Mission Mars Global Surveyor - 8

<h1>PIA05920: Dark Barchan Dunes</h1><div class="PIA05920" lang="en" style="width:601px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>13 May 2004<br />This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows north polar sand dunes in the summertime. During winter and early spring, north polar dunes are covered with bright frost. When the frost sublimes away, the dunes appear darker than their surroundings. To a geologist, sand has a very specific meaning. A sand grain is defined independently of its composition; it is a particle with a size between 62.5 and 2000 microns. Two thousand microns equals 2 millimeters. The dunes are dark because they are composed of sand grains made of dark minerals and/or rock fragments. Usually, dark grains indicate the presence of unoxidized iron, for example, the dark volcanic rocks of Hawaii, Iceland, and elsewhere. This dune field is located near 71.7°N, 51.3°W. Dune slip faces indicate winds that blow from the upper left toward lower right. This picture covers an area approximately 3 km (1.9 mi) across and is illuminated by sunlight from the lower left.</p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA05920" onclick="window.open(this.href); return false;" title="Voir l'image PIA05920: Dark Barchan Dunes sur le site de la NASA">Voir l'image PIA05920: Dark Barchan Dunes sur le site de la NASA.</a></div>
PIA05920: Dark Barchan Dunes
<h1>PIA05921: Layered Rocks in Ritchey</h1><div class="PIA05921" lang="en" style="width:445px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>14 May 2004<br />This March 2004 Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows light- and dark-toned layered rock outcrops on the floor of Ritchey Crater, located near 28.9°S, 50.8°W. Some or all of these rocks may be sedimentary in origin. Erosion has left a couple of buttes standing on a more erosion-resistant plain. This picture covers an area approximately 3 km (1.9 mi) across and is illuminated by sunlight from the upper left.</p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA05921" onclick="window.open(this.href); return false;" title="Voir l'image PIA05921: Layered Rocks in Ritchey sur le site de la NASA">Voir l'image PIA05921: Layered Rocks in Ritchey sur le site de la NASA.</a></div>
PIA05921: Layered Rocks in Ritchey
<h1>PIA05934: Landslide in Aureum Chaos</h1><div class="PIA05934" lang="en" style="width:672px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>15 May 2004<br />This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows the results of a small landslide off of a hillslope in the Aureum Chaos region of Mars. Mass movement occurred from right (the slope) to left (the lobate feature pointed left). Small dark dots in the landslide area are large boulders. This feature is located near 2.6°S, 24.5°W. This picture covers an area approximately 3 km (1.9 mi) across and is illuminated by sunlight from the left/upper left.</p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA05934" onclick="window.open(this.href); return false;" title="Voir l'image PIA05934: Landslide in Aureum Chaos sur le site de la NASA">Voir l'image PIA05934: Landslide in Aureum Chaos sur le site de la NASA.</a></div>
PIA05934: Landslide in Aureum Chaos
<h1>PIA05935: Gullies in Noachis</h1><div class="PIA05935" lang="en" style="width:800px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>16 May 2004<br />This full-resolution (1.5 m/pixel; 5 ft/pixel) Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows gullies on a crater wall in northern Noachis Terra. The gullies might have formed by the seepage of martian groundwater or melting of ice. However, the Mars science community is still studying this topic and no consensus has yet emerged as to whether such gullies could have formed without water. These gullies are located near 32.1°S, 12.9°W. The 300 meter scale bar also equals 328 yards (984 feet). The picture is illuminated by sunlight from the left/upper left.</p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA05935" onclick="window.open(this.href); return false;" title="Voir l'image PIA05935: Gullies in Noachis sur le site de la NASA">Voir l'image PIA05935: Gullies in Noachis sur le site de la NASA.</a></div>
PIA05935: Gullies in Noachis
