|
|
Sunset on an Alien World
| Title |
Sunset on an Alien World |
| Description |
This artist's animation 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. 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. The movie begins at dusk on the imaginary world, when HD 69830, like our Sun, has begun to set over the horizon. Time is sped up to show the onset of night and the appearance of a brilliant band of light. This light comes from dust in a massive asteroid belt, which scatters sunlight. In our solar system, anybody observing the skies on a moonless night far from city lights can see this light. Called zodiacal light and sometimes the "false dawn," it appears as a faint band stretching up from the horizon when the Sun is about to rise or set. The zodiacal light in the HD 69830 system would be 1,000 times brighter than our own, outshining even the disk of our Milky Way galaxy (shown perpendicular to the asteroid-belt light). |
|
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. |
|
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. |
|
Neutral Gas Cloud Around Tit
…
| Description |
Here on the Gallery page you can find the very latest images, videos and products from the Cassini-Huygens mission to Saturn, including the spectacular launch, spacecraft assembly and the exciting trip to Saturn. |
| Full Description |
Images from the magnetospheric imaging instrument and the ion and neutral camera onboard the Cassini spacecraft reveal aspects of the interactions between Saturn's dynamic population of hot energetic ions and the clouds of cold neutral atoms. Future observations may further explain the relationships between these interactions. The most recent image of Titan reveals the emission of high-speed neutral atoms from a globular region approximately 70,000 kilometers (43,496 miles) in diameter, clearly centered on Titan. It is only 1/25 as bright as the region seen toward dawn during Saturn orbit insertion, even though Cassini is now closer to Titan. There is an extended emission region around the Titan cloud, but it is much dimmer than the Titan cloud itself and even dimmer compared to the emission seen in the dawn direction at orbit insertion. In this image, the X marks the direction toward the Sun, the Y marks the direction toward Saturn's dawn, and the Z marks Saturn's rotation axis. The dot in the center marks Titan. 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 magnetospheric imaging instrument team is based at Johns Hopkins University, Laurel, Md. For more information about the Cassini-Huygens mission, visit http://saturn.jpl.nasa.gov and the instrument team's home page, http://sd-www.jhuapl.edu/CASSINI/index.html . Image Credit: NASA/JPL/JHU/APL/Max-Plank-Institut f¿r Aeronomie/University of Maryland/University of Kansas/University of Arizona/CESR/Bell Laboratories |
|
August 2006: View of the Pla
…
| 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 |
|
Clouds at Dawn
| Description |
Clouds at Dawn |
| Full Description |
Saturn's clouds billow and swirl in the turbulent zones of shear between eastward- and westward-flowing jets. This view looks toward the terminator on Saturn, where night gives way to day. The image was taken using a spectral filter sensitive to wavelengths of infrared light centered at 728 nanometers. The image was obtained with the Cassini spacecraft wide-angle camera on Aug. 16, 2006 at a distance of approximately 338,000 kilometers (210,000 miles) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 67 degrees. Image scale is 17 kilometers (10 miles) per pixel. 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 mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . Credit: NASA/JPL/Space Science Institute |
| Date |
September 20, 2006 |
|
Dawn for Odysseus
| Description |
Dawn for Odysseus |
| Full Description |
The eastern rim of the large crater Odysseus is visible along the terminator in this image of Saturn's moon Tethys. This enormous impact feature is the largest on Tethys, at approximately 450 kilometers (280 miles) across. The shadowy rim of another smaller crater can be seen at the bottom. Tethys is 1,060 kilometers (659 miles) across. This Cassini view shows principally the leading hemisphere of Tethys. The image was taken in visible light with the Cassini spacecraft narrow angle camera on Dec. 18, 2004, at a distance of 1.7 million kilometers (1.1 million miles) from Tethys and at a Sun-Tethys-spacecraft, or phase, angle of 94 degrees. The image scale is about 10 kilometers (6 miles) per pixel. The image has been magnified by a factor of two and contrast enhanced to aid visibility. 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 mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute, Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . For images visit the Cassini imaging team home page http://ciclops.org *Credit*: NASA/JPL/Space Science Institute |
