Mission Mars Global Surveyor - 6

<h1>PIA03038: Filled/Eroded Craters</h1><div class="PIA03038" lang="en" style="width:672px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>14 October 2005<br />This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows rugged terrain in northern Arabia Terra. The circular features are the remains of old meteor impact craters -- either the eroded remnants of the interiors of craters, or the remains of craters that were filled by layered material. The martian bedrock has craters of all sizes and states of erosion interbedded with its layered materials.<p>Location near: 31.4°N, 299.0°W <br />Image width: width: ~3 km (~1.9 mi) <br />Illumination from: lower left <br />Season: Northern Winter </p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA03038" onclick="window.open(this.href); return false;" title="Voir l'image PIA03038: Filled/Eroded Craters sur le site de la NASA">Voir l'image PIA03038: Filled/Eroded Craters sur le site de la NASA.</a></div>
PIA03038: Filled/Eroded Craters
<h1>PIA03042: Defrosting Patterns</h1><div class="PIA03042" lang="en" style="width:669px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>15 October 2005<br />This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a frost-covered surface in the martian south polar region. As the seasonal frost begins to sublime away, local variations in surface texture-mostly dendritic cracks, in this case-lead to early defrosting in some areas. Those areas already defrosted appear dark in the image.<p>Location near: 79.1°S, 340.1°W <br />Image width: width: ~3 km (~1.9 mi) <br />Illumination from: upper left <br />Season: Southern Spring </p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA03042" onclick="window.open(this.href); return false;" title="Voir l'image PIA03042: Defrosting Patterns sur le site de la NASA">Voir l'image PIA03042: Defrosting Patterns sur le site de la NASA.</a></div>
PIA03042: Defrosting Patterns
<h1>PIA03043: Cerberus Flood Features</h1><div class="PIA03043" lang="en" style="width:445px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>16 October 2005<br />This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows streamlined landforms carved by catastrophic floods that occurred in the eastern Cerberus region, some time in the distant martian past.<p>Location near: 15.1°N, 193.5°W <br />Image width: width: ~3 km (~1.9 mi) <br />Illumination from: lower left <br />Season: Northern Autumn </p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA03043" onclick="window.open(this.href); return false;" title="Voir l'image PIA03043: Cerberus Flood Features sur le site de la NASA">Voir l'image PIA03043: Cerberus Flood Features sur le site de la NASA.</a></div>
PIA03043: Cerberus Flood Features
<h1>PIA03044: Mars Polar Lander NOT Found</h1><div class="PIA03044" lang="en" style="width:604px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>17 October 2005<br />Following the loss of Mars Polar Lander in December 1999, the MOC team began a 2-month intensive effort to acquire 1.5 meters per pixel (~5 feet per pixel) images of the landing ellipse, in hopes of spotting the lander and, perhaps, to provide additional insight as to its fate. Those search efforts were described in two previous Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) releases:<br><a href="/catalog/PIA02353">PIA02353</a>: Mars Polar Lander: The Search Continues 24 January 2000</a><a href="/catalog/PIA02349">PIA02349</a>: Mars Polar Lander: The Search Begins 21 December 1999</a>.<br><br>In addition, a later year 2000 release included the full MOC imagemosaic of the site obtained during the search:<br><br><a href="/catalog/PIA02815">PIA02815</a>: South Polar Terrain in "3-D" 16 October 2000</a>.</p><p>Based upon the configuration of Mars Exploration Rovers Spirit (<a href="/catalog/PIA05248">PIA05248</a>) and Opportunity (<a href="/catalog/PIA05229">PIA05229</a>, <a href="/catalog/PIA05230">PIA05230,</a> <a href="/catalog/PIA05231">PIA05231</a>), lander hardware observed from orbit by MOC in early 2004, we revisited the December 1999/January 2000 images of the Mars Polar Lander site. Earlier this year, we identified a location in images acquired in January 2000 that included features reminiscent of those that might be expected to exist at the location where the Mars Polar Lander reached the surface. Specifically, we identified a bright feature that resembled a parachute, and a dark area with a small, light-toned central spot that could be the location of the lander amid a dust-deflated area cleared by the lander's descent engines. This finding, alongwith a definitive image of the Viking 2 lander, was detailed in:<br><a href="http://www.msss.com/mars_images/moc/2005/05/05/index.html">MGS Finds Viking Lander 2 and Mars Polar Lander (Maybe) 5 May 2005</a>.