|
|
Antarctic Plumbing: Lake Eng
…
| Title |
Antarctic Plumbing: Lake Englehardt's Subglacial Hydraulic System |
| Abstract |
ICESat satellite laser altimeter elevation profiles from 2003-2006 collected over West Antarctica reveal numerous regions of temporally varying elevation. MODIS satellite imagery over roughly the same time period collaborates where these subglacial fluctuations have occurred. These observations have led scientists to conclude that subglacial water movement is happening in this lake region, revealing a widespread, dynamic subglacial water system that could provide important insights into ice flow and the mass balance of Antarctica's ice. |
| Completed |
2007-02-13 |
|
First HiRISE Image of Mars:
…
| title |
First HiRISE Image of Mars: Topographic Model from Photoclinometry |
| Description |
http://www.nasa.gov/mro [ http://www.nasa.gov/mro ] or http://HiRISE.lpl.arizona.edu [ http://HiRISE.lpl.arizona.edu ]. For information about NASA and agency programs on the Web, visit: http://www.nasa.gov [ http://www.nasa.gov ]. 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 is the prime contractor for the project and built the spacecraft. The HiRISE camera was built by Ball Aerospace and Technology Corporation and is operated by the University of Arizona. Credit: NASA/JPL/University of Arizona/USGS, This is a topographic map of part of the area covered by the first image of Mars obtained by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter spacecraft. The image was processed at the U.S. Geological Survey, Flagstaff, by a technique called photoclinometry (or, more descriptively, "shape-from-shading"). This method allows elevations to be reconstructed from a single image by noting how surfaces sloping toward the sun appear brighter than areas that slope away from it. This image is almost ideal for such interpretation because the low sun angle reveals even subtle slopes with dramatic contrast, and variations in the brightness of surface materials (which could be confused with slopes) are minimal. At left is the region of the image that was analyzed, tinted to approximate the visual appearance of the Martian surface. This region is a square 20.4 kilometers (12.7 miles) wide (8,192 pixels by 8,192 pixels at a scale of 2.49 meters or 8.17 feet per pixel). At right is a color-coded topographic contour map of the same area. The total range of elevations is 1.6 kilometers (1 mile), with low areas shown in purple and high areas in red. Contours mark each 20-meter (66-foot) change in elevation. Photoclinometry gives relative rather than absolute heights, but the overall height and shape of features in this map, such as the ridge Ogygis Rupes in the center, agree reasonably well with results from the Mars Orbiter Laser Altimeter on NASA's Mars Odyssey spacecraft, an instrument with high absolute accuracy but relatively low spatial resolution. The real value of mapping by photoclinometry, however, is that it reveals the details of the smallest topographic features resolved by the image. In this example, the image was resampled by a factor of 2 before processing, so the topographic map has a scale of 5 meters (16 feet) per pixel and resolves features as small as 15 meters (49 feet). Computer-generated three-dimensional close-ups of the surface provide one way to visualize these small but important clues to Martian geologic history. This illustration shows a subset of AEB_000001_0000_Red, which was taken by the HiRISE camera on March 24, 2006. The image is oriented such that north is 7 degrees to the left of up. The range to the target was 2,493 kilometers (1,549 miles). At this distance the image scale is 2.49 meters (8.17 feet) per pixel, so objects as small as 7.5 meters (24.6 feet) are resolved. The image was taken at a local Mars time of 07:33 and the scene is illuminated from the upper right with a solar incidence angle of 78.1 degrees, thus the sun was about 11.9 degrees above the horizon. At an Ls of 29 degrees (with Ls an indicator of Mars' position in its orbit around the sun), the season on Mars is southern autumn. Images from the High Resolution Imaging Science Experiment and additional information about the Mars Reconnaissance Orbiter are available online at: |
|
Jason Satellite Observes Mil
…
PIA01939
Sol (our sun)
Altimeter
| Title |
Jason Satellite Observes Mild El Nino in 2006 |
| Original Caption Released with Image |
In September 2006, NASA satellite data indicated that El Niño had returned to the tropical Pacific Ocean, although it was relatively weak. As of early October, scientists were not sure if the event would persist, and it was much less intense than the last major El Niño episode, which happened in 1997-1998. That event brought devastating floods to California that cost millions of dollars in damage while severe drought struck Indonesia, Australia, and the Philippines. Among the ocean characteristics that signal developing El Niño events is a change in average sea surface height compared to normal sea level. When water warms, it expands a little, which changes its volume slightly. When heat begins to build up in the Pacific during an El Niño event, the sea surface height begins to creep up. NASA observes changes in average sea surface height using its Jason satellite. The image is based on the average of 10 days of data centered on September 15, 2006, compared to the long-term average of observations from 1993-2005. In this image, places where the Pacific sea surface height is higher (warmer) than normal are yellow, orange, and red, and places where the sea surface is lower (cooler) than normal are blue and purple. Green shows where conditions are near normal. The swath of red in the center of the scene reveals that an El Niño was in progress when Jason observed the Pacific. El Niño is a cyclical warming of the ocean waters in the central and eastern tropical Pacific that generally occurs every 3 to 7 years. It is linked with changes in air pressure and high-level winds that can affect weather worldwide. Typically peaking during the Northern Hemisphere winter months, El Niño is the warm phase of the El Niño/Southern Oscillation. It alternates with La Niña, the cooling of ocean waters in the same region of the Pacific. According to Bill Patzert, oceanographer and climatologist at NASA's Jet Propulsion Laboratory, "The present conditions indicate that the intensity of this El Niño is too weak to have a major influence on current weather patterns. But, if the ocean waters continue to warm and spread eastward, this event would likely strengthen, perhaps bringing much-needed rainfall to the southwestern and southeastern United States this winter." The Jason satellite carries a dual-frequency radar altimeter. This instrument beams microwave pulses-at 13.6 and 5.3 Gigahertz, respectively-downward toward the Earth. To determine the ocean's height, the instrument precisely measures the time it takes for the microwave pulses to bounce off the surface and return to the spacecraft. This measure, multiplied by the speed of light, gives the range from the satellite to the ocean surface. The joint U.S.-French Topex/Poseidon mission is managed by the JPL for NASA's Science Mission Directorate, NASA Headquarters, Washington, D.C. JPL is a division of the California Institute of Technology in Pasadena. Research on Earth's oceans using Jason and other, space-based capabilities is conducted by NASA's Science Mission Directorate to better understand and protect our home planet. For more information on NASA's ocean surface topography missions, see http://sealevel.jpl.nasa.gov/ [ http://sealevel.jpl.nasa.gov/ ] or to view the latest Jason data see http://sealevel.jpl.nasa.gov/science/jason1-quick-look/ [ http://sealevel.jpl.nasa.gov/science/jason1-quick-look/ ]. |
|
Procedure for Finding New Im
…
PIA09021
Sol (our sun)
Mars Orbiter Camera
| Title |
