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Giant Landslide on Iapetus
| Description |
Giant Landslide on Iapetus |
| Full Description |
A spectacular landslide within the low-brightness region of Iapetus's surface known as Cassini Regio is visible in this image from Cassini. Iapetus is one of the moons of Saturn. The landslide material appears to have collapsed from a scarp 15 kilometers high (9 miles) that forms the rim of an ancient 600 kilometer (375 mile) impact basin. Unconsolidated rubble from the landslide extends halfway across a conspicuous, 120-kilometer diameter (75-mile) flat-floored impact crater that lies just inside the basin scarp. Landslides are common geological phenomena on many planetary bodies, including Earth and Mars. The appearance of this landslide on an icy satellite with low-brightness cratered terrain is reminiscent of landslide features that were observed during NASA's Galileo mission on the Jovian satellite Callisto. The fact that the Iapetus landslide traveled many kilometers from the basin scarp could indicate that the surface material is very fine-grained, and perhaps was fluffed by mechanical forces that allowed the landslide debris to flow extended distances. In this view, north is to the left of the picture and solar illumination is from the bottom of the frame. The image was obtained in visible light with the Cassini spacecraft narrow angle camera on Dec. 31, 2004, at a distance of about 123,400 kilometers (76,677 miles) from Iapetus and at a Sun-Iapetus-spacecraft, or phase, angle of 78 degrees. Resolution achieved in the original image was 740 meters (2,428 feet) per pixel. The image has been contrast-enhanced and magnified by a factor of two 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 7, 2005 |
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Largest Asteroid May Be 'Min
…
| Title |
Largest Asteroid May Be 'Mini Planet' with Water Ice |
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Three Years of Monitoring Ma
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PIA04297
Sol (our sun)
Thermal Emission Spectromete
…
| Title |
Three Years of Monitoring Mars' Atmospheric Dust (Animation) |
| Original Caption Released with Image |
[ http://photojournal.jpl.nasa.gov/archive/PIA04297.mpeg ] Animation This movie shows the daily abundance of dust in the martian atmosphere over a period of three full martian years, from April 1999 through February 2005. The Thermal Emission Spectrometer instrument on NASA's Mars Global Surveyor orbiter has been tracking the weather on Mars for six years. The infrared spectrum observed by this instrument yields information about the spectral properties of the dust and the temperature of the atmosphere. These two properties can then be used to derive how much dust is in the atmosphere. Of particular interest are large regional and global dust storms that occur during summer in the southern hemisphere each Mars year. The 2001 storm was by far the largest, lasting over six months (June to October, 2001) and covering the entire planet. The storms in the other two Mars years shown here were much smaller and never covered the planet. The most recent storm season (June 2003 through January 2005) actually had two separate storms, one in June and a second in December. Unlike most large martian dust storms that start in the southern hemisphere, the December storm began in the north and swept toward the equator. Between storms the atmosphere becomes quite clear, with much smaller dust storms scattered throughout the year and over the planet. Seasons on Mars are determined by the position of Mars in its orbit around the Sun. The position is measured in degrees of solar longitude (Ls) around the orbit, beginning at 0 degrees Ls at the northern spring equinox, progressing to 90 degrees Ls at the start of northern summer, 180 degrees Ls at the fall equinox, 270 degrees Ls at the start of northern winter, and finally back to 360 degrees, or 0 degrees, Ls at the spring equinox. Dust abundance is measured as opacity (tau), with values of 0 tau representing a completely clear atmosphere, and values of 2 indicating that it is nearly impossible to see through to the surface. The Thermal Emission Spectrometer is operated by a team led at Arizona State University, Tempe. Mars Global Surveyor left Earth on Nov. 7, 1996, and began orbiting Mars on Sept. 12, 1997. JPL, a division of the California Institute of Technology, Pasadena, manages Mars Global Surveyor for NASA's Science Mission Directorate, Washington. |
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New Gullies on Martian Sand
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PIA04290
Sol (our sun)
Mars Orbiter Camera
| Title |
New Gullies on Martian Sand Dune |
| Original Caption Released with Image |
), encompassing the dark-toned sand dune field on the floor of a crater located near 49.8 degrees south latitude, 325.4 degrees west longitude. In this image, north is approximately up and sunlight illuminates the scene from the upper left. Based on earlier observations of other dune fields with gullies, camera-team scientists suspect that these gullies form by a process other than water fluidization. An image of a dune in Russell Crater, taken by the Mars Orbiter Camera in March 2001, (figure 3) shows how the morphology of the dune's slip face changes with direction: Gullies form on pole-facing slopes (southwest in this case), while normal slip-face avalanche features ("avalanches" in the figure) are seen on the equator-facing slopes (northwest in this case). Most of the dunes that have gullies on them are located in the Hellespontus and Noachis regions, and are frost-covered during the winter. Based on experience in Antarctica and other cold regions on Earth, it is known that snow and ice can be incorporated into dunes during winter. An example is the layering of snow buried in a sand dune in Victoria Valley, Antarctica, seen in a photograph taken by Michael Malin during the austral summer of 1982-1983 (figure 4). Active sand dunes in cold regions such as Antarctica and northern Canada commonly incorporate wintertime snow as new sand avalanches down a slip face and covers the frozen material. A similar process might occur for middle and high latitude dunes on Mars, although in many cases the "snow" would consist mostly of carbon-dioxide frost, with minimal water ice. What would happen to carbon-dioxide frost incorporated into a martian sand dune? On surfaces that receive early and direct sunlight, the sand would heat and the carbon-dioxide frost would sublime over a period of time, undermining the slope and promoting normal sand sliding. On slopes that were initially shaded and later exposed to direct sunlight, heating would be delayed and the carbon dioxide frost would sublime rapidly. This rapid formation of carbon-dioxide gas may act to fluidize overlying sand, causing it to flow rather than avalanche, and thus create a gully. The Mars Orbiter Camera was built and is operated by Malin Space Science Systems, San Diego, Calif. Mars Global Surveyor left Earth on Nov. 7, 1996, and began orbiting Mars on Sept. 12, 1997. JPL, a division of the California Institute of Technology, Pasadena, manages Mars Global Surveyor for NASA's Science Mission Directorate, Washington., One of the many mysteries associated with martian geology is the origin of gullies found at latitudes poleward of 30 degrees latitude. Most of these gullies are found within craters or other depressions, and appear to be related to the bedrock. Several hypotheses have been proposed for their origin, including groundwater seepage and melting at the base of a dust-mantled snow pack. Some middle-latitude gullies are found on sand dunes. These gullies appear to be different from those found on the slopes of craters, but generally have been interpreted to form by similar processes. In the present martian environment, it is difficult to introduce water to the surface. The temperature and atmospheric pressure may permit water to exist, but the rate of heating of the ground and atmosphere, and the amount of energy available to warm the ground or melt snow, are not conducive to such processes. An alternative process of gully formation on these sand dunes involves frozen carbon dioxide trapped in the winter by windblown sand, then subliming rapidly enough for the escaping carbon-dioxide gas to make the sand flow as a gully-cutting fluid. As part of extended-mission science investigation using the Mars Orbiter Camera on NASA's Mars Global Surveyor spacecraft, the camera team is re-imaging many locations where previous observations revealed gullies. The intent is to see if gully-forming processes are operating on Mars at the present time. The team has found one location where a new gully formed on a dune in an unnamed crater in the Hellespontus region of Mars, west of the Hellas Basin. This pair of narrow-angle images (figure 1) from the Mars Orbiter Camera shows the dune as it appeared on July 17, 2002, (left) and as it appeared on April 27, 2005, (right). The nearly three Earth years of intervening time amount to about 1.4 Mars years. During this period, a couple of gullies formed on the dune slip face. It is critical to recognize that the 2002 image was obtained at a time of year when the incident sunlight was coming in from a lower angle, relative to the horizon, than in the 2005 image. If the gullies had been present in 2002, their appearance would be sharper and more pronounced than they are in the 2005 image. The gullies simply did not exist on July 17, 2002. The steep walls of the gully alcove and channels suggests that the sand in this dune is somewhat cohesive, an observation common among martian sand dunes seen by the Mars Orbiter Camera over the past eight years. Wider context for the dune is shown in a mosaic of two images from the Thermal Emission Imaging System on NASA's Mars Odyssey orbiter (figure 2 |
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New Gullies on Martian Sand
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PIA04290
Sol (our sun)
Mars Orbiter Camera
| Title |
New Gullies on Martian Sand Dune |
| Original Caption Released with Image |
), encompassing the dark-toned sand dune field on the floor of a crater located near 49.8 degrees south latitude, 325.4 degrees west longitude. In this image, north is approximately up and sunlight illuminates the scene from the upper left. Based on earlier observations of other dune fields with gullies, camera-team scientists suspect that these gullies form by a process other than water fluidization. An image of a dune in Russell Crater, taken by the Mars Orbiter Camera in March 2001, (figure 3) shows how the morphology of the dune's slip face changes with direction: Gullies form on pole-facing slopes (southwest in this case), while normal slip-face avalanche features ("avalanches" in the figure) are seen on the equator-facing slopes (northwest in this case). Most of the dunes that have gullies on them are located in the Hellespontus and Noachis regions, and are frost-covered during the winter. Based on experience in Antarctica and other cold regions on Earth, it is known that snow and ice can be incorporated into dunes during winter. An example is the layering of snow buried in a sand dune in Victoria Valley, Antarctica, seen in a photograph taken by Michael Malin during the austral summer of 1982-1983 (figure 4). Active sand dunes in cold regions such as Antarctica and northern Canada commonly incorporate wintertime snow as new sand avalanches down a slip face and covers the frozen material. A similar process might occur for middle and high latitude dunes on Mars, although in many cases the "snow" would consist mostly of carbon-dioxide frost, with minimal water ice. What would happen to carbon-dioxide frost incorporated into a martian sand dune? On surfaces that receive early and direct sunlight, the sand would heat and the carbon-dioxide frost would sublime over a period of time, undermining the slope and promoting normal sand sliding. On slopes that were initially shaded and later exposed to direct sunlight, heating would be delayed and the carbon dioxide frost would sublime rapidly. This rapid formation of carbon-dioxide gas may act to fluidize overlying sand, causing it to flow rather than avalanche, and thus create a gully. The Mars Orbiter Camera was built and is operated by Malin Space Science Systems, San Diego, Calif. Mars Global Surveyor left Earth on Nov. 7, 1996, and began orbiting Mars on Sept. 12, 1997. JPL, a division of the California Institute of Technology, Pasadena, manages Mars Global Surveyor for NASA's Science Mission Directorate, Washington., One of the many mysteries associated with martian geology is the origin of gullies found at latitudes poleward of 30 degrees latitude. Most of these gullies are found within craters or other depressions, and appear to be related to the bedrock. Several hypotheses have been proposed for their origin, including groundwater seepage and melting at the base of a dust-mantled snow pack. Some middle-latitude gullies are found on sand dunes. These gullies appear to be different from those found on the slopes of craters, but generally have been interpreted to form by similar processes. In the present martian environment, it is difficult to introduce water to the surface. The temperature and atmospheric pressure may permit water to exist, but the rate of heating of the ground and atmosphere, and the amount of energy available to warm the ground or melt snow, are not conducive to such processes. An alternative process of gully formation on these sand dunes involves frozen carbon dioxide trapped in the winter by windblown sand, then subliming rapidly enough for the escaping carbon-dioxide gas to make the sand flow as a gully-cutting fluid. As part of extended-mission science investigation using the Mars Orbiter Camera on NASA's Mars Global Surveyor spacecraft, the camera team is re-imaging many locations where previous observations revealed gullies. The intent is to see if gully-forming processes are operating on Mars at the present time. The team has found one location where a new gully formed on a dune in an unnamed crater in the Hellespontus region of Mars, west of the Hellas Basin. This pair of narrow-angle images (figure 1) from the Mars Orbiter Camera shows the dune as it appeared on July 17, 2002, (left) and as it appeared on April 27, 2005, (right). The nearly three Earth years of intervening time amount to about 1.4 Mars years. During this period, a couple of gullies formed on the dune slip face. It is critical to recognize that the 2002 image was obtained at a time of year when the incident sunlight was coming in from a lower angle, relative to the horizon, than in the 2005 image. If the gullies had been present in 2002, their appearance would be sharper and more pronounced than they are in the 2005 image. The gullies simply did not exist on July 17, 2002. The steep walls of the gully alcove and channels suggests that the sand in this dune is somewhat cohesive, an observation common among martian sand dunes seen by the Mars Orbiter Camera over the past eight years. Wider context for the dune is shown in a mosaic of two images from the Thermal Emission Imaging System on NASA's Mars Odyssey orbiter (figure 2 |
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New Gullies on Martian Sand
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PIA04290
Sol (our sun)
Mars Orbiter Camera
| Title |
New Gullies on Martian Sand Dune |
| Original Caption Released with Image |
), encompassing the dark-toned sand dune field on the floor of a crater located near 49.8 degrees south latitude, 325.4 degrees west longitude. In this image, north is approximately up and sunlight illuminates the scene from the upper left. Based on earlier observations of other dune fields with gullies, camera-team scientists suspect that these gullies form by a process other than water fluidization. An image of a dune in Russell Crater, taken by the Mars Orbiter Camera in March 2001, (figure 3) shows how the morphology of the dune's slip face changes with direction: Gullies form on pole-facing slopes (southwest in this case), while normal slip-face avalanche features ("avalanches" in the figure) are seen on the equator-facing slopes (northwest in this case). Most of the dunes that have gullies on them are located in the Hellespontus and Noachis regions, and are frost-covered during the winter. Based on experience in Antarctica and other cold regions on Earth, it is known that snow and ice can be incorporated into dunes during winter. An example is the layering of snow buried in a sand dune in Victoria Valley, Antarctica, seen in a photograph taken by Michael Malin during the austral summer of 1982-1983 (figure 4). Active sand dunes in cold regions such as Antarctica and northern Canada commonly incorporate wintertime snow as new sand avalanches down a slip face and covers the frozen material. A similar process might occur for middle and high latitude dunes on Mars, although in many cases the "snow" would consist mostly of carbon-dioxide frost, with minimal water ice. What would happen to carbon-dioxide frost incorporated into a martian sand dune? On surfaces that receive early and direct sunlight, the sand would heat and the carbon-dioxide frost would sublime over a period of time, undermining the slope and promoting normal sand sliding. On slopes that were initially shaded and later exposed to direct sunlight, heating would be delayed and the carbon dioxide frost would sublime rapidly. This rapid formation of carbon-dioxide gas may act to fluidize overlying sand, causing it to flow rather than avalanche, and thus create a gully. The Mars Orbiter Camera was built and is operated by Malin Space Science Systems, San Diego, Calif. Mars Global Surveyor left Earth on Nov. 7, 1996, and began orbiting Mars on Sept. 12, 1997. JPL, a division of the California Institute of Technology, Pasadena, manages Mars Global Surveyor for NASA's Science Mission Directorate, Washington., One of the many mysteries associated with martian geology is the origin of gullies found at latitudes poleward of 30 degrees latitude. Most of these gullies are found within craters or other depressions, and appear to be related to the bedrock. Several hypotheses have been proposed for their origin, including groundwater seepage and melting at the base of a dust-mantled snow pack. Some middle-latitude gullies are found on sand dunes. These gullies appear to be different from those found on the slopes of craters, but generally have been interpreted to form by similar processes. In the present martian environment, it is difficult to introduce water to the surface. The temperature and atmospheric pressure may permit water to exist, but the rate of heating of the ground and atmosphere, and the amount of energy available to warm the ground or melt snow, are not conducive to such processes. An alternative process of gully formation on these sand dunes involves frozen carbon dioxide trapped in the winter by windblown sand, then subliming rapidly enough for the escaping carbon-dioxide gas to make the sand flow as a gully-cutting fluid. As part of extended-mission science investigation using the Mars Orbiter Camera on NASA's Mars Global Surveyor spacecraft, the camera team is re-imaging many locations where previous observations revealed gullies. The intent is to see if gully-forming processes are operating on Mars at the present time. The team has found one location where a new gully formed on a dune in an unnamed crater in the Hellespontus region of Mars, west of the Hellas Basin. This pair of narrow-angle images (figure 1) from the Mars Orbiter Camera shows the dune as it appeared on July 17, 2002, (left) and as it appeared on April 27, 2005, (right). The nearly three Earth years of intervening time amount to about 1.4 Mars years. During this period, a couple of gullies formed on the dune slip face. It is critical to recognize that the 2002 image was obtained at a time of year when the incident sunlight was coming in from a lower angle, relative to the horizon, than in the 2005 image. If the gullies had been present in 2002, their appearance would be sharper and more pronounced than they are in the 2005 image. The gullies simply did not exist on July 17, 2002. The steep walls of the gully alcove and channels suggests that the sand in this dune is somewhat cohesive, an observation common among martian sand dunes seen by the Mars Orbiter Camera over the past eight years. Wider context for the dune is shown in a mosaic of two images from the Thermal Emission Imaging System on NASA's Mars Odyssey orbiter (figure 2 |
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New Gullies on Martian Sand
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PIA04290
Sol (our sun)
Mars Orbiter Camera
| Title |
New Gullies on Martian Sand Dune |
| Original Caption Released with Image |
), encompassing the dark-toned sand dune field on the floor of a crater located near 49.8 degrees south latitude, 325.4 degrees west longitude. In this image, north is approximately up and sunlight illuminates the scene from the upper left. Based on earlier observations of other dune fields with gullies, camera-team scientists suspect that these gullies form by a process other than water fluidization. An image of a dune in Russell Crater, taken by the Mars Orbiter Camera in March 2001, (figure 3) shows how the morphology of the dune's slip face changes with direction: Gullies form on pole-facing slopes (southwest in this case), while normal slip-face avalanche features ("avalanches" in the figure) are seen on the equator-facing slopes (northwest in this case). Most of the dunes that have gullies on them are located in the Hellespontus and Noachis regions, and are frost-covered during the winter. Based on experience in Antarctica and other cold regions on Earth, it is known that snow and ice can be incorporated into dunes during winter. An example is the layering of snow buried in a sand dune in Victoria Valley, Antarctica, seen in a photograph taken by Michael Malin during the austral summer of 1982-1983 (figure 4). Active sand dunes in cold regions such as Antarctica and northern Canada commonly incorporate wintertime snow as new sand avalanches down a slip face and covers the frozen material. A similar process might occur for middle and high latitude dunes on Mars, although in many cases the "snow" would consist mostly of carbon-dioxide frost, with minimal water ice. What would happen to carbon-dioxide frost incorporated into a martian sand dune? On surfaces that receive early and direct sunlight, the sand would heat and the carbon-dioxide frost would sublime over a period of time, undermining the slope and promoting normal sand sliding. On slopes that were initially shaded and later exposed to direct sunlight, heating would be delayed and the carbon dioxide frost would sublime rapidly. This rapid formation of carbon-dioxide gas may act to fluidize overlying sand, causing it to flow rather than avalanche, and thus create a gully. The Mars Orbiter Camera was built and is operated by Malin Space Science Systems, San Diego, Calif. Mars Global Surveyor left Earth on Nov. 7, 1996, and began orbiting Mars on Sept. 12, 1997. JPL, a division of the California Institute of Technology, Pasadena, manages Mars Global Surveyor for NASA's Science Mission Directorate, Washington., One of the many mysteries associated with martian geology is the origin of gullies found at latitudes poleward of 30 degrees latitude. Most of these gullies are found within craters or other depressions, and appear to be related to the bedrock. Several hypotheses have been proposed for their origin, including groundwater seepage and melting at the base of a dust-mantled snow pack. Some middle-latitude gullies are found on sand dunes. These gullies appear to be different from those found on the slopes of craters, but generally have been interpreted to form by similar processes. In the present martian environment, it is difficult to introduce water to the surface. The temperature and atmospheric pressure may permit water to exist, but the rate of heating of the ground and atmosphere, and the amount of energy available to warm the ground or melt snow, are not conducive to such processes. An alternative process of gully formation on these sand dunes involves frozen carbon dioxide trapped in the winter by windblown sand, then subliming rapidly enough for the escaping carbon-dioxide gas to make the sand flow as a gully-cutting fluid. As part of extended-mission science investigation using the Mars Orbiter Camera on NASA's Mars Global Surveyor spacecraft, the camera team is re-imaging many locations where previous observations revealed gullies. The intent is to see if gully-forming processes are operating on Mars at the present time. The team has found one location where a new gully formed on a dune in an unnamed crater in the Hellespontus region of Mars, west of the Hellas Basin. This pair of narrow-angle images (figure 1) from the Mars Orbiter Camera shows the dune as it appeared on July 17, 2002, (left) and as it appeared on April 27, 2005, (right). The nearly three Earth years of intervening time amount to about 1.4 Mars years. During this period, a couple of gullies formed on the dune slip face. It is critical to recognize that the 2002 image was obtained at a time of year when the incident sunlight was coming in from a lower angle, relative to the horizon, than in the 2005 image. If the gullies had been present in 2002, their appearance would be sharper and more pronounced than they are in the 2005 image. The gullies simply did not exist on July 17, 2002. The steep walls of the gully alcove and channels suggests that the sand in this dune is somewhat cohesive, an observation common among martian sand dunes seen by the Mars Orbiter Camera over the past eight years. Wider context for the dune is shown in a mosaic of two images from the Thermal Emission Imaging System on NASA's Mars Odyssey orbiter (figure 2 |