</p><p>At the time of this identification in early 2005, the Mars Polar Lander landing ellipse was covered by seasonal carbon dioxide frost. As the frost began to sublime away and spring gave way to summer, we attempted to acquire an image of the candidate Mars Polar Lander site at a spatial resolution that is higher than we were able to achieve during the initial search in December 1999/January 2000. To obtain an image with an effective spatial resolution better than 1 meter per pixel, we used the cPROTO (compensated Pitch and ROll Targeted Observation) technique described and illustrated last year in:<br><a href="/catalog/PIA06880">PIA06880</a>: cPROTO Views of Spirit's Rover Tracks and Athabasca Vallis Flood Features 27 September 2004</a>.</p><p>Hitting a specific target with the cPROTO technique is challenging, and often it takes 3-4 attempts before we hit. For the candidate Mars Polar Lander location, we made 6 attempts. The first was in April 2005, when the surface was still covered with frost -- that image was saturated white because of the frost. The next attempts were made after the frost had sublimed away -- these were made in July, August, and September 2005. We finally hit the candidate lander location on 27 September 2005.</p><p>The figure above compares the features extracted from the earlier, January 2000, image with the same location seen in the new, September 2005, image. The two pictures were taken under nearly identical illumination and atmospheric conditions, almost exactly 3 Mars years apart. The feature identified as a candidate for Mars Polar Lander's parachute is found be the illuminated slope of a small hill. The hill is part of a group of similar hills in the area. The dark feature that was identified as possible rocket blast zone has faded (which would be expected owing to dust deposited by dust storms), but, more importantly, the spot interpreted to be the lander has disappeared. In reality, this spot is a pixel whose value differed from its neighbors in the first image owing to a bigger than average contribution of noise. Close inspection of the January 2000 image (bottom left) shows many small bright and dark blurry spots that do not show up in the September 2005 image (bottom right). There are even smaller, blurry spots in the second image, they are also noise. The fact that these pixels do not coincide is excellent evidence that they are not real features on the surface of Mars.</p><p>We conclude that our interpretation of these features was in error. This is NOT the location of the Mars Polar Lander. Because the landing uncertainty ellipse is so much larger than our images, and we do not have another candidate to which to target additional cPROTOs, we cannot continue to hunt for the lander. Finding it now falls to the High Resolution Imaging Science Experiment (<a href="http://marsoweb.nas.nasa.gov/HiRISE/">HiRISE</a>) presently en route to Mars on-board the Mars Reconnaissance Orbiter (MRO) spacecraft.</p><p>Location near: 76.7°S, 195.3°W <br />The 125 meter scale bar = ~ 410 feet <br />Illumination from: upper left <br />Season: Southern Summer (M11-03986 Ls=291.5°; S10-01322 Ls=295.7°)</p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA03044" onclick="window.open(this.href); return false;" title="Voir l'image PIA03044: Mars Polar Lander NOT Found sur le site de la NASA">Voir l'image PIA03044: Mars Polar Lander NOT Found sur le site de la NASA.</a></div>
PIA03044: Mars Polar Lander NOT Found
<h1>PIA03049: Martian Lava Flows</h1><div class="PIA03049" lang="en" style="width:504px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>19 October 2005<br />This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows lava flows at the southeast base of the giant volcano, Olympus Mons. The flat plain in the south-southeast (bottom/lower right) portion of the image is younger than and cuts off the ends of many of the lava flows that came from the northwest (upper left). Many of the lava flows in this image exhibit channels with levees bounding their margins. As each lava flow was advancing, its outer margins cooled and hardened, forming a channel or tube through which the molten rock continued to advance.<p>Location near: 17.2°N, 129.0°W <br />Image width: width: ~3 km (~1.9 mi) <br />Illumination from: lower left <br />Season: Northern Winter</p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA03049" onclick="window.open(this.href); return false;" title="Voir l'image PIA03049: Martian Lava Flows sur le site de la NASA">Voir l'image PIA03049: Martian Lava Flows sur le site de la NASA.</a></div>
PIA03049: Martian Lava Flows
<h1>PIA03050: Wind Streak in Daedalia</h1><div class="PIA03050" lang="en" style="width:609px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>20 October 2005<br />This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a wind streak formed in the lee of an impact crater in western Daedalia Planum.<p>Location near: 12.7°S, 136.6°W <br />Image width: width: ~3 km (~1.9 mi) <br />Illumination from: lower left <br />Season: Southern Spring </p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA03050" onclick="window.open(this.href); return false;" title="Voir l'image PIA03050: Wind Streak in Daedalia sur le site de la NASA">Voir l'image PIA03050: Wind Streak in Daedalia sur le site de la NASA.</a></div>
PIA03050: Wind Streak in Daedalia
