NASA/JPL/Malin Space Science Systems
|This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a group of sand dunes, covered by seasonal carbon dioxide frost, in the martian north polar region. Over the course of northern hemisphere spring, the carbon dioxide frost sublimes away, slowly revealing the dark sand that makes up the dunes. The dark spots in this image may be patches of freshly-exposed sand, or they could be places where the CO2 frost has changed, either becoming rougher, coarser-grained (larger crystals), or both. A rougher or coarser-grained surface will appear darker because of an increase in shadowing of the surface by the small-scale roughness elements.|
|Location near: 75.2°N, 51.3°W|
|Image width: ~3 km (~1.9 mi)|
|Illumination from: lower left|
|Season: Northern Spring|
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.