraft's seventh orbit around Jupiter, from a range of about 190,000 kilometers (118,060 miles). Surface temperatures derived from the strength of infrared radiation, as was done here, are called "brightness temperatures", and may be slightly in error. The PPR instrument builds up an image by slowly scanning across the target over a period of up to one hour. The motion of Galileo relative to Ganymede during this time causes distortions in the satellite shape on the image, which therefore appears slightly non-circular. The small overlapping circles that make up the image show the size of the area, about 450 kilometers (280 miles) across, covered by each individual PPR measurement. Blue spots in the dark sky in the left-hand portion of the image are due to noise. JPL manages the Galileo mission for NASA's Office of Space Science, Washington, D.C. |
|
Earth - Moon Conjunction
PIA00134
Sol (our sun)
Solid-State Imaging
| Title |
Earth - Moon Conjunction |
| Original Caption Released with Image |
On December 16, 1992, 8 days after its encounter with Earth, the Galileo spacecraft looked back from a distance of about 6.2 million kilometers (3.9 million miles) to capture this remarkable view of the Moon in orbit about Earth. The composite photograph was constructed from images taken through visible (violet, red) and near-infrared (1.0-micron) filters. The Moon is in the foreground, its orbital path is from left to right. Brightly colored Earth contrasts strongly with the Moon, which reacts only about one-third as much sunlight as our world. To improve the visibility of both bodies, contrast and color have been computer enhanced. At the bottom of Earth's disk, Antarctica is visible through clouds. The Moon's far side can also be seen. The shadowy indentation in the Moon's dawn terminator--the boundary between its dark and lit sides--is the South Pole-Aitken Basin, one of the largest and oldest lunar impact features. This feature was studied extensively by Galileo during the first Earth flyby in December 1990. |
|
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/ ]. |
|
Galileo Optical Experiment (
…
PIA00230
Sol (our sun)
Solid-State Imaging
| Title |
Galileo Optical Experiment (GOPEX) |
| Original Caption Released with Image |
Two sets of laser pulses transmitted from Earth to a spacecraft over a distance of 1.4 million kilometers (870,000 miles) in a communications experiment are shown in this long-exposure image made by the Galileo spacecraft's imaging system. In the image, taken on Dec. 10, second day of the 8-day experiment, the sunlit part of the planet (west central United States) is to the right, the night side to the left. The camera was scanned from bottom to top of the frame (approximately south to north), smearing terrain features but showing individual pulses. The five larger spots in a vertical column near the pre-dawn centerline of the frame represent pulses from the U.S. Air Force Phillips Laboratory's Starfire Optical Range near Albuquerque, NM, at a pulse rate of 10 Hz. Those to the left are from the Jet Propulsion Laboratory's Table Mountain Observatory near Wrightwood, CA, at a rate of 15 Hz. Spots near the day/night terminator to the right are noise events not associated with the laser transmissions. The experiment, called GOPEX (Galileo Optical Experiment), is demonstrating a laser "uplink" from Earth to spacecraft. Laser "downlinks" may be used in the future to send large volumes of data from spacecraft to Earth. The experiment is operated by JPL's Tracking and Data Acquisition Technology Development Office for NASA's Office of Space Communications Advanced Systems Proqram. |
|
Earth - Departing Image by G
…
PIA00232
Sol (our sun)
Solid-State Imaging
| Title |
Earth - Departing Image by Galileo |
| Original Caption Released with Image |
This color image of the Earth was taken by the Galileo spacecraft on December 11 as it departed on its 3-year flight to Jupiter, about 2 1/2 days after the second Earth flyby. The distance to Earth is about 1.9 million kilometers (1.2 million miles). Antarctica is visible at the bottom of the image, and dawn is rising over the Pacific Ocean. The Galileo project, whose primary mission is the exploration of the Jupiter system in 1995-97, is managed for NASA's Office of Space Science and Applications by the Jet Propulsion Laboratory. |
|
01 January 2000 On The Red P
…
PIA02350
Sol (our sun)
Mars Orbiter Camera
| Title |
01 January 2000 On The Red Planet |
| Original Caption Released with Image |