Procedure for Finding New Impact Sites on Mars Using the Mars Global Surveyor Mars Orbiter Camera |
| Original Caption Released with Image |
), the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) science operations team considered it possible to find more such impact sites using the MOC red wide angle camera. The most recent, freshest craters would be expected to be quite small, ranging from a few meters across to maybe a few hundred meters or so, at most, in diameter (100 meters is about 109 yards, compare that with a 100 yard U.S.-style football field). Something less than 100 meters across would not show up easily in a 240 meters per pixel red wide angle image. But the 6 January 2006 image showed that it could, because these small impacts, if they occur in an area thickly mantled with dust, will create a much larger "blast zone" around them. Thus, the MOC science operations team set out to image a few of the dustiest regions on Mars -- Tharsis, Amazonis, and Arabia -- with the red wide angle camera. The same camera had, in May and early June 1999, already imaged most of the planet at about 240 meters per pixel scale. By repeating areas already imaged in May/June 1999 during the January/March 2006 timeframe, we would be able to identify more dark spots. And, so, that is what we did. The Tharsis, Amazonis, and Arabia regions were re-imaged using the MOC red wide angle camera during January through March 2006. The data covered about 21,506,000 square kilometers (~8.3 million square miles, ~1/3 the surface area of Mars and more than twice the area of the United States). As each picture was received on Earth, we compared it with the images acquired during May/June 1999. Over the entire area surveyed, we found 39 dark spots that were present in early 2006 but not visible in May/June 1999. The 39 dark spots, then, were the candidate impact sites. Each one of these became a target for the MOC narrow angle camera, which would be used to take an image of about 1.5 meters (4.9 feet) per pixel of each site. The targets were entered into the MOC database. Then, as the predicted MGS ground track came near each site, the MOC team targeted an image by working with the spacecraft engineers at Lockheed Martin Astronautics (Denver, Colorado) and the Caltech/Jet Propulsion Laboratory (JPL, Pasadena, California) to point the spacecraft and camera at each site using the Roll Only Targeted Observation (ROTO) maneuver. Of the 39 dark spots, 20 turned out to be fresh impact sites, and 19 of them were not. The other 19 included mistaken identifications (one was a transient, large dust devil shadow, several were craters that had been present in earlier images but had changed in brightness owing to dust removal), new dark wind streaks, and new dark slope streaks created by avalanching dust on steep slopes. Some of the 20 new impact sites received further attention, as the spacecraft and MOC were used to obtain cPROTO (compensated Pitch and Roll Targeted Observations) views that have a spatial resolution of 0.5 meters (1.6 feet) in the downtrack dimension and 1.5 meters (4.9 feet) in the cross, Having realized that a new dark spot on Mars, seen in a red wide angle camera image acquired on 6 January 2006, might be an indication of a recent meteor impact site (see PIA09020 [ http://photojournal.jpl.nasa.gov/catalog/PIA09020 ] or MOC2-1611 [ http://www.msss.com/mars_images/moc/2006/12/06/craters/site1/index.html ], track direction. The cPROTO views, where obtained, have a higher resolution and better signal-to-noise ratio than the original ROTO images. Finally, while our approach of comparing MOC red wide angle camera images obtained in May/June 1999 with those obtained in January/March 2006 constrains the 20 craters all to having formed during the May 1999 to March 2006 time interval, we found in all cases that there were already other images that had been received on Earth that helped constrain the time of the impact more tightly. In some cases, the date of the impact could be pinned down to within a month or two, in other cases the interval covered several years. Data from the MGS MOC, Mars Odyssey Thermal Emission Imaging System (THEMIS) [ http://themis.asu.edu/ ], and Mars Express High Resolution Stereo Camera (HRSC) [ http://berlinadmin.dlr.de/Missions/express/indexeng.shtml ], were all employed in the search. Shown on this page (above) are pictures that illustrate our work to find new impact craters: Figure A: This picture shows one of the new impact sites identified by the MOC team. Located in northern Arabia Terra near 29.3°N, 333.2°W, the actual crater is quite small, only 11.2 ± 3.0 meters in diameter. This is a sub-frame of MOC image S16-01105, acquired using a ROTO maneuver on 12 March 2006. Figures B and C: These pictures are MOC red wide angle camera images, obtained at a scale of about 240 meters per pixel, of portions of Arabia Terra. Figure B is M01-01610 and was acquired during the MOC Geodesy Campaign (see PIA02022 and PIA02023, or MOC2-127) on 14 May 1999. Figure C, MOC S14-02741, was obtained on 26 January 2006 as part of the campaign to find new impact craters. By comparing the two images, one from 1999 and one from 2006, we were able to identify all new dark spots that formed during that interval. In this case, the new dark spot seen in the 2006 image, S14-02741, is inside the white circle. The same location is also indicated by a circle in the May 1999 image, but no dark spot is present there. In both cases, the white circle is about 12 km (7.5 mi) across. Figure D: This map of Mars, showing the location of all the MOC red wide angle camera images acquired for the search for new craters during January through March 2006. These images cover most of Amazonis, Tharsis, and Arabia Terra. The base map is a product that combines the May/June 1999 MOC red wide angle data (plus later data for the south polar region) and laser altimeter data from MGS. Figure E: This picture shows portions of two red wide angle camera context images that more tightly constrain when the new crater shown here (above, top, left) formed. The first picture, R05-00427, was acquired on 5 May 2003 and shows no dark spot at the site of the impact. The second picture, S05-01885, shows that the dark spot was present on 29 April 2005. Thus, these two images tell us that the impact occurred sometime between those dates: 5 May 2003 and 29 April 2005. The Mars Global Surveyor mission is managed for NASA's Office of Space Science, Washington, by the Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Malin Space Science Systems, San Diego, Calif., built and operates the Mars Orbiter Camera. For more information about images from the Mars Orbiter Camera, see http://www.msss.com/mgs/moc/index.html [ http://www.msss.com/mgs/moc/index.html ]. |
|
Procedure for Finding New Im
…
PIA09021
Sol (our sun)
Mars Orbiter Camera
| Title |
Procedure for Finding New Impact Sites on Mars Using the Mars Global Surveyor Mars Orbiter Camera |
| Original Caption Released with Image |
