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Mars: Closest Approach 2007
| Title |
Mars: Closest Approach 2007 |
| General Information |
What is Hubble Heritage? A monthly showcase of new and archival Hubble images. Go to the Heritage site. NASA's Hubble Space Telescope took this close-up of the red planet Mars when it was just 55 million miles ? 88 million kilometers ? away. This color image was assembled from a series of exposures taken within 36 hours of the Mars closest approach with Hubble's Wide Field and Planetary Camera 2. Mars will be closest to Earth on December 18, at 11:45 p.m. Universal Time (6:45 p.m. EST). |
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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
…
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
…
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
…
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
…
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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Stretched View Showing 'Vict
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PIA08446
Sol (our sun)
Panoramic Camera
| Title |
Stretched View Showing 'Victoria' |
| Original Caption Released with Image |
Stretched View Showing 'Victoria' This pair of images from the panoramic camera on NASA's Mars Exploration Rover Opportunity served as initial confirmation that the two-year-old rover is within sight of "Victoria Crater," which it has been approaching for more than a year. Engineers on the rover team were unsure whether Opportunity would make it as far as Victoria, but scientists hoped for the chance to study such a large crater with their roving geologist. Victoria Crater is 800 meters (nearly half a mile) in diameter, about six times wider than "Endurance Crater," where Opportunity spent several months in 2004 examining rock layers affected by ancient water. When scientists using orbital data calculated that they should be able to detect Victoria's rim in rover images, they scrutinized frames taken in the direction of the crater by the panoramic camera. To positively characterize the subtle horizon profile of the crater and some of the features leading up to it, researchers created a vertically-stretched image (top) from a mosaic of regular frames from the panoramic camera (bottom), taken on Opportunity's 804th Martian day (April 29, 2006). The stretched image makes mild nearby dunes look like more threatening peaks, but that is only a result of the exaggerated vertical dimension. This vertical stretch technique was first applied to Viking Lander 2 panoramas by Philip Stooke, of the University of Western Ontario, Canada, to help locate the lander with respect to orbiter images. Vertically stretching the image allows features to be more readily identified by the Mars Exploration Rover science team. The bright white dot near the horizon to the right of center (barely visible without labeling or zoom-in) is thought to be a light-toned outcrop on the far wall of the crater, suggesting that the rover can see over the low rim of Victoria. In figure 1, the northeast and southeast rims are labeled in bright green. Finally, the light purple lines and arrow highlight a small crater. |
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Stretched View Showing 'Vict
…
PIA08446
Sol (our sun)
Panoramic Camera
| Title |
Stretched View Showing 'Victoria' |
| Original Caption Released with Image |
Stretched View Showing 'Victoria' This pair of images from the panoramic camera on NASA's Mars Exploration Rover Opportunity served as initial confirmation that the two-year-old rover is within sight of "Victoria Crater," which it has been approaching for more than a year. Engineers on the rover team were unsure whether Opportunity would make it as far as Victoria, but scientists hoped for the chance to study such a large crater with their roving geologist. Victoria Crater is 800 meters (nearly half a mile) in diameter, about six times wider than "Endurance Crater," where Opportunity spent several months in 2004 examining rock layers affected by ancient water. When scientists using orbital data calculated that they should be able to detect Victoria's rim in rover images, they scrutinized frames taken in the direction of the crater by the panoramic camera. To positively characterize the subtle horizon profile of the crater and some of the features leading up to it, researchers created a vertically-stretched image (top) from a mosaic of regular frames from the panoramic camera (bottom), taken on Opportunity's 804th Martian day (April 29, 2006). The stretched image makes mild nearby dunes look like more threatening peaks, but that is only a result of the exaggerated vertical dimension. This vertical stretch technique was first applied to Viking Lander 2 panoramas by Philip Stooke, of the University of Western Ontario, Canada, to help locate the lander with respect to orbiter images. Vertically stretching the image allows features to be more readily identified by the Mars Exploration Rover science team. The bright white dot near the horizon to the right of center (barely visible without labeling or zoom-in) is thought to be a light-toned outcrop on the far wall of the crater, suggesting that the rover can see over the low rim of Victoria. In figure 1, the northeast and southeast rims are labeled in bright green. Finally, the light purple lines and arrow highlight a small crater. |