As many people on Earth celebrated the dawn of a new year, a new century, and a new millennium, the Mars Global Surveyor(MGS) Mars Orbiter Camera (MOC) continued its journey that began with a proposal to NASA nearly 15 years earlier in 1985. As the clock rolled over to 2000 A.D., MOC was busily snapping its daily global weather maps and a variety of higher-resolution images such as the two shown here. On December 25, 1999, Mars passed its northern hemisphere winter solstice, marking the beginning of northern winter (and summer in the southern hemisphere). The pictures shown here are from the northern hemisphere among the mesas and buttes of the Nilosyrtis Mensae. This region, if it were on Earth, would be located in western Afghanistan around 33° N latitude, 63° E longitude (297°W on Mars). The picture was one of the first high resolution views of Mars taken by the MGS MOC on January 1, 2000, at 06:42 UTC (6 hours, 42 minutes after the new year began in the Greenwich Time Zone). The picture on the left is a context frame that covers an area 115 km (71 mi) across. The white box shows the location of the new millennium Mars image, which also appears on the right. This high resolution view shows a wide variety of surface textures caused mainly by unknown, possibly uniquely "martian" geologic processes. The view also includes small, bright, windblown drifts. The high resolution view covers an area 3 km across at a resolution of 4.5 meters (15 feet) per pixel. The sun illuminates both scenes from the lower left. The MGS MOC began taking pictures from Mars orbit in September 1997. It's primary mission will last through January 2001. After that, an extended mission might be approved by NASA--this would allow the camera to continue its activities well into 2002 or beyond. |
|
01 January 2000 On The Red P
…
PIA02350
Sol (our sun)
Mars Orbiter Camera
| Title |
01 January 2000 On The Red Planet |
| Original Caption Released with Image |
As many people on Earth celebrated the dawn of a new year, a new century, and a new millennium, the Mars Global Surveyor(MGS) Mars Orbiter Camera (MOC) continued its journey that began with a proposal to NASA nearly 15 years earlier in 1985. As the clock rolled over to 2000 A.D., MOC was busily snapping its daily global weather maps and a variety of higher-resolution images such as the two shown here. On December 25, 1999, Mars passed its northern hemisphere winter solstice, marking the beginning of northern winter (and summer in the southern hemisphere). The pictures shown here are from the northern hemisphere among the mesas and buttes of the Nilosyrtis Mensae. This region, if it were on Earth, would be located in western Afghanistan around 33° N latitude, 63° E longitude (297°W on Mars). The picture was one of the first high resolution views of Mars taken by the MGS MOC on January 1, 2000, at 06:42 UTC (6 hours, 42 minutes after the new year began in the Greenwich Time Zone). The picture on the left is a context frame that covers an area 115 km (71 mi) across. The white box shows the location of the new millennium Mars image, which also appears on the right. This high resolution view shows a wide variety of surface textures caused mainly by unknown, possibly uniquely "martian" geologic processes. The view also includes small, bright, windblown drifts. The high resolution view covers an area 3 km across at a resolution of 4.5 meters (15 feet) per pixel. The sun illuminates both scenes from the lower left. The MGS MOC began taking pictures from Mars orbit in September 1997. It's primary mission will last through January 2001. After that, an extended mission might be approved by NASA--this would allow the camera to continue its activities well into 2002 or beyond. |
|
Meteor Search by Spirit, Sol
…
PIA03613
Sol (our sun)
Panoramic Camera
| Title |
Meteor Search by Spirit, Sol 643 |
| Original Caption Released with Image |
, and Selsis et al. (2005) Nature, vol 435, p. 581). On Earth, some meteors come in "storms" or "showers" at predictable times of the year, like the famous Perseid meteor shower in August or the Leonid meteor shower in November. These "storms" happen when Earth passes through the same parts of space where comets sometimes pass. The meteors we see at these times are from leftover debris that was shed off of these comets. The same kind of thing is predicted for Mars, as well. Inspired by calculations about Martian meteor storms by meteor scientists from the University of Western Ontario in Canada and the Centre de Recherche en Astrophysique de Lyon in France, and also aided by other meteor research colleagues from NASA's Marshall Space Flight Center, scientists on the rover team planned some observations to try to detect