), the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) science operations team considered it possible to find more such impact sites using the MOC red wide angle camera. The most recent, freshest craters would be expected to be quite small, ranging from a few meters across to maybe a few hundred meters or so, at most, in diameter (100 meters is about 109 yards, compare that with a 100 yard U.S.-style football field). Something less than 100 meters across would not show up easily in a 240 meters per pixel red wide angle image. But the 6 January 2006 image showed that it could, because these small impacts, if they occur in an area thickly mantled with dust, will create a much larger "blast zone" around them. Thus, the MOC science operations team set out to image a few of the dustiest regions on Mars -- Tharsis, Amazonis, and Arabia -- with the red wide angle camera. The same camera had, in May and early June 1999, already imaged most of the planet at about 240 meters per pixel scale. By repeating areas already imaged in May/June 1999 during the January/March 2006 timeframe, we would be able to identify more dark spots. And, so, that is what we did. The Tharsis, Amazonis, and Arabia regions were re-imaged using the MOC red wide angle camera during January through March 2006. The data covered about 21,506,000 square kilometers (~8.3 million square miles, ~1/3 the surface area of Mars and more than twice the area of the United States). As each picture was received on Earth, we compared it with the images acquired during May/June 1999. Over the entire area surveyed, we found 39 dark spots that were present in early 2006 but not visible in May/June 1999. The 39 dark spots, then, were the candidate impact sites. Each one of these became a target for the MOC narrow angle camera, which would be used to take an image of about 1.5 meters (4.9 feet) per pixel of each site. The targets were entered into the MOC database. Then, as the predicted MGS ground track came near each site, the MOC team targeted an image by working with the spacecraft engineers at Lockheed Martin Astronautics (Denver, Colorado) and the Caltech/Jet Propulsion Laboratory (JPL, Pasadena, California) to point the spacecraft and camera at each site using the Roll Only Targeted Observation (ROTO) maneuver. Of the 39 dark spots, 20 turned out to be fresh impact sites, and 19 of them were not. The other 19 included mistaken identifications (one was a transient, large dust devil shadow, several were craters that had been present in earlier images but had changed in brightness owing to dust removal), new dark wind streaks, and new dark slope streaks created by avalanching dust on steep slopes. Some of the 20 new impact sites received further attention, as the spacecraft and MOC were used to obtain cPROTO (compensated Pitch and Roll Targeted Observations) views that have a spatial resolution of 0.5 meters (1.6 feet) in the downtrack dimension and 1.5 meters (4.9 feet) in the cross, Having realized that a new dark spot on Mars, seen in a red wide angle camera image acquired on 6 January 2006, might be an indication of a recent meteor impact site (see PIA09020 [ http://photojournal.jpl.nasa.gov/catalog/PIA09020 ] or MOC2-1611 [ http://www.msss.com/mars_images/moc/2006/12/06/craters/site1/index.html ], track direction. The cPROTO views, where obtained, have a higher resolution and better signal-to-noise ratio than the original ROTO images. Finally, while our approach of comparing MOC red wide angle camera images obtained in May/June 1999 with those obtained in January/March 2006 constrains the 20 craters all to having formed during the May 1999 to March 2006 time interval, we found in all cases that there were already other images that had been received on Earth that helped constrain the time of the impact more tightly. In some cases, the date of the impact could be pinned down to within a month or two, in other cases the interval covered several years. Data from the MGS MOC, Mars Odyssey Thermal Emission Imaging System (THEMIS) [ http://themis.asu.edu/ ], and Mars Express High Resolution Stereo Camera (HRSC) [ http://berlinadmin.dlr.de/Missions/express/indexeng.shtml ], were all employed in the search. Shown on this page (above) are pictures that illustrate our work to find new impact craters: Figure A: This picture shows one of the new impact sites identified by the MOC team. Located in northern Arabia Terra near 29.3°N, 333.2°W, the actual crater is quite small, only 11.2 ± 3.0 meters in diameter. This is a sub-frame of MOC image S16-01105, acquired using a ROTO maneuver on 12 March 2006. Figures B and C: These pictures are MOC red wide angle camera images, obtained at a scale of about 240 meters per pixel, of portions of Arabia Terra. Figure B is M01-01610 and was acquired during the MOC Geodesy Campaign (see PIA02022 and PIA02023, or MOC2-127) on 14 May 1999. Figure C, MOC S14-02741, was obtained on 26 January 2006 as part of the campaign to find new impact craters. By comparing the two images, one from 1999 and one from 2006, we were able to identify all new dark spots that formed during that interval. In this case, the new dark spot seen in the 2006 image, S14-02741, is inside the white circle. The same location is also indicated by a circle in the May 1999 image, but no dark spot is present there. In both cases, the white circle is about 12 km (7.5 mi) across. Figure D: This map of Mars, showing the location of all the MOC red wide angle camera images acquired for the search for new craters during January through March 2006. These images cover most of Amazonis, Tharsis, and Arabia Terra. The base map is a product that combines the May/June 1999 MOC red wide angle data (plus later data for the south polar region) and laser altimeter data from MGS. Figure E: This picture shows portions of two red wide angle camera context images that more tightly constrain when the new crater shown here (above, top, left) formed. The first picture, R05-00427, was acquired on 5 May 2003 and shows no dark spot at the site of the impact. The second picture, S05-01885, shows that the dark spot was present on 29 April 2005. Thus, these two images tell us that the impact occurred sometime between those dates: 5 May 2003 and 29 April 2005. The Mars Global Surveyor mission is managed for NASA's Office of Space Science, Washington, by the Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Malin Space Science Systems, San Diego, Calif., built and operates the Mars Orbiter Camera. For more information about images from the Mars Orbiter Camera, see http://www.msss.com/mgs/moc/index.html [ http://www.msss.com/mgs/moc/index.html ]. |
|
Procedure for Finding New Im
…
PIA09021
Sol (our sun)
Mars Orbiter Camera
| Title |
Procedure for Finding New Impact Sites on Mars Using the Mars Global Surveyor Mars Orbiter Camera |
| Original Caption Released with Image |
), the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) science operations team considered it possible to find more such impact sites using the MOC red wide angle camera. The most recent, freshest craters would be expected to be quite small, ranging from a few meters across to maybe a few hundred meters or so, at most, in diameter (100 meters is about 109 yards, compare that with a 100 yard U.S.-style football field). Something less than 100 meters across would not show up easily in a 240 meters per pixel red wide angle image. But the 6 January 2006 image showed that it could, because these small impacts, if they occur in an area thickly mantled with dust, will create a much larger "blast zone" around them. Thus, the MOC science operations team set out to image a few of the dustiest regions on Mars -- Tharsis, Amazonis, and Arabia -- with the red wide angle camera. The same camera had, in May and early June 1999, already imaged most of the planet at about 240 meters per pixel scale. By repeating areas already imaged in May/June 1999 during the January/March 2006 timeframe, we would be able to identify more dark spots. And, so, that is what we did. The Tharsis, Amazonis, and Arabia regions were re-imaged using the MOC red wide angle camera during January through March 2006. The data covered about 21,506,000 square kilometers (~8.3 million square miles, ~1/3 the surface area of Mars and more than twice the area of the United States). As each picture was received on Earth, we compared it with the images acquired during May/June 1999. Over the entire area surveyed, we found 39 dark spots that were present in early 2006 but not visible in May/June 1999. The 39 dark spots, then, were the candidate impact sites. Each one of these became a target for the MOC narrow angle camera, which would be used to take an image of about 1.5 meters (4.9 feet) per pixel of each site. The targets were entered into the MOC