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A Change in the Weather
PIA09346
Sol (our sun)
CRISM
| Title |
A Change in the Weather |
| Original Caption Released with Image |
These two Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) images were acquired over the northern plains of Mars near one of the possible landing sites for NASA's Phoenix mission, set to launch in August 2007. The lower right image was acquired first, on Nov. 29, 2006, at 0720 UTC (2:20 a.m. EST), while the upper left image was acquired about one month later on Dec. 26, 2006, at 0030 UTC (or Dec. 25, 2006, at 7:30 p.m. EST). The CRISM data were taken in 544 colors covering the wavelength range from 0.36-3.92 micrometers, and show features as small as about 20 meters (66 feet) across. The images shown above are red-green-blue color composites using wavelengths 0.71, 0.6, and 0.53 micrometers, respectively (or infrared, red, and green light), and are overlain on a mosaic of Mars Odyssey Thermal Emission Imaging System (THEMIS) visible data. Each image covers a region about 11 kilometers (6.6 miles) wide at its narrowest, and they overlap near 71.0 degrees north latitude, 252.8 degrees east longitude The Earth equivalent to the season and latitude of this site is late summer in northern Canada, above the Arctic Circle. At that season and latitude, Martian weather conditions are transitioning from summer with generally clear skies, occasional weather fronts, and infrequent dust storms, to an autumn with pervasive, thick water-ice clouds. The striking difference in the appearance of the images is caused by the seasonal development of water-ice clouds. The earlier (lower right) image is cloud-free, and surface features can clearly be seen - like the small crater in the upper left. However, the clouds and haze in the later (upper left) image make it hard to see the surface. There are variations in the thickness and spacing of the clouds, just like clouds on Earth. On other days when nearby sites were imaged, the cloud cover varied day-to-day, but as the seasons change the trend is more and thicker clouds. With the onset of autumn the clouds will gradually cover the area and, just as with autumn on Earth, the Martian day is getting shorter at these high northern latitudes. In a few more months this area will settle into winter darkness and be covered in a layer of frost and carbon dioxide snow. CRISM's mission: Find the spectral fingerprints of aqueous and hydrothermal deposits and map the geology, composition and stratigraphy of surface features. The instrument will also watch the seasonal variations in Martian dust and ice aerosols, and water content in surface materials -- leading to new understanding of the climate. The Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) is one of six science instruments on NASA's Mars Reconnaissance Orbiter. Led by The Johns Hopkins University Applied Physics Laboratory, the CRISM team includes expertise from universities, government agencies and small businesses in the United States and abroad. |
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Mars Researchers Rendezvous
…
PIA03714
Sol (our sun)
Multi-angle Imaging SpectroR
…
| Title |
Mars Researchers Rendezvous on Remote Arctic Island |
| Original Caption Released with Image |
Devon Island is situated in an isolated part of Canada's Nunavut Territory, and is usually considered to be the largest uninhabited island in the world. However, each summer since 1999, researchers from NASA's Haughton-Mars Project and the Mars Society reside at this "polar desert" location to study the geologic and environmental characteristics of a site which is considered to be an excellent "Mars analog": a terrestrial location wherein specific conditions approximate environmental features reported on Mars. Base camps established amidst the rocks and rubble surrounding the Haughton impact crater enable researchers to conduct surveys designed to test the habitat, equipment and technology that may be deployed during a human mission to Mars. One of the many objectives of the project scientists is to understand the ice formations around the Haughton area, in the hopes that this might ultimately assist with the recognition of areas where ice can be found at shallow depth on Mars. These images of Devon Island from NASA's Multi-angle Imaging SpectroRadiometer (MISR) instrument provide contrasting views of the spectral and angular reflectance "signatures" of different surfaces within the region. The top panel is a natural color view created with data from the red, green and blue-bands of MISR's nadir (vertical-viewing) camera. The bottom panel is a false-color multiangular composite of the same area, utilizing red band data from MISR's 60-degree backward, nadir, and 60-degree forward-viewing cameras, displayed as red, green and blue, respectively. In this representation, colors highlight textural properties