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Alluvial Fan Along a Crater
…
PIA09666
Sol (our sun)
HiRISE
| Title |
Alluvial Fan Along a Crater Wall |
| Original Caption Released with Image |
Click on image for larger version This HiRISE image (PSP_003269_1600 [ http://hirise.lpl.arizona.edu/PSP_003269_1600 ]) covers an alluvial fan along the wall of a large crater in the mid latitudes of the southern hemisphere of Mars. The fan was formed when water and sediments drained down the steep wall of the crater creating a cone-shaped pile of debris at the base. As the fan grew with time, the channels carrying water and sediment across the fan surface changed locations, producing a layered deposit capped by channels radiating from the fan apex along the crater wall. Subsequent stripping of the fan surface by the wind has left the coarser channel deposits in relief and exposed the fine scale layering within the fan in many locations. While is it is not known whether the source of the water responsible for creating the fan was related runoff from precipitation or groundwater or perhaps both, alluvial fans of broadly similar form are observed in many locations on Earth and are usually formed by runoff from precipitation. Observation Toolbox Acquisition date: 4 April 2007 Local Mars time: 3:42 PM Degrees latitude (centered): -19.9° Degrees longitude (East): 123.2° Range to target site: 258.6 km (161.6 miles) Original image scale range: 25.9 cm/pixel (with 1 x 1 binning) so objects ~78 cm across are resolved Map-projected scale: 25 cm/pixel and north is up Map-projection: EQUIRECTANGULAR Emission angle: 4.7° Phase angle: 48.6° Solar incidence angle: 53°, with the Sun about 37° above the horizon Solar longitude: 215.1°, Northern Autumn NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft. The High Resolution Imaging Science Experiment is operated by the University of Arizona, Tucson, and the instrument was built by Ball Aerospace and Technology Corp., Boulder, Colo. |
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Alluvial Fan Along a Crater
…
PIA09666
Sol (our sun)
HiRISE
| Title |
Alluvial Fan Along a Crater Wall |
| Original Caption Released with Image |
Click on image for larger version This HiRISE image (PSP_003269_1600 [ http://hirise.lpl.arizona.edu/PSP_003269_1600 ]) covers an alluvial fan along the wall of a large crater in the mid latitudes of the southern hemisphere of Mars. The fan was formed when water and sediments drained down the steep wall of the crater creating a cone-shaped pile of debris at the base. As the fan grew with time, the channels carrying water and sediment across the fan surface changed locations, producing a layered deposit capped by channels radiating from the fan apex along the crater wall. Subsequent stripping of the fan surface by the wind has left the coarser channel deposits in relief and exposed the fine scale layering within the fan in many locations. While is it is not known whether the source of the water responsible for creating the fan was related runoff from precipitation or groundwater or perhaps both, alluvial fans of broadly similar form are observed in many locations on Earth and are usually formed by runoff from precipitation. Observation Toolbox Acquisition date: 4 April 2007 Local Mars time: 3:42 PM Degrees latitude (centered): -19.9° Degrees longitude (East): 123.2° Range to target site: 258.6 km (161.6 miles) Original image scale range: 25.9 cm/pixel (with 1 x 1 binning) so objects ~78 cm across are resolved Map-projected scale: 25 cm/pixel and north is up Map-projection: EQUIRECTANGULAR Emission angle: 4.7° Phase angle: 48.6° Solar incidence angle: 53°, with the Sun about 37° above the horizon Solar longitude: 215.1°, Northern Autumn NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft. The High Resolution Imaging Science Experiment is operated by the University of Arizona, Tucson, and the instrument was built by Ball Aerospace and Technology Corp., Boulder, Colo. |
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Alluvial Fans in Mojave Crat
…
PIA09399
Sol (our sun)
HiRISE
| Title |
Alluvial Fans in Mojave Crater: Did It Rain on Mars? |
| Original Caption Released with Image |