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New Gullies on Martian Sand
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PIA04290
Sol (our sun)
Mars Orbiter Camera
| Title |
New Gullies on Martian Sand Dune |
| Original Caption Released with Image |
), encompassing the dark-toned sand dune field on the floor of a crater located near 49.8 degrees south latitude, 325.4 degrees west longitude. In this image, north is approximately up and sunlight illuminates the scene from the upper left. Based on earlier observations of other dune fields with gullies, camera-team scientists suspect that these gullies form by a process other than water fluidization. An image of a dune in Russell Crater, taken by the Mars Orbiter Camera in March 2001, (figure 3) shows how the morphology of the dune's slip face changes with direction: Gullies form on pole-facing slopes (southwest in this case), while normal slip-face avalanche features ("avalanches" in the figure) are seen on the equator-facing slopes (northwest in this case). Most of the dunes that have gullies on them are located in the Hellespontus and Noachis regions, and are frost-covered during the winter. Based on experience in Antarctica and other cold regions on Earth, it is known that snow and ice can be incorporated into dunes during winter. An example is the layering of snow buried in a sand dune in Victoria Valley, Antarctica, seen in a photograph taken by Michael Malin during the austral summer of 1982-1983 (figure 4). Active sand dunes in cold regions such as Antarctica and northern Canada commonly incorporate wintertime snow as new sand avalanches down a slip face and covers the frozen material. A similar process might occur for middle and high latitude dunes on Mars, although in many cases the "snow" would consist mostly of carbon-dioxide frost, with minimal water ice. What would happen to carbon-dioxide frost incorporated into a martian sand dune? On surfaces that receive early and direct sunlight, the sand would heat and the carbon-dioxide frost would sublime over a period of time, undermining the slope and promoting normal sand sliding. On slopes that were initially shaded and later exposed to direct sunlight, heating would be delayed and the carbon dioxide frost would sublime rapidly. This rapid formation of carbon-dioxide gas may act to fluidize overlying sand, causing it to flow rather than avalanche, and thus create a gully. The Mars Orbiter Camera was built and is operated by Malin Space Science Systems, San Diego, Calif. Mars Global Surveyor left Earth on Nov. 7, 1996, and began orbiting Mars on Sept. 12, 1997. JPL, a division of the California Institute of Technology, Pasadena, manages Mars Global Surveyor for NASA's Science Mission Directorate, Washington., One of the many mysteries associated with martian geology is the origin of gullies found at latitudes poleward of 30 degrees latitude. Most of these gullies are found within craters or other depressions, and appear to be related to the bedrock. Several hypotheses have been proposed for their origin, including groundwater seepage and melting at the base of a dust-mantled snow pack. Some middle-latitude gullies are found on sand dunes. These gullies appear to be different from those found on the slopes of craters, but generally have been interpreted to form by similar processes. In the present martian environment, it is difficult to introduce water to the surface. The temperature and atmospheric pressure may permit water to exist, but the rate of heating of the ground and atmosphere, and the amount of energy available to warm the ground or melt snow, are not conducive to such processes. An alternative process of gully formation on these sand dunes involves frozen carbon dioxide trapped in the winter by windblown sand, then subliming rapidly enough for the escaping carbon-dioxide gas to make the sand flow as a gully-cutting fluid. As part of extended-mission science investigation using the Mars Orbiter Camera on NASA's Mars Global Surveyor spacecraft, the camera team is re-imaging many locations where previous observations revealed gullies. The intent is to see if gully-forming processes are operating on Mars at the present time. The team has found one location where a new gully formed on a dune in an unnamed crater in the Hellespontus region of Mars, west of the Hellas Basin. This pair of narrow-angle images (figure 1) from the Mars Orbiter Camera shows the dune as it appeared on July 17, 2002, (left) and as it appeared on April 27, 2005, (right). The nearly three Earth years of intervening time amount to about 1.4 Mars years. During this period, a couple of gullies formed on the dune slip face. It is critical to recognize that the 2002 image was obtained at a time of year when the incident sunlight was coming in from a lower angle, relative to the horizon, than in the 2005 image. If the gullies had been present in 2002, their appearance would be sharper and more pronounced than they are in the 2005 image. The gullies simply did not exist on July 17, 2002. The steep walls of the gully alcove and channels suggests that the sand in this dune is somewhat cohesive, an observation common among martian sand dunes seen by the Mars Orbiter Camera over the past eight years. Wider context for the dune is shown in a mosaic of two images from the Thermal Emission Imaging System on NASA's Mars Odyssey orbiter (figure 2 |
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Scarp at Head of Chasma Bore
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PIA04296
Sol (our sun)
Mars Orbiter Camera
| Title |
Scarp at Head of Chasma Boreale |
| Original Caption Released with Image |
This view shows sharp detail of a scarp at the head of Chasma Boreale, a large trough cut by erosion into the martian north polar cap and the layered material beneath the ice cap. The picture is a mosaic of two images acquired in January 2005 by the Mars Orbiter Camera on NASA's Mars Global Surveyor, using a resolution-enhancing technique called "compensated pitch and roll targeted observation." The camera team considers this the best pair of images yet acquired using that technique. During each northern summer on Mars, there occurs a narrow window in time of two to three months when conditions are ideal to image the north polar cap at high resolution. Throughout this period, the atmosphere is generally clear over the cap, and the seasonal carbon-dioxide frost from the previous winter and spring has sublimed away, permitting a good view of the surface geology. The two images in this mosaic were acquired during this brief period during the most recent northern summer. Within a few weeks of when these images were acquired, dust storm activity picked up in the north polar region, making the atmosphere too dusty to obtain any more detailed views until late 2006. Chasma Boreale is cut into the layered material that lies beneath the water ice of the north polar cap. For decades, these layered materials were assumed to consist of a mixture of ice and dust. Mars Orbiter Camera images obtained in 1999 and 2001 began to show that some of the layers are a source for windblown sand. The science objective for the two images shown in this mosaic was to look for boulders in the debris shed from the steep slopes cut into the north polar layers by Chasma Boreale. Finding boulders would imply that the layers that are the most resistant to erosion in the polar region are as competent as solid rock, perhaps giving a new insight into the nature of the polar layered materials. The pictured site is near 84.8 degrees north latitude, 356.4 degrees west longitude. Examination of the high-resolution mosaic shows that there are indeed some large boulders that have eroded out of the layered materials and rolled down the slopes. It is possible, therefore, that the north polar layers are not simply a mixture of ice, dust, and sand. Some layers may actually be rock, cemented by minerals rather than by ice. Alternatively, if the materials are cemented by ice, then a future high-resolution view might show that the boulders have become smaller over time. In addition to the observation of boulders eroding out of the polar layered materials, the mosaic also helps confirm that dark sand is eroding out of the polar layered materials, and that there are three different groups of layers under the polar ice. The upper unit is light-toned, finely layered, and more resistant to erosion (more competent, less easily destroyed by erosion) than the middle unit, which is rich in dark sand but also has several shelf-forming layers in it. Finally, below the dark, sandy layer is a third, unit that is light-toned and has a different appearance relative to the other two units. Some of its layers have surfaces that have been broken by shallow fractures into polygonal and linear forms, also implying that they are hard, resistant rock. The level of detail seen in the mosaic was made possible by the development of a resolution-enhancing technique for using the Mars Orbiter Camera. During 2003 and 2004, the Mars Orbiter Camera operations team at Malin Space Science Systems, San Diego, Calif., worked closely with the Mars Global Surveyor operations teams at the Jet Propulsion Laboratory, Pasadena, Calif., and Lockheed Martin Space Systems, Denver, Colo., to develop a new technique in which the spacecraft does a maneuver that permits the camera to acquire images at a higher spatial resolution than normal. Usually, Mars Orbiter Camera images have a resolution of about 1.5 meters (5 feet) per pixel, and the camera can be commanded to acquire lower resolution data when desired. To obtain a higher resolution, the whole spacecraft must be pitched at such a rate that the camera over-samples its view of the martian surface in the down-track direction. Called compensated pitch and roll targeted observation, or cPROTO, this technique allows Mars Orbiter Camera to obtain images that have a resolution of about 50 centimeters (20 inches) per pixel in the down-track direction, and 150 centimeters (5 feet) per pixel in the cross-track dimension. The Mars Orbiter Camera was built and is operated by Malin Space Science Systems, San Diego, Calif. Mars Global Surveyor left Earth on Nov. 7, 1996, and began orbiting Mars on Sept. 12, 1997. JPL, a division of the California Institute of Technology, Pasadena, manages Mars Global Surveyor for NASA's Science Mission Directorate, Washington. |
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Depth-to-Ice Map of an Arcti
…
PIA09335
Sol (our sun)
Thermal Emission Imaging Sys
…
| Title |
Depth-to-Ice Map of an Arctic Site on Mars |
| Original Caption Released with Image |
Color coding in this map of a far-northern site on Mars indicates the change in nighttime ground-surface temperature between summer and fall. This site, like most of high-latitude Mars, has water ice mixed with soil near the surface. The ice is probably in a rock-hard frozen layer beneath a few centimeters or inches of looser, dry soil. The amount of temperature change at the surface likely corresponds to how close to the surface the icy material lies. The dense, icy layer retains heat better than the looser soil above it, so where the icy layer is closer to the surface, the surface temperature changes more slowly than where the icy layer is buried deeper. On the map, areas of the surface that cooled more slowly between summer and autumn (interpreted as having the ice closer to the surface) are coded blue and green. Areas that cooled more quickly (interpreted as having more distance to the ice) are coded red and yellow. The depth to the top of the icy layer estimated from these observations, as little as 5 centimeters (2 inches), matches modeling of where it would be if Mars has an active cycle of water being exchanged by diffusion between atmospheric water vapor and subsurface water ice. This map and its interpretation are in a May 3, 2007, report in the journal "Nature", by Joshua Bandfield of Arizona State University, Tempe. The Thermal Emission Imaging System camera on NASA's Mars Odyssey orbiter collected the data presented in the map. The site is centered near 67.5 degrees north latitude, 132 degrees east longitude, in the Martian arctic plains called Vastitas Borealis. It was formerly a candidate landing site for NASA's Phoenix Mars Lander mission. This site is within the portion of the planet where, in 2002, the Gamma Ray Spectrometer suite of instruments on Mars Odyssey found evidence for water ice lying just below the surface. The information from the Gamma Ray Spectrometer is averaged over patches of ground hundreds of kilometers or miles wide. The information from the Thermal Emission Imaging System allows more than 100-fold higher resolution in mapping variations in the depth to ice. The Thermal Emission Imaging System observed the site in infrared wavelengths during night time, providing surface-temperature information, once on March 13, 2005, during summer in Mars' northern hemisphere, and again on April 8, 2005, during autumn there. The colors on this map signify relative differences in how much the surface temperature changed between those two observations. Blue indicates the locations with the least change. Red indicates areas with most change. Modeling provides estimates that the range of temperature changes shown in this map corresponds to a range in depth-to-ice of 5 centimeters (2 inches) to more than 18 centimeters (more than 7 inches). The sensitivity of this method for estimating the depth is not good for depths greater than about 20 centimeters (8 inches). The temperature-change data are overlaid on a mosaic of black-and-white, daytime images taken in visible-light wavelengths by the same camera, providing information about shapes in the landscape. The 10-kilometer scale bar is 6.2 miles long. NASA's Jet Propulsion Laboratory manages the Mars Odyssey mission for NASA's Science Mission Directorate, Washington, D.C. The Thermal Emission Imaging System was developed by Arizona State University in collaboration with Raytheon Santa Barbara Remote Sensing. Lockheed Martin Space Systems, 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. |
|
Second of Two Fresh Impact C
…
PIA09024
Sol (our sun)
Mars Orbiter Camera
| Title |
Second of Two Fresh Impact Crater Sites With "Before" and "After" Narrow Angle Mars Orbiter Camera Images |
| Original Caption Released with Image |
Pictured here is the second of 2 of the 20 new impact craters identified by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) science operations team to have formed between May 1999 and March 2006 that occur at a location that the MOC narrow angle camera imaged previously. This is surprising, given that the narrow angle camera, with its 3 kilometer- (1.9 miles)-wide field of view, has only covered about 5.2% of the martian surface. The other such case is described in an accompanying release, "One of Two Fresh Impact Crater Sites With Before and After Narrow Angle Mars Orbiter Camera Images" (see PIA09023 [ http://photojournal.jpl.nasa.gov/catalog/PIA09023 ] or MOC2-1614 [ http://www.msss.com/mars_images/moc/2006/12/06/craters/site11/index.html ]). Figure A: This picture shows the impact site. It is located in Arabia Terra near 25.8°N, 308.0°W. The figure is a composite of sub-frames of MOC images S15-02322, obtained on 22 February 2006, and S17-01393, from 17 April 2006. The largest crater at the center of the impact zone has a diameter of about 16.0 ± 1.7 meters (about 52 feet). Several other smaller craters were formed by this impact event. Figure B: This figure shows how the impact site appeared in a previous MOC narrow angle camera image, R13-00039, on 1 January 2004, before the impact occurred. This is compared with MOC image S15-02322, obtained after the impact. Figure C: This figure shows the impact site as it appeared to the Mars Odyssey Thermal Emission Imaging System (THEMIS) [ http://themis.asu.edu/ ] visible camera on 21 December 2005. Most importantly, the crater did not exist on 21 December 2005, but the dark spot the impact produced was seen 42 days later in MOC red wide angle image S14-03311 on 31 January 2006. In other words, the impact occurred between 21 December 2005 and 31 January 2006. It is possible that the crater formed in January 2006, after we began our survey for fresh martian impact craters! The Mars Global Surveyor mission is managed for NASA's Office of Space Science, Washington, by the Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Malin Space Science Systems, San Diego, Calif., built and operates the Mars Orbiter Camera. For more information about images from the Mars Orbiter Camera, see http://www.msss.com/mgs/moc/index.html [ http://www.msss.com/mgs/moc/index.html ]. |
|
Second of Two Fresh Impact C
…
PIA09024
Sol (our sun)
Mars Orbiter Camera
| Title |
Second of Two Fresh Impact Crater Sites With "Before" and "After" Narrow Angle Mars Orbiter Camera Images |
| Original Caption Released with Image |
Pictured here is the second of 2 of the 20 new impact craters identified by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) science operations team to have formed between May 1999 and March 2006 that occur at a location that the MOC narrow angle camera imaged previously. This is surprising, given that the narrow angle camera, with its 3 kilometer- (1.9 miles)-wide field of view, has only covered about 5.2% of the martian surface. The other such case is described in an accompanying release, "One of Two Fresh Impact Crater Sites With Before and After Narrow Angle Mars Orbiter Camera Images" (see PIA09023 [ http://photojournal.jpl.nasa.gov/catalog/PIA09023 ] or MOC2-1614 [ http://www.msss.com/mars_images/moc/2006/12/06/craters/site11/index.html ]). Figure A: This picture shows the impact site. It is located in Arabia Terra near 25.8°N, 308.0°W. The figure is a composite of sub-frames of MOC images S15-02322, obtained on 22 February 2006, and S17-01393, from 17 April 2006. The largest crater at the center of the impact zone has a diameter of about 16.0 ± 1.7 meters (about 52 feet). Several other smaller craters were formed by this impact event. Figure B: This figure shows how the impact site appeared in a previous MOC narrow angle camera image, R13-00039, on 1 January 2004, before the impact occurred. This is compared with MOC image S15-02322, obtained after the impact. Figure C: This figure shows the impact site as it appeared to the Mars Odyssey Thermal Emission Imaging System (THEMIS) [ http://themis.asu.edu/ ] visible camera on 21 December 2005. Most importantly, the crater did not exist on 21 December 2005, but the dark spot the impact produced was seen 42 days later in MOC red wide angle image S14-03311 on 31 January 2006. In other words, the impact occurred between 21 December 2005 and 31 January 2006. It is possible that the crater formed in January 2006, after we began our survey for fresh martian impact craters! The Mars Global Surveyor mission is managed for NASA's Office of Space Science, Washington, by the Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Malin Space Science Systems, San Diego, Calif., built and operates the Mars Orbiter Camera. For more information about images from the Mars Orbiter Camera, see http://www.msss.com/mgs/moc/index.html [ http://www.msss.com/mgs/moc/index.html ]. |
|
Second of Two Fresh Impact C
…
PIA09024
Sol (our sun)
Mars Orbiter Camera
| Title |
Second of Two Fresh Impact Crater Sites With "Before" and "After" Narrow Angle Mars Orbiter Camera Images |
| Original Caption Released with Image |
Pictured here is the second of 2 of the 20 new impact craters identified by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) science operations team to have formed between May 1999 and March 2006 that occur at a location that the MOC narrow angle camera imaged previously. This is surprising, given that the narrow angle camera, with its 3 kilometer- (1.9 miles)-wide field of view, has only covered about 5.2% of the martian surface. The other such case is described in an accompanying release, "One of Two Fresh Impact Crater Sites With Before and After Narrow Angle Mars Orbiter Camera Images" (see PIA09023 [ http://photojournal.jpl.nasa.gov/catalog/PIA09023 ] or MOC2-1614 [ http://www.msss.com/mars_images/moc/2006/12/06/craters/site11/index.html ]). Figure A: This picture shows the impact site. It is located in Arabia Terra near 25.8°N, 308.0°W. The figure is a composite of sub-frames of MOC images S15-02322, obtained on 22 February 2006, and S17-01393, from 17 April 2006. The largest crater at the center of the impact zone has a diameter of about 16.0 ± 1.7 meters (about 52 feet). Several other smaller craters were formed by this impact event. Figure B: This figure shows how the impact site appeared in a previous MOC narrow angle camera image, R13-00039, on 1 January 2004, before the impact occurred. This is compared with MOC image S15-02322, obtained after the impact. Figure C: This figure shows the impact site as it appeared to the Mars Odyssey Thermal Emission Imaging System (THEMIS) [ http://themis.asu.edu/ ] visible camera on 21 December 2005. Most importantly, the crater did not exist on 21 December 2005, but the dark spot the impact produced was seen 42 days later in MOC red wide angle image S14-03311 on 31 January 2006. In other words, the impact occurred between 21 December 2005 and 31 January 2006. It is possible that the crater formed in January 2006, after we began our survey for fresh martian impact craters! The Mars Global Surveyor mission is managed for NASA's Office of Space Science, Washington, by the Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Malin Space Science Systems, San Diego, Calif., built and operates the Mars Orbiter Camera. For more information about images from the Mars Orbiter Camera, see http://www.msss.com/mgs/moc/index.html [ http://www.msss.com/mgs/moc/index.html ]. |
|
Second of Two Fresh Impact C
…
PIA09024
Sol (our sun)
Mars Orbiter Camera
| Title |
Second of Two Fresh Impact Crater Sites With "Before" and "After" Narrow Angle Mars Orbiter Camera Images |
| Original Caption Released with Image |
Pictured here is the second of 2 of the 20 new impact craters identified by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) science operations team to have formed between May 1999 and March 2006 that occur at a location that the MOC narrow angle camera imaged previously. This is surprising, given that the narrow angle camera, with its 3 kilometer- (1.9 miles)-wide field of view, has only covered about 5.2% of the martian surface. The other such case is described in an accompanying release, "One of Two Fresh Impact Crater Sites With Before and After Narrow Angle Mars Orbiter Camera Images" (see PIA09023 [ http://photojournal.jpl.nasa.gov/catalog/PIA09023 ] or MOC2-1614 [ http://www.msss.com/mars_images/moc/2006/12/06/craters/site11/index.html ]). Figure A: This picture shows the impact site. It is located in Arabia Terra near 25.8°N, 308.0°W. The figure is a composite of sub-frames of MOC images S15-02322, obtained on 22 February 2006, and S17-01393, from 17 April 2006. The largest crater at the center of the impact zone has a diameter of about 16.0 ± 1.7 meters (about 52 feet). Several other smaller craters were formed by this impact event. Figure B: This figure shows how the impact site appeared in a previous MOC narrow angle camera image, R13-00039, on 1 January 2004, before the impact occurred. This is compared with MOC image S15-02322, obtained after the impact. Figure C: This figure shows the impact site as it appeared to the Mars Odyssey Thermal Emission Imaging System (THEMIS) [ http://themis.asu.edu/ ] visible camera on 21 December 2005. Most importantly, the crater did not exist on 21 December 2005, but the dark spot the impact produced was seen 42 days later in MOC red wide angle image S14-03311 on 31 January 2006. In other words, the impact occurred between 21 December 2005 and 31 January 2006. It is possible that the crater formed in January 2006, after we began our survey for fresh martian impact craters! The Mars Global Surveyor mission is managed for NASA's Office of Space Science, Washington, by the Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Malin Space Science Systems, San Diego, Calif., built and operates the Mars Orbiter Camera. For more information about images from the Mars Orbiter Camera, see http://www.msss.com/mgs/moc/index.html [ http://www.msss.com/mgs/moc/index.html ]. |
|
Second of Two Fresh Impact C
…
PIA09024
Sol (our sun)
Mars Orbiter Camera
| Title |
Second of Two Fresh Impact Crater Sites With "Before" and "After" Narrow Angle Mars Orbiter Camera Images |
| Original Caption Released with Image |