database. Then, as the predicted MGS ground track came near each site, the MOC team targeted an image by working with the spacecraft engineers at Lockheed Martin Astronautics (Denver, Colorado) and the Caltech/Jet Propulsion Laboratory (JPL, Pasadena, California) to point the spacecraft and camera at each site using the Roll Only Targeted Observation (ROTO) maneuver. Of the 39 dark spots, 20 turned out to be fresh impact sites, and 19 of them were not. The other 19 included mistaken identifications (one was a transient, large dust devil shadow, several were craters that had been present in earlier images but had changed in brightness owing to dust removal), new dark wind streaks, and new dark slope streaks created by avalanching dust on steep slopes. Some of the 20 new impact sites received further attention, as the spacecraft and MOC were used to obtain cPROTO (compensated Pitch and Roll Targeted Observations) views that have a spatial resolution of 0.5 meters (1.6 feet) in the downtrack dimension and 1.5 meters (4.9 feet) in the cross, Having realized that a new dark spot on Mars, seen in a red wide angle camera image acquired on 6 January 2006, might be an indication of a recent meteor impact site (see PIA09020 [ http://photojournal.jpl.nasa.gov/catalog/PIA09020 ] or MOC2-1611 [ http://www.msss.com/mars_images/moc/2006/12/06/craters/site1/index.html ], track direction. The cPROTO views, where obtained, have a higher resolution and better signal-to-noise ratio than the original ROTO images. Finally, while our approach of comparing MOC red wide angle camera images obtained in May/June 1999 with those obtained in January/March 2006 constrains the 20 craters all to having formed during the May 1999 to March 2006 time interval, we found in all cases that there were already other images that had been received on Earth that helped constrain the time of the impact more tightly. In some cases, the date of the impact could be pinned down to within a month or two, in other cases the interval covered several years. Data from the MGS MOC, Mars Odyssey Thermal Emission Imaging System (THEMIS) [ http://themis.asu.edu/ ], and Mars Express High Resolution Stereo Camera (HRSC) [ http://berlinadmin.dlr.de/Missions/express/indexeng.shtml ], were all employed in the search. Shown on this page (above) are pictures that illustrate our work to find new impact craters: Figure A: This picture shows one of the new impact sites identified by the MOC team. Located in northern Arabia Terra near 29.3°N, 333.2°W, the actual crater is quite small, only 11.2 ± 3.0 meters in diameter. This is a sub-frame of MOC image S16-01105, acquired using a ROTO maneuver on 12 March 2006. Figures B and C: These pictures are MOC red wide angle camera images, obtained at a scale of about 240 meters per pixel, of portions of Arabia Terra. Figure B is M01-01610 and was acquired during the MOC Geodesy Campaign (see PIA02022 and PIA02023, or MOC2-127) on 14 May 1999. Figure C, MOC S14-02741, was obtained on 26 January 2006 as part of the campaign to find new impact craters. By comparing the two images, one from 1999 and one from 2006, we were able to identify all new dark spots that formed during that interval. In this case, the new dark spot seen in the 2006 image, S14-02741, is inside the white circle. The same location is also indicated by a circle in the May 1999 image, but no dark spot is present there. In both cases, the white circle is about 12 km (7.5 mi) across. Figure D: This map of Mars, showing the location of all the MOC red wide angle camera images acquired for the search for new craters during January through March 2006. These images cover most of Amazonis, Tharsis, and Arabia Terra. The base map is a product that combines the May/June 1999 MOC red wide angle data (plus later data for the south polar region) and laser altimeter data from MGS. Figure E: This picture shows portions of two red wide angle camera context images that more tightly constrain when the new crater shown here (above, top, left) formed. The first picture, R05-00427, was acquired on 5 May 2003 and shows no dark spot at the site of the impact. The second picture, S05-01885, shows that the dark spot was present on 29 April 2005. Thus, these two images tell us that the impact occurred sometime between those dates: 5 May 2003 and 29 April 2005. The Mars Global Surveyor mission is managed for NASA's Office of Space Science, Washington, by the Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Malin Space Science Systems, San Diego, Calif., built and operates the Mars Orbiter Camera. For more information about images from the Mars Orbiter Camera, see http://www.msss.com/mgs/moc/index.html [ http://www.msss.com/mgs/moc/index.html ]. |
|
Procedure for Finding New Im
…
PIA09021
Sol (our sun)
Mars Orbiter Camera
| Title |
Procedure for Finding New Impact Sites on Mars Using the Mars Global Surveyor Mars Orbiter Camera |
| Original Caption Released with Image |
), the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) science operations team considered it possible to find more such impact sites using the MOC red wide angle camera. The most recent, freshest craters would be expected to be quite small, ranging from a few meters across to maybe a few hundred meters or so, at most, in diameter (100 meters is about 109 yards, compare that with a 100 yard U.S.-style football field). Something less than 100 meters across would not show up easily in a 240 meters per pixel red wide angle image. But the 6 January 2006 image showed that it could, because these small impacts, if they occur in an area thickly mantled with dust, will create a much larger "blast zone" around them. Thus, the MOC science operations team set out to image a few of the dustiest regions on Mars -- Tharsis, Amazonis, and Arabia -- with the red wide angle camera. The same camera had, in May and early June 1999, already imaged most of the planet at about 240 meters per pixel scale. By repeating areas already imaged in May/June 1999 during the January/March 2006 timeframe, we would be able to identify more dark spots. And, so, that is what we did. The Tharsis, Amazonis, and Arabia regions were re-imaged using the MOC red wide angle camera during January through March 2006. The data covered about 21,506,000 square kilometers (~8.3 million square miles, ~1/3 the surface area of Mars and more than twice the area of the United States). As each picture was received on Earth, we compared it with the images acquired during May/June 1999. Over the entire area surveyed, we found 39 dark spots that were present in early 2006 but not visible in May/June 1999. The 39 dark spots, then, were the candidate impact sites. Each one of these became a target for the MOC narrow angle camera, which would be used to take an image of about 1.5 meters (4.9 feet) per pixel of each site. The targets were entered into the MOC database. Then, as the predicted MGS ground track came near each site, the MOC team targeted an image by working with the spacecraft engineers at Lockheed Martin Astronautics (Denver, Colorado) and the Caltech/Jet Propulsion Laboratory (JPL, Pasadena, California) to point the spacecraft and camera at each site using the Roll Only Targeted Observation (ROTO) maneuver. Of the 39 dark spots, 20 turned out to be fresh impact sites, and 19 of them were not. The other 19 included mistaken identifications (one was a transient, large dust devil shadow, several were craters that had been present in earlier images but had changed in brightness owing to dust removal), new dark wind streaks, and new dark slope streaks created by avalanching dust on steep slopes. Some of the 20 new impact sites received further attention, as the spacecraft and MOC were used to obtain cPROTO (compensated Pitch and Roll Targeted Observations) views that have a spatial resolution of 0.5 meters (1.6 feet) in the downtrack dimension and 1.5 meters (4.9 