predicted meteor storms in October and November, 2005. The views shown here are a composite of nine 60-second exposures taken with the panoramic camera on Spirit during night hours of sol 643 (Oct. 25, 2005), during a week when Mars was predicted to pass through a meteor stream associated with comet P/2001R1 LONEOS. Many stars can be seen in the images, appearing as curved "dash-dot" streaks. The star trails are curved because Mars is rotating while the camera takes the images. The dash-dot pattern is an artifact of taking an image for 60 seconds, then pausing about 10 seconds while the image is processed and stored by the rover's computer, then taking another image for 60 seconds, etc., for a total of about 10 minutes worth of "staring" at the night sky. Many stars from the southern constellations Octans and Pavonis can be seen in the images. The brightest ones in this view would be easily visible to the naked eye, but the faintest ones are slightly dimmer than the human eye can detect. In addition to the star trails, there are several smaller linear streaks, dots and splotches that are the trails left by cosmic rays hitting the camera detectors. Cosmic rays are high-energy particles that are created in the Sun and in other stars throughout our galaxy and travel through space in all directions. Some of them strike Earth or other planets, and ones that strike a digital camera detector can leave little tracks or splotches like those seen in these images. Because they come from all directions, some strike the detector face-on, and others strike at glancing angles. Some even skip across the detector like flat rocks skipped across a pond. These are very common phenomena to astronomers used to working with sensitive digital cameras like those in the Mars rovers, the Hubble Space Telescope, or other space probes, and while they can be a nuisance when taking pictures, they generally do not cause any lasting damage to the cameras. One streak in the image, crossing at an angle very different from the direction of the stars'"motion," might be a meteor trail or could be the mark of another cosmic ray. While hunting for meteors on Mars, Annotated Meteor Search by Spirit, Sol 643 The panoramic cameras on NASA's Mars Exploration Rovers are about as sensitive as the human eye at night. The cameras can see the same bright stars that we can see from Earth, and the same patterns of constellations dot the night sky. Scientists on the rover team have been taking images of some of these bright stars as part of several different projects. One project is designed to try to capture "shooting stars," or meteors, in the Martian night sky. "Meteoroids" are small pieces of comets and asteroids that travel through space and eventually run into a planet. On Earth, we can sometimes see meteoroids become brilliant, long "meteors" streaking across the night sky as they burn up from the friction in our atmosphere. Some of these meteors survive their fiery flight and land on the surface (or in the ocean) where, if found, they are called "meteorites." The same thing happens in the Martian atmosphere, and Spirit even accidentally discovered a meteor while attempting to obtain images of Earth in the pre-dawn sky back in March, 2004 (see http://marsrovers.jpl.nasa.gov/gallery/press/spirit/20040311a.html [ http://marsrovers.jpl.nasa.gov/gallery/press/spirit/20040311a.html ], is fun, ultimately the team wants to use the images and results for scientific purposes. These include helping to validate the models and predictions for interplanetary meteor storms, providing information on the rate of impacts of small meteoroids with Mars for comparison with rates for the Earth and Moon, assessing the rate and intensity of cosmic ray impact events in the Martian environment, and looking at whether some bright stars are being dimmed occasionally by water ice or dust clouds occurring at night during different Martian seasons. |
|
Meteor Search by Spirit, Sol
…
PIA03613
Sol (our sun)
Panoramic Camera
| Title |
Meteor Search by Spirit, Sol 643 |
| Original Caption Released with Image |