Pictured here is the second of 2 of the 20 new impact craters identified by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) science operations team to have formed between May 1999 and March 2006 that occur at a location that the MOC narrow angle camera imaged previously. This is surprising, given that the narrow angle camera, with its 3 kilometer- (1.9 miles)-wide field of view, has only covered about 5.2% of the martian surface. The other such case is described in an accompanying release, "One of Two Fresh Impact Crater Sites With Before and After Narrow Angle Mars Orbiter Camera Images" (see PIA09023 [ http://photojournal.jpl.nasa.gov/catalog/PIA09023 ] or MOC2-1614 [ http://www.msss.com/mars_images/moc/2006/12/06/craters/site11/index.html ]). Figure A: This picture shows the impact site. It is located in Arabia Terra near 25.8°N, 308.0°W. The figure is a composite of sub-frames of MOC images S15-02322, obtained on 22 February 2006, and S17-01393, from 17 April 2006. The largest crater at the center of the impact zone has a diameter of about 16.0 ± 1.7 meters (about 52 feet). Several other smaller craters were formed by this impact event. Figure B: This figure shows how the impact site appeared in a previous MOC narrow angle camera image, R13-00039, on 1 January 2004, before the impact occurred. This is compared with MOC image S15-02322, obtained after the impact. Figure C: This figure shows the impact site as it appeared to the Mars Odyssey Thermal Emission Imaging System (THEMIS) [ http://themis.asu.edu/ ] visible camera on 21 December 2005. Most importantly, the crater did not exist on 21 December 2005, but the dark spot the impact produced was seen 42 days later in MOC red wide angle image S14-03311 on 31 January 2006. In other words, the impact occurred between 21 December 2005 and 31 January 2006. It is possible that the crater formed in January 2006, after we began our survey for fresh martian impact craters! The Mars Global Surveyor mission is managed for NASA's Office of Space Science, Washington, by the Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Malin Space Science Systems, San Diego, Calif., built and operates the Mars Orbiter Camera. For more information about images from the Mars Orbiter Camera, see http://www.msss.com/mgs/moc/index.html [ http://www.msss.com/mgs/moc/index.html ]. |
|
Second of Two Fresh Impact C
…
PIA09024
Sol (our sun)
Mars Orbiter Camera
| Title |
Second of Two Fresh Impact Crater Sites With "Before" and "After" Narrow Angle Mars Orbiter Camera Images |
| Original Caption Released with Image |
Pictured here is the second of 2 of the 20 new impact craters identified by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) science operations team to have formed between May 1999 and March 2006 that occur at a location that the MOC narrow angle camera imaged previously. This is surprising, given that the narrow angle camera, with its 3 kilometer- (1.9 miles)-wide field of view, has only covered about 5.2% of the martian surface. The other such case is described in an accompanying release, "One of Two Fresh Impact Crater Sites With Before and After Narrow Angle Mars Orbiter Camera Images" (see PIA09023 [ http://photojournal.jpl.nasa.gov/catalog/PIA09023 ] or MOC2-1614 [ http://www.msss.com/mars_images/moc/2006/12/06/craters/site11/index.html ]). Figure A: This picture shows the impact site. It is located in Arabia Terra near 25.8°N, 308.0°W. The figure is a composite of sub-frames of MOC images S15-02322, obtained on 22 February 2006, and S17-01393, from 17 April 2006. The largest crater at the center of the impact zone has a diameter of about 16.0 ± 1.7 meters (about 52 feet). Several other smaller craters were formed by this impact event. Figure B: This figure shows how the impact site appeared in a previous MOC narrow angle camera image, R13-00039, on 1 January 2004, before the impact occurred. This is compared with MOC image S15-02322, obtained after the impact. Figure C: This figure shows the impact site as it appeared to the Mars Odyssey Thermal Emission Imaging System (THEMIS) [ http://themis.asu.edu/ ] visible camera on 21 December 2005. Most importantly, the crater did not exist on 21 December 2005, but the dark spot the impact produced was seen 42 days later in MOC red wide angle image S14-03311 on 31 January 2006. In other words, the impact occurred between 21 December 2005 and 31 January 2006. It is possible that the crater formed in January 2006, after we began our survey for fresh martian impact craters! The Mars Global Surveyor mission is managed for NASA's Office of Space Science, Washington, by the Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Malin Space Science Systems, San Diego, Calif., built and operates the Mars Orbiter Camera. For more information about images from the Mars Orbiter Camera, see http://www.msss.com/mgs/moc/index.html [ http://www.msss.com/mgs/moc/index.html ]. |
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New Gully Deposit in a Crate
…
PIA09027
Sol (our sun)
Mars Orbiter Camera
| Title |
New Gully Deposit in a Crater in Terra Sirenum |
| Original Caption Released with Image |
Has liquid water flowed on Mars in this decade? In June 2000, we reported the discovery, using the Mars Global Surveyor's Mars Orbiter Camera, of very youthful-looking gullies found on slopes at middle and high latitudes on Mars. Since that time, tens of thousands of gullies have been imaged by all of the Mars orbiting spacecraft: Mars Global Surveyor, Mars Odyssey, Mars Express and Mars Reconnaissance Orbiter. During the years since the original June 2000 report, the Mars Global Surveyor's camera was used to test the hypothesis that the gullies may be so young that some of them could still be active today. The test was very simple: re-image gullies previously seen by the camera and see if anything has changed. In two cases, something changed. One of those cases is presented here. A gully on the wall of an unnamed crater in Terra Sirenum, at 36.6 degrees south, 161.8 degrees west, was initially imaged by the camera on Dec. 22, 2001 (Figure A, left). It showed nothing noteworthy at the location where a change would later be observed, but a group of nearby gullies exhibited an unusual patch of light-toned material. As part of our routine campaign to re-image gully sites using the camera, another image of this location was acquired on April 24, 2005. A new light-toned deposit had appeared in what was otherwise a nondescript gully (Figure A, right). This deposit was imaged again by the camera on Aug. 26, 2005, at a time when the sun angle and season were the same as in the original December 2001 image, to confirm that indeed the light-toned feature was something new, not just a trick of differing lighting conditions. In August 2005, the feature was still present. Figure A: This set of images shows a comparison of the gully site as it appeared on Dec. 22, 2001 (left), with a mosaic of two images acquired after the change occurred (the two images are from Aug. 26, 2005, and Sept. 25, 2005). Sunlight illuminates each scene from the northwest (top left). The 150-meter scale bar represents 164 yards. Figure B: This is a mosaic of images that cover the entire unnamed crater in Terra Sirenum. The location of the light-toned gully deposits, old and new, is indicated. This is a mosaic of images acquired by the camera in 2005 and 2006. The 500-meter scale bar equals approximately 547 yards. Figure C: This image shows an enlargement of a portion of another image from August 2005, showing details of the new, light-toned gully deposit. The new material covers the entire gully floor, from the point at which the gully emerged from beneath a mantled slope, down to the spot at which the channel meets the crater floor. At this break in slope, the gully material, as it was emplaced, spread out into five or six different fingers (this is called a "digitate" termination as in finger digits). The 75-meter scale bar represents a distance of about 82 yards. Figure D: To confirm that the new, light-toned gully deposit is not just a trick of changing, Laboratory, Pasadena, Calif., a division of the California Institute of Technology, also in Pasadena. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Malin Space Science Systems, San Diego, Calif., built and operates the Mars Orbiter Camera. For more information about images from the Mars Orbiter Camera, see http://www.msss.com/mgs/moc/index.html [ http://www.msss.com/mgs/moc/index.html ]., illumination conditions as the sun rises to different levels in the sky each season, the Mars Orbiter Camera team repeatedly imaged this site throughout 2005 and 2006. Four examples are shown here, acquired in April 2005, August 2005, February 2006 and April 2006. The "i=" indicates solar-incidence angle, or the height of the sun in the local sky, relative to a case where the sun would be directly overhead (i=0 degrees). Thus, the higher the incidence angle, the lower the sun would appear in the sky to an observer on the ground. These images show that a material flowed down through a gully channel, once between December 2001 and April 2005. After the flow stopped, it left behind evidence -- the light-toned deposit. The deposit is thin enough that its thickness cannot be measured in the camera's 1.5-meters-per-pixel images. However, it does exhibit a digitate termination, suggesting that the material flowed in a fluid-like manner down the approximately 25 degree slope before splaying out into multiple small lobes at the point where the crater wall meets the crater floor and the slope suddenly drops to near zero. This deposit, and a similar one in a crater in the Centauri Montes, together suggests that the materials involved were low-volume debris flows containing a mixture of sediment and a liquid that had the physical properties of liquid water. In this case, we propose that the water came from below the surface, emerged somewhere beneath the mantle covering the original crater wall, and then ran down through a previously existing gully channel. No new gully was formed, but an old one was re-activated. The light tone of the new gully deposit, and that of the older, neighboring gullies, is intriguing. We cannot know from these images whether the light tone indicates that ice is still present in and on the surface of the deposit. Indeed, ice may not be likely: under present conditions on the surface of Mars, ice would be expected to have sublimed, or vaporized, away fairly shortly after the new deposit formed. However, the light-toned material could be frost that forms and re-forms frequently as trapped water-ice sublimes and "exhales" from within the deposit. Alternatively, the light-tone may result if the deposit consists of significantly finer grains (for example, fine silt) than the surrounding surfaces, or if the deposit's surface is covered with minerals such as salts formed as water evaporated from the material. Do these images prove that water has flowed on Mars? No, they cannot. However, they provide the first very tantalizing evidence that this may have occurred. While the surface environment on Mars is extremely dry, drier than the most arid deserts on Earth, liquid water from beneath the Martian surface may have come out of the ground and flowed across this little portion of the red planet in this decade. The Mars Global Surveyor mission is managed for NASA's Office of Space Science, Washington, by NASA's Jet Propulsion |
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New Gully Deposit in a Crate
…
PIA09027
Sol (our sun)
Mars Orbiter Camera
| Title |
New Gully Deposit in a Crater in Terra Sirenum |
| Original Caption Released with Image |
Has liquid water flowed on Mars in this decade? In June 2000, we reported the discovery, using the Mars Global Surveyor's Mars Orbiter Camera, of very youthful-looking gullies found on slopes at middle and high latitudes on Mars. Since that time, tens of thousands of gullies have been imaged by all of the Mars orbiting spacecraft: Mars Global Surveyor, Mars Odyssey, Mars Express and Mars Reconnaissance Orbiter. During the years since the original June 2000 report, the Mars Global Surveyor's camera was used to test the hypothesis that the gullies may be so young that some of them could still be active today. The test was very simple: re-image gullies previously seen by the camera and see if anything has changed. In two cases, something changed. One of those cases is presented here. A gully on the wall of an unnamed crater in Terra Sirenum, at 36.6 degrees south, 161.8 degrees west, was initially imaged by the camera on Dec. 22, 2001 (Figure A, left). It showed nothing noteworthy at the location where a change would later be observed, but a group of nearby gullies exhibited an unusual patch of light-toned material. As part of our routine campaign to re-image gully sites using the camera, another image of this location was acquired on April 24, 2005. A new light-toned deposit had appeared in what was otherwise a nondescript gully (Figure A, right). This deposit was imaged again by the camera on Aug. 26, 2005, at a time when the sun angle and season were the same as in the original December 2001 image, to confirm that indeed the light-toned feature was something new, not just a trick of differing lighting conditions. In August 2005, the feature was still present. Figure A: This set of images shows a comparison of the gully site as it appeared on Dec. 22, 2001 (left), with a mosaic of two images acquired after the change occurred (the two images are from Aug. 26, 2005, and Sept. 25, 2005). Sunlight illuminates each scene from the northwest (top left). The 150-meter scale bar represents 164 yards. Figure B: This is a mosaic of images that cover the entire unnamed crater in Terra Sirenum. The location of the light-toned gully deposits, old and new, is indicated. This is a mosaic of images acquired by the camera in 2005 and 2006. The 500-meter scale bar equals approximately 547 yards. Figure C: This image shows an enlargement of a portion of another image from August 2005, showing details of the new, light-toned gully deposit. The new material covers the entire gully floor, from the point at which the gully emerged from beneath a mantled slope, down to the spot at which the channel meets the crater floor. At this break in slope, the gully material, as it was emplaced, spread out into five or six different fingers (this is called a "digitate" termination as in finger digits). The 75-meter scale bar represents a distance of about 82 yards. Figure D: To confirm that the new, light-toned gully deposit is not just a trick of changing, Laboratory, Pasadena, Calif., a division of the California Institute of Technology, also in Pasadena. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Malin Space Science Systems, San Diego, Calif., built and operates the Mars Orbiter Camera. For more information about images from the Mars Orbiter Camera, see http://www.msss.com/mgs/moc/index.html [ http://www.msss.com/mgs/moc/index.html ]., illumination conditions as the sun rises to different levels in the sky each season, the Mars Orbiter Camera team repeatedly imaged this site throughout 2005 and 2006. Four examples are shown here, acquired in April 2005, August 2005, February 2006 and April 2006. The "i=" indicates solar-incidence angle, or the height of the sun in the local sky, relative to a case where the sun would be directly overhead (i=0 degrees). Thus, the higher the incidence angle, the lower the sun would appear in the sky to an observer on the ground. These images show that a material flowed down through a gully channel, once between December 2001 and April 2005. After the flow stopped, it left behind evidence -- the light-toned deposit. The deposit is thin enough that its thickness cannot be measured in the camera's 1.5-meters-per-pixel images. However, it does exhibit a digitate termination, suggesting that the material flowed in a fluid-like manner down the approximately 25 degree slope before splaying out into multiple small lobes at the point where the crater wall meets the crater floor and the slope suddenly drops to near zero. This deposit, and a similar one in a crater in the Centauri Montes, together suggests that the materials involved were low-volume debris flows containing a mixture of sediment and a liquid that had the physical properties of liquid water. In this case, we propose that the water came from below the surface, emerged somewhere beneath the mantle covering the original crater wall, and then ran down through a previously existing gully channel. No new gully was formed, but an old one was re-activated. The light tone of the new gully deposit, and that of the older, neighboring gullies, is intriguing. We cannot know from these images whether the light tone indicates that ice is still present in and on the surface of the deposit. Indeed, ice may not be likely: under present conditions on the surface of Mars, ice would be expected to have sublimed, or vaporized, away fairly shortly after the new deposit formed. However, the light-toned material could be frost that forms and re-forms frequently as trapped water-ice sublimes and "exhales" from within the deposit. Alternatively, the light-tone may result if the deposit consists of significantly finer grains (for example, fine silt) than the surrounding surfaces, or if the deposit's surface is covered with minerals such as salts formed as water evaporated from the material. Do these images prove that water has flowed on Mars? No, they cannot. However, they provide the first very tantalizing evidence that this may have occurred. While the surface environment on Mars is extremely dry, drier than the most arid deserts on Earth, liquid water from beneath the Martian surface may have come out of the ground and flowed across this little portion of the red planet in this decade. The Mars Global Surveyor mission is managed for NASA's Office of Space Science, Washington, by NASA's Jet Propulsion |
|
New Gully Deposit in a Crate
…
PIA09027
Sol (our sun)
Mars Orbiter Camera
| Title |
New Gully Deposit in a Crater in Terra Sirenum |
| Original Caption Released with Image |
Has liquid water flowed on Mars in this decade? In June 2000, we reported the discovery, using the Mars Global Surveyor's Mars Orbiter Camera, of very youthful-looking gullies found on slopes at middle and high latitudes on Mars. Since that time, tens of thousands of gullies have been imaged by all of the Mars orbiting spacecraft: Mars Global Surveyor, Mars Odyssey, Mars Express and Mars Reconnaissance Orbiter. During the years since the original June 2000 report, the Mars Global Surveyor's camera was used to test the hypothesis that the gullies may be so young that some of them could still be active today. The test was very simple: re-image gullies previously seen by the camera and see if anything has changed. In two cases, something changed. One of those cases is presented here. A gully on the wall of an unnamed crater in Terra Sirenum, at 36.6 degrees south, 161.8 degrees west, was initially imaged by the camera on Dec. 22, 2001 (Figure A, left). It showed nothing noteworthy at the location where a change would later be observed, but a group of nearby gullies exhibited an unusual patch of light-toned material. As part of our routine campaign to re-image gully sites using the camera, another image of this location was acquired on April 24, 2005. A new light-toned deposit had appeared in what was otherwise a nondescript gully (Figure A, right). This deposit was imaged again by the camera on Aug. 26, 2005, at a time when the sun angle and season were the same as in the original December 2001 image, to confirm that indeed the light-toned feature was something new, not just a trick of differing lighting conditions. In August 2005, the feature was still present. Figure A: This set of images shows a comparison of the gully site as it appeared on Dec. 22, 2001 (left), with a mosaic of two images acquired after the change occurred (the two images are from Aug. 26, 2005, and Sept. 25, 2005). Sunlight illuminates each scene from the northwest (top left). The 150-meter scale bar represents 164 yards. Figure B: This is a mosaic of images that cover the entire unnamed crater in Terra Sirenum. The location of the light-toned gully deposits, old and new, is indicated. This is a mosaic of images acquired by the camera in 2005 and 2006. The 500-meter scale bar equals approximately 547 yards. Figure C: This image shows an enlargement of a portion of another image from August 2005, showing details of the new, light-toned gully deposit. The new material covers the entire gully floor, from the point at which the gully emerged from beneath a mantled slope, down to the spot at which the channel meets the crater floor. At this break in slope, the gully material, as it was emplaced, spread out into five or six different fingers (this is called a "digitate" termination as in finger digits). The 75-meter scale bar represents a distance of about 82 yards. Figure D: To confirm that the new, light-toned gully deposit is not just a trick of changing, Laboratory, Pasadena, Calif., a division of the California Institute of Technology, also in Pasadena. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Malin Space Science Systems, San Diego, Calif., built and operates the Mars Orbiter Camera. For more information about images from the Mars Orbiter Camera, see http://www.msss.com/mgs/moc/index.html [ http://www.msss.com/mgs/moc/index.html ]., illumination conditions as the sun rises to different levels in the sky each season, the Mars Orbiter Camera team repeatedly imaged this site throughout 2005 and 2006. Four examples are shown here, acquired in April 2005, August 2005, February 2006 and April 2006. The "i=" indicates solar-incidence angle, or the height of the sun in the local sky, relative to a case where the sun would be directly overhead (i=0 degrees). Thus, the higher the incidence angle, the lower the sun would appear in the sky to an observer on the ground. These images show that a material flowed down through a gully channel, once between December 2001 and April 2005. After the flow stopped, it left behind evidence -- the light-toned deposit. The deposit is thin enough that its thickness cannot be measured in the camera's 1.5-meters-per-pixel images. However, it does exhibit a digitate termination, suggesting that the material flowed in a fluid-like manner down the approximately 25 degree slope before splaying out into multiple small lobes at the point where the crater wall meets the crater floor and the slope suddenly drops to near zero. This deposit, and a similar one in a crater in the Centauri Montes, together suggests that the materials involved were low-volume debris flows containing a mixture of sediment and a liquid that had the physical properties of liquid water. In this case, we propose that the water came from below the surface, emerged somewhere beneath the mantle covering the original crater wall, and then ran down through a previously existing gully channel. No new gully was formed, but an old one was re-activated. The light tone of the new gully deposit, and that of the older, neighboring gullies, is intriguing. We cannot know from these images whether the light tone indicates that ice is still present in and on the surface of the deposit. Indeed, ice may not be likely: under present conditions on the surface of Mars, ice would be expected to have sublimed, or vaporized, away fairly shortly after the new deposit formed. However, the light-toned material could be frost that forms and re-forms frequently as trapped water-ice sublimes and "exhales" from within the deposit. Alternatively, the light-tone may result if the deposit consists of significantly finer grains (for example, fine silt) than the surrounding surfaces, or if the deposit's surface is covered with minerals such as salts formed as water evaporated from the material. Do these images prove that water has flowed on Mars? No, they cannot. However, they provide the first very tantalizing evidence that this may have occurred. While the surface environment on Mars is extremely dry, drier than the most arid deserts on Earth, liquid water from beneath the Martian surface may have come out of the ground and flowed across this little portion of the red planet in this decade. The Mars Global Surveyor mission is managed for NASA's Office of Space Science, Washington, by NASA's Jet Propulsion |
|
New Gully Deposit in a Crate
…
PIA09027
Sol (our sun)
Mars Orbiter Camera
| Title |
New Gully Deposit in a Crater in Terra Sirenum |
| Original Caption Released with Image |