Click on image for larger version This HiRISE image at up to 29 cm/pixel scale supports the alluvial fan interpretation, in particular by showing that the sizes of the largest rocks decrease away from the mouths of the fans. Aptly-named Mojave crater in the Xanthe Terra region has alluvial fans that look remarkably similar to landforms in the Mojave Desert of southeastern California and portions of Nevada and Arizona. Alluvial fans are fan-shaped deposits of water-transported material (alluvium). They typically form at the base of hills or mountains where there is a marked break, or flattening of slope. They typically deposit big rocks near their mouths (close to the mountains) and smaller rocks at greater distances. Alluvial fans form as a result of heavy desert downpours, typically thundershowers. Because deserts are poorly vegetated, heavy and short-lived downpours create a great deal of erosion and nearby deposition. There are fans inside and around the outsides of Mojave crater on Mars that perfectly match the morphology of alluvial fans on Earth, with the exception of a few small impact craters dotting this Martian landscape. Channels begin at the apex of topographic ridges, consistent with precipitation as the source of water, rather than groundwater. This remarkable landscape was first discovered from Mars Orbital Camera images. Mars researchers have suggested that impact-induced atmospheric precipitation may have created these unique landscapes. Image PSP_001415_1875 [ http://hiroc.lpl.arizona.edu/images/PSP/PSP_001415_1875/ ] was taken by the High Resolution Imaging Science Experiment (HiRISE) camera onboard the Mars Reconnaissance Orbiter spacecraft on November 14, 2006. The complete image is centered at 7.6 degrees latitude, 327.4 degrees East longitude. The range to the target site was 273.5 km (170.9 miles). At this distance the image scale ranges from 27.4 cm/pixel (with 1 x 1 binning) to 109.4 cm/pixel (with 4 x 4 binning). The image shown here has been map-projected to 25 cm/pixel and north is up. The image was taken at a local Mars time of 3:29 PM and the scene is illuminated from the west with a solar incidence angle of 52 degrees, thus the sun was about 38 degrees above the horizon. At a solar longitude of 135.4 degrees, the season on Mars is Northern Summer. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft. The High Resolution Imaging Science Experiment is operated by the University of Arizona, Tucson, and the instrument was built by Ball Aerospace and Technology Corp., Boulder, Colo. |
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Alluvial Fans in Mojave Crat
…
PIA09399
Sol (our sun)
HiRISE
| Title |
Alluvial Fans in Mojave Crater: Did It Rain on Mars? |
| Original Caption Released with Image |
Click on image for larger version This HiRISE image at up to 29 cm/pixel scale supports the alluvial fan interpretation, in particular by showing that the sizes of the largest rocks decrease away from the mouths of the fans. Aptly-named Mojave crater in the Xanthe Terra region has alluvial fans that look remarkably similar to landforms in the Mojave Desert of southeastern California and portions of Nevada and Arizona. Alluvial fans are fan-shaped deposits of water-transported material (alluvium). They typically form at the base of hills or mountains where there is a marked break, or flattening of slope. They typically deposit big rocks near their mouths (close to the mountains) and smaller rocks at greater distances. Alluvial fans form as a result of heavy desert downpours, typically thundershowers. Because deserts are poorly vegetated, heavy and short-lived downpours create a great deal of erosion and nearby deposition. There are fans inside and around the outsides of Mojave crater on Mars that perfectly match the morphology of alluvial fans on Earth, with the exception of a few small impact craters dotting this Martian landscape. Channels begin at the apex of topographic ridges, consistent with precipitation as the source of water, rather than groundwater. This remarkable landscape was first discovered from Mars Orbital Camera images. Mars researchers have suggested that impact-induced atmospheric precipitation may have created these unique landscapes. Image PSP_001415_1875 [ http://hiroc.lpl.arizona.edu/images/PSP/PSP_001415_1875/ ] was taken by the High Resolution Imaging Science Experiment (HiRISE) camera onboard the Mars Reconnaissance Orbiter spacecraft on November 14, 2006. The complete image is centered at 7.6 degrees latitude, 327.4 degrees East longitude. The range to the target site was 273.5 km (170.9 miles). At this distance the image scale ranges from 27.4 cm/pixel (with 1 x 1 binning) to 109.4 cm/pixel (with 4 x 4 binning). The image shown here has been map-projected to 25 cm/pixel and north is up. The image was taken at a local Mars time of 3:29 PM and the scene is illuminated from the west with a solar incidence angle of 52 degrees, thus the sun was about 38 degrees above the horizon. At a solar longitude of 135.4 degrees, the season on Mars is Northern Summer. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft. The High Resolution Imaging Science Experiment is operated by the University of Arizona, Tucson, and the instrument was built by Ball Aerospace and Technology Corp., Boulder, Colo. |
