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Mars Global Surveyor
Mars Orbiter Camera

Defrosty Dunes

MGS MOC Release No. MOC2-1528, 19 July 2006

Medium-sized view of MGS MOC Picture of the Day, updated daily
NASA/JPL/Malin Space Science Systems

This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a portion of a sand dune field in the north polar region of Mars. The dunes are covered with frozen carbon dioxide which accumulated over the autumn and winter months in the northern hemisphere. During the spring, the time at which this image was acquired, the carbon dioxide begins to sublime away, going directly from solid to gas, just as dry ice does here on Earth. The dark spots, streaked by blowing winds, may be places where the frost has been removed (exposing underlying dark sand), places where the grain size or roughness of the frost has increased (increasing shadowing due to the change in texture), or both.
Location near: 79.7°N, 148.3°W
Image width: ~3 km (~1.9 mi)
Illumination from: lower left
Season: Northern Spring


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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, California. 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, California and Denver, Colorado.

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