Has liquid water flowed on Mars in this decade? In June 2000, we reported the discovery, using the Mars Global Surveyor's Mars Orbiter Camera, of very youthful-looking gullies found on slopes at middle and high latitudes on Mars. Since that time, tens of thousands of gullies have been imaged by all of the Mars orbiting spacecraft: Mars Global Surveyor, Mars Odyssey, Mars Express and Mars Reconnaissance Orbiter. During the years since the original June 2000 report, the Mars Global Surveyor's camera was used to test the hypothesis that the gullies may be so young that some of them could still be active today. The test was very simple: re-image gullies previously seen by the camera and see if anything has changed. In two cases, something changed. One of those cases is presented here. A gully on the wall of an unnamed crater in Terra Sirenum, at 36.6 degrees south, 161.8 degrees west, was initially imaged by the camera on Dec. 22, 2001 (Figure A, left). It showed nothing noteworthy at the location where a change would later be observed, but a group of nearby gullies exhibited an unusual patch of light-toned material. As part of our routine campaign to re-image gully sites using the camera, another image of this location was acquired on April 24, 2005. A new light-toned deposit had appeared in what was otherwise a nondescript gully (Figure A, right). This deposit was imaged again by the camera on Aug. 26, 2005, at a time when the sun angle and season were the same as in the original December 2001 image, to confirm that indeed the light-toned feature was something new, not just a trick of differing lighting conditions. In August 2005, the feature was still present. Figure A: This set of images shows a comparison of the gully site as it appeared on Dec. 22, 2001 (left), with a mosaic of two images acquired after the change occurred (the two images are from Aug. 26, 2005, and Sept. 25, 2005). Sunlight illuminates each scene from the northwest (top left). The 150-meter scale bar represents 164 yards. Figure B: This is a mosaic of images that cover the entire unnamed crater in Terra Sirenum. The location of the light-toned gully deposits, old and new, is indicated. This is a mosaic of images acquired by the camera in 2005 and 2006. The 500-meter scale bar equals approximately 547 yards. Figure C: This image shows an enlargement of a portion of another image from August 2005, showing details of the new, light-toned gully deposit. The new material covers the entire gully floor, from the point at which the gully emerged from beneath a mantled slope, down to the spot at which the channel meets the crater floor. At this break in slope, the gully material, as it was emplaced, spread out into five or six different fingers (this is called a "digitate" termination as in finger digits). The 75-meter scale bar represents a distance of about 82 yards. Figure D: To confirm that the new, light-toned gully deposit is not just a trick of changing, Laboratory, Pasadena, Calif., a division of the California Institute of Technology, also in Pasadena. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Malin Space Science Systems, San Diego, Calif., built and operates the Mars Orbiter Camera. For more information about images from the Mars Orbiter Camera, see http://www.msss.com/mgs/moc/index.html [ http://www.msss.com/mgs/moc/index.html ]., illumination conditions as the sun rises to different levels in the sky each season, the Mars Orbiter Camera team repeatedly imaged this site throughout 2005 and 2006. Four examples are shown here, acquired in April 2005, August 2005, February 2006 and April 2006. The "i=" indicates solar-incidence angle, or the height of the sun in the local sky, relative to a case where the sun would be directly overhead (i=0 degrees). Thus, the higher the incidence angle, the lower the sun would appear in the sky to an observer on the ground. These images show that a material flowed down through a gully channel, once between December 2001 and April 2005. After the flow stopped, it left behind evidence -- the light-toned deposit. The deposit is thin enough that its thickness cannot be measured in the camera's 1.5-meters-per-pixel images. However, it does exhibit a digitate termination, suggesting that the material flowed in a fluid-like manner down the approximately 25 degree slope before splaying out into multiple small lobes at the point where the crater wall meets the crater floor and the slope suddenly drops to near zero. This deposit, and a similar one in a crater in the Centauri Montes, together suggests that the materials involved were low-volume debris flows containing a mixture of sediment and a liquid that had the physical properties of liquid water. In this case, we propose that the water came from below the surface, emerged somewhere beneath the mantle covering the original crater wall, and then ran down through a previously existing gully channel. No new gully was formed, but an old one was re-activated. The light tone of the new gully deposit, and that of the older, neighboring gullies, is intriguing. We cannot know from these images whether the light tone indicates that ice is still present in and on the surface of the deposit. Indeed, ice may not be likely: under present conditions on the surface of Mars, ice would be expected to have sublimed, or vaporized, away fairly shortly after the new deposit formed. However, the light-toned material could be frost that forms and re-forms frequently as trapped water-ice sublimes and "exhales" from within the deposit. Alternatively, the light-tone may result if the deposit consists of significantly finer grains (for example, fine silt) than the surrounding surfaces, or if the deposit's surface is covered with minerals such as salts formed as water evaporated from the material. Do these images prove that water has flowed on Mars? No, they cannot. However, they provide the first very tantalizing evidence that this may have occurred. While the surface environment on Mars is extremely dry, drier than the most arid deserts on Earth, liquid water from beneath the Martian surface may have come out of the ground and flowed across this little portion of the red planet in this decade. The Mars Global Surveyor mission is managed for NASA's Office of Space Science, Washington, by NASA's Jet Propulsion |
|
New Gully Deposit in a Crate
…
PIA09027
Sol (our sun)
Mars Orbiter Camera
| Title |
New Gully Deposit in a Crater in Terra Sirenum |
| Original Caption Released with Image |
Has liquid water flowed on Mars in this decade? In June 2000, we reported the discovery, using the Mars Global Surveyor's Mars Orbiter Camera, of very youthful-looking gullies found on slopes at middle and high latitudes on Mars. Since that time, tens of thousands of gullies have been imaged by all of the Mars orbiting spacecraft: Mars Global Surveyor, Mars Odyssey, Mars Express and Mars Reconnaissance Orbiter. During the years since the original June 2000 report, the Mars Global Surveyor's camera was used to test the hypothesis that the gullies may be so young that some of them could still be active today. The test was very simple: re-image gullies previously seen by the camera and see if anything has changed. In two cases, something changed. One of those cases is presented here. A gully on the wall of an unnamed crater in Terra Sirenum, at 36.6 degrees south, 161.8 degrees west, was initially imaged by the camera on Dec. 22, 2001 (Figure A, left). It showed nothing noteworthy at the location where a change would later be observed, but a group of nearby gullies exhibited an unusual patch of light-toned material. As part of our routine campaign to re-image gully sites using the camera, another image of this location was acquired on April 24, 2005. A new light-toned deposit had appeared in what was otherwise a nondescript gully (Figure A, right). This deposit was imaged again by the camera on Aug. 26, 2005, at a time when the sun angle and season were the same as in the original December 2001 image, to confirm that indeed the light-toned feature was something new, not just a trick of differing lighting conditions. In August 2005, the feature was still present. Figure A: This set of images shows a comparison of the gully site as it appeared on Dec. 22, 2001 (left), with a mosaic of two images acquired after the change occurred (the two images are from Aug. 26, 2005, and Sept. 25, 2005). Sunlight illuminates each scene from the northwest (top left). The 150-meter scale bar represents 164 yards. Figure B: This is a mosaic of images that cover the entire unnamed crater in Terra Sirenum. The location of the light-toned gully deposits, old and new, is indicated. This is a mosaic of images acquired by the camera in 2005 and 2006. The 500-meter scale bar equals approximately 547 yards. Figure C: This image shows an enlargement of a portion of another image from August 2005, showing details of the new, light-toned gully deposit. The new material covers the entire gully floor, from the point at which the gully emerged from beneath a mantled slope, down to the spot at which the channel meets the crater floor. At this break in slope, the gully material, as it was emplaced, spread out into five or six different fingers (this is called a "digitate" termination as in finger digits). The 75-meter scale bar represents a distance of about 82 yards. Figure D: To confirm that the new, light-toned gully deposit is not just a trick of changing, Laboratory, Pasadena, Calif., a division of the California Institute of Technology, also in Pasadena. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Malin Space Science Systems, San Diego, Calif., built and operates the Mars Orbiter Camera. For more information about images from the Mars Orbiter Camera, see http://www.msss.com/mgs/moc/index.html [ http://www.msss.com/mgs/moc/index.html ]., illumination conditions as the sun rises to different levels in the sky each season, the Mars Orbiter Camera team repeatedly imaged this site throughout 2005 and 2006. Four examples are shown here, acquired in April 2005, August 2005, February 2006 and April 2006. The "i=" indicates solar-incidence angle, or the height of the sun in the local sky, relative to a case where the sun would be directly overhead (i=0 degrees). Thus, the higher the incidence angle, the lower the sun would appear in the sky to an observer on the ground. These images show that a material flowed down through a gully channel, once between December 2001 and April 2005. After the flow stopped, it left behind evidence -- the light-toned deposit. The deposit is thin enough that its thickness cannot be measured in the camera's 1.5-meters-per-pixel images. However, it does exhibit a digitate termination, suggesting that the material flowed in a fluid-like manner down the approximately 25 degree slope before splaying out into multiple small lobes at the point where the crater wall meets the crater floor and the slope suddenly drops to near zero. This deposit, and a similar one in a crater in the Centauri Montes, together suggests that the materials involved were low-volume debris flows containing a mixture of sediment and a liquid that had the physical properties of liquid water. In this case, we propose that the water came from below the surface, emerged somewhere beneath the mantle covering the original crater wall, and then ran down through a previously existing gully channel. No new gully was formed, but an old one was re-activated. The light tone of the new gully deposit, and that of the older, neighboring gullies, is intriguing. We cannot know from these images whether the light tone indicates that ice is still present in and on the surface of the deposit. Indeed, ice may not be likely: under present conditions on the surface of Mars, ice would be expected to have sublimed, or vaporized, away fairly shortly after the new deposit formed. However, the light-toned material could be frost that forms and re-forms frequently as trapped water-ice sublimes and "exhales" from within the deposit. Alternatively, the light-tone may result if the deposit consists of significantly finer grains (for example, fine silt) than the surrounding surfaces, or if the deposit's surface is covered with minerals such as salts formed as water evaporated from the material. Do these images prove that water has flowed on Mars? No, they cannot. However, they provide the first very tantalizing evidence that this may have occurred. While the surface environment on Mars is extremely dry, drier than the most arid deserts on Earth, liquid water from beneath the Martian surface may have come out of the ground and flowed across this little portion of the red planet in this decade. The Mars Global Surveyor mission is managed for NASA's Office of Space Science, Washington, by NASA's Jet Propulsion |
|
New Gully Deposit in a Crate
…
PIA09027
Sol (our sun)
Mars Orbiter Camera
| Title |
New Gully Deposit in a Crater in Terra Sirenum |
| Original Caption Released with Image |
Has liquid water flowed on Mars in this decade? In June 2000, we reported the discovery, using the Mars Global Surveyor's Mars Orbiter Camera, of very youthful-looking gullies found on slopes at middle and high latitudes on Mars. Since that time, tens of thousands of gullies have been imaged by all of the Mars orbiting spacecraft: Mars Global Surveyor, Mars Odyssey, Mars Express and Mars Reconnaissance Orbiter. During the years since the original June 2000 report, the Mars Global Surveyor's camera was used to test the hypothesis that the gullies may be so young that some of them could still be active today. The test was very simple: re-image gullies previously seen by the camera and see if anything has changed. In two cases, something changed. One of those cases is presented here. A gully on the wall of an unnamed crater in Terra Sirenum, at 36.6 degrees south, 161.8 degrees west, was initially imaged by the camera on Dec. 22, 2001 (Figure A, left). It showed nothing noteworthy at the location where a change would later be observed, but a group of nearby gullies exhibited an unusual patch of light-toned material. As part of our routine campaign to re-image gully sites using the camera, another image of this location was acquired on April 24, 2005. A new light-toned deposit had appeared in what was otherwise a nondescript gully (Figure A, right). This deposit was imaged again by the camera on Aug. 26, 2005, at a time when the sun angle and season were the same as in the original December 2001 image, to confirm that indeed the light-toned feature was something new, not just a trick of differing lighting conditions. In August 2005, the feature was still present. Figure A: This set of images shows a comparison of the gully site as it appeared on Dec. 22, 2001 (left), with a mosaic of two images acquired after the change occurred (the two images are from Aug. 26, 2005, and Sept. 25, 2005). Sunlight illuminates each scene from the northwest (top left). The 150-meter scale bar represents 164 yards. Figure B: This is a mosaic of images that cover the entire unnamed crater in Terra Sirenum. The location of the light-toned gully deposits, old and new, is indicated. This is a mosaic of images acquired by the camera in 2005 and 2006. The 500-meter scale bar equals approximately 547 yards. Figure C: This image shows an enlargement of a portion of another image from August 2005, showing details of the new, light-toned gully deposit. The new material covers the entire gully floor, from the point at which the gully emerged from beneath a mantled slope, down to the spot at which the channel meets the crater floor. At this break in slope, the gully material, as it was emplaced, spread out into five or six different fingers (this is called a "digitate" termination as in finger digits). The 75-meter scale bar represents a distance of about 82 yards. Figure D: To confirm that the new, light-toned gully deposit is not just a trick of changing, Laboratory, Pasadena, Calif., a division of the California Institute of Technology, also in Pasadena. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Malin Space Science Systems, San Diego, Calif., built and operates the Mars Orbiter Camera. For more information about images from the Mars Orbiter Camera, see http://www.msss.com/mgs/moc/index.html [ http://www.msss.com/mgs/moc/index.html ]., illumination conditions as the sun rises to different levels in the sky each season, the Mars Orbiter Camera team repeatedly imaged this site throughout 2005 and 2006. Four examples are shown here, acquired in April 2005, August 2005, February 2006 and April 2006. The "i=" indicates solar-incidence angle, or the height of the sun in the local sky, relative to a case where the sun would be directly overhead (i=0 degrees). Thus, the higher the incidence angle, the lower the sun would appear in the sky to an observer on the ground. These images show that a material flowed down through a gully channel, once between December 2001 and April 2005. After the flow stopped, it left behind evidence -- the light-toned deposit. The deposit is thin enough that its thickness cannot be measured in the camera's 1.5-meters-per-pixel images. However, it does exhibit a digitate termination, suggesting that the material flowed in a fluid-like manner down the approximately 25 degree slope before splaying out into multiple small lobes at the point where the crater wall meets the crater floor and the slope suddenly drops to near zero. This deposit, and a similar one in a crater in the Centauri Montes, together suggests that the materials involved were low-volume debris flows containing a mixture of sediment and a liquid that had the physical properties of liquid water. In this case, we propose that the water came from below the surface, emerged somewhere beneath the mantle covering the original crater wall, and then ran down through a previously existing gully channel. No new gully was formed, but an old one was re-activated. The light tone of the new gully deposit, and that of the older, neighboring gullies, is intriguing. We cannot know from these images whether the light tone indicates that ice is still present in and on the surface of the deposit. Indeed, ice may not be likely: under present conditions on the surface of Mars, ice would be expected to have sublimed, or vaporized, away fairly shortly after the new deposit formed. However, the light-toned material could be frost that forms and re-forms frequently as trapped water-ice sublimes and "exhales" from within the deposit. Alternatively, the light-tone may result if the deposit consists of significantly finer grains (for example, fine silt) than the surrounding surfaces, or if the deposit's surface is covered with minerals such as salts formed as water evaporated from the material. Do these images prove that water has flowed on Mars? No, they cannot. However, they provide the first very tantalizing evidence that this may have occurred. While the surface environment on Mars is extremely dry, drier than the most arid deserts on Earth, liquid water from beneath the Martian surface may have come out of the ground and flowed across this little portion of the red planet in this decade. The Mars Global Surveyor mission is managed for NASA's Office of Space Science, Washington, by NASA's Jet Propulsion |
|
New Gully Deposit in a Crate
…
PIA09027
Sol (our sun)
Mars Orbiter Camera
| Title |
New Gully Deposit in a Crater in Terra Sirenum |
| Original Caption Released with Image |
Has liquid water flowed on Mars in this decade? In June 2000, we reported the discovery, using the Mars Global Surveyor's Mars Orbiter Camera, of very youthful-looking gullies found on slopes at middle and high latitudes on Mars. Since that time, tens of thousands of gullies have been imaged by all of the Mars orbiting spacecraft: Mars Global Surveyor, Mars Odyssey, Mars Express and Mars Reconnaissance Orbiter. During the years since the original June 2000 report, the Mars Global Surveyor's camera was used to test the hypothesis that the gullies may be so young that some of them could still be active today. The test was very simple: re-image gullies previously seen by the camera and see if anything has changed. In two cases, something changed. One of those cases is presented here. A gully on the wall of an unnamed crater in Terra Sirenum, at 36.6 degrees south, 161.8 degrees west, was initially imaged by the camera on Dec. 22, 2001 (Figure A, left). It showed nothing noteworthy at the location where a change would later be observed, but a group of nearby gullies exhibited an unusual patch of light-toned material. As part of our routine campaign to re-image gully sites using the camera, another image of this location was acquired on April 24, 2005. A new light-toned deposit had appeared in what was otherwise a nondescript gully (Figure A, right). This deposit was imaged again by the camera on Aug. 26, 2005, at a time when the sun angle and season were the same as in the original December 2001 image, to confirm that indeed the light-toned feature was something new, not just a trick of differing lighting conditions. In August 2005, the feature was still present. Figure A: This set of images shows a comparison of the gully site as it appeared on Dec. 22, 2001 (left), with a mosaic of two images acquired after the change occurred (the two images are from Aug. 26, 2005, and Sept. 25, 2005). Sunlight illuminates each scene from the northwest (top left). The 150-meter scale bar represents 164 yards. Figure B: This is a mosaic of images that cover the entire unnamed crater in Terra Sirenum. The location of the light-toned gully deposits, old and new, is indicated. This is a mosaic of images acquired by the camera in 2005 and 2006. The 500-meter scale bar equals approximately 547 yards. Figure C: This image shows an enlargement of a portion of another image from August 2005, showing details of the new, light-toned gully deposit. The new material covers the entire gully floor, from the point at which the gully emerged from beneath a mantled slope, down to the spot at which the channel meets the crater floor. At this break in slope, the gully material, as it was emplaced, spread out into five or six different fingers (this is called a "digitate" termination as in finger digits). The 75-meter scale bar represents a distance of about 82 yards. Figure D: To confirm that the new, light-toned gully deposit is not just a trick of changing, Laboratory, Pasadena, Calif., a division of the California Institute of Technology, also in Pasadena. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Malin Space Science Systems, San Diego, Calif., built and operates the Mars Orbiter Camera. For more information about images from the Mars Orbiter Camera, see http://www.msss.com/mgs/moc/index.html [ http://www.msss.com/mgs/moc/index.html ]., illumination conditions as the sun rises to different levels in the sky each season, the Mars Orbiter Camera team repeatedly imaged this site throughout 2005 and 2006. Four examples are shown here, acquired in April 2005, August 2005, February 2006 and April 2006. The "i=" indicates solar-incidence angle, or the height of the sun in the local sky, relative to a case where the sun would be directly overhead (i=0 degrees). Thus, the higher the incidence angle, the lower the sun would appear in the sky to an observer on the ground. These images show that a material flowed down through a gully channel, once between December 2001 and April 2005. After the flow stopped, it left behind evidence -- the light-toned deposit. The deposit is thin enough that its thickness cannot be measured in the camera's 1.5-meters-per-pixel images. However, it does exhibit a digitate termination, suggesting that the material flowed in a fluid-like manner down the approximately 25 degree slope before splaying out into multiple small lobes at the point where the crater wall meets the crater floor and the slope suddenly drops to near zero. This deposit, and a similar one in a crater in the Centauri Montes, together suggests that the materials involved were low-volume debris flows containing a mixture of sediment and a liquid that had the physical properties of liquid water. In this case, we propose that the water came from below the surface, emerged somewhere beneath the mantle covering the original crater wall, and then ran down through a previously existing gully channel. No new gully was formed, but an old one was re-activated. The light tone of the new gully deposit, and that of the older, neighboring gullies, is intriguing. We cannot know from these images whether the light tone indicates that ice is still present in and on the surface of the deposit. Indeed, ice may not be likely: under present conditions on the surface of Mars, ice would be expected to have sublimed, or vaporized, away fairly shortly after the new deposit formed. However, the light-toned material could be frost that forms and re-forms frequently as trapped water-ice sublimes and "exhales" from within the deposit. Alternatively, the light-tone may result if the deposit consists of significantly finer grains (for example, fine silt) than the surrounding surfaces, or if the deposit's surface is covered with minerals such as salts formed as water evaporated from the material. Do these images prove that water has flowed on Mars? No, they cannot. However, they provide the first very tantalizing evidence that this may have occurred. While the surface environment on Mars is extremely dry, drier than the most arid deserts on Earth, liquid water from beneath the Martian surface may have come out of the ground and flowed across this little portion of the red planet in this decade. The Mars Global Surveyor mission is managed for NASA's Office of Space Science, Washington, by NASA's Jet Propulsion |
|
Procedure for Finding New Im
…
PIA09021
Sol (our sun)
Mars Orbiter Camera
| Title |
Procedure for Finding New Impact Sites on Mars Using the Mars Global Surveyor Mars Orbiter Camera |
| Original Caption Released with Image |