, and Selsis et al. (2005) Nature, vol 435, p. 581). On Earth, some meteors come in "storms" or "showers" at predictable times of the year, like the famous Perseid meteor shower in August or the Leonid meteor shower in November. These "storms" happen when Earth passes through the same parts of space where comets sometimes pass. The meteors we see at these times are from leftover debris that was shed off of these comets. The same kind of thing is predicted for Mars, as well. Inspired by calculations about Martian meteor storms by meteor scientists from the University of Western Ontario in Canada and the Centre de Recherche en Astrophysique de Lyon in France, and also aided by other meteor research colleagues from NASA's Marshall Space Flight Center, scientists on the rover team planned some observations to try to detect predicted meteor storms in October and November, 2005. The views shown here are a composite of nine 60-second exposures taken with the panoramic camera on Spirit during night hours of sol 643 (Oct. 25, 2005), during a week when Mars was predicted to pass through a meteor stream associated with comet P/2001R1 LONEOS. Many stars can be seen in the images, appearing as curved "dash-dot" streaks. The star trails are curved because Mars is rotating while the camera takes the images. The dash-dot pattern is an artifact of taking an image for 60 seconds, then pausing about 10 seconds while the image is processed and stored by the rover's computer, then taking another image for 60 seconds, etc., for a total of about 10 minutes worth of "staring" at the night sky. Many stars from the southern constellations Octans and Pavonis can be seen in the images. The brightest ones in this view would be easily visible to the naked eye, but the faintest ones are slightly dimmer than the human eye can detect. In addition to the star trails, there are several smaller linear streaks, dots and splotches that are the trails left by cosmic rays hitting the camera detectors. Cosmic rays are high-energy particles that are created in the Sun and in other stars throughout our galaxy and travel through space in all directions. Some of them strike Earth or other planets, and ones that strike a digital camera detector can leave little tracks or splotches like those seen in these images. Because they come from all directions, some strike the detector face-on, and others strike at glancing angles. Some even skip across the detector like flat rocks skipped across a pond. These are very common phenomena to astronomers used to working with sensitive digital cameras like those in the Mars rovers, the Hubble Space Telescope, or other space probes, and while they can be a nuisance when taking pictures, they generally do not cause any lasting damage to the cameras. One streak in the image, crossing at an angle very different from the direction of the stars'"motion," might be a meteor trail or could be the mark of another cosmic ray. While hunting for meteors on Mars, Annotated Meteor Search by Spirit, Sol 643 The panoramic cameras on NASA's Mars Exploration Rovers are about as sensitive as the human eye at night. The cameras can see the same bright stars that we can see from Earth, and the same patterns of constellations dot the night sky. Scientists on the rover team have been taking images of some of these bright stars as part of several different projects. One project is designed to try to capture "shooting stars," or meteors, in the Martian night sky. "Meteoroids" are small pieces of comets and asteroids that travel through space and eventually run into a planet. On Earth, we can sometimes see meteoroids become brilliant, long "meteors" streaking across the night sky as they burn up from the friction in our atmosphere. Some of these meteors survive their fiery flight and land on the surface (or in the ocean) where, if found, they are called "meteorites." The same thing happens in the Martian atmosphere, and Spirit even accidentally discovered a meteor while attempting to obtain images of Earth in the pre-dawn sky back in March, 2004 (see http://marsrovers.jpl.nasa.gov/gallery/press/spirit/20040311a.html [ http://marsrovers.jpl.nasa.gov/gallery/press/spirit/20040311a.html ], is fun, ultimately the team wants to use the images and results for scientific purposes. These include helping to validate the models and predictions for interplanetary meteor storms, providing information on the rate of impacts of small meteoroids with Mars for comparison with rates for the Earth and Moon, assessing the rate and intensity of cosmic ray impact events in the Martian environment, and looking at whether some bright stars are being dimmed occasionally by water ice or dust clouds occurring at night during different Martian seasons. |
|
Meteor Search by Spirit, Sol
…
PIA03615
Sol (our sun)
Panoramic Camera
| Title |
Meteor Search by Spirit, Sol 668 |
| Original Caption Released with Image |