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Evidence for Recent Liquid W
…
PIA01036
Sol (our sun)
Mars Orbiter Camera
| Title |
Evidence for Recent Liquid Water on Mars: Seepage Sites in "Aerobraking Crater" Revisited |
| Original Caption Released with Image |
The first clue that there might be places on Mars where liquid groundwater seeps out onto the surface came from a picture taken by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) during the pre-mapping Orbit Insertion Phase of the mission. The picture, shown in (A)above, was taken at the end of December 1997 while the spacecraft was still in the midst of aerobraking maneuvers to put it into the circular orbit needed for the Mapping Phase of the project. The Aerobraking 1 image, AB1-07707, showed dark, v-shaped scars on the western wall of a 50 kilometer-(31 mile)-diameter impact crater in southern Noachis Terra at 65°S, 15°W (see B, above, for context). The v-shaped features taper downslope to form narrow, somewhat curved channels. The relationship seen here was interpreted by MOC scientists to be similar to seepage landforms on Earth that form where springs emerge on a slope and water runs downhill. Once MGS achieved its Mapping Orbit in March 1999, the MOC was in a better position to take pictures of 10 times higher resolution than the Aerobraking AB1-07707 image. The opportunity to take a new picture of the proposed "seepage" sites on the wall of the crater in southern Noachis finally arose in January 2000. The result is MOC image M11-00530, shown above in (top) and (C). This new close-up shows that the darkly-shaped scars host many small channels of only a few meters (yards) across. These small channels run downslope and coalesce at the apex (or point) of each "v". Amid the small channels are many large boulders, some of them the size of houses, that have eroded out of the crater wall. A 3-D view created using the AB1 and M11 images is shown in (D). The stereo picture (red-blue "3D" glasses required) emphasizes the presence of small channels and valleys, and shows that these valleys start almost at the very top of the v-shaped dark areas. The context picture in (B) is a mosaic of Viking 2 orbiter images 497B47 and 497B48 acquired December 28, 1977. The Aerobraking MGS MOC image, AB1-07707, is shown overlain on the Viking context image, it was taken 20 years later on December 29, 1997. The smaller white box in the context picture shows the location of MOC Mapping Phase image M11-00530, roughly 2 years later on January 4, 2000. North is "up" in pictures (A) and (B), and to the lower right in (top), (C), and (D). Sunlight illuminates (A) from the upper left, (B) from the upper right, and (top) and (C) from the upper right. The top image in (top) is the aerobraking image, AB1-07707, with a white box indicating the location of the lower image, M11-00530, and the stereo pair in (D). The white box on the left in (C) shows the location of the close-up on the right in (C). |
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Evidence for Recent Liquid W
…
PIA01036
Sol (our sun)
Mars Orbiter Camera
| Title |
Evidence for Recent Liquid Water on Mars: Seepage Sites in "Aerobraking Crater" Revisited |
| Original Caption Released with Image |
The first clue that there might be places on Mars where liquid groundwater seeps out onto the surface came from a picture taken by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) during the pre-mapping Orbit Insertion Phase of the mission. The picture, shown in (A)above, was taken at the end of December 1997 while the spacecraft was still in the midst of aerobraking maneuvers to put it into the circular orbit needed for the Mapping Phase of the project. The Aerobraking 1 image, AB1-07707, showed dark, v-shaped scars on the western wall of a 50 kilometer-(31 mile)-diameter impact crater in southern Noachis Terra at 65°S, 15°W (see B, above, for context). The v-shaped features taper downslope to form narrow, somewhat curved channels. The relationship seen here was interpreted by MOC scientists to be similar to seepage landforms on Earth that form where springs emerge on a slope and water runs downhill. Once MGS achieved its Mapping Orbit in March 1999, the MOC was in a better position to take pictures of 10 times higher resolution than the Aerobraking AB1-07707 image. The opportunity to take a new picture of the proposed "seepage" sites on the wall of the crater in southern Noachis finally arose in January 2000. The result is MOC image M11-00530, shown above in (top) and (C). This new close-up shows that the darkly-shaped scars host many small channels of only a few meters (yards) across. These small channels run downslope and coalesce at the apex (or point) of each "v". Amid the small channels are many large boulders, some of them the size of houses, that have eroded out of the crater wall. A 3-D view created using the AB1 and M11 images is shown in (D). The stereo picture (red-blue "3D" glasses required) emphasizes the presence of small channels and valleys, and shows that these valleys start almost at the very top of the v-shaped dark areas. The context picture in (B) is a mosaic of Viking 2 orbiter images 497B47 and 497B48 acquired December 28, 1977. The Aerobraking MGS MOC image, AB1-07707, is shown overlain on the Viking context image, it was taken 20 years later on December 29, 1997. The smaller white box in the context picture shows the location of MOC Mapping Phase image M11-00530, roughly 2 years later on January 4, 2000. North is "up" in pictures (A) and (B), and to the lower right in (top), (C), and (D). Sunlight illuminates (A) from the upper left, (B) from the upper right, and (top) and (C) from the upper right. The top image in (top) is the aerobraking image, AB1-07707, with a white box indicating the location of the lower image, M11-00530, and the stereo pair in (D). The white box on the left in (C) shows the location of the close-up on the right in (C). |
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Evidence for Recent Liquid W
…
PIA01036
Sol (our sun)
Mars Orbiter Camera
| Title |
Evidence for Recent Liquid Water on Mars: Seepage Sites in "Aerobraking Crater" Revisited |
| Original Caption Released with Image |
The first clue that there might be places on Mars where liquid groundwater seeps out onto the surface came from a picture taken by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) during the pre-mapping Orbit Insertion Phase of the mission. The picture, shown in (A)above, was taken at the end of December 1997 while the spacecraft was still in the midst of aerobraking maneuvers to put it into the circular orbit needed for the Mapping Phase of the project. The Aerobraking 1 image, AB1-07707, showed dark, v-shaped scars on the western wall of a 50 kilometer-(31 mile)-diameter impact crater in southern Noachis Terra at 65°S, 15°W (see B, above, for context). The v-shaped features taper downslope to form narrow, somewhat curved channels. The relationship seen here was interpreted by MOC scientists to be similar to seepage landforms on Earth that form where springs emerge on a slope and water runs downhill. Once MGS achieved its Mapping Orbit in March 1999, the MOC was in a better position to take pictures of 10 times higher resolution than the Aerobraking AB1-07707 image. The opportunity to take a new picture of the proposed "seepage" sites on the wall of the crater in southern Noachis finally arose in January 2000. The result is MOC image M11-00530, shown above in (top) and (C). This new close-up shows that the darkly-shaped scars host many small channels of only a few meters (yards) across. These small channels run downslope and coalesce at the apex (or point) of each "v". Amid the small channels are many large boulders, some of them the size of houses, that have eroded out of the crater wall. A 3-D view created using the AB1 and M11 images is shown in (D). The stereo picture (red-blue "3D" glasses required) emphasizes the presence of small channels and valleys, and shows that these valleys start almost at the very top of the v-shaped dark areas. The context picture in (B) is a mosaic of Viking 2 orbiter images 497B47 and 497B48 acquired December 28, 1977. The Aerobraking MGS MOC image, AB1-07707, is shown overlain on the Viking context image, it was taken 20 years later on December 29, 1997. The smaller white box in the context picture shows the location of MOC Mapping Phase image M11-00530, roughly 2 years later on January 4, 2000. North is "up" in pictures (A) and (B), and to the lower right in (top), (C), and (D). Sunlight illuminates (A) from the upper left, (B) from the upper right, and (top) and (C) from the upper right. The top image in (top) is the aerobraking image, AB1-07707, with a white box indicating the location of the lower image, M11-00530, and the stereo pair in (D). The white box on the left in (C) shows the location of the close-up on the right in (C). |
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Evidence for Recent Liquid W
…
PIA01036
Sol (our sun)
Mars Orbiter Camera
| Title |
Evidence for Recent Liquid Water on Mars: Seepage Sites in "Aerobraking Crater" Revisited |
| Original Caption Released with Image |