feet) in the cross, Having realized that a new dark spot on Mars, seen in a red wide angle camera image acquired on 6 January 2006, might be an indication of a recent meteor impact site (see PIA09020 [ http://photojournal.jpl.nasa.gov/catalog/PIA09020 ] or MOC2-1611 [ http://www.msss.com/mars_images/moc/2006/12/06/craters/site1/index.html ], track direction. The cPROTO views, where obtained, have a higher resolution and better signal-to-noise ratio than the original ROTO images. Finally, while our approach of comparing MOC red wide angle camera images obtained in May/June 1999 with those obtained in January/March 2006 constrains the 20 craters all to having formed during the May 1999 to March 2006 time interval, we found in all cases that there were already other images that had been received on Earth that helped constrain the time of the impact more tightly. In some cases, the date of the impact could be pinned down to within a month or two, in other cases the interval covered several years. Data from the MGS MOC, Mars Odyssey Thermal Emission Imaging System (THEMIS) [ http://themis.asu.edu/ ], and Mars Express High Resolution Stereo Camera (HRSC) [ http://berlinadmin.dlr.de/Missions/express/indexeng.shtml ], were all employed in the search. Shown on this page (above) are pictures that illustrate our work to find new impact craters: Figure A: This picture shows one of the new impact sites identified by the MOC team. Located in northern Arabia Terra near 29.3°N, 333.2°W, the actual crater is quite small, only 11.2 ± 3.0 meters in diameter. This is a sub-frame of MOC image S16-01105, acquired using a ROTO maneuver on 12 March 2006. Figures B and C: These pictures are MOC red wide angle camera images, obtained at a scale of about 240 meters per pixel, of portions of Arabia Terra. Figure B is M01-01610 and was acquired during the MOC Geodesy Campaign (see PIA02022 and PIA02023, or MOC2-127) on 14 May 1999. Figure C, MOC S14-02741, was obtained on 26 January 2006 as part of the campaign to find new impact craters. By comparing the two images, one from 1999 and one from 2006, we were able to identify all new dark spots that formed during that interval. In this case, the new dark spot seen in the 2006 image, S14-02741, is inside the white circle. The same location is also indicated by a circle in the May 1999 image, but no dark spot is present there. In both cases, the white circle is about 12 km (7.5 mi) across. Figure D: This map of Mars, showing the location of all the MOC red wide angle camera images acquired for the search for new craters during January through March 2006. These images cover most of Amazonis, Tharsis, and Arabia Terra. The base map is a product that combines the May/June 1999 MOC red wide angle data (plus later data for the south polar region) and laser altimeter data from MGS. Figure E: This picture shows portions of two red wide angle camera context images that more tightly constrain when the new crater shown here (above, top, left) formed. The first picture, R05-00427, was acquired on 5 May 2003 and shows no dark spot at the site of the impact. The second picture, S05-01885, shows that the dark spot was present on 29 April 2005. Thus, these two images tell us that the impact occurred sometime between those dates: 5 May 2003 and 29 April 2005. The Mars Global Surveyor mission is managed for NASA's Office of Space Science, Washington, by the Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Malin Space Science Systems, San Diego, Calif., built and operates the Mars Orbiter Camera. For more information about images from the Mars Orbiter Camera, see http://www.msss.com/mgs/moc/index.html [ http://www.msss.com/mgs/moc/index.html ]. |
|
Procedure for Finding New Im
…
PIA09021
Sol (our sun)
Mars Orbiter Camera
| Title |
Procedure for Finding New Impact Sites on Mars Using the Mars Global Surveyor Mars Orbiter Camera |
| Original Caption Released with Image |
), the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) science operations team considered it possible to find more such impact sites using the MOC red wide angle camera. The most recent, freshest craters would be expected to be quite small, ranging from a few meters across to maybe a few hundred meters or so, at most, in diameter (100 meters is about 109 yards, compare that with a 100 yard U.S.-style football field). Something less than 100 meters across would not show up easily in a 240 meters per pixel red wide angle image. But the 6 January 2006 image showed that it could, because these small impacts, if they occur in an area thickly mantled with dust, will create a much larger "blast zone" around them. Thus, the MOC science operations team set out to image a few of the dustiest regions on Mars -- Tharsis, Amazonis, and Arabia -- with the red wide angle camera. The same camera had, in May and early June 1999, already imaged most of the planet at about 240 meters per pixel scale. By repeating areas already imaged in May/June 1999 during the January/March 2006 timeframe, we would be able to identify more dark spots. And, so, that is what we did. The Tharsis, Amazonis, and Arabia regions were re-imaged using the MOC red wide angle camera during January through March 2006. The data covered about 21,506,000 square kilometers (~8.3 million square miles, ~1/3 the surface area of Mars and more than twice the area of the United States). As each picture was received on Earth, we compared it with the images acquired during May/June 1999. Over the entire area surveyed, we found 39 dark spots that were present in early 2006 but not visible in May/June 1999. The 39 dark spots, then, were the candidate impact sites. Each one of these became a target for the MOC narrow angle camera, which would be used to take an image of about 1.5 meters (4.9 feet) per pixel of each site. The targets were entered into the MOC database. Then, as the predicted MGS ground track came near each site, the MOC team targeted an image by working with the spacecraft engineers at Lockheed Martin Astronautics (Denver, Colorado) and the Caltech/Jet Propulsion Laboratory (JPL, Pasadena, California) to point the spacecraft and camera at each site using the Roll Only Targeted Observation (ROTO) maneuver. Of the 39 dark spots, 20 turned out to be fresh impact sites, and 19 of them were not. The other 19 included mistaken identifications (one was a transient, large dust devil shadow, several were craters that had been present in earlier images but had changed in brightness owing to dust removal), new dark wind streaks, and new dark slope streaks created by avalanching dust on steep slopes. Some of the 20 new impact sites received further attention, as the spacecraft and MOC were used to obtain cPROTO (compensated Pitch and Roll Targeted Observations) views that have a spatial resolution of 0.5 meters (1.6 feet) in the downtrack dimension and 1.5 meters (4.9 feet) in the cross, Having realized that a new dark spot on Mars, seen in a red wide angle camera image acquired on 6 January 2006, might be an indication of a recent meteor impact site (see PIA09020 [ http://photojournal.jpl.nasa.gov/catalog/PIA09020 ] or MOC2-1611 [ http://www.msss.com/mars_images/moc/2006/12/06/craters/site1/index.html ], track direction. The cPROTO views, where obtained, have a higher resolution and better signal-to-noise ratio than the original ROTO images. Finally, while our approach of comparing MOC red wide angle camera images obtained in May/June 1999 with those obtained in January/March 2006 constrains the 20 craters all to having formed during the May 1999 to March 2006 time interval, we found in all cases that there were already other images that had been received on Earth that helped constrain the time of the impact more tightly. In some cases, the date of the impact could be pinned down to within a month or two, in other cases the interval covered several years. Data from the MGS