<h1>PIA03051: Sirenum Fossae Troughs</h1><div class="PIA03051" lang="en" style="width:621px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>21 October 2005<br />This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows two troughs/depressions formed along the trend of the Sirenum Fossae, a suite of very extensive troughs formed by faults that are radial to the giant Tharsis Bulge. As the Tharsis region bulged outward, adjacent terrain expanded and formed a series of long, extensional fault systems.<p>Location near: 26.4°S, 142.4°W <br />Image width: width: ~3 km (~1.9 mi) <br />Illumination from: lower left <br />Season: Southern Spring </p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA03051" onclick="window.open(this.href); return false;" title="Voir l'image PIA03051: Sirenum Fossae Troughs sur le site de la NASA">Voir l'image PIA03051: Sirenum Fossae Troughs sur le site de la NASA.</a></div>
PIA03051: Sirenum Fossae Troughs
<h1>PIA03066: Zephyria Platy Flows</h1><div class="PIA03066" lang="en" style="width:594px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>22 October 2005<br />This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows the broken, platy texture of flow surfaces in the Zephyria region of Mars. Some investigators have suggested that these materials represent the remains of an ice-covered lake; others suggest that these are the surfaces of hardened lava that -- when it was erupting -- was very hot and fluid. Although not illustrated here, a key piece of evidence against the ice-covered lake hypothesis is that there are some small craters formed on these surfaces (one can be seen in the lower left/southwest corner), and some of them have boulders in their ejecta. The boulders indicate that the material is rock-solid.<p>Location near: 5.3°N, 208.6°W <br />Image width: width: ~3 km (~1.9 mi) <br />Illumination from: lower left <br />Season: Northern Autumn </p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA03066" onclick="window.open(this.href); return false;" title="Voir l'image PIA03066: Zephyria Platy Flows sur le site de la NASA">Voir l'image PIA03066: Zephyria Platy Flows sur le site de la NASA.</a></div>
PIA03066: Zephyria Platy Flows
<h1>PIA03067: East Arabia Scene</h1><div class="PIA03067" lang="en" style="width:419px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>23 October 2005<br />This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows mesas in northeastern Arabia Terra. This heavily-cratered region of Mars has been severely eroded, although very little evidence regarding the erosive processes has been preserved.<p>Location near: 26.9°N, 293.5°W <br />Image width: width: ~3 km (~1.9 mi) <br />Illumination from: lower left <br />Season: Northern Autumn </p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA03067" onclick="window.open(this.href); return false;" title="Voir l'image PIA03067: East Arabia Scene sur le site de la NASA">Voir l'image PIA03067: East Arabia Scene sur le site de la NASA.</a></div>
PIA03067: East Arabia Scene
<h1>PIA03071: Exhuming Landforms</h1><div class="PIA03071" lang="en" style="width:409px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>26 October 2005<br />This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a crater and adjacent terrain that have been exhumed from beneath a wind-eroded material. The sharp, pointy ridges inside and immediately adjacent to the crater are the remains of a material that once covered the entire scene. Wind has stripped these materials away, forming yardangs. Inside the crater, the erosion has revealed an older, eroded layered material. This smooth-surfaced layered feature inside the crater was already eroded to nearly its present shape before the yardang-forming material was deposited (and then eroded away).</p><p>Location near: 7.2°N, 156.4°W <br />Image width: width: ~3 km (~1.9 mi) <br />Illumination from: lower left <br />Season: Northern Winter </p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA03071" onclick="window.open(this.href); return false;" title="Voir l'image PIA03071: Exhuming Landforms sur le site de la NASA">Voir l'image PIA03071: Exhuming Landforms sur le site de la NASA.</a></div>
PIA03071: Exhuming Landforms
<h1>PIA03072: Oudemans Layers</h1><div class="PIA03072" lang="en" style="width:512px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>27 October 2005<br /> This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows outcrops of light-toned, layered rock exposed in the central peak of Oudemans Crater, near the Labyrinthus Noctis of the western Valles Marineris complex. The rocks in this August 2005 image were once below the ground and flat-lying. Now they are tilted on edge-a product of the impact that formed Oudemans Crater. Their regular layering and light tone suggest these might be ancient sedimentary rocks.</p><p>Location near: 10.0°S, 92.1°W <br />Image width: width: ~3 km (~1.9 mi) <br />Illumination from: lower left <br />Season: Southern Spring </p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA03072" onclick="window.open(this.href); return false;" title="Voir l'image PIA03072: Oudemans Layers sur le site de la NASA">Voir l'image PIA03072: Oudemans Layers sur le site de la NASA.</a></div>
PIA03072: Oudemans Layers