), the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) science operations team considered it possible to find more such impact sites using the MOC red wide angle camera. The most recent, freshest craters would be expected to be quite small, ranging from a few meters across to maybe a few hundred meters or so, at most, in diameter (100 meters is about 109 yards, compare that with a 100 yard U.S.-style football field). Something less than 100 meters across would not show up easily in a 240 meters per pixel red wide angle image. But the 6 January 2006 image showed that it could, because these small impacts, if they occur in an area thickly mantled with dust, will create a much larger "blast zone" around them. Thus, the MOC science operations team set out to image a few of the dustiest regions on Mars -- Tharsis, Amazonis, and Arabia -- with the red wide angle camera. The same camera had, in May and early June 1999, already imaged most of the planet at about 240 meters per pixel scale. By repeating areas already imaged in May/June 1999 during the January/March 2006 timeframe, we would be able to identify more dark spots. And, so, that is what we did. The Tharsis, Amazonis, and Arabia regions were re-imaged using the MOC red wide angle camera during January through March 2006. The data covered about 21,506,000 square kilometers (~8.3 million square miles, ~1/3 the surface area of Mars and more than twice the area of the United States). As each picture was received on Earth, we compared it with the images acquired during May/June 1999. Over the entire area surveyed, we found 39 dark spots that were present in early 2006 but not visible in May/June 1999. The 39 dark spots, then, were the candidate impact sites. Each one of these became a target for the MOC narrow angle camera, which would be used to take an image of about 1.5 meters (4.9 feet) per pixel of each site. The targets were entered into the MOC database. Then, as the predicted MGS ground track came near each site, the MOC team targeted an image by working with the spacecraft engineers at Lockheed Martin Astronautics (Denver, Colorado) and the Caltech/Jet Propulsion Laboratory (JPL, Pasadena, California) to point the spacecraft and camera at each site using the Roll Only Targeted Observation (ROTO) maneuver. Of the 39 dark spots, 20 turned out to be fresh impact sites, and 19 of them were not. The other 19 included mistaken identifications (one was a transient, large dust devil shadow, several were craters that had been present in earlier images but had changed in brightness owing to dust removal), new dark wind streaks, and new dark slope streaks created by avalanching dust on steep slopes. Some of the 20 new impact sites received further attention, as the spacecraft and MOC were used to obtain cPROTO (compensated Pitch and Roll Targeted Observations) views that have a spatial resolution of 0.5 meters (1.6 feet) in the downtrack dimension and 1.5 meters (4.9 feet) in the cross, Having realized that a new dark spot on Mars, seen in a red wide angle camera image acquired on 6 January 2006, might be an indication of a recent meteor impact site (see PIA09020 [ http://photojournal.jpl.nasa.gov/catalog/PIA09020 ] or MOC2-1611 [ http://www.msss.com/mars_images/moc/2006/12/06/craters/site1/index.html ], track direction. The cPROTO views, where obtained, have a higher resolution and better signal-to-noise ratio than the original ROTO images. Finally, while our approach of comparing MOC red wide angle camera images obtained in May/June 1999 with those obtained in January/March 2006 constrains the 20 craters all to having formed during the May 1999 to March 2006 time interval, we found in all cases that there were already other images that had been received on Earth that helped constrain the time of the impact more tightly. In some cases, the date of the impact could be pinned down to within a month or two, in other cases the interval covered several years. Data from the MGS MOC, Mars Odyssey Thermal Emission Imaging System (THEMIS) [ http://themis.asu.edu/ ], and Mars Express High Resolution Stereo Camera (HRSC) [ http://berlinadmin.dlr.de/Missions/express/indexeng.shtml ], were all employed in the search. Shown on this page (above) are pictures that illustrate our work to find new impact craters: Figure A: This picture shows one of the new impact sites identified by the MOC team. Located in northern Arabia Terra near 29.3°N, 333.2°W, the actual crater is quite small, only 11.2 ± 3.0 meters in diameter. This is a sub-frame of MOC image S16-01105, acquired using a ROTO maneuver on 12 March 2006. Figures B and C: These pictures are MOC red wide angle camera images, obtained at a scale of about 240 meters per pixel, of portions of Arabia Terra. Figure B is M01-01610 and was acquired during the MOC Geodesy Campaign (see PIA02022 and PIA02023, or MOC2-127) on 14 May 1999. Figure C, MOC S14-02741, was obtained on 26 January 2006 as part of the campaign to find new impact craters. By comparing the two images, one from 1999 and one from 2006, we were able to identify all new dark spots that formed during that interval. In this case, the new dark spot seen in the 2006 image, S14-02741, is inside the white circle. The same location is also indicated by a circle in the May 1999 image, but no dark spot is present there. In both cases, the white circle is about 12 km (7.5 mi) across. Figure D: This map of Mars, showing the location of all the MOC red wide angle camera images acquired for the search for new craters during January through March 2006. These images cover most of Amazonis, Tharsis, and Arabia Terra. The base map is a product that combines the May/June 1999 MOC red wide angle data (plus later data for the south polar region) and laser altimeter data from MGS. Figure E: This picture shows portions of two red wide angle camera context images that more tightly constrain when the new crater shown here (above, top, left) formed. The first picture, R05-00427, was acquired on 5 May 2003 and shows no dark spot at the site of the impact. The second picture, S05-01885, shows that the dark spot was present on 29 April 2005. Thus, these two images tell us that the impact occurred sometime between those dates: 5 May 2003 and 29 April 2005. The Mars Global Surveyor mission is managed for NASA's Office of Space Science, Washington, by the Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Malin Space Science Systems, San Diego, Calif., built and operates the Mars Orbiter Camera. For more information about images from the Mars Orbiter Camera, see http://www.msss.com/mgs/moc/index.html [ http://www.msss.com/mgs/moc/index.html ]. |
|
Procedure for Finding New Im
…
PIA09021
Sol (our sun)
Mars Orbiter Camera
| Title |
Procedure for Finding New Impact Sites on Mars Using the Mars Global Surveyor Mars Orbiter Camera |
| Original Caption Released with Image |
), the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) science operations team considered it possible to find more such impact sites using the MOC red wide angle camera. The most recent, freshest craters would be expected to be quite small, ranging from a few meters across to maybe a few hundred meters or so, at most, in diameter (100 meters is about 109 yards, compare that with a 100 yard U.S.-style football field). Something less than 100 meters across would not show up easily in a 240 meters per pixel red wide angle image. But the 6 January 2006 image showed that it could, because these small impacts, if they occur in an area thickly mantled with dust, will create a much larger "blast zone" around them. Thus, the MOC science operations team set out to image a few of the dustiest regions on Mars -- Tharsis, Amazonis, and Arabia -- with the red wide angle camera. The same camera had, in May and early June 1999, already imaged most of the planet at about 240 meters per pixel scale. By repeating areas already imaged in May/June 1999 during the January/March 2006 timeframe, we would be able to identify more dark spots. And, so, that is what we did. The Tharsis, Amazonis, and Arabia regions were re-imaged using the MOC red wide angle camera during January through March 2006. The data covered about 21,506,000 square kilometers (~8.3 million square miles, ~1/3 the surface area of Mars and more than twice the area of the United States). As each picture was received on Earth, we compared it with the images acquired during May/June 1999. Over the entire area surveyed, we found 39 dark spots that were present in early 2006 but not visible in May/June 1999. The 39 dark spots, then, were the candidate impact sites. Each one of these became a target for the MOC narrow angle camera, which would be used to take an image of about 1.5 meters (4.9 feet) per pixel of each site. The targets were entered into the MOC database. Then, as the predicted MGS ground track came near each site, the MOC team targeted an image by working with the spacecraft engineers at Lockheed Martin Astronautics (Denver, Colorado) and the Caltech/Jet Propulsion Laboratory (JPL, Pasadena, California) to point the spacecraft and camera at each site using the Roll Only Targeted Observation (ROTO) maneuver. Of the 39 dark spots, 20 turned out to be fresh impact sites, and 19 of them were not. The other 19 included mistaken identifications (one was a transient, large dust devil shadow, several were craters that had been present in earlier images but had changed in brightness owing to dust removal), new dark wind streaks, and new dark slope streaks created by avalanching dust on steep slopes. Some of the 20 new impact sites received further attention, as the spacecraft and MOC were used to obtain cPROTO (compensated Pitch and Roll Targeted Observations) views that have a spatial resolution of 0.5 meters (1.6 feet) in the downtrack dimension and 1.5 meters (4.9 feet) in the cross, Having realized that a new dark spot on Mars, seen in a red wide angle camera image acquired on 6 January 2006, might be an indication of a recent meteor impact site (see PIA09020 [ http://photojournal.jpl.nasa.gov/catalog/PIA09020 ] or MOC2-1611 [ http://www.msss.com/mars_images/moc/2006/12/06/craters/site1/index.html ], track direction. The cPROTO views, where obtained, have a higher resolution and better signal-to-noise ratio than the original ROTO images. Finally, while our approach of comparing MOC red wide angle camera images obtained in May/June 1999 with those obtained in January/March 2006 constrains the 20 craters all to having formed during the May 1999 to March 2006 time interval, we found in all cases that there were already other images that had been received on Earth that helped constrain the time of the impact more tightly. In some cases, the date of the impact could be pinned down to within a month or two, in other cases the interval covered several years. Data from the MGS MOC, Mars Odyssey Thermal Emission Imaging System (THEMIS) [ http://themis.asu.edu/ ], and Mars Express High Resolution Stereo Camera (HRSC) [ http://berlinadmin.dlr.de/Missions/express/indexeng.shtml ], were all employed in the search. Shown on this page (above) are pictures that illustrate our work to find new impact craters: Figure A: This picture shows one of the new impact sites identified by the MOC team. Located in northern Arabia Terra near 29.3°N, 333.2°W, the actual crater is quite small, only 11.2 ± 3.0 meters in diameter. This is a sub-frame of MOC image S16-01105, acquired using a ROTO maneuver on 12 March 2006. Figures B and C: These pictures are MOC red wide angle camera images, obtained at a scale of about 240 meters per pixel, of portions of Arabia Terra. Figure B is M01-01610 and was acquired during the MOC Geodesy Campaign (see PIA02022 and PIA02023, or MOC2-127) on 14 May 1999. Figure C, MOC S14-02741, was obtained on 26 January 2006 as part of the campaign to find new impact craters. By comparing the two images, one from 1999 and one from 2006, we were able to identify all new dark spots that formed during that interval. In this case, the new dark spot seen in the 2006 image, S14-02741, is inside the white circle. The same location is also indicated by a circle in the May 1999 image, but no dark spot is present there. In both cases, the white circle is about 12 km (7.5 mi) across. Figure D: This map of Mars, showing the location of all the MOC red wide angle camera images acquired for the search for new craters during January through March 2006. These images cover most of Amazonis, Tharsis, and Arabia Terra. The base map is a product that combines the May/June 1999 MOC red wide angle data (plus later data for the south polar region) and laser altimeter data from MGS. Figure E: This picture shows portions of two red wide angle camera context images that more tightly constrain when the new crater shown here (above, top, left) formed. The first picture, R05-00427, was acquired on 5 May 2003 and shows no dark spot at the site of the impact. The second picture, S05-01885, shows that the dark spot was present on 29 April 2005. Thus, these two images tell us that the impact occurred sometime between those dates: 5 May 2003 and 29 April 2005. The Mars Global Surveyor mission is managed for NASA's Office of Space Science, Washington, by the Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Malin Space Science Systems, San Diego, Calif., built and operates the Mars Orbiter Camera. For more information about images from the Mars Orbiter Camera, see http://www.msss.com/mgs/moc/index.html [ http://www.msss.com/mgs/moc/index.html ]. |
|
Procedure for Finding New Im
…
PIA09021
Sol (our sun)
Mars Orbiter Camera
| Title |
Procedure for Finding New Impact Sites on Mars Using the Mars Global Surveyor Mars Orbiter Camera |
| Original Caption Released with Image |
), the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) science operations team considered it possible to find more such impact sites using the MOC red wide angle camera. The most recent, freshest craters would be expected to be quite small, ranging from a few meters across to maybe a few hundred meters or so, at most, in diameter (100 meters is about 109 yards, compare that with a 100 yard U.S.-style football field). Something less than 100 meters across would not show up easily in a 240 meters per pixel red wide angle image. But the 6 January 2006 image showed that it could, because these small impacts, if they occur in an area thickly mantled with dust, will create a much larger "blast zone" around them. Thus, the MOC science operations team set out to image a few of the dustiest regions on Mars -- Tharsis, Amazonis, and Arabia -- with the red wide angle camera. The same camera had, in May and early June 1999, already imaged most of the planet at about 240 meters per pixel scale. By repeating areas already imaged in May/June 1999 during the January/March 2006 timeframe, we would be able to identify more dark spots. And, so, that is what we did. The Tharsis, Amazonis, and Arabia regions were re-imaged using the MOC red wide angle camera during January through March 2006. The data covered about 21,506,000 square kilometers (~8.3 million square miles, ~1/3 the surface area of Mars and more than twice the area of the United States). As each picture was received on Earth, we compared it with the images acquired during May/June 1999. Over the entire area surveyed, we found 39 dark spots that were present in early 2006 but not visible in May/June 1999. The 39 dark spots, then, were the candidate impact sites. Each one of these became a target for the MOC narrow angle camera, which would be used to take an image of about 1.5 meters (4.9 feet) per pixel of each site. The targets were entered into the MOC database. Then, as the predicted MGS ground track came near each site, the MOC team targeted an image by working with the spacecraft engineers at Lockheed Martin Astronautics (Denver, Colorado) and the Caltech/Jet Propulsion Laboratory (JPL, Pasadena, California) to point the spacecraft and camera at each site using the Roll Only Targeted Observation (ROTO) maneuver. Of the 39 dark spots, 20 turned out to be fresh impact sites, and 19 of them were not. The other 19 included mistaken identifications (one was a transient, large dust devil shadow, several were craters that had been present in earlier images but had changed in brightness owing to dust removal), new dark wind streaks, and new dark slope streaks created by avalanching dust on steep slopes. Some of the 20 new impact sites received further attention, as the spacecraft and MOC were used to obtain cPROTO (compensated Pitch and Roll Targeted Observations) views that have a spatial resolution of 0.5 meters (1.6 feet) in the downtrack dimension and 1.5 meters (4.9 feet) in the cross, Having realized that a new dark spot on Mars, seen in a red wide angle camera image acquired on 6 January 2006, might be an indication of a recent meteor impact site (see PIA09020 [ http://photojournal.jpl.nasa.gov/catalog/PIA09020 ] or MOC2-1611 [ http://www.msss.com/mars_images/moc/2006/12/06/craters/site1/index.html ], track direction. The cPROTO views, where obtained, have a higher resolution and better signal-to-noise ratio than the original ROTO images. Finally, while our approach of comparing MOC red wide angle camera images obtained in May/June 1999 with those obtained in January/March 2006 constrains the 20 craters all to having formed during the May 1999 to March 2006 time interval, we found in all cases that there were already other images that had been received on Earth that helped constrain the time of the impact more tightly. In some cases, the date of the impact could be pinned down to within a month or two, in other cases the interval covered several years. Data from the MGS MOC, Mars Odyssey Thermal Emission Imaging System (THEMIS) [ http://themis.asu.edu/ ], and Mars Express High Resolution Stereo Camera (HRSC) [ http://berlinadmin.dlr.de/Missions/express/indexeng.shtml ], were all employed in the search. Shown on this page (above) are pictures that illustrate our work to find new impact craters: Figure A: This picture shows one of the new impact sites identified by the MOC team. Located in northern Arabia Terra near 29.3°N, 333.2°W, the actual crater is quite small, only 11.2 ± 3.0 meters in diameter. This is a sub-frame of MOC image S16-01105, acquired using a ROTO maneuver on 12 March 2006. Figures B and C: These pictures are MOC red wide angle camera images, obtained at a scale of about 240 meters per pixel, of portions of Arabia Terra. Figure B is M01-01610 and was acquired during the MOC Geodesy Campaign (see PIA02022 and PIA02023, or MOC2-127) on 14 May 1999. Figure C, MOC S14-02741, was obtained on 26 January 2006 as part of the campaign to find new impact craters. By comparing the two images, one from 1999 and one from 2006, we were able to identify all new dark spots that formed during that interval. In this case, the new dark spot seen in the 2006 image, S14-02741, is inside the white circle. The same location is also indicated by a circle in the May 1999 image, but no dark spot is present there. In both cases, the white circle is about 12 km (7.5 mi) across. Figure D: This map of Mars, showing the location of all the MOC red wide angle camera images acquired for the search for new craters during January through March 2006. These images cover most of Amazonis, Tharsis, and Arabia Terra. The base map is a product that combines the May/June 1999 MOC red wide angle data (plus later data for the south polar region) and laser altimeter data from MGS. Figure E: This picture shows portions of two red wide angle camera context images that more tightly constrain when the new crater shown here (above, top, left) formed. The first picture, R05-00427, was acquired on 5 May 2003 and shows no dark spot at the site of the impact. The second picture, S05-01885, shows that the dark spot was present on 29 April 2005. Thus, these two images tell us that the impact occurred sometime between those dates: 5 May 2003 and 29 April 2005. The Mars Global Surveyor mission is managed for NASA's Office of Space Science, Washington, by the Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Malin Space Science Systems, San Diego, Calif., built and operates the Mars Orbiter Camera. For more information about images from the Mars Orbiter Camera, see http://www.msss.com/mgs/moc/index.html [ http://www.msss.com/mgs/moc/index.html ]. |
|
Procedure for Finding New Im
…
PIA09021
Sol (our sun)
Mars Orbiter Camera
| Title |
Procedure for Finding New Impact Sites on Mars Using the Mars Global Surveyor Mars Orbiter Camera |
| Original Caption Released with Image |
), the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) science operations team considered it possible to find more such impact sites using the MOC red wide angle camera. The most recent, freshest craters would be expected to be quite small, ranging from a few meters across to maybe a few hundred meters or so, at most, in diameter (100 meters is about 109 yards, compare that with a 100 yard U.S.-style football field). Something less than 100 meters across would not show up easily in a 240 meters per pixel red wide angle image. But the 6 January 2006 image showed that it could, because these small impacts, if they occur in an area thickly mantled with dust, will create a much larger "blast zone" around them. Thus, the MOC science operations team set out to image a few of the dustiest regions on Mars -- Tharsis, Amazonis, and Arabia -- with the red wide angle camera. The same camera had, in May and early June 1999, already imaged most of the planet at about 240 meters per pixel scale. By repeating areas already imaged in May/June 1999 during the January/March 2006 timeframe, we would be able to identify more dark spots. And, so, that is what we did. The Tharsis, Amazonis, and Arabia regions were re-imaged using the MOC red wide angle camera during January through March 2006. The data covered about 21,506,000 square kilometers (~8.3 million square miles, ~1/3 the surface area of Mars and more than twice the area of the United States). As each picture was received on Earth, we compared it with the images acquired during May/June 1999. Over the entire area surveyed, we found 39 dark spots that were present in early 2006 but not visible in May/June 1999. The 39 dark spots, then, were the candidate impact sites. Each one of these became a target for the MOC narrow angle camera, which would be used to take an image of about 1.5 meters (4.9 feet) per pixel of each site. The targets were entered into the MOC database. Then, as the predicted MGS ground track came near each site, the MOC team targeted an image by working with the spacecraft engineers at Lockheed Martin Astronautics (Denver, Colorado) and the Caltech/Jet Propulsion Laboratory (JPL, Pasadena, California) to point the spacecraft and camera at each site using the Roll Only Targeted Observation (ROTO) maneuver. Of the 39 dark spots, 20 turned out to be fresh impact sites, and 19 of them were not. The other 19 included mistaken identifications (one was a transient, large dust devil shadow, several were craters that had been present in earlier images but had changed in brightness owing to dust removal), new dark wind streaks, and new dark slope streaks created by avalanching dust on steep slopes. Some of the 20 new impact sites received further attention, as the spacecraft and MOC were used to obtain cPROTO (compensated Pitch and Roll Targeted Observations) views that have a spatial resolution of 0.5 meters (1.6 feet) in the downtrack dimension and 1.5 meters (4.9 feet) in the cross, Having realized that a new dark spot on Mars, seen in a red wide angle camera image acquired on 6 January 2006, might be an indication of a recent meteor impact site (see PIA09020 [ http://photojournal.jpl.nasa.gov/catalog/PIA09020 ] or MOC2-1611 [ http://www.msss.com/mars_images/moc/2006/12/06/craters/site1/index.html ], track direction. The cPROTO views, where obtained, have a higher resolution and better signal-to-noise ratio than the original ROTO images. Finally, while our approach of comparing MOC red wide angle camera images obtained in May/June 1999 with those obtained in January/March 2006 constrains the 20 craters all to having formed during the May 1999 to March 2006 time interval, we found in all cases that there were already other images that had been received on Earth that helped constrain the time of the impact more tightly. In some cases, the date of the impact could be pinned down to within a month or two, in other cases the interval covered several years. Data from the MGS MOC, Mars Odyssey Thermal Emission Imaging System (THEMIS) [ http://themis.asu.edu/ ], and Mars Express High Resolution Stereo Camera (HRSC) [ http://berlinadmin.dlr.de/Missions/express/indexeng.shtml ], were all employed in the search. Shown on this page (above) are pictures that illustrate our work to find new impact craters: Figure A: This picture shows one of the new impact sites identified by the MOC team. Located in northern Arabia Terra near 29.3°N, 333.2°W, the actual crater is quite small, only 11.2 ± 3.0 meters in diameter. This is a sub-frame of MOC image S16-01105, acquired using a ROTO maneuver on 12 March 2006. Figures B and C: These pictures are MOC red wide angle camera images, obtained at a scale of about 240 meters per pixel, of portions of Arabia Terra. Figure B is M01-01610 and was acquired during the MOC Geodesy Campaign (see PIA02022 and PIA02023, or MOC2-127) on 14 May 1999. Figure C, MOC S14-02741, was obtained on 26 January 2006 as part of the campaign to find new impact craters. By comparing the two images, one from 1999 and one from 2006, we were able to identify all new dark spots that formed during that interval. In this case, the new dark spot seen in the 2006 image, S14-02741, is inside the white circle. The same location is also indicated by a circle in the May 1999 image, but no dark spot is present there. In both cases, the white circle is about 12 km (7.5 mi) across. Figure D: This map of Mars, showing the location of all the MOC red wide angle camera images acquired for the search for new craters during January through March 2006. These images cover most of Amazonis, Tharsis, and Arabia Terra. The base map is a product that combines the May/June 1999 MOC red wide angle data (plus later data for the south polar region) and laser altimeter data from MGS. Figure E: This picture shows portions of two red wide angle camera context images that more tightly constrain when the new crater shown here (above, top, left) formed. The first picture, R05-00427, was acquired on 5 May 2003 and shows no dark spot at the site of the impact. The second picture, S05-01885, shows that the dark spot was present on 29 April 2005. Thus, these two images tell us that the impact occurred sometime between those dates: 5 May 2003 and 29 April 2005. The Mars Global Surveyor mission is managed for NASA's Office of Space Science, Washington, by the Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Malin Space Science Systems, San Diego, Calif., built and operates the Mars Orbiter Camera. For more information about images from the Mars Orbiter Camera, see http://www.msss.com/mgs/moc/index.html [ http://www.msss.com/mgs/moc/index.html ]. |