<h1>PIA05936: Windblown Sand in Briault</h1><div class="PIA05936" lang="en" style="width:457px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>17 May 2004<br />This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows low, broad sand dunes and sheets in southern Briault Crater near 10.1°S, 270.7°W. In this case, winds have swept up all available sand in Briault Crater, and moved it toward the south side of the basin. The wind streak pattern of these landforms indicates that the dominant winds blow from the north (top) toward the south. The image covers an area about 3 km (1.9 mi) wide and is illuminated by sunlight from the upper left.</p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA05936" onclick="window.open(this.href); return false;" title="Voir l'image PIA05936: Windblown Sand in Briault sur le site de la NASA">Voir l'image PIA05936: Windblown Sand in Briault sur le site de la NASA.</a></div>
PIA05936: Windblown Sand in Briault
<h1>PIA05937: Large Ripples in Cerberus</h1><div class="PIA05937" lang="en" style="width:800px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>18 May 2004<br />Mars is a desert planet, upon which wind has a great influence on the expression of its surface materials. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows large ripples (or small dunes) of windblown sediment among hills in the southeastern Cerberus region near 11.0°N, 199.5°W. Ripple orientations vary throughout the scene, indicating that dominant winds are influenced by the interplay of wind and local topographic features such as craters and hills. The picture covers an area about 3 km (1.9 mi) across and is illuminated by sunlight from the left/lower left.</p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA05937" onclick="window.open(this.href); return false;" title="Voir l'image PIA05937: Large Ripples in Cerberus sur le site de la NASA">Voir l'image PIA05937: Large Ripples in Cerberus sur le site de la NASA.</a></div>
PIA05937: Large Ripples in Cerberus
<h1>PIA05940: Zephyria Channel System</h1><div class="PIA05940" lang="en" style="width:262px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>10 September 2004<br />This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a portion of an outflow channel system located in the Zephyria region, south of Cerberus, from which vast quantities of rough-surfaced material flowed. The channel system has no name and was not known prior to the MGS mission. The material that flowed through this system may have been extremely fluid lava, or it may have been water-rich mud. Research by members of the Mars science community regarding the nature and origin of flow materials in the Cerberus, Zephyria, and Marte Vallis regions of Mars is on-going. This image is located near 4.6°N, 204.1°W. The image covers an area approximately 3 km (1.9 mi) across and is illuminated by sunlight from the left/lower left.</p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA05940" onclick="window.open(this.href); return false;" title="Voir l'image PIA05940: Zephyria Channel System sur le site de la NASA">Voir l'image PIA05940: Zephyria Channel System sur le site de la NASA.</a></div>
PIA05940: Zephyria Channel System
<h1>PIA05941: Sedimentary Rocks of 8°N, 7°W</h1><div class="PIA05941" lang="en" style="width:672px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>11 September 2004<br />An impact crater in western Arabia Terra at 8°N, 7°W, exhibits some of the most fantastic sedimentary rock outcrops on Mars. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows an example. The crater interior has hundreds of sedimentary rock layers, each of a similar thickness and similar physical properties. The similarities between beds and their repeated nature have been used to suggest that the crater was once the site of a lake. Today, the sedimentary rocks are eroded and dark, windblown sand covers some of them. Faults cut and offset beds in some places. The image covers an area approximately 3 km (1.9 mi) across and is illuminated by sunlight from the left/lower left.</p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA05941" onclick="window.open(this.href); return false;" title="Voir l'image PIA05941: Sedimentary Rocks of 8°N, 7°W sur le site de la NASA">Voir l'image PIA05941: Sedimentary Rocks of 8°N, 7°W sur le site de la NASA.</a></div>
PIA05941: Sedimentary Rocks of 8°N, 7°W
<h1>PIA05943: Exhuming Craters</h1><div class="PIA05943" lang="en" style="width:601px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>13 September 2004<br />This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows about two dozen circular depressions, each with a circular mesa on its floor. These were once meteor impact craters. The craters were filled with layered material, buried, and then exhumed and eroded. The dark, elliptical feature in the lower left (southwest) corner of the image is a butte composed of the layered rock that once completely covered the craters in this image. These landforms are located in a depression eroded into the floor of a much larger, partially-filled impact crater located near 35.1°S, 356.5°W. The image covers an area approximately 3 km (1.9 mi) across and is illuminated by sunlight from the upper left.</p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA05943" onclick="window.open(this.href); return false;" title="Voir l'image PIA05943: Exhuming Craters sur le site de la NASA">Voir l'image PIA05943: Exhuming Craters sur le site de la NASA.</a></div>