<h1>PIA03073: Flows in Kasei</h1><div class="PIA03073" lang="en" style="width:393px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>28 October 2005<br />This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows flow materials-on the east/right side of the image-that have come in among a suite of sharp ridges and grooves on the floor of the vast Kasei Valles system. The ridges and grooves are much older and are believed to be the result of a giant, catastrophic flood. The flows might have been mud or lava that ran part way down the ancient valley at a later date.</p><p>Location near: 16.7°N, 76.5°W <br />Image width: width: ~3 km (~1.9 mi) <br />Illumination from: lower left <br />Season: Northern Winter </p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA03073" onclick="window.open(this.href); return false;" title="Voir l'image PIA03073: Flows in Kasei sur le site de la NASA">Voir l'image PIA03073: Flows in Kasei sur le site de la NASA.</a></div>
PIA03073: Flows in Kasei
<h1>PIA03074: Crater and Flows</h1><div class="PIA03074" lang="en" style="width:331px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>29 October 2005<br />This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a crater surrounded by thin flows in southeastern Kasei Valles. The flows might have been lava or mud. The picture was acquired in August 2005.<p>Location near: 14.2°N, 75.1°W <br />Image width: width: ~3 km (~1.9 mi) <br />Illumination from: left/lower left <br />Season: Northern Autumn </p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA03074" onclick="window.open(this.href); return false;" title="Voir l'image PIA03074: Crater and Flows sur le site de la NASA">Voir l'image PIA03074: Crater and Flows sur le site de la NASA.</a></div>
PIA03074: Crater and Flows
<h1>PIA03075: East Arabia Mesas</h1><div class="PIA03075" lang="en" style="width:676px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>30 October 2005<br />This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows mesas and other eroded landforms in eastern Arabia Terra, near Huo Hsing Vallis. Arabia Terra is generally a cratered terrain that has been severely eroded, although the causes of the erosion -- and where all the material went when it was removed -- are not known.<p>Location near: 27.3°N, 293.2°W <br />Image width: width: ~3 km (~1.9 mi) <br />Illumination from: lower left <br />Season: Northern Summer </p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA03075" onclick="window.open(this.href); return false;" title="Voir l'image PIA03075: East Arabia Mesas sur le site de la NASA">Voir l'image PIA03075: East Arabia Mesas sur le site de la NASA.</a></div>
PIA03075: East Arabia Mesas
<h1>PIA03076: South Polar Mesas</h1><div class="PIA03076" lang="en" style="width:672px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>31 October 2005<br />This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows irregular-shaped mesas in the south polar region of Mars. The bright patches are the remains of seasonal frost. During winter and most of spring, this entire scene would have been covered by carbon dioxide frost.<p>Location near: 79.2°S, 298.6°W <br />Image width: width: ~3 km (~1.9 mi) <br />Illumination from: upper left <br />Season: Southern Spring </p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA03076" onclick="window.open(this.href); return false;" title="Voir l'image PIA03076: South Polar Mesas sur le site de la NASA">Voir l'image PIA03076: South Polar Mesas sur le site de la NASA.</a></div>
PIA03076: South Polar Mesas
<h1>PIA03085: Terby's Layers</h1><div class="PIA03085" lang="en" style="width:711px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>2 November 2005<br />This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows light-toned, layered, sedimentary rock exposures in Terby Crater, just north of Hellas Planitia. These rocks might have formed from sediment deposited in a lake or a larger Hellas-filling sea.<p>Location near: 28.0°S, 285.4°W <br />Image width: width: ~3 km (~1.9 mi) <br />Illumination from: upper left <br />Season: Southern Spring </p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA03085" onclick="window.open(this.href); return false;" title="Voir l'image PIA03085: Terby's Layers sur le site de la NASA">Voir l'image PIA03085: Terby's Layers sur le site de la NASA.</a></div>
PIA03085: Terby's Layers
<h1>PIA03087: Isidis Planitia</h1><div class="PIA03087" lang="en" style="width:644px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>3 November 2005<br />This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a cratered surface in Isidis Planitia, a martian lowland. Light-toned "squiggles" in this August 2005 image are large windblown ripples.<p>Location near: 10.6°N, 275.2°W <br />Image width: width: ~3 km (~1.9 mi) <br />Illumination from: lower left <br />Season: Northern Autumn </p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA03087" onclick="window.open(this.href); return false;" title="Voir l'image PIA03087: Isidis Planitia sur le site de la NASA">Voir l'image PIA03087: Isidis Planitia sur le site de la NASA.</a></div>
PIA03087: Isidis Planitia