of elements within the scene, with blue tones indicating smooth surfaces (which preferentially forward scatter sunlight) and red hues indicating rougher surfaces (which preferentially backscatter). The angular reflectance "signature" of low clouds causes them to appear purple, and this visualization provides a unique way of distinguishing clouds from snow and ice. The data were captured on June 28, 2001, during the early part of the arctic summer, when sea ice becomes thinner and begins to move depending upon localized currents and winds. In winter the entire region is locked with several meters of nearly motionless sea ice, which acts as a thermodynamic barrier to the loss of heat from the comparatively warm ocean to the colder atmosphere. Summer melting of sea ice can be observed at the two large, dark regions of open water, one is present in the Jones Sound (near the top to the left of center), and another appears in the Wellington Channel (left-hand edge). A large crack caused by tidal heaving has broken the ice cover over the Parry Channel (lower right-hand corner). A substantial ice cap permanently occupies the easternmost third of the island (upper right). Surface features such as dendritic meltwater channels incised into the island's surface are apparent. The Haughton-Mars project site is located slightly to the left and above image, center, in an area which appears with relatively little surface ice, near the island's inner "elbow." The images were acquired during Terra orbit 8132 and cover an area of about 334 kilometers x 229 kilometers. They utilize data from blocks 27 to 31 within World Reference System-2 path 42. MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology. |
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Southern Hemisphere Polygona
…
PIA03496
Sol (our sun)
Mars Orbiter Camera
| Title |
Southern Hemisphere Polygonal Patterned Ground |
| Original Caption Released with Image |
On Earth, periglacial is a term that refers to regions and processes where cold climate contributes to the evolution of landforms and landscapes. Common in periglacial environments on Earth, such as the arctic of northern Canada,Siberia, and Alaska, is a phenomenon called patterned ground. The "patterns" in patterned ground often take the form of large polygons, each bounded by either troughs or ridges made up of rock particles different in size from those seen in the interior of the polygon. On Earth, many polygons in periglacial environments are directly linked to water: they typically form from stresses induced by repeated freezing and thawing of water, contraction from stress induced by changing temperatures, and sorting of rocks brought to the surface along polygon boundaries by the freeze-thaw processes. Although not exclusively formed by freezing and thawing of water, that is often the dominant mechanism on Earth. Polygons similar to those found in Earth's arctic and antarctic regions are also found in the polar regions of Mars. Typically, they occur on crater floors, or on intercrater plains, between about 60° and 80° latitude. The polygons are best seen when bright frost or dark sand has been trapped in the troughs that form the polygon boundaries. Three examples of martian polygons seen by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) are shown here. Each is located in the southern hemisphere: * (left) Polygon troughs highlighted by frost as the south polar cap retreats during spring. The circular features are the locations of buried craters that were originally formed by meteor impact. This image, E09-00029, is located at 75.1°S, 331.3°W, and was acquired on 1 October 2001. * (center) Summertime view of polygons, highlighted by dark, windblown sand, on the floor of a crater at 71.2°S, 282.6°W. The image, E12-02319, was obtained on 21January 2002. * (right) Polygon troughs highlighted by the retreating south polar frost cap during southern summer near 80.7°S, 70.4°W. This picture, M11-01795, was taken by MOC on 13 January 2000.Some Mars researchers assume that polygons on the Red Planet are key indictors that ground ice is present or was present in the recent past. However, whether these polygons actually required water ice to form is, in fact, unknown, since dry processes are also known on Earth for form similar polygons. |
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Meteor Search by Spirit, Sol
…
PIA03613
Sol (our sun)
Panoramic Camera
| Title |
Meteor Search by Spirit, Sol 643 |
| Original Caption Released with Image |