PIA05943: Exhuming Craters
<h1>PIA05944: Marte Vallis Channel</h1><div class="PIA05944" lang="en" style="width:216px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>14 September 2004<br />This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a portion of a channel in the Marte Valles outflow system. An old meteor impact crater in the lower left (southwest) corner of the image blocked the erosive fluids that poured through Marte Vallis, creating a streamlined tail in its lee. The materials that flowed through the valley may have been water-rich mud, very fluid lava, or both. The nature of the fluid is still a matter of research and discussion among Mars scientists. This image is located near 12.5°N, 177.5°W. The image covers an area approximately 3 km (1.9 mi) across and is illuminated by sunlight from the left/lower left.</p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA05944" onclick="window.open(this.href); return false;" title="Voir l'image PIA05944: Marte Vallis Channel sur le site de la NASA">Voir l'image PIA05944: Marte Vallis Channel sur le site de la NASA.</a></div>
PIA05944: Marte Vallis Channel
<h1>PIA05945: Wind Streaks Near Schiaparelli</h1><div class="PIA05945" lang="en" style="width:672px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>15 September 2004<br />Mars is a desert world. Today, wind is the most powerful agent of change. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows streak patterns made by wind as it distributed and re-distributed dark sediment across a light-toned substrate. This image is located west of Schiaparelli Crater near 1.0°S, 347.6°W, and covers an area approximately 3 km (1.9 mi) across. The scene is illuminated by sunlight from the left/upper left.</p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA05945" onclick="window.open(this.href); return false;" title="Voir l'image PIA05945: Wind Streaks Near Schiaparelli sur le site de la NASA">Voir l'image PIA05945: Wind Streaks Near Schiaparelli sur le site de la NASA.</a></div>
PIA05945: Wind Streaks Near Schiaparelli
<h1>PIA05946: Carbon Dioxide Mesas</h1><div class="PIA05946" lang="en" style="width:799px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>16 September 2004<br />This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows two large and many small mesas composed of frozen carbon dioxide on the south polar cap of Mars. MGS has observed the south polar cap through three whole summers, and MOC images have shown that the scarps on these mesas retreat an average of 3 meters--some retreat faster, some a bit slower--per martian summer. The south polar cap is the most rapidly-changing landscape on Mars. These mesas are located near 86.5°S, 358.5°W. The image covers an area approximately 2 km (1.2 mi) across and is illuminated by sunlight from the upper left.</p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA05946" onclick="window.open(this.href); return false;" title="Voir l'image PIA05946: Carbon Dioxide Mesas sur le site de la NASA">Voir l'image PIA05946: Carbon Dioxide Mesas sur le site de la NASA.</a></div>
PIA05946: Carbon Dioxide Mesas
<h1>PIA05947: West Arabian Yardangs</h1><div class="PIA05947" lang="en" style="width:512px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>17 September 2004<br />The upper crust of Mars consists of layered bedrock. The terrain located between large impact craters is layered. In some regions, some of these layers have been exposed by erosion. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows rounded and streamlined hills produced by wind erosion. In this case, the dominant, erosive winds blew from the upper right (northeast) toward lower left (southwest). The presence of these erosional forms, yardangs, indicates that the material being eroded contains some amount of sand-sized grains that are easily mobilized by wind. These particular yardangs are located in western Arabia Terra, northwest of the Sinus Meridiani region where the Mars Exploration Rover, Opportunity, has examined ancient sedimentary rocks. These landforms are located near 9.4°N, 6.5°W. The image covers an area approximately 3 km (1.9 mi) across and is illuminated by sunlight from the left.</p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA05947" onclick="window.open(this.href); return false;" title="Voir l'image PIA05947: West Arabian Yardangs sur le site de la NASA">Voir l'image PIA05947: West Arabian Yardangs sur le site de la NASA.</a></div>