Annotated Meteor Search by Spirit, Sol 668 The panoramic cameras on NASA's Mars Exploration Rovers are about as sensitive as the human eye at night. The cameras can see the same bright stars that we can see from Earth, and the same patterns of constellations dot the night sky. Scientists on the rover team have been taking images of some of these bright stars as part of several different projects. One project is designed to try to capture "shooting stars," or meteors, in the martian night sky. "Meteoroids" are small pieces of comets and asteroids that travel through space and eventually run into a planet. On Earth, we can sometimes see meteoroids become brilliant, long "meteors" streaking across the night sky as they burn up from the friction in our atmosphere. Some of these meteors survive their fiery flight and land on the surface (or in the ocean) where, if found, they are called "meteorites." The same thing happens in the martian atmosphere, and Spirit even accidentally discovered a meteor while attempting to obtain images of Earth in the pre-dawn sky back in March, 2004 (see http://marsrovers.jpl.nasa.gov/gallery/press/spirit/20040311a.html, and Selsis et al. (2005) Nature, vol 435, p. 581). On Earth, some meteors come in "storms" or "showers" at predictable times of the year, like the famous Perseid meteor shower in August or the Leonid meteor shower in November. These "storms" happen when Earth passes through the same parts of space where comets sometimes pass. The meteors we see at these times are from leftover debris that was shed off of these comets. The same kind of thing is predicted for Mars, as well. Inspired by calculations about Martian meteor storms by meteor scientists from the University of Western Ontario in Canada and the Centre de Recherche en Astrophysique de Lyon in France, and also aided by other meteor research colleagues from NASA's Marshall Space Flight Center, scientists on the rover team planned some observations to try to detect predicted meteor storms in October and November, 2005. The views shown here are a composite of nine 60-second exposures taken with the panoramic camera on Spirit during night hours of sol 668 (Nov. 18, 2005), during a week when Mars was predicted to pass through a meteor stream associated with Halley's comet. The south celestial pole is at the center of the frame. Many stars can be seen in the images, appearing as short, curved streaks forming arcs around the center point. The star trails are curved because Mars is rotating while the camera takes the images. The brightest stars in this view would be easily visible to the naked eye, but the faintest ones are slightly dimmer than the human eye can detect. In addition to the star trails, there are several smaller linear streaks, dots and splotches that are the trails left by cosmic rays hitting the camera detectors. Cosmic rays are high-energy particles that are created in the Sun and in other stars throughout our galaxy and travel, through space in all directions. Some of them strike Earth or other planets, and ones that strike a digital camera detector can leave little tracks or splotches like those seen in these images. Because they come from all directions, some strike the detector face-on, and others strike at glancing angles. Some even skip across the detector like flat rocks skipped across a pond. These are very common phenomena to astronomers used to working with sensitive digital cameras like those in the Mars rovers, the Hubble Space Telescope, or other space probes, and while they can be a nuisance when taking pictures, they generally do not cause any lasting damage to the cameras. Three of the streaks in the image, including one spanning most of the distance from the left edge of the frame to the center, might be meteor trails or could be the marks of other cosmic rays. While hunting for meteors on Mars is fun, ultimately the team wants to use the images and results for scientific purposes. These include helping to validate the models and predictions for interplanetary meteor storms, providing information on the rate of impacts of small meteoroids with Mars for comparison with rates for the Earth and Moon, assessing the rate and intensity of cosmic ray impact events in the Martian environment, and looking at whether some bright stars are being dimmed occasionally by water ice or dust clouds occurring at night during different Martian seasons. |
|
Meteor Search by Spirit, Sol
…
PIA03615
Sol (our sun)
Panoramic Camera
| Title |
Meteor Search by Spirit, Sol 668 |
| Original Caption Released with Image |