<h1>PIA03088: Ophir Landslide</h1><div class="PIA03088" lang="en" style="width:577px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>4 November 2005<br />This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a small landslide off a steep slope in southwestern Ophir Chasma.<p>Location near: 4.6°S, 72.8°W <br />Image width: width: ~3 km (~1.9 mi) <br />Illumination from: lower left <br />Season: Southern Spring </p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA03088" onclick="window.open(this.href); return false;" title="Voir l'image PIA03088: Ophir Landslide sur le site de la NASA">Voir l'image PIA03088: Ophir Landslide sur le site de la NASA.</a></div>
PIA03088: Ophir Landslide
<h1>PIA03089: Russell Dune Gullies</h1><div class="PIA03089" lang="en" style="width:478px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>5 November 2005<br />This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows gullies and dust devil streaks on the slopes of a large dune in Russell Crater. Gullies on martian dunes typically occur only in the Noachis Terra region, and almost exclusively form on southward-facing slopes. They might be the result of downslope movement of sand mixed with a fluid such as carbon dioxide gas or water that had been trapped as ice in the dune.<p>Location near: 54.6°S, 347.2°W <br />Image width: width: ~3 km (~1.9 mi) <br />Illumination from: upper left <br />Season: Southern Spring </p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA03089" onclick="window.open(this.href); return false;" title="Voir l'image PIA03089: Russell Dune Gullies sur le site de la NASA">Voir l'image PIA03089: Russell Dune Gullies sur le site de la NASA.</a></div>
PIA03089: Russell Dune Gullies
<h1>PIA03090: Sedimentary Rocks</h1><div class="PIA03090" lang="en" style="width:682px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>6 November 2005<br />This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows outcrops of sedimentary rocks in a crater located just north of the Sinus Meridiani region. Perhaps the crater was once the site of a martian lake.<p>Location near: 2.9°N, 359.0°W <br />Image width: width: ~3 km (~1.9 mi) <br />Illumination from: lower left <br />Season: Northern Autumn </p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA03090" onclick="window.open(this.href); return false;" title="Voir l'image PIA03090: Sedimentary Rocks sur le site de la NASA">Voir l'image PIA03090: Sedimentary Rocks sur le site de la NASA.</a></div>
PIA03090: Sedimentary Rocks
<h1>PIA03091: Impact Crater</h1><div class="PIA03091" lang="en" style="width:481px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>7 November 2005<br />This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a meteor impact crater in northern Tharsis. This crater is a bit more than 2 kilometers wide -- about twice the size of the famous Meteor Crater in northern Arizona, U.S.A. Many smaller craters can be seen superimposed upon the ~2 km diameter crater.<p>Location near: 34.4°N, 118.8°W <br />Image width: width: ~3 km (~1.9 mi) <br />Illumination from: lower left <br />Season: Northern Autumn </p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA03091" onclick="window.open(this.href); return false;" title="Voir l'image PIA03091: Impact Crater sur le site de la NASA">Voir l'image PIA03091: Impact Crater sur le site de la NASA.</a></div>
PIA03091: Impact Crater
<h1>PIA03098: Defrosting Terrain</h1><div class="PIA03098" lang="en" style="width:331px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>9 November 2005<br />This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a south polar scene, covered by bright, seasonal, carbon dioxide frost. The dark patches are areas where the frost has begun to sublime away.<p>Location near: 80.0°S, 334.0°W <br />Image width: width: ~3 km (~1.9 mi) <br />Illumination from: upper left <br />Season: Southern Spring </p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA03098" onclick="window.open(this.href); return false;" title="Voir l'image PIA03098: Defrosting Terrain sur le site de la NASA">Voir l'image PIA03098: Defrosting Terrain sur le site de la NASA.</a></div>
PIA03098: Defrosting Terrain
<h1>PIA03099: Herschel's Dunes</h1><div class="PIA03099" lang="en" style="width:602px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>10 November 2005<br />This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows dark, windblown sand dunes in Herschel Crater. The winds responsible for these dunes came from the northeast (upper right).<p>Location near: 15.6°S, 228.6°W <br />Image width: width: ~3 km (~1.9 mi) <br />Illumination from: lower left <br />Season: Southern Spring </p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA03099" onclick="window.open(this.href); return false;" title="Voir l'image PIA03099: Herschel's Dunes sur le site de la NASA">Voir l'image PIA03099: Herschel's Dunes sur le site de la NASA.</a></div>
PIA03099: Herschel's Dunes