PIA05947: West Arabian Yardangs
<h1>PIA05948: Apollinaris Patera Erosion</h1><div class="PIA05948" lang="en" style="width:672px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>18 September 2004<br />Apollinaris Patera is an ancient volcano located northwest of Gusev Crater, the landing site of the Mars Exploration Rover, Spirit. Apollinaris Patera, being rather old, is covered with craters, mantles of dust, and a wind-scoured covering of indurated, fine material. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a small portion of the Apollinaris Patera volcano, revealing the exhumation of older surfaces from beneath a relatively thin, wind-scoured material. This view is located on the upper south slope of the volcano, near 9.5°S, 186.4°W. The image covers an area approximately 3 km (1.9 mi) across and is illuminated by sunlight from the upper left.</p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA05948" onclick="window.open(this.href); return false;" title="Voir l'image PIA05948: Apollinaris Patera Erosion sur le site de la NASA">Voir l'image PIA05948: Apollinaris Patera Erosion sur le site de la NASA.</a></div>
PIA05948: Apollinaris Patera Erosion
<h1>PIA05949: Hale Central Peak</h1><div class="PIA05949" lang="en" style="width:800px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>19 September 2004<br />This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows some of the mountains that make up the central peak region of Hale Crater, located near 35.8°S, 36.5°W. Dark, smooth-surfaced sand dunes are seen to be climbing up the mountainous slopes. The central peak of a crater consists of rock brought up during the impact from below the crater floor. This autumn image is illuminated from the upper left and covers an area approximately 3 km (1.9 mi) across.</p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA05949" onclick="window.open(this.href); return false;" title="Voir l'image PIA05949: Hale Central Peak sur le site de la NASA">Voir l'image PIA05949: Hale Central Peak sur le site de la NASA.</a></div>
PIA05949: Hale Central Peak
<h1>PIA05950: Troughs and Flows</h1><div class="PIA05950" lang="en" style="width:672px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>20 September 2004<br />This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows troughs and a pit chain (on the floor of the deeper trough) located immediately northeast of the giant Tharsis volcano, Arsia Mons. Lava flows have been cut by these troughs, which formed along fault lines when the crust expanded and rock between the fault lines was raised up or dropped down relative to its original position. Troughs formed in this way are known as graben. This image is located near 7.1°S, 115.0°W. The scene covers an area approximately 3 km (1.9 mi) across and is illuminated by sunlight from the upper left.</p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA05950" onclick="window.open(this.href); return false;" title="Voir l'image PIA05950: Troughs and Flows sur le site de la NASA">Voir l'image PIA05950: Troughs and Flows sur le site de la NASA.</a></div>
PIA05950: Troughs and Flows
<h1>PIA05951: High Latitude Polygons</h1><div class="PIA05951" lang="en" style="width:512px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>21 September 2004<br />This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows polygon patterned ground in the south polar region near 82.0°S, 90.8°W. Polygons are fairly common at high latitudes in both martian hemispheres, but they do not occur everywhere. On Earth, features such as these would be good indicators of the presence and freeze-thaw cycles of ground ice. On Mars, the same might (emphasis on might) also be true. This image covers an area approximately 3 km (1.9 mi) across and is illuminated by sunlight from the upper left. Seasonal frost enhances the contrast in the scene; the darkest areas have advanced the farthest in the springtime defrosting process.</p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA05951" onclick="window.open(this.href); return false;" title="Voir l'image PIA05951: High Latitude Polygons sur le site de la NASA">Voir l'image PIA05951: High Latitude Polygons sur le site de la NASA.</a></div>
PIA05951: High Latitude Polygons
<h1>PIA05952: Martian Dunes</h1><div class="PIA05952" lang="en" style="width:799px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA05952" onclick="window.open(this.href); return false;" title="Voir l'image PIA05952: Martian Dunes sur le site de la NASA">Voir l'image PIA05952: Martian Dunes sur le site de la NASA.</a></div>