| Date |
January 26, 2005 |
|
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 |
|
Dawn at the Huygens Site
| Description |
Titan's equatorial latitudes are distinctly different in character from its south polar region, as this image shows. |
| Full Description |
Titan's equatorial latitudes are distinctly different in character from its south polar region, as this image shows. The dark terrain, presumably lowland, seen here does not extend much farther south than about 30 degrees South. The successful Huygens probe landed in such a region. The Huygens probe is rotating into the light here, seeing the dawn of a new day. The bright region toward the right side of Titan's disk is Xanadu. This area is thought to consist of upland terrain that is relatively uncontaminated by the dark material that fills the lowland regions. Near the moon's south pole, and just eastward of the terminator, is the dark feature identified by imaging scientists as the best candidate (so far) for a past or present hydrocarbon lake on Titan (see Clouds in the Distance). Farther east of the lake-like feature, bright clouds arc around the pole. These clouds occupy a latitude range that is consistent with previously-seen convective cloud activity on Titan. Titan is Saturn's largest moon, at 5,150 kilometers (3,200 miles) across. The image was taken with the Cassini spacecraft narrow angle camera on July 7, 2005, at a distance of approximately 1.3 million kilometers (800,000 miles) from Titan and at a Sun-Titan-spacecraft, or phase, angle of 60 degrees. The image was obtained using a filter sensitive to wavelengths of infrared light centered at 938 nanometers. The image scale is 7 kilometers (5 miles) per pixel. 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 mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . Credit: NASA/JPL/Space Science Institute |
| Date |
August 16, 2005 |
|
Hubble Provides the First Im
…
| Title |
Hubble Provides the First Images of Saturn's Aurorae |
|
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 |
|
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 |
|
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. |
|
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. |
|
Comet McNaught Heads for the
…
| 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. |
|
Jupiter, Vesta, and the Milk
…
| 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. |
|
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. |
|
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). |
|
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. |
|
South Melea Planum, By The D
…
PIA02021
Sol (our sun)
Mars Orbiter Camera
| Title |
South Melea Planum, By The Dawn's Early Light |
| Original Caption Released with Image |
MOC "sees" by the dawn's early light! This picture was taken over the high southern polar latitudes during the first week of May 1999. The area shown is currently in southern winter darkness. Because sunlight is scattered over the horizon by aerosols--dust and ice particles--suspended in the atmosphere, sufficient light reaches regions within a few degrees of the terminator (the line dividing night and day) to be visible to the Mars Global Surveyor Mars Orbiter Camera (MOC) when the maximum exposure settings are used. This image shows a bright, wispy cloud hanging over southern Malea Planum. This cloud would not normally be visible, since it is currently in darkness. At the time this picture was taken, the sun was more than 5.7° below the northern horizon. The scene covers an area 3 kilometers (1.9 miles) wide. Again, the illumination is from the top. In this frame, the surface appears a relatively uniform gray. At the time the picture was acquired, the surface was covered with south polar wintertime frost. The highly reflective frost, in fact, may have contributed to the increased visibility of this surface. This "twilight imaging" technique for viewing Mars can only work near the terminator, thus in early May only regions between about 67°S and 74°S were visible in twilight images in the southern hemisphere, and a similar narrow latitude range could be imaged in the northern hemisphere. MOC cannot "see" in the total darkness of full-borne night. 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. |
|
South Melea Planum, By The D
…
PIA02020
Sol (our sun)
Mars Orbiter Camera
| Title |
South Melea Planum, By The Dawn's Early Light |
| Original Caption Released with Image |