<h1>PIA03172: The 2001 Great Dust Storms - Daedalia/Claritas/Syria Dust Plumes</h1><div class="PIA03172" lang="en" style="width:800px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>Although dust storms occur year-round on Mars, they often occur in greater numbers during certain seasons. In particular, it has long been known from Earth-based telescopic observations that the largest, global dust events(those that enshroud the entire planet) occur during the southern spring and summer. As the Mars Global Surveyor (MGS) mission began to monitor this period for the second time, particular attention was paid to local and regional dust storms in anticipation of capturing--for the first time--high spatial-and time-resolution observations of the start of a "global" storm.<p>Throughout the month of June 2001, the MGS Mars Orbiter Camera (MOC)routinely accumulated low resolution (7.5 km/pixel) global maps of Marson an orbit-by-orbit basis. A moderately large number of local dust storms were noted, especially along the retreating margin of the seasonal south polar CO2 frost cap and around the large and deep Hellas impact basin that dominates the southern, eastern highlands. On June 21, an otherwise undistinguished small dust storm surged into the basin from the southwest. When viewed 24 hours later, the storm had circulated clockwise about 1/3of the circumference of Hellas, indicating relatively high winds. For the next three days, this storm brewed north of Hellas and east towards Hesperia, but didn't cross the equator (see <a href="/catalog/PIA03170">PIA03170</a>). Then, sometime between 2 PM local Mars time on June 25 and 2 PM local Mars time on June 26, the storm exploded north across the equator, and in less than 24 hours thereafter, dust was being raised from separate locations in Arabia, Nilosyrtis, and Hesperia, thousands of kilometers away from Hellas. This was the start of the long-anticipated global dust event.<p>Over the following week, dust injected high into the stratosphere during the initial Hellas and Hesperia storms drifted eastward, carried by the prevailing south circumpolar jet stream. Beneath this "veil" of dust, an intense wind front moved across Mars, setting up conditions for many other local and regional dust storms. By July 4, a large regional storm was raging between Daedalia Planitia south of the Tharsis volcanoes and Syria Planum (just south of Labyrinthus Noctis, see <a href="/catalog/PIA03171">PIA03171</a>). Another storm was raising plumes of dust in north central Noachis/southwestern Meridiani. Plumes were rising in Hesperia but not Hellas.<p>Throughout July and August, MOC observations revealed a general pattern of regional storm centers beneath an ever-spreading veil of stratospheric dust. The Daedalia/Claritas/Syria storm created dust plumes on over 90 consecutive days .<p>Previous views and perceptions of global dust events had noted regional brightenings within the overall pall of what was called a "global duststorm." From our new observations, we know that at least this global dust "storm" was really a set of storms, somehow triggered to occur at the same time. We also know that dust was not raised from everywhere on the surface during this global event, but rather from discrete, long-lived centers of activity. We saw, for the first time, rapid, cross-equatorial flow of dust-raising winds.<p>Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA03172" onclick="window.open(this.href); return false;" title="Voir l'image PIA03172: The 2001 Great Dust Storms - Daedalia/Claritas/Syria Dust Plumes sur le site de la NASA">Voir l'image PIA03172: The 2001 Great Dust Storms - Daedalia/Claritas/Syria Dust Plumes sur le site de la NASA.</a></div>
PIA03172: The 2001 Great Dust Storms - Daedalia/Claritas/Syria Dust Plumes
<h1>PIA03174: Fractures/Pits in Northern Plains (Utopia Plains: 44.9 N, 274.7 W)</h1><div class="PIA03174" lang="en" style="width:600px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>Although northern plains are often called "flat" or "featureless" by people who study altimetry data, clearly this isn't true. This area has an indurated (strong or cemented) crust that has been subjected to directional stress (that's why the beaded-pitted fractures are almost all aligned the same direction) and that has been undermined (hence the pitting at both the small scale--the beaded fractures--and the large scale--the large irregular depressions.<p>Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA03174" onclick="window.open(this.href); return false;" title="Voir l'image PIA03174: Fractures/Pits in Northern Plains (Utopia Plains: 44.9 N, 274.7 W) sur le site de la NASA">Voir l'image PIA03174: Fractures/Pits in Northern Plains (Utopia Plains: 44.9 N, 274.7 W) sur le site de la NASA.</a></div>
PIA03174: Fractures/Pits in Northern Plains (Utopia Plains: 44.9 N, 274.7 W)
<h1>PIA03175: Toe of Ganges Chasma Landslide ( 8.0 S, 44.4W)</h1><div class="PIA03175" lang="en" style="width:492px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows shear striations, dark dunes banked up against the toe of the slide and over-riding light-toned ripples and boulders on surface of slide. These features can be used to determine quantitative aspects of surface processes.<p>Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA03175" onclick="window.open(this.href); return false;" title="Voir l'image PIA03175: Toe of Ganges Chasma Landslide ( 8.0 S, 44.4W) sur le site de la NASA">Voir l'image PIA03175: Toe of Ganges Chasma Landslide ( 8.0 S, 44.4W) sur le site de la NASA.</a></div>