MOC, Mars Odyssey Thermal Emission Imaging System (THEMIS) [ http://themis.asu.edu/ ], and Mars Express High Resolution Stereo Camera (HRSC) [ http://berlinadmin.dlr.de/Missions/express/indexeng.shtml ], were all employed in the search. Shown on this page (above) are pictures that illustrate our work to find new impact craters: Figure A: This picture shows one of the new impact sites identified by the MOC team. Located in northern Arabia Terra near 29.3°N, 333.2°W, the actual crater is quite small, only 11.2 ± 3.0 meters in diameter. This is a sub-frame of MOC image S16-01105, acquired using a ROTO maneuver on 12 March 2006. Figures B and C: These pictures are MOC red wide angle camera images, obtained at a scale of about 240 meters per pixel, of portions of Arabia Terra. Figure B is M01-01610 and was acquired during the MOC Geodesy Campaign (see PIA02022 and PIA02023, or MOC2-127) on 14 May 1999. Figure C, MOC S14-02741, was obtained on 26 January 2006 as part of the campaign to find new impact craters. By comparing the two images, one from 1999 and one from 2006, we were able to identify all new dark spots that formed during that interval. In this case, the new dark spot seen in the 2006 image, S14-02741, is inside the white circle. The same location is also indicated by a circle in the May 1999 image, but no dark spot is present there. In both cases, the white circle is about 12 km (7.5 mi) across. Figure D: This map of Mars, showing the location of all the MOC red wide angle camera images acquired for the search for new craters during January through March 2006. These images cover most of Amazonis, Tharsis, and Arabia Terra. The base map is a product that combines the May/June 1999 MOC red wide angle data (plus later data for the south polar region) and laser altimeter data from MGS. Figure E: This picture shows portions of two red wide angle camera context images that more tightly constrain when the new crater shown here (above, top, left) formed. The first picture, R05-00427, was acquired on 5 May 2003 and shows no dark spot at the site of the impact. The second picture, S05-01885, shows that the dark spot was present on 29 April 2005. Thus, these two images tell us that the impact occurred sometime between those dates: 5 May 2003 and 29 April 2005. The Mars Global Surveyor mission is managed for NASA's Office of Space Science, Washington, by the Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Malin Space Science Systems, San Diego, Calif., built and operates the Mars Orbiter Camera. For more information about images from the Mars Orbiter Camera, see http://www.msss.com/mgs/moc/index.html [ http://www.msss.com/mgs/moc/index.html ]. |
|
Procedure for Finding New Im
…
PIA09021
Sol (our sun)
Mars Orbiter Camera
| Title |
Procedure for Finding New Impact Sites on Mars Using the Mars Global Surveyor Mars Orbiter Camera |
| Original Caption Released with Image |
), the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) science operations team considered it possible to find more such impact sites using the MOC red wide angle camera. The most recent, freshest craters would be expected to be quite small, ranging from a few meters across to maybe a few hundred meters or so, at most, in diameter (100 meters is about 109 yards, compare that with a 100 yard U.S.-style football field). Something less than 100 meters across would not show up easily in a 240 meters per pixel red wide angle image. But the 6 January 2006 image showed that it could, because these small impacts, if they occur in an area thickly mantled with dust, will create a much larger "blast zone" around them. Thus, the MOC science operations team set out to image a few of the dustiest regions on Mars -- Tharsis, Amazonis, and Arabia -- with the red wide angle camera. The same camera had, in May and early June 1999, already imaged most of the planet at about 240 meters per pixel scale. By repeating areas already imaged in May/June 1999 during the January/March 2006 timeframe, we would be able to identify more dark spots. And, so, that is what we did. The Tharsis, Amazonis, and Arabia regions were re-imaged using the MOC red wide angle camera during January through March 2006. The data covered about 21,506,000 square kilometers (~8.3 million square miles, ~1/3 the surface area of Mars and more than twice the area of the United States). As each picture was received on Earth, we compared it with the images acquired during May/June 1999. Over the entire area surveyed, we found 39 dark spots that were present in early 2006 but not visible in May/June 1999. The 39 dark spots, then, were the candidate impact sites. Each one of these became a target for the MOC narrow angle camera, which would be used to take an image of about 1.5 meters (4.9 feet) per pixel of each site. The targets were entered into the MOC database. Then, as the predicted MGS ground track came near each site, the MOC team targeted an image by working with the spacecraft engineers at Lockheed Martin Astronautics (Denver, Colorado) and the Caltech/Jet Propulsion Laboratory (JPL, Pasadena, California) to point the spacecraft and camera at each site using the Roll Only Targeted Observation (ROTO) maneuver. Of the 39 dark spots, 20 turned out to be fresh impact sites, and 19 of them were not. The other 19 included mistaken identifications (one was a transient, large dust devil shadow, several were craters that had been present in earlier images but had changed in brightness owing to dust removal), new dark wind streaks, and new dark slope streaks created by avalanching dust on steep slopes. Some of the 20 new impact sites received further attention, as the spacecraft and MOC were used to obtain cPROTO (compensated Pitch and Roll Targeted Observations) views that have a spatial resolution of 0.5 meters (1.6 feet) in the downtrack dimension and 1.5 meters (4.9 feet) in the cross, Having realized that a new dark spot on Mars, seen in a red wide angle camera image acquired on 6 January 2006, might be an indication of a recent meteor impact site (see PIA09020 [ http://photojournal.jpl.nasa.gov/catalog/PIA09020 ] or MOC2-1611 [ http://www.msss.com/mars_images/moc/2006/12/06/craters/site1/index.html ], track direction. The cPROTO views, where obtained, have a higher resolution and better signal-to-noise ratio than the original ROTO images. Finally, while our approach of comparing MOC red wide angle camera images obtained in May/June 1999 with those obtained in January/March 2006 constrains the 20 craters all to having formed during the May 1999 to March 2006 time interval, we found in all cases that there were already other images that had been received on Earth that helped constrain the time of the impact more tightly. In some cases, the date of the impact could be pinned down to within a month or two, in other cases the interval covered several years. Data from the MGS MOC, Mars Odyssey Thermal Emission Imaging System (THEMIS) [ http://themis.asu.edu/ ], and Mars Express High Resolution Stereo Camera (HRSC) [ http://berlinadmin.dlr.de/Missions/express/indexeng.shtml ], were all employed in the search. Shown on this page (above) are pictures that illustrate our work to find new impact craters: Figure A: This picture shows one of the new impact sites identified by the MOC team. Located in northern Arabia Terra near 29.3°N, 333.2°W, the actual crater is quite small, only 11.2 ± 3.0 meters in diameter. This is a sub-frame of MOC image S16-01105, acquired using a ROTO maneuver on 12 March 2006. Figures B and C: These pictures are MOC red wide angle camera images, obtained at a scale of about 240 meters per pixel, of portions of Arabia Terra. Figure B is M01-01610 and was acquired during the MOC Geodesy Campaign (see PIA02022 and PIA02023, or MOC2-127) on 14 May 1999. Figure C, MOC S14-02741, was obtained on 26 January 2006 as part of the campaign to find new impact craters. By