, and Selsis et al. (2005) Nature, vol 435, p. 581). On Earth, some meteors come in "storms" or "showers" at predictable times of the year, like the famous Perseid meteor shower in August or the Leonid meteor shower in November. These "storms" happen when Earth passes through the same parts of space where comets sometimes pass. The meteors we see at these times are from leftover debris that was shed off of these comets. The same kind of thing is predicted for Mars, as well. Inspired by calculations about Martian meteor storms by meteor scientists from the University of Western Ontario in Canada and the Centre de Recherche en Astrophysique de Lyon in France, and also aided by other meteor research colleagues from NASA's Marshall Space Flight Center, scientists on the rover team planned some observations to try to detect predicted meteor storms in October and November, 2005. The views shown here are a composite of nine 60-second exposures taken with the panoramic camera on Spirit during night hours of sol 643 (Oct. 25, 2005), during a week when Mars was predicted to pass through a meteor stream associated with comet P/2001R1 LONEOS. Many stars can be seen in the images, appearing as curved "dash-dot" streaks. The star trails are curved because Mars is rotating while the camera takes the images. The dash-dot pattern is an artifact of taking an image for 60 seconds, then pausing about 10 seconds while the image is processed and stored by the rover's computer, then taking another image for 60 seconds, etc., for a total of about 10 minutes worth of "staring" at the night sky. Many stars from the southern constellations Octans and Pavonis can be seen in the images. The brightest ones in this view would be easily visible to the naked eye, but the faintest ones are slightly dimmer than the human eye can detect. In addition to the star trails, there are several smaller linear streaks, dots and splotches that are the trails left by cosmic rays hitting the camera detectors. Cosmic rays are high-energy particles that are created in the Sun and in other stars throughout our galaxy and travel through space in all directions. Some of them strike Earth or other planets, and ones that strike a digital camera detector can leave little tracks or splotches like those seen in these images. Because they come from all directions, some strike the detector face-on, and others strike at glancing angles. Some even skip across the detector like flat rocks skipped across a pond. These are very common phenomena to astronomers used to working with sensitive digital cameras like those in the Mars rovers, the Hubble Space Telescope, or other space probes, and while they can be a nuisance when taking pictures, they generally do not cause any lasting damage to the cameras. One streak in the image, crossing at an angle very different from the direction of the stars'"motion," might be a meteor trail or could be the mark of another cosmic ray. While hunting for meteors on Mars, Annotated Meteor Search by Spirit, Sol 643 The panoramic cameras on NASA's Mars Exploration Rovers are about as sensitive as the human eye at night. The cameras can see the same bright stars that we can see from Earth, and the same patterns of constellations dot the night sky. Scientists on the rover team have been taking images of some of these bright stars as part of several different projects. One project is designed to try to capture "shooting stars," or meteors, in the Martian night sky. "Meteoroids" are small pieces of comets and asteroids that travel through space and eventually run into a planet. On Earth, we can sometimes see meteoroids become brilliant, long "meteors" streaking across the night sky as they burn up from the friction in our atmosphere. Some of these meteors survive their fiery flight and land on the surface (or in the ocean) where, if found, they are called "meteorites." The same thing happens in the Martian atmosphere, and Spirit even accidentally discovered a meteor while attempting to obtain images of Earth in the pre-dawn sky back in March, 2004 (see http://marsrovers.jpl.nasa.gov/gallery/press/spirit/20040311a.html [ http://marsrovers.jpl.nasa.gov/gallery/press/spirit/20040311a.html ], is fun, ultimately the team wants to use the images and results for scientific purposes. These include helping to validate the models and predictions for interplanetary meteor storms, providing information on the rate of impacts of small meteoroids with Mars for comparison with rates for the Earth and Moon, assessing the rate and intensity of cosmic ray impact events in the Martian environment, and looking at whether some bright stars are being dimmed occasionally by water ice or dust clouds occurring at night during different Martian seasons. |
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Meteor Search by Spirit, Sol
…
PIA03613
Sol (our sun)
Panoramic Camera
| Title |
Meteor Search by Spirit, Sol 643 |
| Original Caption Released with Image |
, and Selsis et al. (2005) Nature, vol 435, p. 581). On Earth, some meteors come in "storms" or "showers" at predictable times of the year, like the famous Perseid meteor shower in August or the Leonid meteor shower in November. These "storms" happen when Earth passes through the same parts of space where comets sometimes pass. The meteors we see at these times are from leftover debris that was shed off of these comets. The same kind of thing is predicted for Mars, as well. Inspired by calculations about Martian meteor storms by meteor scientists from the University of Western Ontario in Canada and the Centre de Recherche en Astrophysique de Lyon in France, and also aided by other meteor research colleagues from NASA's Marshall Space Flight Center, scientists on the rover team planned some observations to try to detect predicted meteor storms in October and