The first clue that there might be places on Mars where liquid groundwater seeps out onto the surface came from a picture taken by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) during the pre-mapping Orbit Insertion Phase of the mission. The picture, shown in (A)above, was taken at the end of December 1997 while the spacecraft was still in the midst of aerobraking maneuvers to put it into the circular orbit needed for the Mapping Phase of the project. The Aerobraking 1 image, AB1-07707, showed dark, v-shaped scars on the western wall of a 50 kilometer-(31 mile)-diameter impact crater in southern Noachis Terra at 65°S, 15°W (see B, above, for context). The v-shaped features taper downslope to form narrow, somewhat curved channels. The relationship seen here was interpreted by MOC scientists to be similar to seepage landforms on Earth that form where springs emerge on a slope and water runs downhill. Once MGS achieved its Mapping Orbit in March 1999, the MOC was in a better position to take pictures of 10 times higher resolution than the Aerobraking AB1-07707 image. The opportunity to take a new picture of the proposed "seepage" sites on the wall of the crater in southern Noachis finally arose in January 2000. The result is MOC image M11-00530, shown above in (top) and (C). This new close-up shows that the darkly-shaped scars host many small channels of only a few meters (yards) across. These small channels run downslope and coalesce at the apex (or point) of each "v". Amid the small channels are many large boulders, some of them the size of houses, that have eroded out of the crater wall. A 3-D view created using the AB1 and M11 images is shown in (D). The stereo picture (red-blue "3D" glasses required) emphasizes the presence of small channels and valleys, and shows that these valleys start almost at the very top of the v-shaped dark areas. The context picture in (B) is a mosaic of Viking 2 orbiter images 497B47 and 497B48 acquired December 28, 1977. The Aerobraking MGS MOC image, AB1-07707, is shown overlain on the Viking context image, it was taken 20 years later on December 29, 1997. The smaller white box in the context picture shows the location of MOC Mapping Phase image M11-00530, roughly 2 years later on January 4, 2000. North is "up" in pictures (A) and (B), and to the lower right in (top), (C), and (D). Sunlight illuminates (A) from the upper left, (B) from the upper right, and (top) and (C) from the upper right. The top image in (top) is the aerobraking image, AB1-07707, with a white box indicating the location of the lower image, M11-00530, and the stereo pair in (D). The white box on the left in (C) shows the location of the close-up on the right in (C). |
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Evidence for Recent Liquid W
…
PIA01036
Sol (our sun)
Mars Orbiter Camera
| Title |
Evidence for Recent Liquid Water on Mars: Seepage Sites in "Aerobraking Crater" Revisited |
| Original Caption Released with Image |
The first clue that there might be places on Mars where liquid groundwater seeps out onto the surface came from a picture taken by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) during the pre-mapping Orbit Insertion Phase of the mission. The picture, shown in (A)above, was taken at the end of December 1997 while the spacecraft was still in the midst of aerobraking maneuvers to put it into the circular orbit needed for the Mapping Phase of the project. The Aerobraking 1 image, AB1-07707, showed dark, v-shaped scars on the western wall of a 50 kilometer-(31 mile)-diameter impact crater in southern Noachis Terra at 65°S, 15°W (see B, above, for context). The v-shaped features taper downslope to form narrow, somewhat curved channels. The relationship seen here was interpreted by MOC scientists to be similar to seepage landforms on Earth that form where springs emerge on a slope and water runs downhill. Once MGS achieved its Mapping Orbit in March 1999, the MOC was in a better position to take pictures of 10 times higher resolution than the Aerobraking AB1-07707 image. The opportunity to take a new picture of the proposed "seepage" sites on the wall of the crater in southern Noachis finally arose in January 2000. The result is MOC image M11-00530, shown above in (top) and (C). This new close-up shows that the darkly-shaped scars host many small channels of only a few meters (yards) across. These small channels run downslope and coalesce at the apex (or point) of each "v". Amid the small channels are many large boulders, some of them the size of houses, that have eroded out of the crater wall. A 3-D view created using the AB1 and M11 images is shown in (D). The stereo picture (red-blue "3D" glasses required) emphasizes the presence of small channels and valleys, and shows that these valleys start almost at the very top of the v-shaped dark areas. The context picture in (B) is a mosaic of Viking 2 orbiter images 497B47 and 497B48 acquired December 28, 1977. The Aerobraking MGS MOC image, AB1-07707, is shown overlain on the Viking context image, it was taken 20 years later on December 29, 1997. The smaller white box in the context picture shows the location of MOC Mapping Phase image M11-00530, roughly 2 years later on January 4, 2000. North is "up" in pictures (A) and (B), and to the lower right in (top), (C), and (D). Sunlight illuminates (A) from the upper left, (B) from the upper right, and (top) and (C) from the upper right. The top image in (top) is the aerobraking image, AB1-07707, with a white box indicating the location of the lower image, M11-00530, and the stereo pair in (D). The white box on the left in (C) shows the location of the close-up on the right in (C). |