|
Procedure for Finding New Im
…
PIA09021
Sol (our sun)
Mars Orbiter Camera
| Title |
Procedure for Finding New Impact Sites on Mars Using the Mars Global Surveyor Mars Orbiter Camera |
| Original Caption Released with Image |
), the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) science operations team considered it possible to find more such impact sites using the MOC red wide angle camera. The most recent, freshest craters would be expected to be quite small, ranging from a few meters across to maybe a few hundred meters or so, at most, in diameter (100 meters is about 109 yards, compare that with a 100 yard U.S.-style football field). Something less than 100 meters across would not show up easily in a 240 meters per pixel red wide angle image. But the 6 January 2006 image showed that it could, because these small impacts, if they occur in an area thickly mantled with dust, will create a much larger "blast zone" around them. Thus, the MOC science operations team set out to image a few of the dustiest regions on Mars -- Tharsis, Amazonis, and Arabia -- with the red wide angle camera. The same camera had, in May and early June 1999, already imaged most of the planet at about 240 meters per pixel scale. By repeating areas already imaged in May/June 1999 during the January/March 2006 timeframe, we would be able to identify more dark spots. And, so, that is what we did. The Tharsis, Amazonis, and Arabia regions were re-imaged using the MOC red wide angle camera during January through March 2006. The data covered about 21,506,000 square kilometers (~8.3 million square miles, ~1/3 the surface area of Mars and more than twice the area of the United States). As each picture was received on Earth, we compared it with the images acquired during May/June 1999. Over the entire area surveyed, we found 39 dark spots that were present in early 2006 but not visible in May/June 1999. The 39 dark spots, then, were the candidate impact sites. Each one of these became a target for the MOC narrow angle camera, which would be used to take an image of about 1.5 meters (4.9 feet) per pixel of each site. The targets were entered into the MOC database. Then, as the predicted MGS ground track came near each site, the MOC team targeted an image by working with the spacecraft engineers at Lockheed Martin Astronautics (Denver, Colorado) and the Caltech/Jet Propulsion Laboratory (JPL, Pasadena, California) to point the spacecraft and camera at each site using the Roll Only Targeted Observation (ROTO) maneuver. Of the 39 dark spots, 20 turned out to be fresh impact sites, and 19 of them were not. The other 19 included mistaken identifications (one was a transient, large dust devil shadow, several were craters that had been present in earlier images but had changed in brightness owing to dust removal), new dark wind streaks, and new dark slope streaks created by avalanching dust on steep slopes. Some of the 20 new impact sites received further attention, as the spacecraft and MOC were used to obtain cPROTO (compensated Pitch and Roll Targeted Observations) views that have a spatial resolution of 0.5 meters (1.6 feet) in the downtrack dimension and 1.5 meters (4.9 feet) in the cross, Having realized that a new dark spot on Mars, seen in a red wide angle camera image acquired on 6 January 2006, might be an indication of a recent meteor impact site (see PIA09020 [ http://photojournal.jpl.nasa.gov/catalog/PIA09020 ] or MOC2-1611 [ http://www.msss.com/mars_images/moc/2006/12/06/craters/site1/index.html ], track direction. The cPROTO views, where obtained, have a higher resolution and better signal-to-noise ratio than the original ROTO images. Finally, while our approach of comparing MOC red wide angle camera images obtained in May/June 1999 with those obtained in January/March 2006 constrains the 20 craters all to having formed during the May 1999 to March 2006 time interval, we found in all cases that there were already other images that had been received on Earth that helped constrain the time of the impact more tightly. In some cases, the date of the impact could be pinned down to within a month or two, in other cases the interval covered several years. Data from the MGS MOC, Mars Odyssey Thermal Emission Imaging System (THEMIS) [ http://themis.asu.edu/ ], and Mars Express High Resolution Stereo Camera (HRSC) [ http://berlinadmin.dlr.de/Missions/express/indexeng.shtml ], were all employed in the search. Shown on this page (above) are pictures that illustrate our work to find new impact craters: Figure A: This picture shows one of the new impact sites identified by the MOC team. Located in northern Arabia Terra near 29.3°N, 333.2°W, the actual crater is quite small, only 11.2 ± 3.0 meters in diameter. This is a sub-frame of MOC image S16-01105, acquired using a ROTO maneuver on 12 March 2006. Figures B and C: These pictures are MOC red wide angle camera images, obtained at a scale of about 240 meters per pixel, of portions of Arabia Terra. Figure B is M01-01610 and was acquired during the MOC Geodesy Campaign (see PIA02022 and PIA02023, or MOC2-127) on 14 May 1999. Figure C, MOC S14-02741, was obtained on 26 January 2006 as part of the campaign to find new impact craters. By comparing the two images, one from 1999 and one from 2006, we were able to identify all new dark spots that formed during that interval. In this case, the new dark spot seen in the 2006 image, S14-02741, is inside the white circle. The same location is also indicated by a circle in the May 1999 image, but no dark spot is present there. In both cases, the white circle is about 12 km (7.5 mi) across. Figure D: This map of Mars, showing the location of all the MOC red wide angle camera images acquired for the search for new craters during January through March 2006. These images cover most of Amazonis, Tharsis, and Arabia Terra. The base map is a product that combines the May/June 1999 MOC red wide angle data (plus later data for the south polar region) and laser altimeter data from MGS. Figure E: This picture shows portions of two red wide angle camera context images that more tightly constrain when the new crater shown here (above, top, left) formed. The first picture, R05-00427, was acquired on 5 May 2003 and shows no dark spot at the site of the impact. The second picture, S05-01885, shows that the dark spot was present on 29 April 2005. Thus, these two images tell us that the impact occurred sometime between those dates: 5 May 2003 and 29 April 2005. The Mars Global Surveyor mission is managed for NASA's Office of Space Science, Washington, by the Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Malin Space Science Systems, San Diego, Calif., built and operates the Mars Orbiter Camera. For more information about images from the Mars Orbiter Camera, see http://www.msss.com/mgs/moc/index.html [ http://www.msss.com/mgs/moc/index.html ]. |
|
Procedure for Finding New Im
…
PIA09021
Sol (our sun)
Mars Orbiter Camera
| Title |
Procedure for Finding New Impact Sites on Mars Using the Mars Global Surveyor Mars Orbiter Camera |
| Original Caption Released with Image |
), the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) science operations team considered it possible to find more such impact sites using the MOC red wide angle camera. The most recent, freshest craters would be expected to be quite small, ranging from a few meters across to maybe a few hundred meters or so, at most, in diameter (100 meters is about 109 yards, compare that with a 100 yard U.S.-style football field). Something less than 100 meters across would not show up easily in a 240 meters per pixel red wide angle image. But the 6 January 2006 image showed that it could, because these small impacts, if they occur in an area thickly mantled with dust, will create a much larger "blast zone" around them. Thus, the MOC science operations team set out to image a few of the dustiest regions on Mars -- Tharsis, Amazonis, and Arabia -- with the red wide angle camera. The same camera had, in May and early June 1999, already imaged most of the planet at about 240 meters per pixel scale. By repeating areas already imaged in May/June 1999 during the January/March 2006 timeframe, we would be able to identify more dark spots. And, so, that is what we did. The Tharsis, Amazonis, and Arabia regions were re-imaged using the MOC red wide angle camera during January through March 2006. The data covered about 21,506,000 square kilometers (~8.3 million square miles, ~1/3 the surface area of Mars and more than twice the area of the United States). As each picture was received on Earth, we compared it with the images acquired during May/June 1999. Over the entire area surveyed, we found 39 dark spots that were present in early 2006 but not visible in May/June 1999. The 39 dark spots, then, were the candidate impact sites. Each one of these became a target for the MOC narrow angle camera, which would be used to take an image of about 1.5 meters (4.9 feet) per pixel of each site. The targets were entered into the MOC database. Then, as the predicted MGS ground track came near each site, the MOC team targeted an image by working with the spacecraft engineers at Lockheed Martin Astronautics (Denver, Colorado) and the Caltech/Jet Propulsion Laboratory (JPL, Pasadena, California) to point the spacecraft and camera at each site using the Roll Only Targeted Observation (ROTO) maneuver. Of the 39 dark spots, 20 turned out to be fresh impact sites, and 19 of them were not. The other 19 included mistaken identifications (one was a transient, large dust devil shadow, several were craters that had been present in earlier images but had changed in brightness owing to dust removal), new dark wind streaks, and new dark slope streaks created by avalanching dust on steep slopes. Some of the 20 new impact sites received further attention, as the spacecraft and MOC were used to obtain cPROTO (compensated Pitch and Roll Targeted Observations) views that have a spatial resolution of 0.5 meters (1.6 feet) in the downtrack dimension and 1.5 meters (4.9 feet) in the cross, Having realized that a new dark spot on Mars, seen in a red wide angle camera image acquired on 6 January 2006, might be an indication of a recent meteor impact site (see PIA09020 [ http://photojournal.jpl.nasa.gov/catalog/PIA09020 ] or MOC2-1611 [ http://www.msss.com/mars_images/moc/2006/12/06/craters/site1/index.html ], track direction. The cPROTO views, where obtained, have a higher resolution and better signal-to-noise ratio than the original ROTO images. Finally, while our approach of comparing MOC red wide angle camera images obtained in May/June 1999 with those obtained in January/March 2006 constrains the 20 craters all to having formed during the May 1999 to March 2006 time interval, we found in all cases that there were already other images that had been received on Earth that helped constrain the time of the impact more tightly. In some cases, the date of the impact could be pinned down to within a month or two, in other cases the interval covered several years. Data from the MGS MOC, Mars Odyssey Thermal Emission Imaging System (THEMIS) [ http://themis.asu.edu/ ], and Mars Express High Resolution Stereo Camera (HRSC) [ http://berlinadmin.dlr.de/Missions/express/indexeng.shtml ], were all employed in the search. Shown on this page (above) are pictures that illustrate our work to find new impact craters: Figure A: This picture shows one of the new impact sites identified by the MOC team. Located in northern Arabia Terra near 29.3°N, 333.2°W, the actual crater is quite small, only 11.2 ± 3.0 meters in diameter. This is a sub-frame of MOC image S16-01105, acquired using a ROTO maneuver on 12 March 2006. Figures B and C: These pictures are MOC red wide angle camera images, obtained at a scale of about 240 meters per pixel, of portions of Arabia Terra. Figure B is M01-01610 and was acquired during the MOC Geodesy Campaign (see PIA02022 and PIA02023, or MOC2-127) on 14 May 1999. Figure C, MOC S14-02741, was obtained on 26 January 2006 as part of the campaign to find new impact craters. By comparing the two images, one from 1999 and one from 2006, we were able to identify all new dark spots that formed during that interval. In this case, the new dark spot seen in the 2006 image, S14-02741, is inside the white circle. The same location is also indicated by a circle in the May 1999 image, but no dark spot is present there. In both cases, the white circle is about 12 km (7.5 mi) across. Figure D: This map of Mars, showing the location of all the MOC red wide angle camera images acquired for the search for new craters during January through March 2006. These images cover most of Amazonis, Tharsis, and Arabia Terra. The base map is a product that combines the May/June 1999 MOC red wide angle data (plus later data for the south polar region) and laser altimeter data from MGS. Figure E: This picture shows portions of two red wide angle camera context images that more tightly constrain when the new crater shown here (above, top, left) formed. The first picture, R05-00427, was acquired on 5 May 2003 and shows no dark spot at the site of the impact. The second picture, S05-01885, shows that the dark spot was present on 29 April 2005. Thus, these two images tell us that the impact occurred sometime between those dates: 5 May 2003 and 29 April 2005. The Mars Global Surveyor mission is managed for NASA's Office of Space Science, Washington, by the Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Malin Space Science Systems, San Diego, Calif., built and operates the Mars Orbiter Camera. For more information about images from the Mars Orbiter Camera, see http://www.msss.com/mgs/moc/index.html [ http://www.msss.com/mgs/moc/index.html ]. |
|
Procedure for Finding New Im
…
PIA09021
Sol (our sun)
Mars Orbiter Camera
| Title |
Procedure for Finding New Impact Sites on Mars Using the Mars Global Surveyor Mars Orbiter Camera |
| Original Caption Released with Image |
), the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) science operations team considered it possible to find more such impact sites using the MOC red wide angle camera. The most recent, freshest craters would be expected to be quite small, ranging from a few meters across to maybe a few hundred meters or so, at most, in diameter (100 meters is about 109 yards, compare that with a 100 yard U.S.-style football field). Something less than 100 meters across would not show up easily in a 240 meters per pixel red wide angle image. But the 6 January 2006 image showed that it could, because these small impacts, if they occur in an area thickly mantled with dust, will create a much larger "blast zone" around them. Thus, the MOC science operations team set out to image a few of the dustiest regions on Mars -- Tharsis, Amazonis, and Arabia -- with the red wide angle camera. The same camera had, in May and early June 1999, already imaged most of the planet at about 240 meters per pixel scale. By repeating areas already imaged in May/June 1999 during the January/March 2006 timeframe, we would be able to identify more dark spots. And, so, that is what we did. The Tharsis, Amazonis, and Arabia regions were re-imaged using the MOC red wide angle camera during January through March 2006. The data covered about 21,506,000 square kilometers (~8.3 million square miles, ~1/3 the surface area of Mars and more than twice the area of the United States). As each picture was received on Earth, we compared it with the images acquired during May/June 1999. Over the entire area surveyed, we found 39 dark spots that were present in early 2006 but not visible in May/June 1999. The 39 dark spots, then, were the candidate impact sites. Each one of these became a target for the MOC narrow angle camera, which would be used to take an image of about 1.5 meters (4.9 feet) per pixel of each site. The targets were entered into the MOC database. Then, as the predicted MGS ground track came near each site, the MOC team targeted an image by working with the spacecraft engineers at Lockheed Martin Astronautics (Denver, Colorado) and the Caltech/Jet Propulsion Laboratory (JPL, Pasadena, California) to point the spacecraft and camera at each site using the Roll Only Targeted Observation (ROTO) maneuver. Of the 39 dark spots, 20 turned out to be fresh impact sites, and 19 of them were not. The other 19 included mistaken identifications (one was a transient, large dust devil shadow, several were craters that had been present in earlier images but had changed in brightness owing to dust removal), new dark wind streaks, and new dark slope streaks created by avalanching dust on steep slopes. Some of the 20 new impact sites received further attention, as the spacecraft and MOC were used to obtain cPROTO (compensated Pitch and Roll Targeted Observations) views that have a spatial resolution of 0.5 meters (1.6 feet) in the downtrack dimension and 1.5 meters (4.9 feet) in the cross, Having realized that a new dark spot on Mars, seen in a red wide angle camera image acquired on 6 January 2006, might be an indication of a recent meteor impact site (see PIA09020 [ http://photojournal.jpl.nasa.gov/catalog/PIA09020 ] or MOC2-1611 [ http://www.msss.com/mars_images/moc/2006/12/06/craters/site1/index.html ], track direction. The cPROTO views, where obtained, have a higher resolution and better signal-to-noise ratio than the original ROTO images. Finally, while our approach of comparing MOC red wide angle camera images obtained in May/June 1999 with those obtained in January/March 2006 constrains the 20 craters all to having formed during the May 1999 to March 2006 time interval, we found in all cases that there were already other images that had been received on Earth that helped constrain the time of the impact more tightly. In some cases, the date of the impact could be pinned down to within a month or two, in other cases the interval covered several years. Data from the MGS MOC, Mars Odyssey Thermal Emission Imaging System (THEMIS) [ http://themis.asu.edu/ ], and Mars Express High Resolution Stereo Camera (HRSC) [ http://berlinadmin.dlr.de/Missions/express/indexeng.shtml ], were all employed in the search. Shown on this page (above) are pictures that illustrate our work to find new impact craters: Figure A: This picture shows one of the new impact sites identified by the MOC team. Located in northern Arabia Terra near 29.3°N, 333.2°W, the actual crater is quite small, only 11.2 ± 3.0 meters in diameter. This is a sub-frame of MOC image S16-01105, acquired using a ROTO maneuver on 12 March 2006. Figures B and C: These pictures are MOC red wide angle camera images, obtained at a scale of about 240 meters per pixel, of portions of Arabia Terra. Figure B is M01-01610 and was acquired during the MOC Geodesy Campaign (see PIA02022 and PIA02023, or MOC2-127) on 14 May 1999. Figure C, MOC S14-02741, was obtained on 26 January 2006 as part of the campaign to find new impact craters. By comparing the two images, one from 1999 and one from 2006, we were able to identify all new dark spots that formed during that interval. In this case, the new dark spot seen in the 2006 image, S14-02741, is inside the white circle. The same location is also indicated by a circle in the May 1999 image, but no dark spot is present there. In both cases, the white circle is about 12 km (7.5 mi) across. Figure D: This map of Mars, showing the location of all the MOC red wide angle camera images acquired for the search for new craters during January through March 2006. These images cover most of Amazonis, Tharsis, and Arabia Terra. The base map is a product that combines the May/June 1999 MOC red wide angle data (plus later data for the south polar region) and laser altimeter data from MGS. Figure E: This picture shows portions of two red wide angle camera context images that more tightly constrain when the new crater shown here (above, top, left) formed. The first picture, R05-00427, was acquired on 5 May 2003 and shows no dark spot at the site of the impact. The second picture, S05-01885, shows that the dark spot was present on 29 April 2005. Thus, these two images tell us that the impact occurred sometime between those dates: 5 May 2003 and 29 April 2005. The Mars Global Surveyor mission is managed for NASA's Office of Space Science, Washington, by the Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Malin Space Science Systems, San Diego, Calif., built and operates the Mars Orbiter Camera. For more information about images from the Mars Orbiter Camera, see http://www.msss.com/mgs/moc/index.html [ http://www.msss.com/mgs/moc/index.html ]. |
|
New Impact Crater in Arabia
…
PIA09022
Sol (our sun)
Mars Orbiter Camera
| Title |
New Impact Crater in Arabia Terra |
| Original Caption Released with Image |
http://www.msss.com/mgs/moc/index.html [ http://www.msss.com/mgs/moc/index.html ]., The images of new martian impact craters reveal many details about the impact event that result from the manner in which the impact process interacted with the dusty surface and thin planetary atmosphere, these data are sure to keep scientists busy for years. Of the 20 new impact craters found on Mars by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) in 2006, the one shown here is perhaps the prettiest. The darkened "blast zone" around the crater exhibits considerable details about how the energy transferred from the impact to the surrounding atmosphere and dust-mantled surface interacted. Wispy dark rays and dark, annular (nearly-circular) zones surround the crater, while several chains of dark spots formed by secondary impact radiate away for hundreds of meters from the tiny crater. This impact site has a single crater of about 22.6 ± 1.7 meters (about 75 feet) in diameter. Compare this with the typical 100 yard U.S.-style football field: 75 feet is about 24.7 yards. The crater is located in Arabia Terra near 26.4°N, 336.5°W. This picture is a colorized view of the crater. The image is a sub-frame of MOC narrow angle camera image S16-01674, obtained on 20 March 2006. The color comes from a look-up table derived from the colors of Mars as seen by the Mars Reconnaissance Orbiter's High Resolution Stereo Camera (HRSC) [ http://berlinadmin.dlr.de/Missions/express/indexeng.shtml ]. Figures A and B: These pictures are grayscale composites of portions of MOC images S16-01674, S17-00795, S17-02191, and S18-01407, showing the impact site and the extensive rays developed during the impact event. These data were acquired during March, April, and May 2006. Figure C: This picture shows how the age of the crater was constrained. The first (left) is a portion of MOC red wide angle camera image R12-00786, acquired on 8 December 2003. The white circle indicates the location of the impact site, but the impact had not yet occurred. The second picture (right) shows the same MOC red wide angle image, overlain by a portion of an image from the Mars Odyssey Thermal Emission Imaging System (THEMIS) [ http://themis.asu.edu/ ]. The THEMIS image is an infrared picture (I17523014, band 9, ~12.6 micrometers) acquired on 26 November 2005. In the infrared image, the impact site shows up as a bright spot because it is warmer than its surroundings during the day. These two pictures, thus, tell us that the impact occurred some time between 8 December 2003 and 26 November 2005. The Mars Global Surveyor mission is managed for NASA's Office of Space Science, Washington, by the Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Malin Space Science Systems, San Diego, Calif., built and operates the Mars Orbiter Camera. For more information about images from the Mars Orbiter Camera, see |
|
New Impact Crater in Arabia
…
PIA09022
Sol (our sun)
Mars Orbiter Camera
| Title |
New Impact Crater in Arabia Terra |
| Original Caption Released with Image |