PIA03175: Toe of Ganges Chasma Landslide ( 8.0 S, 44.4W)
<h1>PIA03176: Dunes in Herschel Crater (Herschel Crater: 15.7 S, 228.8 W)</h1><div class="PIA03176" lang="en" style="width:600px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>This MGS MOC image shows erosional streaks on dunes which means that the dunes are indurated (cemented).<p>Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA03176" onclick="window.open(this.href); return false;" title="Voir l'image PIA03176: Dunes in Herschel Crater (Herschel Crater: 15.7 S, 228.8 W) sur le site de la NASA">Voir l'image PIA03176: Dunes in Herschel Crater (Herschel Crater: 15.7 S, 228.8 W) sur le site de la NASA.</a></div>
PIA03176: Dunes in Herschel Crater (Herschel Crater: 15.7 S, 228.8 W)
<h1>PIA03177: Ancient Layered Rocks in Schiaparelli Crater</h1><div class="PIA03177" lang="en" style="width:595px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>One of the earliest results of the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) investigation shortly after the spacecraft began to orbit Mars in 1997 was the discovery of layered rock outcrops reaching deep down into the martian crust in the walls of the Valles Marineris. Since that time, thousands of MOC images have revealed layered rock in a variety of settings--crater floors, canyon interiors, and scarps exposed by faulting and pitting. This spectacular example taken by MOC in 2001 is found on the floor of an impact crater located near the equator in northwestern Schiaparelli Basin (0.15°N, 345.6°W). The image covers an area approximately 3 km (1.9 miles) across and is illuminated by sunlight from the upper left. Layers of uniform thickness and appearance suggest that these materials are ancient sediments, perhaps deposited in water, or perhaps deposited by wind. Wind has subsequently eroded and exposed the layers. Dark drifts of sand occur at the lower center of the image, and lighter-toned windblown ripples dominate the center and upper right.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA03177" onclick="window.open(this.href); return false;" title="Voir l'image PIA03177: Ancient Layered Rocks in Schiaparelli Crater sur le site de la NASA">Voir l'image PIA03177: Ancient Layered Rocks in Schiaparelli Crater sur le site de la NASA.</a></div>
PIA03177: Ancient Layered Rocks in Schiaparelli Crater
<h1>PIA03178: MOC's 100,000th Image</h1><div class="PIA03178" lang="en" style="width:336px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>Mars Global Surveyor (MGS) was launched from Earth just over five years ago on November 7, 1996. It began to orbit Mars on September 12, 1997. After slightly more than four years in orbit, we have now received our 100,000th image from the MGS Mars Orbiter Camera (MOC). For comparison, the Viking 1 and Viking 2 orbiters together returned ~55,000 images during the time they were operational from 1976 to 1980. The Vikings returned about 70 Gbytes of data; MOC has returned 163 Gbytes (after decompression).<p>MOC's 100,000th image was received on November 5, 2001. Its context frame (below) was received at the same time. The 100,000th image is located near 24.2°N, 127.4°W, in Cyane Sulci, a grouping of ridges northeast of the giant volcano, Olympus Mons. This image shows a valley running diagonally from near the upper right to the lower left, the floor of which is covered by windblown dunes. The slopes on either side of the valley show dark streaks of debris that have slid down from the surrounding ridges. The image has fairly low contrast and a streaked appearance because the atmosphere of Mars was still somewhat hazy following a series of large dust storms that nearly obscured the planet between July and October 2001. Both images are illuminated from the lower left, the high resolution view (above) covers an area 1.5 km (0.9 mi) across, the context view (with white box to indicate location of high resolution view) covers an area 63 km (39 mi) across.<p><a href="/figures/PIA03178_context.gif"></a><p>To date, more than two-thirds of all MOC images, covering the first year and a half of pre-mapping operations and the first full Mars year of mapping, have been carefully examined, validated, cataloged, and archived with the NASA Planetary Data System (PDS). To view these first 78,000+ MOC images, visit the MOC Gallery. Work is on-going to similarly process data being collected during the "extended mission" presently underway, which will be archived in future deliveries to the PDS.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA03178" onclick="window.open(this.href); return false;" title="Voir l'image PIA03178: MOC's 100,000th Image sur le site de la NASA">Voir l'image PIA03178: MOC's 100,000th Image sur le site de la NASA.</a></div>
PIA03178: MOC's 100,000th Image