November, 2005. The views shown here are a composite of nine 60-second exposures taken with the panoramic camera on Spirit during night hours of sol 643 (Oct. 25, 2005), during a week when Mars was predicted to pass through a meteor stream associated with comet P/2001R1 LONEOS. Many stars can be seen in the images, appearing as curved "dash-dot" streaks. The star trails are curved because Mars is rotating while the camera takes the images. The dash-dot pattern is an artifact of taking an image for 60 seconds, then pausing about 10 seconds while the image is processed and stored by the rover's computer, then taking another image for 60 seconds, etc., for a total of about 10 minutes worth of "staring" at the night sky. Many stars from the southern constellations Octans and Pavonis can be seen in the images. The brightest ones in this view would be easily visible to the naked eye, but the faintest ones are slightly dimmer than the human eye can detect. In addition to the star trails, there are several smaller linear streaks, dots and splotches that are the trails left by cosmic rays hitting the camera detectors. Cosmic rays are high-energy particles that are created in the Sun and in other stars throughout our galaxy and travel through space in all directions. Some of them strike Earth or other planets, and ones that strike a digital camera detector can leave little tracks or splotches like those seen in these images. Because they come from all directions, some strike the detector face-on, and others strike at glancing angles. Some even skip across the detector like flat rocks skipped across a pond. These are very common phenomena to astronomers used to working with sensitive digital cameras like those in the Mars rovers, the Hubble Space Telescope, or other space probes, and while they can be a nuisance when taking pictures, they generally do not cause any lasting damage to the cameras. One streak in the image, crossing at an angle very different from the direction of the stars'"motion," might be a meteor trail or could be the mark of another cosmic ray. While hunting for meteors on Mars, Annotated Meteor Search by Spirit, Sol 643 The panoramic cameras on NASA's Mars Exploration Rovers are about as sensitive as the human eye at night. The cameras can see the same bright stars that we can see from Earth, and the same patterns of constellations dot the night sky. Scientists on the rover team have been taking images of some of these bright stars as part of several different projects. One project is designed to try to capture "shooting stars," or meteors, in the Martian night sky. "Meteoroids" are small pieces of comets and asteroids that travel through space and eventually run into a planet. On Earth, we can sometimes see meteoroids become brilliant, long "meteors" streaking across the night sky as they burn up from the friction in our atmosphere. Some of these meteors survive their fiery flight and land on the surface (or in the ocean) where, if found, they are called "meteorites." The same thing happens in the Martian atmosphere, and Spirit even accidentally discovered a meteor while attempting to obtain images of Earth in the pre-dawn sky back in March, 2004 (see http://marsrovers.jpl.nasa.gov/gallery/press/spirit/20040311a.html [ http://marsrovers.jpl.nasa.gov/gallery/press/spirit/20040311a.html ], is fun, ultimately the team wants to use the images and results for scientific purposes. These include helping to validate the models and predictions for interplanetary meteor storms, providing information on the rate of impacts of small meteoroids with Mars for comparison with rates for the Earth and Moon, assessing the rate and intensity of cosmic ray impact events in the Martian environment, and looking at whether some bright stars are being dimmed occasionally by water ice or dust clouds occurring at night during different Martian seasons. |
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Meteor Search by Spirit, Sol
…
PIA03615
Sol (our sun)
Panoramic Camera
| Title |
Meteor Search by Spirit, Sol 668 |
| Original Caption Released with Image |
Annotated Meteor Search by Spirit, Sol 668 The panoramic cameras on NASA's Mars Exploration Rovers are about as sensitive as the human eye at night. The cameras can see the same bright stars that we can see from Earth, and the same patterns of constellations dot the night sky. Scientists on the rover team have been taking images of some of these bright stars as part of several different projects. One project is designed to try to capture "shooting stars," or meteors, in the martian night sky. "Meteoroids" are small pieces of comets and asteroids that travel through space and eventually run into a planet. On Earth, we can sometimes see meteoroids become brilliant, long "meteors" streaking across the night sky as they burn up from the friction in our atmosphere. Some of these meteors survive their fiery flight and land on the surface (or in the ocean) where, if found, they are called "meteorites." The same thing happens in the martian atmosphere, and Spirit even accidentally discovered a meteor while attempting to obtain images of Earth in the pre-dawn sky back in