|
Evidence for Recent Liquid W
…
PIA01036
Sol (our sun)
Mars Orbiter Camera
| Title |
Evidence for Recent Liquid Water on Mars: Seepage Sites in "Aerobraking Crater" Revisited |
| Original Caption Released with Image |
The first clue that there might be places on Mars where liquid groundwater seeps out onto the surface came from a picture taken by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) during the pre-mapping Orbit Insertion Phase of the mission. The picture, shown in (A)above, was taken at the end of December 1997 while the spacecraft was still in the midst of aerobraking maneuvers to put it into the circular orbit needed for the Mapping Phase of the project. The Aerobraking 1 image, AB1-07707, showed dark, v-shaped scars on the western wall of a 50 kilometer-(31 mile)-diameter impact crater in southern Noachis Terra at 65°S, 15°W (see B, above, for context). The v-shaped features taper downslope to form narrow, somewhat curved channels. The relationship seen here was interpreted by MOC scientists to be similar to seepage landforms on Earth that form where springs emerge on a slope and water runs downhill. Once MGS achieved its Mapping Orbit in March 1999, the MOC was in a better position to take pictures of 10 times higher resolution than the Aerobraking AB1-07707 image. The opportunity to take a new picture of the proposed "seepage" sites on the wall of the crater in southern Noachis finally arose in January 2000. The result is MOC image M11-00530, shown above in (top) and (C). This new close-up shows that the darkly-shaped scars host many small channels of only a few meters (yards) across. These small channels run downslope and coalesce at the apex (or point) of each "v". Amid the small channels are many large boulders, some of them the size of houses, that have eroded out of the crater wall. A 3-D view created using the AB1 and M11 images is shown in (D). The stereo picture (red-blue "3D" glasses required) emphasizes the presence of small channels and valleys, and shows that these valleys start almost at the very top of the v-shaped dark areas. The context picture in (B) is a mosaic of Viking 2 orbiter images 497B47 and 497B48 acquired December 28, 1977. The Aerobraking MGS MOC image, AB1-07707, is shown overlain on the Viking context image, it was taken 20 years later on December 29, 1997. The smaller white box in the context picture shows the location of MOC Mapping Phase image M11-00530, roughly 2 years later on January 4, 2000. North is "up" in pictures (A) and (B), and to the lower right in (top), (C), and (D). Sunlight illuminates (A) from the upper left, (B) from the upper right, and (top) and (C) from the upper right. The top image in (top) is the aerobraking image, AB1-07707, with a white box indicating the location of the lower image, M11-00530, and the stereo pair in (D). The white box on the left in (C) shows the location of the close-up on the right in (C). |
|
Evidence for Recent Liquid W
…
PIA01036
Sol (our sun)
Mars Orbiter Camera
| Title |
Evidence for Recent Liquid Water on Mars: Seepage Sites in "Aerobraking Crater" Revisited |
| Original Caption Released with Image |
The first clue that there might be places on Mars where liquid groundwater seeps out onto the surface came from a picture taken by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) during the pre-mapping Orbit Insertion Phase of the mission. The picture, shown in (A)above, was taken at the end of December 1997 while the spacecraft was still in the midst of aerobraking maneuvers to put it into the circular orbit needed for the Mapping Phase of the project. The Aerobraking 1 image, AB1-07707, showed dark, v-shaped scars on the western wall of a 50 kilometer-(31 mile)-diameter impact crater in southern Noachis Terra at 65°S, 15°W (see B, above, for context). The v-shaped features taper downslope to form narrow, somewhat curved channels. The relationship seen here was interpreted by MOC scientists to be similar to seepage landforms on Earth that form where springs emerge on a slope and water runs downhill. Once MGS achieved its Mapping