MOC "sees" by the dawn's early light! This picture was taken over the high southern polar latitudes during the first week of May 1999. The area shown is currently in southern winter darkness. Because sunlight is scattered over the horizon by aerosols--dust and ice particles--suspended in the atmosphere, sufficient light reaches regions within a few degrees of the terminator (the line dividing night and day) to be visible to the Mars Global Surveyor Mars Orbiter Camera (MOC) when the maximum exposure settings are used. This picture shows a polygonally-patterned surface on southern Malea Planum. At the time the picture was taken, the sun was more than 4.5° below the northern horizon. The scene covers an area 3 kilometers (1.9 miles) wide, with the illumination from the top of the picture. In this frame, the surface appears a relatively uniform gray. At the time the picture was acquired, the surface was covered with south polar wintertime frost. The highly reflective frost, in fact, may have contributed to the increased visibility of this surface. This "twilight imaging" technique for viewing Mars can only work near the terminator, thus in early May only regions between about 67°S and 74°S were visible in twilight images in the southern hemisphere, and a similar narrow latitude range could be imaged in the northern hemisphere. MOC cannot "see" in the total darkness of full-borne night. 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. |
|
A New Year for Jupiter and I
…
PIA02879
Sol (our sun)
Imaging Science Subsystem
| Title |
A New Year for Jupiter and Io |
| Original Caption Released with Image |
The Galilean satellite Io floats above the cloudtops of Jupiter in this image captured on the dawn of the new millennium, January 1, 2001 10:00 UTC (spacecraft time), two days after Cassini's closest approach. The image is deceiving: there are 350,000 kilometers -- roughly 2.5 Jupiters -- between Io and Jupiter's clouds. Io is the size of our Moon, and Jupiter is very big. |
|
Clouds at Dawn
PIA08263
Sol (our sun)
Imaging Science Subsystem -
…
| Title |
Clouds at Dawn |
| Original Caption Released with Image |
Saturn's clouds billow and swirl in the turbulent zones of shear between eastward- and westward-flowing jets. This view looks toward the terminator on Saturn, where night gives way to day. The image was taken using a spectral filter sensitive to wavelengths of infrared light centered at 728 nanometers. The image was obtained with the Cassini spacecraft wide-angle camera on Aug. 16, 2006 at a distance of approximately 338,000 kilometers (210,000 miles) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 67 degrees. Image scale is 17 kilometers (10 miles) per pixel. 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 mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov/home/index.cfm [ http://saturn.jpl.nasa.gov ]. The Cassini imaging team homepage is at http://ciclops.org [ http://ciclops.org ]. |
|
Temperature Behavior of Poss
…
PIA09930
Sol (our sun)
Thermal Emission Imaging Sys
…
| Title |
Temperature Behavior of Possible Cave Skylight on Mars |
| Original Caption Released with Image |
Figure 1 Each of the three images in this set covers the same patch of Martian ground, centered on a possible cave skylight informally called "Annie," which has a diameter about double the length of a football field. The Thermal Emission Imaging System camera on NASA's Mars Odyssey orbiter took all three, gathering information that the hole is cooler than surrounding surface in the afternoon and warmer than the surrounding surface at night. This is thermal behavior that would be expected from an opening into an underground space. The left image was taken in visible-wavelength light (figure 1). The other two were taken in thermal infrared wavelengths, indicating the relative temperatures of features in the image. The center image is from mid-afternoon. The hole is warmer than the shadows of nearby pits to the north and south, while cooler than sunlit surfaces. The thermal image at right was taken in the pre-dawn morning, about 4 a.m. local time. At that hour, the hole is warmer than all nearby surfaces. Annie and six other features with similar thermal behavior are on the northern slope of a high Martian volcano named Arsia Mons, which is at 9 degrees south latitude, 239 degrees east longitude. Mars Odyssey is managed by NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena, for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft. The orbiter's Thermal Emission Imaging System was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing, Santa Barbara, Calif., and is operated by Arizona State University. |
|
Temperature Behavior of Poss
…
PIA09930
Sol (our sun)
Thermal Emission Imaging Sys
…
| Title |