PIA05952: Martian Dunes
<h1>PIA05969: South Polar Wind Streak</h1><div class="PIA05969" lang="en" style="width:512px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>19 May 2004<br />This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a small meteor impact crater, about 90 meters (~295 feet) in diameter, with a short, dark wind streak on its down-wind side. The crater is located atop south polar layered materials near 80.2°S, 210.4°W. The March 2004, early autumn picture covers an area about 3 km (1.9 mi) across and is illuminated by sunlight from the upper left.</p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA05969" onclick="window.open(this.href); return false;" title="Voir l'image PIA05969: South Polar Wind Streak sur le site de la NASA">Voir l'image PIA05969: South Polar Wind Streak sur le site de la NASA.</a></div>
PIA05969: South Polar Wind Streak
<h1>PIA05977: Ascraeus Caldera Wall</h1><div class="PIA05977" lang="en" style="width:800px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>20 May 2004<br />This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows the wall on one of the calderae at the summit of the large volcano, Ascraeus Mons. A caldera is a large depression formed by collapse after magma in a volcano is erupted from or withdrawn to a greater depth. After collapse, the wall of this caldera was further modified by downslope movement of debris and it was pelted by small meteors to form a scattering of small craters. This image is located near 11.6°N, 104.6°W, and covers an area about 3 km (1.9 mi) across. The picture is illuminated by sunlight from the lower left.</p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA05977" onclick="window.open(this.href); return false;" title="Voir l'image PIA05977: Ascraeus Caldera Wall sur le site de la NASA">Voir l'image PIA05977: Ascraeus Caldera Wall sur le site de la NASA.</a></div>
PIA05977: Ascraeus Caldera Wall
<h1>PIA05980: 'Columbia Hills' from Orbit</h1><div class="PIA05980" lang="en" style="width:800px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>This view of the "Columbia Hills" in Gusev Crater was made by draping an image from the Mars Orbiter Camera on NASA's Mars Global Surveyor orbiter (image E0300012 from that camera) over a digital elevation model that was derived from two Mars Orbiter Camera images (E0300012 and R0200357).</p><p>This unique view is helpful to the rover team members as they plan the journey of NASA's Mars Exploration Rover Spirit to the base of the Columbia Hills and beyond. Spirit successfully completed a three-month primary mission, and so far remains healthy in an extended mission of bonus exploration. As of sol 135 (on May 21, 2004), Spirit sits approximately 680 meters (0.4 miles) away from its first target at the western base of the hills, a spot informally called "West Spur." The team estimates that Spirit will reach West Spur by sol 146 (June 1, 2004). Spirit will most likely remain there for about a week to study the outcrops and rocks associated with this location.</p><p>When done there, Spirit will head approximately 620 meters (0.38 miles) to a higher-elevation location informally called "Lookout Point." Spirit might reach Lookout Point by around sol 165 (June 20, 2004). On the way, the rover will pass by and study ripple-shaped wind deposits that may reveal more information about wind processes on Mars.</p><p>Lookout Point will provide a great vantage point for scientists to remotely study the inner basin area of the Columbia Hills. This basin contains a broad range of interesting geological targets including the informally named "Home Plate" and other possible layered outcrops. These features suggest that the hills contain rock layers. Spirit might investigate the layers to determine whether they are water-deposited sedimentary rock.</p><p>Once at Lookout Point, Spirit will acquire 360-degree panoramic images of the entire area to help define the rover's next steps. Assuming the rover stays healthy, Spirit will eventually drive down into the basin to get an up-close look at interesting features there.</p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA05980" onclick="window.open(this.href); return false;" title="Voir l'image PIA05980: 'Columbia Hills' from Orbit sur le site de la NASA">Voir l'image PIA05980: 'Columbia Hills' from Orbit sur le site de la NASA.</a></div>
PIA05980: 'Columbia Hills' from Orbit