<h1>PIA03179: MOC Observes Changes in the South Polar Cap: Evidence for Recent Climate Change on Mars</h1><div class="PIA03179" lang="en" style="width:800px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>Compare each image on the left with their counterparts on the right. Small hills vanished and pit walls expanded between 1999 and 2001. The pits are formed in frozen carbon dioxide, and the carbon dioxide is subliming away a little more each Martian year. Sunlight illuminates each of the four different scenes from the upper left.<p><a href="/figures/PIA03179_anim.gif">CLICK HERE</a> for animation of all 4 of these panels (6.2 MBytes).<p>One of the most profound benefits of being able to continue photographing Mars in the Mars Global Surveyor (MGS) Extended Mission is the opportunity to go back and re-image a site that was seen in the previous martian year. New MGS Mars Orbiter Camera (MOC) images have provided a startling observation: The residual martian south polar cap is changing. The fact that it is changing suggests that Mars may have major, global climate changes that are occurring on the same time scales as Earth's most recent climate shifts, including the last Ice Age.<p>MOC images of the south polar cap taken in 1999 were compared with images of the same locations taken in 2001, and it was discovered that pits had enlarged, mesas had shrunk, and small buttes had vanished. In all, the scarps that enclose the pits and bound the mesas and buttes retreated about 3 meters (3.3 yards) in 1 martian year (687 Earth days). This rapid retreat of polar scarps can only occur if the ice is frozen carbon dioxide (also known as "dryice"). Retreat of scarps made of water ice is much slower and would not have been measurable from one martian year to the next.<p>The portion of the martian south polar cap that persists through summer is called the residual polar cap. The two sets of four pictures shown here are from four places on the residual south polar cap. The pictures from 1999 were taken in October of that year, the corresponding pictures from 2001 were acquired in August, approximately 1 Mars year after the 1999 images were obtained. In each case, the pictures are illuminated by sunlight from the upper left, and each shows an area about 250 meters (273 yards) across. The polarcap is layered, and the layers have eroded to form pits, troughs, mesas, and buttes. The pits form as sunlight warms frozen carbon dioxide during southern spring and summer, and the ice sublimes away. There is so much carbon dioxide that it does not all go away in one summer--in fact, it may take hundreds to thousands of years to disappear.<p>These new observations indicate that the south polar residual cap is not permanent. It is disappearing, a little bit more each southern spring and summer season. At the present rate, a layer 3 m thick can be completely eroded away in a few tens of martian years. Since each layer is equivalent to about 1% of the mass of the present atmosphere (which is 95% carbon dioxide), if sufficient carbon dioxide is buried in the south polar cap, the mass of the atmosphere could double in a few hundred to a thousand Mars years. That could lead to profound changes in the environment. For example, it would change how much and where wind erosion would occur, and where and for how long liquid water could survive at or near the surface.<p>It also means that Mars may have been very different in the recent past (perhaps only a few thousands of years ago). On today's Mars, the ice is eroding, but in the past that material had to have been deposited. The martian climate was probably colder, and there was more carbon dioxide in the atmosphere. For some reason, large amounts of carbon dioxide froze at the south pole--one might say that there was a "Martian Ice Age"--and this freezing occurred on a time scale similar to that of the most recent Ice Age on Earth.<p>Mars is changing, and it is changing on a time scale that we can measure and observe. If all of the carbon dioxide that is being released into the atmosphere from the south polar cap is not freezing out somewhere else, and if it is not being adsorbed into the martian soil, then it must be causing the atmospheric pressure to increase. If this so, and if one were to assume that the entire known volume of the polar cap is made of carbon dioxide that sublimes at the same rate we see today, then it could increase the martian atmospheric pressure by as much as 10 times, to about 1/10th the density of Earth's atmosphere, in just the next few thousand years. Although this atmosphere would not be breathable, carbon dioxide is a "greenhouse gas" that would cause the global temperature to increase considerably and make it easier for liquid water to persist elsewhere on the planet. Perhaps, just perhaps, a thickening martian atmosphere would eventually make it easier for people to live on Mars.<br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA03179" onclick="window.open(this.href); return false;" title="Voir l'image PIA03179: MOC Observes Changes in the South Polar Cap: Evidence for Recent Climate Change on Mars sur le site de la NASA">Voir l'image PIA03179: MOC Observes Changes in the South Polar Cap: Evidence for Recent Climate Change on Mars sur le site de la NASA.</a></div>
PIA03179: MOC Observes Changes in the South Polar Cap: Evidence for Recent Climate Change on Mars

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