http://www.msss.com/mgs/moc/index.html [ http://www.msss.com/mgs/moc/index.html ]., The images of new martian impact craters reveal many details about the impact event that result from the manner in which the impact process interacted with the dusty surface and thin planetary atmosphere, these data are sure to keep scientists busy for years. Of the 20 new impact craters found on Mars by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) in 2006, the one shown here is perhaps the prettiest. The darkened "blast zone" around the crater exhibits considerable details about how the energy transferred from the impact to the surrounding atmosphere and dust-mantled surface interacted. Wispy dark rays and dark, annular (nearly-circular) zones surround the crater, while several chains of dark spots formed by secondary impact radiate away for hundreds of meters from the tiny crater. This impact site has a single crater of about 22.6 ± 1.7 meters (about 75 feet) in diameter. Compare this with the typical 100 yard U.S.-style football field: 75 feet is about 24.7 yards. The crater is located in Arabia Terra near 26.4°N, 336.5°W. This picture is a colorized view of the crater. The image is a sub-frame of MOC narrow angle camera image S16-01674, obtained on 20 March 2006. The color comes from a look-up table derived from the colors of Mars as seen by the Mars Reconnaissance Orbiter's High Resolution Stereo Camera (HRSC) [ http://berlinadmin.dlr.de/Missions/express/indexeng.shtml ]. Figures A and B: These pictures are grayscale composites of portions of MOC images S16-01674, S17-00795, S17-02191, and S18-01407, showing the impact site and the extensive rays developed during the impact event. These data were acquired during March, April, and May 2006. Figure C: This picture shows how the age of the crater was constrained. The first (left) is a portion of MOC red wide angle camera image R12-00786, acquired on 8 December 2003. The white circle indicates the location of the impact site, but the impact had not yet occurred. The second picture (right) shows the same MOC red wide angle image, overlain by a portion of an image from the Mars Odyssey Thermal Emission Imaging System (THEMIS) [ http://themis.asu.edu/ ]. The THEMIS image is an infrared picture (I17523014, band 9, ~12.6 micrometers) acquired on 26 November 2005. In the infrared image, the impact site shows up as a bright spot because it is warmer than its surroundings during the day. These two pictures, thus, tell us that the impact occurred some time between 8 December 2003 and 26 November 2005. The Mars Global Surveyor mission is managed for NASA's Office of Space Science, Washington, by the Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Malin Space Science Systems, San Diego, Calif., built and operates the Mars Orbiter Camera. For more information about images from the Mars Orbiter Camera, see |
|
New Impact Crater in Arabia
…
PIA09022
Sol (our sun)
Mars Orbiter Camera
| Title |
New Impact Crater in Arabia Terra |
| Original Caption Released with Image |
http://www.msss.com/mgs/moc/index.html [ http://www.msss.com/mgs/moc/index.html ]., The images of new martian impact craters reveal many details about the impact event that result from the manner in which the impact process interacted with the dusty surface and thin planetary atmosphere, these data are sure to keep scientists busy for years. Of the 20 new impact craters found on Mars by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) in 2006, the one shown here is perhaps the prettiest. The darkened "blast zone" around the crater exhibits considerable details about how the energy transferred from the impact to the surrounding atmosphere and dust-mantled surface interacted. Wispy dark rays and dark, annular (nearly-circular) zones surround the crater, while several chains of dark spots formed by secondary impact radiate away for hundreds of meters from the tiny crater. This impact site has a single crater of about 22.6 ± 1.7 meters (about 75 feet) in diameter. Compare this with the typical 100 yard U.S.-style football field: 75 feet is about 24.7 yards. The crater is located in Arabia Terra near 26.4°N, 336.5°W. This picture is a colorized view of the crater. The image is a sub-frame of MOC narrow angle camera image S16-01674, obtained on 20 March 2006. The color comes from a look-up table derived from the colors of Mars as seen by the Mars Reconnaissance Orbiter's High Resolution Stereo Camera (HRSC) [ http://berlinadmin.dlr.de/Missions/express/indexeng.shtml ]. Figures A and B: These pictures are grayscale composites of portions of MOC images S16-01674, S17-00795, S17-02191, and S18-01407, showing the impact site and the extensive rays developed during the impact event. These data were acquired during March, April, and May 2006. Figure C: This picture shows how the age of the crater was constrained. The first (left) is a portion of MOC red wide angle camera image R12-00786, acquired on 8 December 2003. The white circle indicates the location of the impact site, but the impact had not yet occurred. The second picture (right) shows the same MOC red wide angle image, overlain by a portion of an image from the Mars Odyssey Thermal Emission Imaging System (THEMIS) [ http://themis.asu.edu/ ]. The THEMIS image is an infrared picture (I17523014, band 9, ~12.6 micrometers) acquired on 26 November 2005. In the infrared image, the impact site shows up as a bright spot because it is warmer than its surroundings during the day. These two pictures, thus, tell us that the impact occurred some time between 8 December 2003 and 26 November 2005. The Mars Global Surveyor mission is managed for NASA's Office of Space Science, Washington, by the Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Malin Space Science Systems, San Diego, Calif., built and operates the Mars Orbiter Camera. For more information about images from the Mars Orbiter Camera, see |
|
New Impact Crater in Arabia
…
PIA09022
Sol (our sun)
Mars Orbiter Camera
| Title |
New Impact Crater in Arabia Terra |
| Original Caption Released with Image |
http://www.msss.com/mgs/moc/index.html [ http://www.msss.com/mgs/moc/index.html ]., The images of new martian impact craters reveal many details about the impact event that result from the manner in which the impact process interacted with the dusty surface and thin planetary atmosphere, these data are sure to keep scientists busy for years. Of the 20 new impact craters found on Mars by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) in 2006, the one shown here is perhaps the prettiest. The darkened "blast zone" around the crater exhibits considerable details about how the energy transferred from the impact to the surrounding atmosphere and dust-mantled surface interacted. Wispy dark rays and dark, annular (nearly-circular) zones surround the crater, while several chains of dark spots formed by secondary impact radiate away for hundreds of meters from the tiny crater. This impact site has a single crater of about 22.6 ± 1.7 meters (about 75 feet) in diameter. Compare this with the typical 100 yard U.S.-style football field: 75 feet is about 24.7 yards. The crater is located in Arabia Terra near 26.4°N, 336.5°W. This picture is a colorized view of the crater. The image is a sub-frame of MOC narrow angle camera image S16-01674, obtained on 20 March 2006. The color comes from a look-up table derived from the colors of Mars as seen by the Mars Reconnaissance Orbiter's High Resolution Stereo Camera (HRSC) [ http://berlinadmin.dlr.de/Missions/express/indexeng.shtml ]. Figures A and B: These pictures are grayscale composites of portions of MOC images S16-01674, S17-00795, S17-02191, and S18-01407, showing the impact site and the extensive rays developed during the impact event. These data were acquired during March, April, and May 2006. Figure C: This picture shows how the age of the crater was constrained. The first (left) is a portion of MOC red wide angle camera image R12-00786, acquired on 8 December 2003. The white circle indicates the location of the impact site, but the impact had not yet occurred. The second picture (right) shows the same MOC red wide angle image, overlain by a portion of an image from the Mars Odyssey Thermal Emission Imaging System (THEMIS) [ http://themis.asu.edu/ ]. The THEMIS image is an infrared picture (I17523014, band 9, ~12.6 micrometers) acquired on 26 November 2005. In the infrared image, the impact site shows up as a bright spot because it is warmer than its surroundings during the day. These two pictures, thus, tell us that the impact occurred some time between 8 December 2003 and 26 November 2005. The Mars Global Surveyor mission is managed for NASA's Office of Space Science, Washington, by the Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Malin Space Science Systems, San Diego, Calif., built and operates the Mars Orbiter Camera. For more information about images from the Mars Orbiter Camera, see |
|
New Impact Crater in Arabia
…
PIA09022
Sol (our sun)
Mars Orbiter Camera
| Title |
New Impact Crater in Arabia Terra |
| Original Caption Released with Image |
http://www.msss.com/mgs/moc/index.html [ http://www.msss.com/mgs/moc/index.html ]., The images of new martian impact craters reveal many details about the impact event that result from the manner in which the impact process interacted with the dusty surface and thin planetary atmosphere, these data are sure to keep scientists busy for years. Of the 20 new impact craters found on Mars by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) in 2006, the one shown here is perhaps the prettiest. The darkened "blast zone" around the crater exhibits considerable details about how the energy transferred from the impact to the surrounding atmosphere and dust-mantled surface interacted. Wispy dark rays and dark, annular (nearly-circular) zones surround the crater, while several chains of dark spots formed by secondary impact radiate away for hundreds of meters from the tiny crater. This impact site has a single crater of about 22.6 ± 1.7 meters (about 75 feet) in diameter. Compare this with the typical 100 yard U.S.-style football field: 75 feet is about 24.7 yards. The crater is located in Arabia Terra near 26.4°N, 336.5°W. This picture is a colorized view of the crater. The image is a sub-frame of MOC narrow angle camera image S16-01674, obtained on 20 March 2006. The color comes from a look-up table derived from the colors of Mars as seen by the Mars Reconnaissance Orbiter's High Resolution Stereo Camera (HRSC) [ http://berlinadmin.dlr.de/Missions/express/indexeng.shtml ]. Figures A and B: These pictures are grayscale composites of portions of MOC images S16-01674, S17-00795, S17-02191, and S18-01407, showing the impact site and the extensive rays developed during the impact event. These data were acquired during March, April, and May 2006. Figure C: This picture shows how the age of the crater was constrained. The first (left) is a portion of MOC red wide angle camera image R12-00786, acquired on 8 December 2003. The white circle indicates the location of the impact site, but the impact had not yet occurred. The second picture (right) shows the same MOC red wide angle image, overlain by a portion of an image from the Mars Odyssey Thermal Emission Imaging System (THEMIS) [ http://themis.asu.edu/ ]. The THEMIS image is an infrared picture (I17523014, band 9, ~12.6 micrometers) acquired on 26 November 2005. In the infrared image, the impact site shows up as a bright spot because it is warmer than its surroundings during the day. These two pictures, thus, tell us that the impact occurred some time between 8 December 2003 and 26 November 2005. The Mars Global Surveyor mission is managed for NASA's Office of Space Science, Washington, by the Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Malin Space Science Systems, San Diego, Calif., built and operates the Mars Orbiter Camera. For more information about images from the Mars Orbiter Camera, see |
|
New Impact Crater in Arabia
…
PIA09022
Sol (our sun)
Mars Orbiter Camera
| Title |
New Impact Crater in Arabia Terra |
| Original Caption Released with Image |
http://www.msss.com/mgs/moc/index.html [ http://www.msss.com/mgs/moc/index.html ]., The images of new martian impact craters reveal many details about the impact event that result from the manner in which the impact process interacted with the dusty surface and thin planetary atmosphere, these data are sure to keep scientists busy for years. Of the 20 new impact craters found on Mars by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) in 2006, the one shown here is perhaps the prettiest. The darkened "blast zone" around the crater exhibits considerable details about how the energy transferred from the impact to the surrounding atmosphere and dust-mantled surface interacted. Wispy dark rays and dark, annular (nearly-circular) zones surround the crater, while several chains of dark spots formed by secondary impact radiate away for hundreds of meters from the tiny crater. This impact site has a single crater of about 22.6 ± 1.7 meters (about 75 feet) in diameter. Compare this with the typical 100 yard U.S.-style football field: 75 feet is about 24.7 yards. The crater is located in Arabia Terra near 26.4°N, 336.5°W. This picture is a colorized view of the crater. The image is a sub-frame of MOC narrow angle camera image S16-01674, obtained on 20 March 2006. The color comes from a look-up table derived from the colors of Mars as seen by the Mars Reconnaissance Orbiter's High Resolution Stereo Camera (HRSC) [ http://berlinadmin.dlr.de/Missions/express/indexeng.shtml ]. Figures A and B: These pictures are grayscale composites of portions of MOC images S16-01674, S17-00795, S17-02191, and S18-01407, showing the impact site and the extensive rays developed during the impact event. These data were acquired during March, April, and May 2006. Figure C: This picture shows how the age of the crater was constrained. The first (left) is a portion of MOC red wide angle camera image R12-00786, acquired on 8 December 2003. The white circle indicates the location of the impact site, but the impact had not yet occurred. The second picture (right) shows the same MOC red wide angle image, overlain by a portion of an image from the Mars Odyssey Thermal Emission Imaging System (THEMIS) [ http://themis.asu.edu/ ]. The THEMIS image is an infrared picture (I17523014, band 9, ~12.6 micrometers) acquired on 26 November 2005. In the infrared image, the impact site shows up as a bright spot because it is warmer than its surroundings during the day. These two pictures, thus, tell us that the impact occurred some time between 8 December 2003 and 26 November 2005. The Mars Global Surveyor mission is managed for NASA's Office of Space Science, Washington, by the Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Malin Space Science Systems, San Diego, Calif., built and operates the Mars Orbiter Camera. For more information about images from the Mars Orbiter Camera, see |
|
New Gully Deposit in a Crate
…
PIA09028
Sol (our sun)
Mars Orbiter Camera
| Title |
New Gully Deposit in a Crater in the Centauri Montes Region |
| Original Caption Released with Image |
). The second case, in an unnamed crater in the Centauri Montes region, east of the Hellas Basin, is described here. Gullies were first described by Mars Orbiter Camera scientists in June 2000, and many examples were presented in our June 2000 web releases and in a paper published in the journal Science. Additional examples of these middle and high-latitude landforms can be seen among the other more than 1,600 web releases. The new gully deposit in an unnamed crater in the Centauri Montes region is located near 38.7 degrees south latitude, 263.3 degrees west longitude. Like the new gully deposit in Terra Sirenum, this one has a light tone relative to its surroundings. It is on an equator-facing slope on which numerous narrow gully channels occur. As this slope is always in sunlight during the afternoons when Mars Global Surveyor passes overhead, the gullies always appear somewhat "washed out," just as craters on a full Moon do when viewed from Earth with a telescope. The new, light-toned flow was first noticed by the Mars Orbiter Camera science operations team in an image acquired on Sept. 10, 2005. Re-examination of other images of this crater showed that the new deposit had actually been present on Feb. 21, 2004, when the distal (down-slope) end of the deposit was captured in other images. In February 2004, the deposit had gone unnoticed because only a small portion of it was imaged. This location was first imaged by the Mars Orbiter Camera on Aug. 30, 1999. The deposit was not present at that time. Thus, it formed between Aug. 30, 1999 and Feb. 21, 2004. Roughly 20 percent brighter than the surface as it appeared before the flow occurred, the new deposit exhibits characteristics consistent with transport and deposition of a fluid that behaved like liquid water and likely transported some fine-grained sediment along with it. The distal end of the flow broke into several branches, or digits, and the material diverted and flowed around low obstacles. As with the example in Terra Sirenum, the depth of the flow is too thin to be measured in 1.5-meter-per-pixel (1.7-yard-per-pixel) images, so a very small volume of liquid and sediment was involved. While the material flowed and easily budded into several branches, it also must have moved slow enough to not topple over some of the low obstacles in its path. This picture is a colorized view of the light-toned gully deposit, draped over a topographic image derived from Mars Global Surveyor's Mars Orbiter Laser Altimeter data. The color comes from a table derived from the colors of Mars as seen by the Mars Reconnaissance Orbiter's High Resolution Imaging Science Experiment. Figure A: This figure shows the southeast wall of the unnamed crater in the Centauri Montes region, as it appeared in August 1999, and later in September 2005. No light-toned deposit was present in August 1999, but appeared by February 2004. The 300-meter scale bar represents 328 yards. Figure B: The second figure is a, Two Martian southern mid-latitude craters have new light-toned deposits that formed in gully settings during the course of the Mars Global Surveyor mission. Images from the Mars Orbiter Camera documented one case in an unnamed crater in Terra Sirenum, described in an accompanying release (see PIA09027 [ http://photojournal.jpl.nasa.gov/catalog/PIA09027 ] or MOC2-1618 [ http://www.msss.com/mars_images/moc/2006/12/06/gullies/sirenum_crater/index.html ], mosaic of several Mars Global Surveyor images, colorized using a table derived from Mars Reconnaissance Orbiter camera color data and overlain on a sub-frame of a Mars Odyssey Thermal Emission Imaging System image. The 1-kilometer scale bar represents about 0.62 miles. Figure C: The third figure is a colorized view of the light-toned gully deposit as viewed from an oblique perspective, draped over topography derived from Mars Global Surveyor's Mars Orbiter Laser Altimeter data. The color comes from a table derived from the colors of Mars as seen by the Mars Reconnaissance Orbiter camera. The new light-toned flow, by itself, does not prove that liquid water was involved in its genesis. However, this observation and the similar light-toned flow in Terra Sirenum together show that some gully sites are indeed changing today, providing tantalizing evidence there might be sources of liquid water beneath the surface of Mars right now. In both cases, these new flows may be indicating the locations of aquifers (subsurface rocks saturated with water) that could be detected by orbiting, ground-penetrating radar systems such as the Mars Express Mars Advanced Radar for Subsurface and Ionosphere Sounding or the Mars Reconnaissance Orbiter's Mars Shallow Subsurface Radar. The Mars Global Surveyor mission is managed for NASA's Office of Space Science, Washington, by NASA's Jet Propulsion Laboratory, Pasadena, Calif., a division of the California Institute of Technology, also in Pasadena. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Malin Space Science Systems, San Diego, Calif., built and operates the Mars Orbiter Camera. For more information about images from the Mars Orbiter Camera, see http://www.msss.com/mgs/moc/index.html [ http://www.msss.com/mgs/moc/index.html ]. |
|
New Gully Deposit in a Crate
…
PIA09028
Sol (our sun)
Mars Orbiter Camera
| Title |
New Gully Deposit in a Crater in the Centauri Montes Region |
| Original Caption Released with Image |
). The second case, in an unnamed crater in the Centauri Montes region, east of the Hellas Basin, is described here. Gullies were first described by Mars Orbiter Camera scientists in June 2000, and many examples were presented in our June 2000 web releases and in a paper published in the journal Science. Additional examples of these middle and high-latitude landforms can be seen among the other more than 1,600 web releases. The new gully deposit in an unnamed crater in the Centauri Montes region is located near 38.7 degrees south latitude, 263.3 degrees west longitude. Like the new gully deposit in Terra Sirenum, this one has a light tone relative to its surroundings. It is on an equator-facing slope on which numerous narrow gully channels occur. As this slope is always in sunlight during the afternoons when Mars Global Surveyor passes overhead, the gullies always appear somewhat "washed out," just as craters on a full Moon do when viewed from Earth with a telescope. The new, light-toned flow was first noticed by the Mars Orbiter Camera science operations team in an image acquired on Sept. 10, 2005. Re-examination of other images of this crater showed that the new deposit had actually been present on Feb. 21, 2004, when the distal (down-slope) end of the deposit was captured in other images. In February 2004, the deposit had gone unnoticed because only a small portion of it was imaged. This location was first imaged by the Mars Orbiter Camera on Aug. 30, 1999. The deposit was not present at that time. Thus, it formed between Aug. 30, 1999 and Feb. 21, 2004. Roughly 20 percent brighter than the surface as it appeared before the flow occurred, the new deposit exhibits characteristics consistent with transport and deposition of a fluid that behaved like liquid water and likely transported some fine-grained sediment along with it. The distal end of the flow broke into several branches, or digits, and the material diverted and flowed around low obstacles. As with the example in Terra Sirenum, the depth of the flow is too thin to be measured in 1.5-meter-per-pixel (1.7-yard-per-pixel) images, so a very small volume of liquid and sediment was involved. While the material flowed and easily budded into several branches, it also must have moved slow enough to not topple over some of the low obstacles in its path. This picture is a colorized view of the light-toned gully deposit, draped over a topographic image derived from Mars Global Surveyor's Mars Orbiter Laser Altimeter data. The color comes from a table derived from the colors of Mars as seen by the Mars Reconnaissance Orbiter's High Resolution Imaging Science Experiment. Figure A: This figure shows the southeast wall of the unnamed crater in the Centauri Montes region, as it appeared in August 1999, and later in September 2005. No light-toned deposit was present in August 1999, but appeared by February 2004. The 300-meter scale bar represents 328 yards. Figure B: The second figure is a, Two Martian southern mid-latitude craters have new light-toned deposits that formed in gully settings during the course of the Mars Global Surveyor mission. Images from the Mars Orbiter Camera documented one case in an unnamed crater in Terra Sirenum, described in an accompanying release (see PIA09027 [ http://photojournal.jpl.nasa.gov/catalog/PIA09027 ] or MOC2-1618 [ http://www.msss.com/mars_images/moc/2006/12/06/gullies/sirenum_crater/index.html ], mosaic of several Mars Global Surveyor images, colorized using a table derived from Mars Reconnaissance Orbiter camera color data and overlain on a sub-frame of a Mars Odyssey Thermal Emission Imaging System image. The 1-kilometer scale bar represents about 0.62 miles. Figure C: The third figure is a colorized view of the light-toned gully deposit as viewed from an oblique perspective, draped over topography derived from Mars Global Surveyor's Mars Orbiter Laser Altimeter data. The color comes from a table derived from the colors of Mars as seen by the Mars Reconnaissance Orbiter camera. The new light-toned flow, by itself, does not prove that liquid water was involved in its genesis. However, this observation and the similar light-toned flow in Terra Sirenum together show that some gully sites are indeed changing today, providing tantalizing evidence there might be sources of liquid water beneath the surface of Mars right now. In both cases, these new flows may be indicating the locations of aquifers (subsurface rocks saturated with water) that could be detected by orbiting, ground-penetrating radar systems such as the Mars Express Mars Advanced Radar for Subsurface and Ionosphere Sounding or the Mars Reconnaissance Orbiter's Mars Shallow Subsurface Radar. The Mars Global Surveyor mission is managed for NASA's Office of Space Science, Washington, by NASA's Jet Propulsion Laboratory, Pasadena, Calif., a division of the California Institute of Technology, also in Pasadena. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Malin Space Science Systems, San Diego, Calif., built and operates the Mars Orbiter Camera. For more information about images from the Mars Orbiter Camera, see http://www.msss.com/mgs/moc/index.html [ http://www.msss.com/mgs/moc/index.html ]. |