comparing the two images, one from 1999 and one from 2006, we were able to identify all new dark spots that formed during that interval. In this case, the new dark spot seen in the 2006 image, S14-02741, is inside the white circle. The same location is also indicated by a circle in the May 1999 image, but no dark spot is present there. In both cases, the white circle is about 12 km (7.5 mi) across. Figure D: This map of Mars, showing the location of all the MOC red wide angle camera images acquired for the search for new craters during January through March 2006. These images cover most of Amazonis, Tharsis, and Arabia Terra. The base map is a product that combines the May/June 1999 MOC red wide angle data (plus later data for the south polar region) and laser altimeter data from MGS. Figure E: This picture shows portions of two red wide angle camera context images that more tightly constrain when the new crater shown here (above, top, left) formed. The first picture, R05-00427, was acquired on 5 May 2003 and shows no dark spot at the site of the impact. The second picture, S05-01885, shows that the dark spot was present on 29 April 2005. Thus, these two images tell us that the impact occurred sometime between those dates: 5 May 2003 and 29 April 2005. The Mars Global Surveyor mission is managed for NASA's Office of Space Science, Washington, by the Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Malin Space Science Systems, San Diego, Calif., built and operates the Mars Orbiter Camera. For more information about images from the Mars Orbiter Camera, see http://www.msss.com/mgs/moc/index.html [ http://www.msss.com/mgs/moc/index.html ]. |
|
Procedure for Finding New Im
…
PIA09021
Sol (our sun)
Mars Orbiter Camera
| Title |
Procedure for Finding New Impact Sites on Mars Using the Mars Global Surveyor Mars Orbiter Camera |
| Original Caption Released with Image |
), the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) science operations team considered it possible to find more such impact sites using the MOC red wide angle camera. The most recent, freshest craters would be expected to be quite small, ranging from a few meters across to maybe a few hundred meters or so, at most, in diameter (100 meters is about 109 yards, compare that with a 100 yard U.S.-style football field). Something less than 100 meters across would not show up easily in a 240 meters per pixel red wide angle image. But the 6 January 2006 image showed that it could, because these small impacts, if they occur in an area thickly mantled with dust, will create a much larger "blast zone" around them. Thus, the MOC science operations team set out to image a few of the dustiest regions on Mars -- Tharsis, Amazonis, and Arabia -- with the red wide angle camera. The same camera had, in May and early June 1999, already imaged most of the planet at about 240 meters per pixel scale. By repeating areas already imaged in May/June 1999 during the January/March 2006 timeframe, we would be able to identify more dark spots. And, so, that is what we did. The Tharsis, Amazonis, and Arabia regions were re-imaged using the MOC red wide angle camera during January through March 2006. The data covered about 21,506,000 square kilometers (~8.3 million square miles, ~1/3 the surface area of Mars and more than twice the area of the United States). As each picture was received on Earth, we compared it with the images acquired during May/June 1999. Over the entire area surveyed, we found 39 dark spots that were present in early 2006 but not visible in May/June 1999. The 39 dark spots, then, were the candidate impact sites. Each one of these became a target for the MOC narrow angle camera, which would be used to take an image of about 1.5 meters (4.9 feet) per pixel of each site. The targets were entered into the MOC database. Then, as the predicted MGS ground track came near each site, the MOC team targeted an image by working with the spacecraft engineers at Lockheed Martin Astronautics (Denver, Colorado) and the Caltech/Jet Propulsion Laboratory (JPL, Pasadena, California) to point the spacecraft and camera at each site using the Roll Only Targeted Observation (ROTO) maneuver. Of the 39 dark spots, 20 turned out to be fresh impact sites, and 19 of them were not. The other 19 included mistaken identifications (one was a transient, large dust devil shadow, several were craters that had been present in earlier images but had changed in brightness owing to dust removal), new dark wind streaks, and new dark slope streaks created by avalanching dust on steep slopes. Some of the 20 new impact sites received further attention, as the spacecraft and MOC were used to obtain cPROTO (compensated Pitch and Roll Targeted Observations) views that have a spatial resolution of 0.5 meters (1.6 feet) in the downtrack dimension and 1.5 meters (4.9 feet) in the cross, Having realized that a new dark spot on Mars, seen in a red wide angle camera image acquired on 6 January 2006, might be an indication of a recent meteor impact site (see PIA09020 [ http://photojournal.jpl.nasa.gov/catalog/PIA09020 ] or MOC2-1611 [ http://www.msss.com/mars_images/moc/2006/12/06/craters/site1/index.html ], track direction. The cPROTO views, where obtained, have a higher resolution and better signal-to-noise ratio than the original ROTO images. Finally, while our approach of comparing MOC red wide angle camera images obtained in May/June 1999 with those obtained in January/March 2006 constrains the 20 craters all to having formed during the May 1999 to March 2006 time interval, we found in all cases that there were already other images that had been received on Earth that helped constrain the time of the impact more tightly. In some cases, the date of the impact could be pinned down to within a month or two, in other cases the interval covered several years. Data from the MGS MOC, Mars Odyssey Thermal Emission Imaging System (THEMIS) [ http://themis.asu.edu/ ], and Mars Express High Resolution Stereo Camera (HRSC) [ http://berlinadmin.dlr.de/Missions/express/indexeng.shtml ], were all employed in the search. Shown on this page (above) are pictures that illustrate our work to find new impact craters: Figure A: This picture shows one of the new impact sites identified by the MOC team. Located in northern Arabia Terra near 29.3°N, 333.2°W, the actual crater is quite small, only 11.2 ± 3.0 meters in diameter. This is a sub-frame of MOC image S16-01105, acquired using a ROTO maneuver on 12 March 2006. Figures B and C: These pictures are MOC red wide angle camera images, obtained at a scale of about 240 meters per pixel, of portions of Arabia Terra. Figure B is M01-01610 and was acquired during the MOC Geodesy Campaign (see PIA02022 and PIA02023, or MOC2-127) on 14 May 1999. Figure C, MOC S14-02741, was obtained on 26 January 2006 as part of the campaign to find new impact craters. By comparing the two images, one from 1999 and one from 2006, we were able to identify all new dark spots that formed during that interval. In this case, the new dark spot seen in the 2006 image, S14-02741, is inside the white circle. The same location is also indicated by a circle in the May 1999 image, but no dark spot is present there. In both cases, the white circle is about 12 km (7.5 mi) across. Figure D: This map of Mars, showing the location of all the MOC red wide angle camera images acquired for the search for new craters during January through March 2006. These images cover most of Amazonis, Tharsis, and Arabia Terra. The base map is a product that combines the May/June 1999 MOC red wide angle data (plus later data for the south polar region) and laser altimeter data from MGS. Figure E: This picture shows portions of two red wide angle camera context images that more tightly constrain when the new crater shown here (above, top, left) formed. The first picture, R05-00427, was acquired on 5 May 2003 and shows no dark spot at the site of the impact. The second picture, S05-01885, shows that the dark spot was present on 29 April 2005. Thus, these two images tell us that the impact occurred sometime between those dates: 5 May 2003 and 29 April 2005. The Mars Global Surveyor mission is managed for NASA's Office of Space Science, Washington, by the Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Malin Space Science Systems, San Diego, Calif., built and operates the Mars Orbiter Camera. For more information about images from the Mars Orbiter Camera, see http://www.msss.com/mgs/moc/index.html [ http://www.msss.com/mgs/moc/index.html ]. |