March, 2004 (see http://marsrovers.jpl.nasa.gov/gallery/press/spirit/20040311a.html, and Selsis et al. (2005) Nature, vol 435, p. 581). On Earth, some meteors come in "storms" or "showers" at predictable times of the year, like the famous Perseid meteor shower in August or the Leonid meteor shower in November. These "storms" happen when Earth passes through the same parts of space where comets sometimes pass. The meteors we see at these times are from leftover debris that was shed off of these comets. The same kind of thing is predicted for Mars, as well. Inspired by calculations about Martian meteor storms by meteor scientists from the University of Western Ontario in Canada and the Centre de Recherche en Astrophysique de Lyon in France, and also aided by other meteor research colleagues from NASA's Marshall Space Flight Center, scientists on the rover team planned some observations to try to detect predicted meteor storms in October and November, 2005. The views shown here are a composite of nine 60-second exposures taken with the panoramic camera on Spirit during night hours of sol 668 (Nov. 18, 2005), during a week when Mars was predicted to pass through a meteor stream associated with Halley's comet. The south celestial pole is at the center of the frame. Many stars can be seen in the images, appearing as short, curved streaks forming arcs around the center point. The star trails are curved because Mars is rotating while the camera takes the images. The brightest stars in this view would be easily visible to the naked eye, but the faintest ones are slightly dimmer than the human eye can detect. In addition to the star trails, there are several smaller linear streaks, dots and splotches that are the trails left by cosmic rays hitting the camera detectors. Cosmic rays are high-energy particles that are created in the Sun and in other stars throughout our galaxy and travel, through space in all directions. Some of them strike Earth or other planets, and ones that strike a digital camera detector can leave little tracks or splotches like those seen in these images. Because they come from all directions, some strike the detector face-on, and others strike at glancing angles. Some even skip across the detector like flat rocks skipped across a pond. These are very common phenomena to astronomers used to working with sensitive digital cameras like those in the Mars rovers, the Hubble Space Telescope, or other space probes, and while they can be a nuisance when taking pictures, they generally do not cause any lasting damage to the cameras. Three of the streaks in the image, including one spanning most of the distance from the left edge of the frame to the center, might be meteor trails or could be the marks of other cosmic rays. While hunting for meteors on Mars is fun, ultimately the team wants to use the images and results for scientific purposes. These include helping to validate the models and predictions for interplanetary meteor storms, providing information on the rate of impacts of small meteoroids with Mars for comparison with rates for the Earth and Moon, assessing the rate and intensity of cosmic ray impact events in the Martian environment, and looking at whether some bright stars are being dimmed occasionally by water ice or dust clouds occurring at night during different Martian seasons. |
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Meteor Search by Spirit, Sol
…
PIA03615
Sol (our sun)
Panoramic Camera
| Title |
Meteor Search by Spirit, Sol 668 |
| Original Caption Released with Image |
Annotated Meteor Search by Spirit, Sol 668 The panoramic cameras on NASA's Mars Exploration Rovers are about as sensitive as the human eye at night. The cameras can see the same bright stars that we can see from Earth, and the same patterns of constellations dot the night sky. Scientists on the rover team have been taking images of some of these bright stars as part of several different projects. One project is designed to try to capture "shooting stars," or meteors, in the martian night sky. "Meteoroids" are small pieces of comets and asteroids that travel through space and eventually run into a planet. On Earth, we can sometimes see meteoroids become brilliant, long "meteors" streaking across the night sky as they burn up from the friction in our atmosphere. Some of these meteors survive their fiery flight and land on the surface (or in the ocean) where, if found, they are called "meteorites." The same thing happens in the martian atmosphere, and Spirit even accidentally discovered a meteor while attempting to obtain images of Earth in the pre-dawn sky back in March, 2004 (see http://marsrovers.jpl.nasa.gov/gallery/press/spirit/20040311a.html, and Selsis et al. (2005) Nature, vol 435, p. 581). On Earth, some meteors come in "storms" or "showers" at predictable times of the year, like the famous Perseid meteor shower in August or the Leonid meteor shower in November. These "storms" happen when Earth passes through the same parts of space where comets sometimes pass. The meteors we see at these times are from leftover debris that was shed off of these comets. The same kind of thing is predicted for Mars, as