Temperature Behavior of Possible Cave Skylight on Mars |
| Original Caption Released with Image |
Figure 1 Each of the three images in this set covers the same patch of Martian ground, centered on a possible cave skylight informally called "Annie," which has a diameter about double the length of a football field. The Thermal Emission Imaging System camera on NASA's Mars Odyssey orbiter took all three, gathering information that the hole is cooler than surrounding surface in the afternoon and warmer than the surrounding surface at night. This is thermal behavior that would be expected from an opening into an underground space. The left image was taken in visible-wavelength light (figure 1). The other two were taken in thermal infrared wavelengths, indicating the relative temperatures of features in the image. The center image is from mid-afternoon. The hole is warmer than the shadows of nearby pits to the north and south, while cooler than sunlit surfaces. The thermal image at right was taken in the pre-dawn morning, about 4 a.m. local time. At that hour, the hole is warmer than all nearby surfaces. Annie and six other features with similar thermal behavior are on the northern slope of a high Martian volcano named Arsia Mons, which is at 9 degrees south latitude, 239 degrees east longitude. Mars Odyssey is managed by NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena, for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft. The orbiter's Thermal Emission Imaging System was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing, Santa Barbara, Calif., and is operated by Arizona State University. |
|
Pre-Dawn Martian Sky
PIA00918
Sol (our sun)
Imager for Mars Pathfinder
| Title |
Pre-Dawn Martian Sky |
| Original Caption Released with Image |
On Sol 39 there were wispy blue clouds in the pre-dawn sky of Mars, as seen by the Imager for Mars Pathfinder (IMP). The color image was made by taking blue, green, and red images and then combining them into a single color image. The clouds appear to have a bluish side and a greenish side because they moved (in the wind from the northeast) between images. This picture was made an hour and twenty minutes before sunrise -- the sun is not shining directly on the water ice clouds, but they are illuminated by the dawn twilight. Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator. |
|
Pre-Dawn Clouds Over Mars
PIA00919
Sol (our sun)
Imager for Mars Pathfinder
| Title |
Pre-Dawn Clouds Over Mars |
| Original Caption Released with Image |
These are more wispy blue clouds from Sol 39 as seen by the Imager for Mars Pathfinder. The bright clouds near the bottom are about 30 degrees above the horizon. The clouds are believed to be at an altitude of 10 to 15 km, and are thought to be made of small water ice particles. The picture was taken about 35 minutes before sunrise. Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator. |
|
Alien Asteroid Belt Compared
…
PIA07853
| Title |
Alien Asteroid Belt Compared to our Own |
| Original Caption Released with Image |
Figure 1: Band of Light Comparison 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, see Figure 1). 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. The movie begins at dusk on the imaginary world, when HD 69830, like our Sun, has begun to set over the horizon. Time is sped up to show the onset of night and the appearance of a brilliant band of light. This light comes from dust in a massive asteroid belt, which scatters sunlight. 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
…
PIA07853
| Title |
Alien Asteroid Belt Compared to our Own |
| Original Caption Released with Image |
Figure 1: Band of Light Comparison 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, see Figure 1). 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. The movie begins at dusk on the imaginary world, when HD 69830, like our Sun, has begun to set over the horizon. Time is sped up to show the onset of night and the appearance of a brilliant band of light. This light comes from dust in a massive asteroid belt, which scatters sunlight. 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. |
|
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/ ]. |
|
Neutral Gas Cloud Around Tit
…
PIA06409
Saturn
Ion and Neutral Mass Spectro
…
| Title |
Neutral Gas Cloud Around Titan |
| Original Caption Released with Image |