|
First HiRISE Image of Mars:
…
PIA08053
Sol (our sun)
HiRISE
| Title |
First HiRISE Image of Mars: Topographic Model from Photoclinometry |
| Original Caption Released with Image |
, which was taken by the HiRISE camera on March 24, 2006. The image is oriented such that north is 7 degrees to the left of up. The range to the target was 2,493 kilometers (1,549 miles). At this distance the image scale is 2.49 meters (8.17 feet) per pixel, so objects as small as 7.5 meters (24.6 feet) are resolved. The image was taken at a local Mars time of 07:33 and the scene is illuminated from the upper right with a solar incidence angle of 78.1 degrees, thus the sun was about 11.9 degrees above the horizon. At an Ls of 29 degrees (with Ls an indicator of Mars' position in its orbit around the sun), the season on Mars is southern autumn. Images from the High Resolution Imaging Science Experiment and additional information about the Mars Reconnaissance Orbiter are available online at: http://www.nasa.gov/mro [ http://www.nasa.gov/mro ] or http://HiRISE.lpl.arizona.edu [ http://HiRISE.lpl.arizona.edu ]. For information about NASA and agency programs on the Web, visit: http://www.nasa.gov [ http://www.nasa.gov ]. JPL, 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 is the prime contractor for the project and built the spacecraft. The HiRISE camera was built by Ball Aerospace and Technology Corporation and is operated by the University of Arizona., Annotated Topographic Map This is a topographic map of part of the area covered by the first image of Mars obtained by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter spacecraft. The image was processed at the U.S. Geological Survey, Flagstaff, by a technique called photoclinometry (or, more descriptively, "shape-from-shading"). This method allows elevations to be reconstructed from a single image by noting how surfaces sloping toward the sun appear brighter than areas that slope away from it. This image is almost ideal for such interpretation because the low sun angle reveals even subtle slopes with dramatic contrast, and variations in the brightness of surface materials (which could be confused with slopes) are minimal. At left is the region of the image that was analyzed, tinted to approximate the visual appearance of the Martian surface. This region is a square 20.4 kilometers (12.7 miles) wide (8,192 pixels by 8,192 pixels at a scale of 2.49 meters or 8.17 feet per pixel). At right is a color-coded topographic contour map of the same area. The total range of elevations is 1.6 kilometers (1 mile), with low areas shown in purple and high areas in red. Contours mark each 20-meter (66-foot) change in elevation. Photoclinometry gives relative rather than absolute heights, but the overall height and shape of features in this map, such as the ridge Ogygis Rupes in the center, agree reasonably well with results from the Mars Orbiter Laser Altimeter on NASA's Mars Odyssey spacecraft, an instrument with high absolute accuracy but relatively low spatial resolution. The real value of mapping by photoclinometry, however, is that it reveals the details of the smallest topographic features resolved by the image. In this example, the image was resampled by a factor of 2 before processing, so the topographic map has a scale of 5 meters (16 feet) per pixel and resolves features as small as 15 meters (49 feet). Computer-generated three-dimensional close-ups of the surface provide one way to visualize these small but important clues to Martian geologic history. This illustration shows a subset of PIA08014 [ http://photojournal.jpl.nasa.gov/catalog/PIA08014 ] |
|
First HiRISE Image of Mars:
…
PIA08053
Sol (our sun)
HiRISE
| Title |
First HiRISE Image of Mars: Topographic Model from Photoclinometry |
| Original Caption Released with Image |
, which was taken by the HiRISE camera on March 24, 2006. The image is oriented such that north is 7 degrees to the left of up. The range to the target was 2,493 kilometers (1,549 miles). At this distance the image scale is 2.49 meters (8.17 feet) per pixel, so objects as small as 7.5 meters (24.6 feet) are resolved. The image was taken at a local Mars time of 07:33 and the scene is illuminated from the upper right with a solar incidence angle of 78.1 degrees, thus the sun was about 11.9 degrees above the horizon. At an Ls of 29 degrees (with Ls an indicator of Mars' position in its orbit around the sun), the season on Mars is southern autumn. Images from the High Resolution Imaging Science Experiment and additional information about the Mars Reconnaissance Orbiter are available online at: http://www.nasa.gov/mro [ http://www.nasa.gov/mro ] or http://HiRISE.lpl.arizona.edu [ http://HiRISE.lpl.arizona.edu ]. For information about NASA and agency programs on the Web, visit: http://www.nasa.gov [ http://www.nasa.gov ]. JPL, 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 is the prime contractor for the project and built the spacecraft. The HiRISE camera was built by Ball Aerospace and Technology Corporation and is operated by the University of Arizona., Annotated Topographic Map This is a topographic map of part of the area covered by the first image of Mars obtained by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter spacecraft. The image was processed at the U.S. Geological Survey, Flagstaff, by a technique called photoclinometry (or, more descriptively, "shape-from-shading"). This method allows elevations to be reconstructed from a single image by noting how surfaces sloping toward the sun appear brighter than areas that slope away from it. This image is almost ideal for such interpretation because the low sun angle reveals even subtle slopes with dramatic contrast, and variations in the brightness of surface materials (which could be confused with slopes) are minimal. At left is the region of the image that was analyzed, tinted to approximate the visual appearance of the Martian surface. This region is a square 20.4 kilometers (12.7 miles) wide (8,192 pixels by 8,192 pixels at a scale of 2.49 meters or 8.17 feet per pixel). At right is a color-coded topographic contour map of the same area. The total range of elevations is 1.6 kilometers (1 mile), with low areas shown in purple and high areas in red. Contours mark each 20-meter (66-foot) change in elevation. Photoclinometry gives relative rather than absolute heights, but the overall height and shape of features in this map, such as the ridge Ogygis Rupes in the center, agree reasonably well with results from the Mars Orbiter Laser Altimeter on NASA's Mars Odyssey spacecraft, an instrument with high absolute accuracy but relatively low spatial resolution. The real value of mapping by photoclinometry, however, is that it reveals the details of the smallest topographic features resolved by the image. In this example, the image was resampled by a factor of 2 before processing, so the topographic map has a scale of 5 meters (16 feet) per pixel and resolves features as small as 15 meters (49 feet). Computer-generated three-dimensional close-ups of the surface provide one way to visualize these small but important clues to Martian geologic history. This illustration shows a subset of PIA08014 [ http://photojournal.jpl.nasa.gov/catalog/PIA08014 ] |
|
|