well. Inspired by calculations about Martian meteor storms by meteor scientists from the University of Western Ontario in Canada and the Centre de Recherche en Astrophysique de Lyon in France, and also aided by other meteor research colleagues from NASA's Marshall Space Flight Center, scientists on the rover team planned some observations to try to detect predicted meteor storms in October and November, 2005. The views shown here are a composite of nine 60-second exposures taken with the panoramic camera on Spirit during night hours of sol 668 (Nov. 18, 2005), during a week when Mars was predicted to pass through a meteor stream associated with Halley's comet. The south celestial pole is at the center of the frame. Many stars can be seen in the images, appearing as short, curved streaks forming arcs around the center point. The star trails are curved because Mars is rotating while the camera takes the images. The brightest stars in this view would be easily visible to the naked eye, but the faintest ones are slightly dimmer than the human eye can detect. In addition to the star trails, there are several smaller linear streaks, dots and splotches that are the trails left by cosmic rays hitting the camera detectors. Cosmic rays are high-energy particles that are created in the Sun and in other stars throughout our galaxy and travel, through space in all directions. Some of them strike Earth or other planets, and ones that strike a digital camera detector can leave little tracks or splotches like those seen in these images. Because they come from all directions, some strike the detector face-on, and others strike at glancing angles. Some even skip across the detector like flat rocks skipped across a pond. These are very common phenomena to astronomers used to working with sensitive digital cameras like those in the Mars rovers, the Hubble Space Telescope, or other space probes, and while they can be a nuisance when taking pictures, they generally do not cause any lasting damage to the cameras. Three of the streaks in the image, including one spanning most of the distance from the left edge of the frame to the center, might be meteor trails or could be the marks of other cosmic rays. While hunting for meteors on Mars is fun, ultimately the team wants to use the images and results for scientific purposes. These include helping to validate the models and predictions for interplanetary meteor storms, providing information on the rate of impacts of small meteoroids with Mars for comparison with rates for the Earth and Moon, assessing the rate and intensity of cosmic ray impact events in the Martian environment, and looking at whether some bright stars are being dimmed occasionally by water ice or dust clouds occurring at night during different Martian seasons. |
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Northern Plains Patterns
PIA04795
Sol (our sun)
Mars Orbiter Camera
| Title |
Northern Plains Patterns |
| Original Caption Released with Image |
MGS MOC Release No. MOC2-513, 14 October 2003 Patterns are common on the northern plains of Mars. Like their terrestrial counterparts in places like Siberia, Alaska, and northern Canada, "patterned ground" on Mars might be an indicator of the presence of ground ice. Whether it is true that the patterns on Mars are related to ground ice and whether the ice is still present beneath the martian surface are unknown. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) picture shows an example of patterned ground on the martian northern plains near 72.4°N, 252.6°W. The dark dots and lines are low mounds and chains of mounds. The circular feature near the center of the image is the location of a buried meteor impact crater, its presence today is marked only by the dark boulders on its rim and ejecta blanket that have managed to remain uncovered at the martian surface. The area shown is 3 km (1.9 mi) wide and illuminated by sunlight from the lower left. |
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Hills in Arctic Canada with
…
PIA06012
Sol (our sun)
| Title |
Hills in Arctic Canada with Impact Origin |
| Original Caption Released with Image |
While most hills and mountains on Earth originate from tectonic motions or volcanism, Earth also has some examples of hills that originated from impacts of large meteorites, the predominant origin for hills and mountains on the Moon. The grey hills in this image from Devon Island in arctic Canada are material ejected from an impact about 20 million years ago. The site is at 75 degrees north latitude. Researchers' tents at the left give a sense of scale. Source: Dr. James Rice, Arizona State University For related images, see PIA06010 [ http://photojournal.jpl.nasa.gov/catalog/PIA06010 ] and PIA06011 [ http://photojournal.jpl.nasa.gov/catalog/PIA06011 ]. |
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Stretched View Showing 'Beag
…
PIA08565
Sol (our sun)
Panoramic Camera
| Title |
Stretched View Showing 'Beagle Crater' |
| Original Caption Released with Image |