|
New Gully Deposit in a Crate
…
PIA09028
Sol (our sun)
Mars Orbiter Camera
| Title |
New Gully Deposit in a Crater in the Centauri Montes Region |
| Original Caption Released with Image |
). The second case, in an unnamed crater in the Centauri Montes region, east of the Hellas Basin, is described here. Gullies were first described by Mars Orbiter Camera scientists in June 2000, and many examples were presented in our June 2000 web releases and in a paper published in the journal Science. Additional examples of these middle and high-latitude landforms can be seen among the other more than 1,600 web releases. The new gully deposit in an unnamed crater in the Centauri Montes region is located near 38.7 degrees south latitude, 263.3 degrees west longitude. Like the new gully deposit in Terra Sirenum, this one has a light tone relative to its surroundings. It is on an equator-facing slope on which numerous narrow gully channels occur. As this slope is always in sunlight during the afternoons when Mars Global Surveyor passes overhead, the gullies always appear somewhat "washed out," just as craters on a full Moon do when viewed from Earth with a telescope. The new, light-toned flow was first noticed by the Mars Orbiter Camera science operations team in an image acquired on Sept. 10, 2005. Re-examination of other images of this crater showed that the new deposit had actually been present on Feb. 21, 2004, when the distal (down-slope) end of the deposit was captured in other images. In February 2004, the deposit had gone unnoticed because only a small portion of it was imaged. This location was first imaged by the Mars Orbiter Camera on Aug. 30, 1999. The deposit was not present at that time. Thus, it formed between Aug. 30, 1999 and Feb. 21, 2004. Roughly 20 percent brighter than the surface as it appeared before the flow occurred, the new deposit exhibits characteristics consistent with transport and deposition of a fluid that behaved like liquid water and likely transported some fine-grained sediment along with it. The distal end of the flow broke into several branches, or digits, and the material diverted and flowed around low obstacles. As with the example in Terra Sirenum, the depth of the flow is too thin to be measured in 1.5-meter-per-pixel (1.7-yard-per-pixel) images, so a very small volume of liquid and sediment was involved. While the material flowed and easily budded into several branches, it also must have moved slow enough to not topple over some of the low obstacles in its path. This picture is a colorized view of the light-toned gully deposit, draped over a topographic image derived from Mars Global Surveyor's Mars Orbiter Laser Altimeter data. The color comes from a table derived from the colors of Mars as seen by the Mars Reconnaissance Orbiter's High Resolution Imaging Science Experiment. Figure A: This figure shows the southeast wall of the unnamed crater in the Centauri Montes region, as it appeared in August 1999, and later in September 2005. No light-toned deposit was present in August 1999, but appeared by February 2004. The 300-meter scale bar represents 328 yards. Figure B: The second figure is a, Two Martian southern mid-latitude craters have new light-toned deposits that formed in gully settings during the course of the Mars Global Surveyor mission. Images from the Mars Orbiter Camera documented one case in an unnamed crater in Terra Sirenum, described in an accompanying release (see PIA09027 [ http://photojournal.jpl.nasa.gov/catalog/PIA09027 ] or MOC2-1618 [ http://www.msss.com/mars_images/moc/2006/12/06/gullies/sirenum_crater/index.html ], mosaic of several Mars Global Surveyor images, colorized using a table derived from Mars Reconnaissance Orbiter camera color data and overlain on a sub-frame of a Mars Odyssey Thermal Emission Imaging System image. The 1-kilometer scale bar represents about 0.62 miles. Figure C: The third figure is a colorized view of the light-toned gully deposit as viewed from an oblique perspective, draped over topography derived from Mars Global Surveyor's Mars Orbiter Laser Altimeter data. The color comes from a table derived from the colors of Mars as seen by the Mars Reconnaissance Orbiter camera. The new light-toned flow, by itself, does not prove that liquid water was involved in its genesis. However, this observation and the similar light-toned flow in Terra Sirenum together show that some gully sites are indeed changing today, providing tantalizing evidence there might be sources of liquid water beneath the surface of Mars right now. In both cases, these new flows may be indicating the locations of aquifers (subsurface rocks saturated with water) that could be detected by orbiting, ground-penetrating radar systems such as the Mars Express Mars Advanced Radar for Subsurface and Ionosphere Sounding or the Mars Reconnaissance Orbiter's Mars Shallow Subsurface Radar. The Mars Global Surveyor mission is managed for NASA's Office of Space Science, Washington, by NASA's Jet Propulsion Laboratory, Pasadena, Calif., a division of the California Institute of Technology, also in Pasadena. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Malin Space Science Systems, San Diego, Calif., built and operates the Mars Orbiter Camera. For more information about images from the Mars Orbiter Camera, see http://www.msss.com/mgs/moc/index.html [ http://www.msss.com/mgs/moc/index.html ]. |
|
New Gully Deposit in a Crate
…
PIA09028
Sol (our sun)
Mars Orbiter Camera
| Title |
New Gully Deposit in a Crater in the Centauri Montes Region |
| Original Caption Released with Image |
). The second case, in an unnamed crater in the Centauri Montes region, east of the Hellas Basin, is described here. Gullies were first described by Mars Orbiter Camera scientists in June 2000, and many examples were presented in our June 2000 web releases and in a paper published in the journal Science. Additional examples of these middle and high-latitude landforms can be seen among the other more than 1,600 web releases. The new gully deposit in an unnamed crater in the Centauri Montes region is located near 38.7 degrees south latitude, 263.3 degrees west longitude. Like the new gully deposit in Terra Sirenum, this one has a light tone relative to its surroundings. It is on an equator-facing slope on which numerous narrow gully channels occur. As this slope is always in sunlight during the afternoons when Mars Global Surveyor passes overhead, the gullies always appear somewhat "washed out," just as craters on a full Moon do when viewed from Earth with a telescope. The new, light-toned flow was first noticed by the Mars Orbiter Camera science operations team in an image acquired on Sept. 10, 2005. Re-examination of other images of this crater showed that the new deposit had actually been present on Feb. 21, 2004, when the distal (down-slope) end of the deposit was captured in other images. In February 2004, the deposit had gone unnoticed because only a small portion of it was imaged. This location was first imaged by the Mars Orbiter Camera on Aug. 30, 1999. The deposit was not present at that time. Thus, it formed between Aug. 30, 1999 and Feb. 21, 2004. Roughly 20 percent brighter than the surface as it appeared before the flow occurred, the new deposit exhibits characteristics consistent with transport and deposition of a fluid that behaved like liquid water and likely transported some fine-grained sediment along with it. The distal end of the flow broke into several branches, or digits, and the material diverted and flowed around low obstacles. As with the example in Terra Sirenum, the depth of the flow is too thin to be measured in 1.5-meter-per-pixel (1.7-yard-per-pixel) images, so a very small volume of liquid and sediment was involved. While the material flowed and easily budded into several branches, it also must have moved slow enough to not topple over some of the low obstacles in its path. This picture is a colorized view of the light-toned gully deposit, draped over a topographic image derived from Mars Global Surveyor's Mars Orbiter Laser Altimeter data. The color comes from a table derived from the colors of Mars as seen by the Mars Reconnaissance Orbiter's High Resolution Imaging Science Experiment. Figure A: This figure shows the southeast wall of the unnamed crater in the Centauri Montes region, as it appeared in August 1999, and later in September 2005. No light-toned deposit was present in August 1999, but appeared by February 2004. The 300-meter scale bar represents 328 yards. Figure B: The second figure is a, Two Martian southern mid-latitude craters have new light-toned deposits that formed in gully settings during the course of the Mars Global Surveyor mission. Images from the Mars Orbiter Camera documented one case in an unnamed crater in Terra Sirenum, described in an accompanying release (see PIA09027 [ http://photojournal.jpl.nasa.gov/catalog/PIA09027 ] or MOC2-1618 [ http://www.msss.com/mars_images/moc/2006/12/06/gullies/sirenum_crater/index.html ], mosaic of several Mars Global Surveyor images, colorized using a table derived from Mars Reconnaissance Orbiter camera color data and overlain on a sub-frame of a Mars Odyssey Thermal Emission Imaging System image. The 1-kilometer scale bar represents about 0.62 miles. Figure C: The third figure is a colorized view of the light-toned gully deposit as viewed from an oblique perspective, draped over topography derived from Mars Global Surveyor's Mars Orbiter Laser Altimeter data. The color comes from a table derived from the colors of Mars as seen by the Mars Reconnaissance Orbiter camera. The new light-toned flow, by itself, does not prove that liquid water was involved in its genesis. However, this observation and the similar light-toned flow in Terra Sirenum together show that some gully sites are indeed changing today, providing tantalizing evidence there might be sources of liquid water beneath the surface of Mars right now. In both cases, these new flows may be indicating the locations of aquifers (subsurface rocks saturated with water) that could be detected by orbiting, ground-penetrating radar systems such as the Mars Express Mars Advanced Radar for Subsurface and Ionosphere Sounding or the Mars Reconnaissance Orbiter's Mars Shallow Subsurface Radar. The Mars Global Surveyor mission is managed for NASA's Office of Space Science, Washington, by NASA's Jet Propulsion Laboratory, Pasadena, Calif., a division of the California Institute of Technology, also in Pasadena. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Malin Space Science Systems, San Diego, Calif., built and operates the Mars Orbiter Camera. For more information about images from the Mars Orbiter Camera, see http://www.msss.com/mgs/moc/index.html [ http://www.msss.com/mgs/moc/index.html ]. |
|
New Gully Deposit in a Crate
…
PIA09028
Sol (our sun)
Mars Orbiter Camera
| Title |
New Gully Deposit in a Crater in the Centauri Montes Region |
| Original Caption Released with Image |
). The second case, in an unnamed crater in the Centauri Montes region, east of the Hellas Basin, is described here. Gullies were first described by Mars Orbiter Camera scientists in June 2000, and many examples were presented in our June 2000 web releases and in a paper published in the journal Science. Additional examples of these middle and high-latitude landforms can be seen among the other more than 1,600 web releases. The new gully deposit in an unnamed crater in the Centauri Montes region is located near 38.7 degrees south latitude, 263.3 degrees west longitude. Like the new gully deposit in Terra Sirenum, this one has a light tone relative to its surroundings. It is on an equator-facing slope on which numerous narrow gully channels occur. As this slope is always in sunlight during the afternoons when Mars Global Surveyor passes overhead, the gullies always appear somewhat "washed out," just as craters on a full Moon do when viewed from Earth with a telescope. The new, light-toned flow was first noticed by the Mars Orbiter Camera science operations team in an image acquired on Sept. 10, 2005. Re-examination of other images of this crater showed that the new deposit had actually been present on Feb. 21, 2004, when the distal (down-slope) end of the deposit was captured in other images. In February 2004, the deposit had gone unnoticed because only a small portion of it was imaged. This location was first imaged by the Mars Orbiter Camera on Aug. 30, 1999. The deposit was not present at that time. Thus, it formed between Aug. 30, 1999 and Feb. 21, 2004. Roughly 20 percent brighter than the surface as it appeared before the flow occurred, the new deposit exhibits characteristics consistent with transport and deposition of a fluid that behaved like liquid water and likely transported some fine-grained sediment along with it. The distal end of the flow broke into several branches, or digits, and the material diverted and flowed around low obstacles. As with the example in Terra Sirenum, the depth of the flow is too thin to be measured in 1.5-meter-per-pixel (1.7-yard-per-pixel) images, so a very small volume of liquid and sediment was involved. While the material flowed and easily budded into several branches, it also must have moved slow enough to not topple over some of the low obstacles in its path. This picture is a colorized view of the light-toned gully deposit, draped over a topographic image derived from Mars Global Surveyor's Mars Orbiter Laser Altimeter data. The color comes from a table derived from the colors of Mars as seen by the Mars Reconnaissance Orbiter's High Resolution Imaging Science Experiment. Figure A: This figure shows the southeast wall of the unnamed crater in the Centauri Montes region, as it appeared in August 1999, and later in September 2005. No light-toned deposit was present in August 1999, but appeared by February 2004. The 300-meter scale bar represents 328 yards. Figure B: The second figure is a, Two Martian southern mid-latitude craters have new light-toned deposits that formed in gully settings during the course of the Mars Global Surveyor mission. Images from the Mars Orbiter Camera documented one case in an unnamed crater in Terra Sirenum, described in an accompanying release (see PIA09027 [ http://photojournal.jpl.nasa.gov/catalog/PIA09027 ] or MOC2-1618 [ http://www.msss.com/mars_images/moc/2006/12/06/gullies/sirenum_crater/index.html ], mosaic of several Mars Global Surveyor images, colorized using a table derived from Mars Reconnaissance Orbiter camera color data and overlain on a sub-frame of a Mars Odyssey Thermal Emission Imaging System image. The 1-kilometer scale bar represents about 0.62 miles. Figure C: The third figure is a colorized view of the light-toned gully deposit as viewed from an oblique perspective, draped over topography derived from Mars Global Surveyor's Mars Orbiter Laser Altimeter data. The color comes from a table derived from the colors of Mars as seen by the Mars Reconnaissance Orbiter camera. The new light-toned flow, by itself, does not prove that liquid water was involved in its genesis. However, this observation and the similar light-toned flow in Terra Sirenum together show that some gully sites are indeed changing today, providing tantalizing evidence there might be sources of liquid water beneath the surface of Mars right now. In both cases, these new flows may be indicating the locations of aquifers (subsurface rocks saturated with water) that could be detected by orbiting, ground-penetrating radar systems such as the Mars Express Mars Advanced Radar for Subsurface and Ionosphere Sounding or the Mars Reconnaissance Orbiter's Mars Shallow Subsurface Radar. The Mars Global Surveyor mission is managed for NASA's Office of Space Science, Washington, by NASA's Jet Propulsion Laboratory, Pasadena, Calif., a division of the California Institute of Technology, also in Pasadena. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Malin Space Science Systems, San Diego, Calif., built and operates the Mars Orbiter Camera. For more information about images from the Mars Orbiter Camera, see http://www.msss.com/mgs/moc/index.html [ http://www.msss.com/mgs/moc/index.html ]. |
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New Gully Deposit in a Crate
…
PIA09028
Sol (our sun)
Mars Orbiter Camera
| Title |
New Gully Deposit in a Crater in the Centauri Montes Region |
| Original Caption Released with Image |
). The second case, in an unnamed crater in the Centauri Montes region, east of the Hellas Basin, is described here. Gullies were first described by Mars Orbiter Camera scientists in June 2000, and many examples were presented in our June 2000 web releases and in a paper published in the journal Science. Additional examples of these middle and high-latitude landforms can be seen among the other more than 1,600 web releases. The new gully deposit in an unnamed crater in the Centauri Montes region is located near 38.7 degrees south latitude, 263.3 degrees west longitude. Like the new gully deposit in Terra Sirenum, this one has a light tone relative to its surroundings. It is on an equator-facing slope on which numerous narrow gully channels occur. As this slope is always in sunlight during the afternoons when Mars Global Surveyor passes overhead, the gullies always appear somewhat "washed out," just as craters on a full Moon do when viewed from Earth with a telescope. The new, light-toned flow was first noticed by the Mars Orbiter Camera science operations team in an image acquired on Sept. 10, 2005. Re-examination of other images of this crater showed that the new deposit had actually been present on Feb. 21, 2004, when the distal (down-slope) end of the deposit was captured in other images. In February 2004, the deposit had gone unnoticed because only a small portion of it was imaged. This location was first imaged by the Mars Orbiter Camera on Aug. 30, 1999. The deposit was not present at that time. Thus, it formed between Aug. 30, 1999 and Feb. 21, 2004. Roughly 20 percent brighter than the surface as it appeared before the flow occurred, the new deposit exhibits characteristics consistent with transport and deposition of a fluid that behaved like liquid water and likely transported some fine-grained sediment along with it. The distal end of the flow broke into several branches, or digits, and the material diverted and flowed around low obstacles. As with the example in Terra Sirenum, the depth of the flow is too thin to be measured in 1.5-meter-per-pixel (1.7-yard-per-pixel) images, so a very small volume of liquid and sediment was involved. While the material flowed and easily budded into several branches, it also must have moved slow enough to not topple over some of the low obstacles in its path. This picture is a colorized view of the light-toned gully deposit, draped over a topographic image derived from Mars Global Surveyor's Mars Orbiter Laser Altimeter data. The color comes from a table derived from the colors of Mars as seen by the Mars Reconnaissance Orbiter's High Resolution Imaging Science Experiment. Figure A: This figure shows the southeast wall of the unnamed crater in the Centauri Montes region, as it appeared in August 1999, and later in September 2005. No light-toned deposit was present in August 1999, but appeared by February 2004. The 300-meter scale bar represents 328 yards. Figure B: The second figure is a, Two Martian southern mid-latitude craters have new light-toned deposits that formed in gully settings during the course of the Mars Global Surveyor mission. Images from the Mars Orbiter Camera documented one case in an unnamed crater in Terra Sirenum, described in an accompanying release (see PIA09027 [ http://photojournal.jpl.nasa.gov/catalog/PIA09027 ] or MOC2-1618 [ http://www.msss.com/mars_images/moc/2006/12/06/gullies/sirenum_crater/index.html ], mosaic of several Mars Global Surveyor images, colorized using a table derived from Mars Reconnaissance Orbiter camera color data and overlain on a sub-frame of a Mars Odyssey Thermal Emission Imaging System image. The 1-kilometer scale bar represents about 0.62 miles. Figure C: The third figure is a colorized view of the light-toned gully deposit as viewed from an oblique perspective, draped over topography derived from Mars Global Surveyor's Mars Orbiter Laser Altimeter data. The color comes from a table derived from the colors of Mars as seen by the Mars Reconnaissance Orbiter camera. The new light-toned flow, by itself, does not prove that liquid water was involved in its genesis. However, this observation and the similar light-toned flow in Terra Sirenum together show that some gully sites are indeed changing today, providing tantalizing evidence there might be sources of liquid water beneath the surface of Mars right now. In both cases, these new flows may be indicating the locations of aquifers (subsurface rocks saturated with water) that could be detected by orbiting, ground-penetrating radar systems such as the Mars Express Mars Advanced Radar for Subsurface and Ionosphere Sounding or the Mars Reconnaissance Orbiter's Mars Shallow Subsurface Radar. The Mars Global Surveyor mission is managed for NASA's Office of Space Science, Washington, by NASA's Jet Propulsion Laboratory, Pasadena, Calif., a division of the California Institute of Technology, also in Pasadena. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Malin Space Science Systems, San Diego, Calif., built and operates the Mars Orbiter Camera. For more information about images from the Mars Orbiter Camera, see http://www.msss.com/mgs/moc/index.html [ http://www.msss.com/mgs/moc/index.html ]. |
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Viking 1's 30th!
PIA08616
Sol (our sun)
Mars Orbiter Camera
| Title |
Viking 1's 30th! |
| Original Caption Released with Image |
20 July 2006 Viking 1 landed 30 years ago today, on 20 July 1976. It was the first U.S. landing on Mars and a very exciting time for Mars exploration. Since that time, four additional spacecraft have successfully landed on Mars and conducted their science investigations. Today, new missions to the martian surface are in the works, with landings expected in 2008 (Phoenix) and 2010 (Mars Science Laboratory). The Viking 1 lander is difficult to see in Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) images. The western Chryse Planitia landing site is often obscured by dust hazes and occasional storms, especially during northern winter, which would otherwise be the best time to look for the lander from orbit because the sun casts longer shadows in winter. When the atmosphere is clearest, in portions of the spring and summer, the sun is higher in the sky as seen from MGS's orbit. The spacecraft always passes over the landing site region around 2 p.m. in the afternoon. The suite of pictures shown here describes the best MOC view of the landing site. These were previously released in May 2005 [ http://www.msss.com/mars_images/moc/2005/05/09/ ], but the MOC team felt that 20 July 2006 is an appropriate time to review this story. The first figure (left) visually tells how the lander was found. The initial observations of the location of Viking 1, as originally determined by members of the Viking science team based on sightlines to various crater rims seen in the lander images (black lines), did not show the detailed features we knew from the lander pictures (middle) to be in the area. Using geodetic measurements, the late Merton Davies of the RAND Corporation, a MGS MOC Co-Investigator, suggested that we should image areas to the east and north of where Viking 1 was thought to be. Timothy J. Parker of the Jet Propulsion Laboratory (Pasadena, California), using sightlines to crater rims seen in the lander images (white lines), deduced a location very close to that suggested by Davies. The MOC image of that location, acquired in 2003, showed additional near-field features (rocks associated with a nearby crater) that closely matched the Viking 1 images (center and right frame, where B denotes "Volkswagen Rock"). The inset (upper right) is an enlargement that shows the location of the Viking 1 lander. The MOC image of the Viking 1 lander site (right) was acquired during a test of the MGS Pitch and Roll Observation (PROTO) technique conducted on 11 May 2003. (Following initial tests, the "c" part of "cPROTO" was begun by adding compensation for the motion of the planet to the technique). The PROTO or cPROTO approach allows MOC to obtain images with better than its nominal 1.5 meters (5 ft) per pixel resolution. The image shown here (right) was map projected at 50 centimeters (~20 inches) per pixel. The full 11 May 2003 image can be viewed in the MOC Gallery [ http://www.msss.com/moc_gallery/ ], it is image, R05-00966 [ http://www.msss.com/moc_gallery/r03_r09/images/R05/R0500966.html ]. In addition to celebrating the 30th anniversary of the first U.S. robotic Mars landing, we note that 20 July is also the 37th anniversary of the first human landing on the Moon, on 20 July 1969. There are two dates that are most sacred in the space business (three, if you count the 4 October 1957 launch of Sputnik 1). The other date is 12 April, which celebrates the 1961 launch of the first human in space, and the 1981 launch of the first space shuttle orbiter. |
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