Orbit in March 1999, the MOC was in a better position to take pictures of 10 times higher resolution than the Aerobraking AB1-07707 image. The opportunity to take a new picture of the proposed "seepage" sites on the wall of the crater in southern Noachis finally arose in January 2000. The result is MOC image M11-00530, shown above in (top) and (C). This new close-up shows that the darkly-shaped scars host many small channels of only a few meters (yards) across. These small channels run downslope and coalesce at the apex (or point) of each "v". Amid the small channels are many large boulders, some of them the size of houses, that have eroded out of the crater wall. A 3-D view created using the AB1 and M11 images is shown in (D). The stereo picture (red-blue "3D" glasses required) emphasizes the presence of small channels and valleys, and shows that these valleys start almost at the very top of the v-shaped dark areas. The context picture in (B) is a mosaic of Viking 2 orbiter images 497B47 and 497B48 acquired December 28, 1977. The Aerobraking MGS MOC image, AB1-07707, is shown overlain on the Viking context image, it was taken 20 years later on December 29, 1997. The smaller white box in the context picture shows the location of MOC Mapping Phase image M11-00530, roughly 2 years later on January 4, 2000. North is "up" in pictures (A) and (B), and to the lower right in (top), (C), and (D). Sunlight illuminates (A) from the upper left, (B) from the upper right, and (top) and (C) from the upper right. The top image in (top) is the aerobraking image, AB1-07707, with a white box indicating the location of the lower image, M11-00530, and the stereo pair in (D). The white box on the left in (C) shows the location of the close-up on the right in (C). |
|
Evidence for Recent Liquid W
…
PIA01036
Sol (our sun)
Mars Orbiter Camera
| Title |
Evidence for Recent Liquid Water on Mars: Seepage Sites in "Aerobraking Crater" Revisited |
| Original Caption Released with Image |
The first clue that there might be places on Mars where liquid groundwater seeps out onto the surface came from a picture taken by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) during the pre-mapping Orbit Insertion Phase of the mission. The picture, shown in (A)above, was taken at the end of December 1997 while the spacecraft was still in the midst of aerobraking maneuvers to put it into the circular orbit needed for the Mapping Phase of the project. The Aerobraking 1 image, AB1-07707, showed dark, v-shaped scars on the western wall of a 50 kilometer-(31 mile)-diameter impact crater in southern Noachis Terra at 65°S, 15°W (see B, above, for context). The v-shaped features taper downslope to form narrow, somewhat curved channels. The relationship seen here was interpreted by MOC scientists to be similar to seepage landforms on Earth that form where springs emerge on a slope and water runs downhill. Once MGS achieved its Mapping Orbit in March 1999, the MOC was in a better position to take pictures of 10 times higher resolution than the Aerobraking AB1-07707 image. The opportunity to take a new picture of the proposed "seepage" sites on the wall of the crater in southern Noachis finally arose in January 2000. The result is MOC image M11-00530, shown above in (top) and (C). This new close-up shows that the darkly-shaped scars host many small channels of only a few meters (yards) across. These small channels run downslope and coalesce at the apex (or point) of each "v". Amid the small channels are many large boulders, some of them the size of houses, that have eroded out of the crater wall. A 3-D view created using the AB1 and M11 images is shown in (D). The stereo picture (red-blue "3D" glasses required) emphasizes the presence of small channels and valleys, and shows that these valleys start almost at the very top of the v-shaped dark areas. The context picture in (B) is a mosaic of Viking 2 orbiter images 497B47 and 497B48 acquired December 28, 1977. The Aerobraking MGS MOC image, AB1-07707, is shown overlain on the Viking context image, it was taken 20 years later on December 29, 1997. The smaller white box in the context picture shows the location of MOC Mapping Phase image M11-00530, roughly 2 years later on January 4, 2000. North is "up" in pictures (A) and (B), and to the lower right in (top), (C), and (D). Sunlight illuminates (A) from the upper left, (B) from the upper right, and (top) and (C) from the upper right. The top image in (top) is the aerobraking image, AB1-07707, with a white box indicating the location of the lower image, M11-00530, and the stereo pair in (D). The white box on the left in (C) shows the location of the close-up on the right in (C). |
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