NASA/JPL/Malin Space Science Systems
This is a mid-southern spring view, taken in August 2003, of defrosting patterns on sand dunes in Richardson Crater. The picture was acquired by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC). The frost on these dunes might be a combination of frozen carbon dioxide left over from the previous winter, and water ice. As the ices sublime away, they create dark spots. Winds create dark streaks, either by moving the dark sand that underlies the frost, or by removing frost to expose the sand. Alternatively, the frost itself is roughened by the wind or has been made coarse by wind and sublimation processes. The Richardson dune field undergoes a long series of changes as it defrosts from late winter through spring and into early summer. Summer will arrive at the end of September 2003. This picture is located near 72°S, 181°W, and covers an area 3 km (1.9 mi) across. Sunlight illuminates the scene from the upper left.
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.