<h1>PIA05991: Lycus Sulci Slope Streaks</h1><div class="PIA05991" lang="en" style="width:672px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>21 May 2004<br />This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows dark slope streaks coming off of rugged hills in the Lycus Sulci region, north of the Olympus Mons volcano. These slopes are mantled with fine, bright dust. From time to time, the dust will avalanche down a slope, forming a slope streak. The behavior of this dry, granular material can be somewhat fluid-like. New slope streaks can form at any time and, for an area the size of that shown here, may form at a rate of one per Mars year (687 Earth days). Naturally, some scientists have suggested that water plays a role in forming these streaks, but, in general, Mars is drier than the driest deserts on Earth and these streaks are contemporary features that occur in the dustiest regions of the planet. The image is located near 29.8°N, 133.4°W, and covers an area about 3 km (1.9 mi) across. The picture is illuminated by sunlight from the lower left. </p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA05991" onclick="window.open(this.href); return false;" title="Voir l'image PIA05991: Lycus Sulci Slope Streaks sur le site de la NASA">Voir l'image PIA05991: Lycus Sulci Slope Streaks sur le site de la NASA.</a></div>
PIA05991: Lycus Sulci Slope Streaks
<h1>PIA05992: Apsus Vallis Region</h1><div class="PIA05992" lang="en" style="width:512px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>22 May 2004<br />This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows light-toned, windblown ripples on the floors of channels of the Apsus Vallis system. The fluid responsible for forming the valleys is unknown; it might have been water. No primary landforms, other than the channels themselves, have been preserved in a way that would indicate the nature of the fluid that carved the valleys. Apsus Vallis is located just west of the Elysium volcanic region; the area in the picture is located near 35.5°N, 225.6°W. The image covers an area about 3 km (1.9 mi) across and is illuminated by sunlight from the lower left.</p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA05992" onclick="window.open(this.href); return false;" title="Voir l'image PIA05992: Apsus Vallis Region sur le site de la NASA">Voir l'image PIA05992: Apsus Vallis Region sur le site de la NASA.</a></div>
PIA05992: Apsus Vallis Region
<h1>PIA05993: Dipping Rock Layers</h1><div class="PIA05993" lang="en" style="width:800px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>23 May 2004<br />The central peak of Oudemans Crater, located at the edge of the Labyrinthus Noctis trough system, consists of steeply-dipping rock layers that were uplifted and tilted by the meteor impact that formed the crater. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows an example. The banded features are layers of light-toned, possibly sedimentary, rock that were brought to the surface and uplifted by the impact process that formed the crater and its central peak. Oudemans Crater's central peak serves as a means for probing the nature of rock that lies beneath the plains cut by the Labyrinthus Noctis troughs, which are part of the vast Valles Marineris system. This March 2004 picture is located near 10.2°S, 92.0°W. The image covers an area about 3 km (1.9 mi) across and is illuminated by sunlight from the upper left.</p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA05993" onclick="window.open(this.href); return false;" title="Voir l'image PIA05993: Dipping Rock Layers sur le site de la NASA">Voir l'image PIA05993: Dipping Rock Layers sur le site de la NASA.</a></div>
PIA05993: Dipping Rock Layers
<h1>PIA05994: Ganges Sedimentary Rocks</h1><div class="PIA05994" lang="en" style="width:800px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>24 May 2004<br />Mariner 9 images acquired in 1972 first revealed a large, light-toned, layered mound in Ganges Chasma, part of the vast Valles Marineris trough system. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a higher-resolution view of these rocks than was achieved by Mariner 9 or Viking, and higher than can be obtained by Mars Odyssey or Mars Express. The image, with a resolution of about 3.7 meters (12 feet) per pixel, shows eroded layered rock outcrops in Ganges Chasma. These rocks record a history of events that occurred either in Ganges Chasma, or in the rocks brought to the surface by the opening of Ganges Chasma. Either way, the story they might tell could be as fascinating and unprecedented as the story told by sedimentary rocks investigated this year in Meridiani Planum by the Opportunity Mars Exploration Rover ... no one knows. The image is located near 7.3°S, 48.8°W, and covers an area about 3 km (1.9 mi) across. The picture is illuminated by sunlight from the upper left.</p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA05994" onclick="window.open(this.href); return false;" title="Voir l'image PIA05994: Ganges Sedimentary Rocks sur le site de la NASA">Voir l'image PIA05994: Ganges Sedimentary Rocks sur le site de la NASA.</a></div>