Figure 1 This imagery from the panoramic camera on NASA's Mars Exploration Rover Opportunity shows the outcrop-rimmed "Beagle Crater" appearing on the horizon as Opportunity approaches it. The top version is vertically stretched to make horizon details easier to see. The lower version has normal proportions. The image is a mosaic of frames taken during Opportunity's 855th Martian day, or sol (June 20, 2006). Beagle Crater is 35 meters (115 feet) in diameter. The Opportunity science and engineering teams hope to have the rover visit it on the way to "Victoria Crater." Beagle Crater was 310 meters (1,107 feet) away from Opportunity when this picture was taken. Even at this distance, blocks of ejecta can be seen around the prominent, raised rim of Beagle crater, suggesting that it may be among the youngest craters visited by Opportunity. When scientists using orbital data calculated that they should be able to detect Victoria's rim in rover images, they scrutinized frames taken in the direction of the crater by the panoramic camera. To positively characterize the subtle horizon profile of the crater and some of the features leading up to it, researchers created this vertically-stretched image (top). The stretched image makes mild nearby dunes look like more threatening peaks, but that is only a result of the exaggerated vertical dimension. This vertical stretch technique was first applied to Viking Lander 2 panoramas by Philip Stooke, of the University of Western Ontario, Canada, to help locate the lander with respect to orbiter images. Vertically stretching the image allows features to be more readily identified by the Mars Exploration Rover science team. The bright white dot on the horizon near the upper left corner of the panorama, labeled "Outcrop Promontory," was thought to be a light-toned outcrop on the far wall of Victoria, based on a single azimuth measurement on sol 804 (April 28, 2006), suggesting that the rover was seeing over the low rim of Victoria. But comparing the azimuth angle of this feature in the sol 855 panorama and the angle of the same feature in the sol 804 panoramic image, PIA08447 [ http://photojournal.jpl.nasa.gov/catalog/PIA08447 ] (a process known as triangulation) revealed that this outcrop must instead be on the near rim of the crater. The southeast rim of Victoria is labeled in bright green. The northeast rim is beyond the left edge of this panorama. The salmon-color lines and arrows highlight two small craters on the dark "annulus," or ring, around Victoria Crater. |
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Stretched View Showing 'Beag
…
PIA08565
Sol (our sun)
Panoramic Camera
| Title |
Stretched View Showing 'Beagle Crater' |
| Original Caption Released with Image |
Figure 1 This imagery from the panoramic camera on NASA's Mars Exploration Rover Opportunity shows the outcrop-rimmed "Beagle Crater" appearing on the horizon as Opportunity approaches it. The top version is vertically stretched to make horizon details easier to see. The lower version has normal proportions. The image is a mosaic of frames taken during Opportunity's 855th Martian day, or sol (June 20, 2006). Beagle Crater is 35 meters (115 feet) in diameter. The Opportunity science and engineering teams hope to have the rover visit it on the way to "Victoria Crater." Beagle Crater was 310 meters (1,107 feet) away from Opportunity when this picture was taken. Even at this distance, blocks of ejecta can be seen around the prominent, raised rim of Beagle crater, suggesting that it may be among the youngest craters visited by Opportunity. When scientists using orbital data calculated that they should be able to detect Victoria's rim in rover images, they scrutinized frames taken in the direction of the crater by the panoramic camera. To positively characterize the subtle horizon profile of the crater and some of the features leading up to it, researchers created this vertically-stretched image (top). The stretched image makes mild nearby dunes look like more threatening peaks, but that is only a result of the exaggerated vertical dimension. This vertical stretch technique was first applied to Viking Lander 2 panoramas by Philip Stooke, of the University of Western Ontario, Canada, to help locate the lander with respect to orbiter images. Vertically stretching the image allows features to be more readily identified by the Mars Exploration Rover science team. The bright white dot on the horizon near the upper left corner of the panorama, labeled "Outcrop Promontory," was thought to be a light-toned outcrop on the far wall of Victoria, based on a single azimuth measurement on sol 804 (April 28, 2006), suggesting that the rover was seeing over the low rim of Victoria. But comparing the azimuth angle of this feature in the sol 855 panorama and the angle of the same feature in the sol 804 panoramic image, PIA08447 [ http://photojournal.jpl.nasa.gov/catalog/PIA08447 ] (a process known as triangulation) revealed that this outcrop must instead be on the near rim of the crater. The southeast rim of Victoria is labeled in bright green. The northeast rim is beyond the left edge of this panorama. The salmon-color lines and arrows highlight two small craters on the dark "annulus," or ring, around Victoria Crater. |
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