Annotated Meteor Search by Spirit, Sol 668 The panoramic cameras on NASA's Mars Exploration Rovers are about as sensitive as the human eye at night. The cameras can see the same bright stars that we can see from Earth, and the same patterns of constellations dot the night sky. Scientists on the rover team have been taking images of some of these bright stars as part of several different projects. One project is designed to try to capture "shooting stars," or meteors, in the martian night sky. "Meteoroids" are small pieces of comets and asteroids that travel through space and eventually run into a planet. On Earth, we can sometimes see meteoroids become brilliant, long "meteors" streaking across the night sky as they burn up from the friction in our atmosphere. Some of these meteors survive their fiery flight and land on the surface (or in the ocean) where, if found, they are called "meteorites." The same thing happens in the martian atmosphere, and Spirit even accidentally discovered a meteor while attempting to obtain images of Earth in the pre-dawn sky back in March, 2004 (see http://marsrovers.jpl.nasa.gov/gallery/press/spirit/20040311a.html, and Selsis et al. (2005) Nature, vol 435, p. 581). On Earth, some meteors come in "storms" or "showers" at predictable times of the year, like the famous Perseid meteor shower in August or the Leonid meteor shower in November. These "storms" happen when Earth passes through the same parts of space where comets sometimes pass. The meteors we see at these times are from leftover debris that was shed off of these comets. The same kind of thing is predicted for Mars, as well. Inspired by calculations about Martian meteor storms by meteor scientists from the University of Western Ontario in Canada and the Centre de Recherche en Astrophysique de Lyon in France, and also aided by other meteor research colleagues from NASA's Marshall Space Flight Center, scientists on the rover team planned some observations to try to detect predicted meteor storms in October and November, 2005. The views shown here are a composite of nine 60-second exposures taken with the panoramic camera on Spirit during night hours of sol 668 (Nov. 18, 2005), during a week when Mars was predicted to pass through a meteor stream associated with Halley's comet. The south celestial pole is at the center of the frame. Many stars can be seen in the images, appearing as short, curved streaks forming arcs around the center point. The star trails are curved because Mars is rotating while the camera takes the images. The brightest stars in this view would be easily visible to the naked eye, but the faintest ones are slightly dimmer than the human eye can detect. In addition to the star trails, there are several smaller linear streaks, dots and splotches that are the trails left by cosmic rays hitting the camera detectors. Cosmic rays are high-energy particles that are created in the Sun and in other stars throughout our galaxy and travel, through space in all directions. Some of them strike Earth or other planets, and ones that strike a digital camera detector can leave little tracks or splotches like those seen in these images. Because they come from all directions, some strike the detector face-on, and others strike at glancing angles. Some even skip across the detector like flat rocks skipped across a pond. These are very common phenomena to astronomers used to working with sensitive digital cameras like those in the Mars rovers, the Hubble Space Telescope, or other space probes, and while they can be a nuisance when taking pictures, they generally do not cause any lasting damage to the cameras. Three of the streaks in the image, including one spanning most of the distance from the left edge of the frame to the center, might be meteor trails or could be the marks of other cosmic rays. While hunting for meteors on Mars is fun, ultimately the team wants to use the images and results for scientific purposes. These include helping to validate the models and predictions for interplanetary meteor storms, providing information on the rate of impacts of small meteoroids with Mars for comparison with rates for the Earth and Moon, assessing the rate and intensity of cosmic ray impact events in the Martian environment, and looking at whether some bright stars are being dimmed occasionally by water ice or dust clouds occurring at night during different Martian seasons. |
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| General Description |
Exploration Imagery |
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KENNEDY SPACE CENTER, FLA. -
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| 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 |
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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 |
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