PIA05994: Ganges Sedimentary Rocks
<h1>PIA05995: Dust Event</h1><div class="PIA05995" lang="en" style="width:800px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>25 May 2004<br />From time to time, the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) catches--in action-an afternoon dust storm, dust devil, or other dust-raising event. The dust-raising event shown here, probably the result of a sudden strong gust of wind, occurred in November 2003 in a crater located near 57.5°S, 60.6°W. Sunlight illuminates the scene from the upper left, so the dark area below the dust plume is its shadow. The picture covers an area about 3 km (1.9 mi) across.</p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA05995" onclick="window.open(this.href); return false;" title="Voir l'image PIA05995: Dust Event sur le site de la NASA">Voir l'image PIA05995: Dust Event sur le site de la NASA.</a></div>
PIA05995: Dust Event
<h1>PIA05996: Dark Polar Dunes</h1><div class="PIA05996" lang="en" style="width:768px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>26 May 2004<br />The north polar cap of Mars is surrounded by fields of dark sand dunes. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows several dunes in the north polar region. The winds responsible for them blow from the lower left toward the upper right. The picture is located near 78.6°N, 243.9°W. Sunlight illuminates the scene from the lower left, and the picture covers an area about 3 km (1.9 mi) across.</p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA05996" onclick="window.open(this.href); return false;" title="Voir l'image PIA05996: Dark Polar Dunes sur le site de la NASA">Voir l'image PIA05996: Dark Polar Dunes sur le site de la NASA.</a></div>
PIA05996: Dark Polar Dunes
<h1>PIA05997: Arabia Crater Cluster</h1><div class="PIA05997" lang="en" style="width:800px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>27 May 2004<br />This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a portion of a large field of small craters clustered together in northeastern Arabia Terra. Crater clusters usually result from the secondary impact of debris thrown from a much larger impact or from the break-up and impact of fragments of a large meteor. Each crater has subsequently been partially filled by material that erodes to form a rugged crater floor surface, and the general appearance of each crater has been somewhat eroded and modified, as well. The image is located near 34.7°N, 314.7°W, and covers an area about 3 km (1.9 mi) across. Sunlight illuminates the scene from the lower left.</p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA05997" onclick="window.open(this.href); return false;" title="Voir l'image PIA05997: Arabia Crater Cluster sur le site de la NASA">Voir l'image PIA05997: Arabia Crater Cluster sur le site de la NASA.</a></div>
PIA05997: Arabia Crater Cluster
<h1>PIA05998: Sand Dunes in Noachis</h1><div class="PIA05998" lang="en" style="width:465px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>28 May 2004<br />This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows dark sand dunes on the floor of a crater in Noachis Terra. The picture was acquired in early southern autumn in March 2004; it is located near 52.4°S, 336.9°W. The image covers an area about 3 km (1.9 mi) across; sunlight illuminates the scene from the upper left.</p><br /><br /><a href="http://photojournal.jpl.nasa.gov/catalog/PIA05998" onclick="window.open(this.href); return false;" title="Voir l'image PIA05998: Sand Dunes in Noachis sur le site de la NASA">Voir l'image PIA05998: Sand Dunes in Noachis sur le site de la NASA.</a></div>
PIA05998: Sand Dunes in Noachis
<h1>PIA06008: Rippled Valley Floor</h1><div class="PIA06008" lang="en" style="width:662px;text-align:left;margin:auto;background-color:#000;padding:10px;max-height:150px;overflow:auto;"><p>15 September 2005<br />This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a ripple-covered valley floor in the Hyblaeus Fossae region. Winds blowing up and down the length of the valley have helped to concentrate windblown grains to form these large, megaripples.<p>Location near: 26.3°N, 225.1°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/PIA06008" onclick="window.open(this.href); return false;" title="Voir l'image PIA06008: Rippled Valley Floor sur le site de la NASA">Voir l'image PIA06008: Rippled Valley Floor sur le site de la NASA.</a></div>
PIA06008: Rippled Valley Floor

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