Description
1 July 2004
This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows dark sand dunes in a crater in Noachis Terra near 45.8°S, 323.4°W. Martian dunes, unlike the majority of their terrestrial counterparts, are dark because they are composed of minerals or rock fragments rich in unoxidized iron and magnesium. This image covers an area about 3 km (1.9 mi) wide. Sunlight illuminates this autumn scene from the upper left.