Images from the magnetospheric imaging instrument and the ion and neutral camera onboard the Cassini spacecraft reveal aspects of the interactions between Saturn's dynamic population of hot energetic ions and the clouds of cold neutral atoms. Future observations may further explain the relationships between these interactions. The most recent image of Titan reveals the emission of high-speed neutral atoms from a globular region approximately 70,000 kilometers (43,496 miles) in diameter, clearly centered on Titan. It is only 1/25 as bright as the region seen toward dawn during Saturn orbit insertion, even though Cassini is now closer to Titan. There is an extended emission region around the Titan cloud, but it is much dimmer than the Titan cloud itself and even dimmer compared to the emission seen in the dawn direction at orbit insertion. In this image, the X marks the direction toward the Sun, the Y marks the direction toward Saturn's dawn, and the Z marks Saturn's rotation axis. The dot in the center marks Titan. 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 magnetospheric imaging instrument team is based at Johns Hopkins University, Laurel, Md. For more information, about the Cassini-Huygens mission visit, http://saturn.jpl.nasa.gov [ http://saturn.jpl.nasa.gov/ ] and the Cassini Magnetospheric Imaging Instrument home page, http://sd-www.jhuapl.edu/CASSINI/ [ http://sd-www.jhuapl.edu/CASSINI/ ]. |
|
Dawn at the Huygens Site
PIA07565
Saturn
Imaging Science Subsystem -
…
| Title |
Dawn at the Huygens Site |
| Original Caption Released with Image |
Titan's equatorial latitudes are distinctly different in character from its south polar region, as this image shows. The dark terrain, presumably lowland, seen here does not extend much farther south than about 30 degrees South. The successful Huygens probe landed in such a region. The Huygens probe is rotating into the light here, seeing the dawn of a new day. The bright region toward the right side of Titan's disk is Xanadu. This area is thought to consist of upland terrain that is relatively uncontaminated by the dark material that fills the lowland regions. Near the moon's south pole, and just eastward of the terminator, is the dark feature identified by imaging scientists as the best candidate (so far) for a past or present hydrocarbon lake on Titan (see PIA06241 [ http://photojournal.jpl.nasa.gov/catalog/PIA06241 ]). Farther east of the lake-like feature, bright clouds arc around the pole. These clouds occupy a latitude range that is consistent with previously-seen convective cloud activity on Titan. Titan is Saturn's largest moon, at 5,150 kilometers (3,200 miles) across. The image was taken with the Cassini spacecraft narrow angle camera on July 7, 2005, at a distance of approximately 1.3 million kilometers (800,000 miles) from Titan and at a Sun-Titan-spacecraft, or phase, angle of 60 degrees. The image was obtained using a filter sensitive to wavelengths of infrared light centered at 938 nanometers. The image scale is 7 kilometers (5 miles) per pixel. 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 mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute, Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov [ http://saturn.jpl.nasa.gov ]. For additional images visit the Cassini imaging team homepage http://ciclops.org [ http://ciclops.org ]. |
|
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. |
|
Dawn for Odysseus
PIA06571
Saturn
Imaging Science Subsystem -
…
| Title |
Dawn for Odysseus |
| Original Caption Released with Image |
The eastern rim of the large crater Odysseus is visible along the terminator in this image of Saturn's moon Tethys. This enormous impact feature is the largest on Tethys, at approximately 450 kilometers (280 miles) across. The shadowy rim of another smaller crater can be seen at the bottom. Tethys is 1,060 kilometers (659 miles) across. This Cassini view shows principally the leading hemisphere of Tethys. The image was taken in visible light with the Cassini spacecraft narrow angle camera on Dec. 18, 2004, at a distance of 1.7 million kilometers (1.1 million miles) from Tethys and at a Sun-Tethys-spacecraft, or phase, angle of 94 degrees. The image scale is about 10 kilometers (6 miles) per pixel. The image has been magnified by a factor of two and contrast enhanced to aid visibility. 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 mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute, Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov [ http://saturn.jpl.nasa.gov ]. For images visit the Cassini imaging team home page http://ciclops.org [ http://ciclops.org ]. |
|
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 ] |
|
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. |
|
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. |
|
Dunes in Twilight
PIA05242
Sol (our sun)
Mars Orbiter Camera
| Title |
Dunes in Twilight |
| Original Caption Released with Image |
17 January 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows frost-covered north polar dunes in early January 2004. When this picture was taken, the dunes were in twilight, just before the late winter dawn that would come a few days later. These dunes spent many of the last several months in complete darkness. In this image, they are illuminated only by sunlight that has been scattered over the horizon by the martian atmosphere. These dunes are located near 77.0°N, 246.2°W. The image covers an area 3 km (1.9 mi) wide and has been expanded by 200% from its original 12 meters (39 ft.) per pixel scale. While the sun had not yet risen when the image was obtained, illumination is mostly from the lower left. |
|
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. |
|
Clouds Over Morning Limb
PIA04562
Sol (our sun)
Mars Orbiter Camera
| Title |
Clouds Over Morning Limb |
| Original Caption Released with Image |
MGS MOC Release No. MOC2-380, 3 June 2003 Mars Global Surveyor orbits the red planet 12 times each day. Half of each orbit is spent on the day side of Mars, which is where most Mars Orbiter Camera (MOC) images are obtained because sunlight is required to illuminate the surfaces being observed. However, on the night side of Mars, the wide angle cameras can see clouds and hazes above the sunward martian limb. The limb is the edge of the planet as it appears when viewed from an oblique perspective. This blue wide angle camera image, obtained on the night side of Mars on May 15, 2003, shows clouds picking up the first sunlight before dawn near 55° north latitude. The scene is illuminated by sunlight from the right. The sun is actually on the other side of the planet, and has not yet risen over this region. The dark area on the left side of the picture is the martian surface at night. The dark band on the right side is outer space. The bright features just right of center are the clouds hanging above the martian limb over the planet's northern plains. North is toward the top and east is to the right, the spacecraft was moving southward when the image was acquired. |
|
Impact Crater
PIA04049
Sol (our sun)
Thermal Emission Imaging Sys
…
| Title |
Impact Crater |
| Original Caption Released with Image |
Today marks the 45th anniversary of the dawn of the Space Age (October 4, 1957). On this date the former Soviet Union launched the world's first satellite, Sputnik 1. Sputnik means fellow traveler. For comparison Sputnik 1 weighed only 83.6 kg (184 pounds) while Mars Odyssey weighs in at 758 kg (1,671 pounds). This scene shows several interesting geologic features associated with impact craters on Mars. The continuous lobes of material that make up the ejecta blanket of the large impact crater are evidence that the crater ejecta were fluidized upon impact of the meteor that formed the crater. Volatiles within the surface mixed with the ejecta upon impact thus creating the fluidized form. Several smaller impact craters are also observed within the ejecta blanket of the larger impact crater giving a relative timing of events. Layering of geologic units is also observed within the large impact crater walls and floor and may represent different compositional units that erode at variable rates. Cliff faces, dissected gullies, and heavily eroded impact craters are observed in the bottom half of the image at the terminus of a flat-topped plateau. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena. |
|
Impact Crater
PIA04049
Sol (our sun)
Thermal Emission Imaging Sys
…
| Title |
Impact Crater |
| Original Caption Released with Image |
Today marks the 45th anniversary of the dawn of the Space Age (October 4, 1957). On this date the former Soviet Union launched the world's first satellite, Sputnik 1. Sputnik means fellow traveler. For comparison Sputnik 1 weighed only 83.6 kg (184 pounds) while Mars Odyssey weighs in at 758 kg (1,671 pounds). This scene shows several interesting geologic features associated with impact craters on Mars. The continuous lobes of material that make up the ejecta blanket of the large impact crater are evidence that the crater ejecta were fluidized upon impact of the meteor that formed the crater. Volatiles within the surface mixed with the ejecta upon impact thus creating the fluidized form. Several smaller impact craters are also observed within the ejecta blanket of the larger impact crater giving a relative timing of events. Layering of geologic units is also observed within the large impact crater walls and floor and may represent different compositional units that erode at variable rates. Cliff faces, dissected gullies, and heavily eroded impact craters are observed in the bottom half of the image at the terminus of a flat-topped plateau. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena. |
|
|
