2 July 2004
Beneath the ice caps of both martian poles lies extensive deposits of layered material. Whether the material includes ice is unknown. In the north polar region, some of the layers contain dark sand, others may consist of dust cemented by ice. The south polar layers are a little bit more challenging to understand. In most places, they have been covered by thin mantles of debris that mask the true nature of the layered material. This is the case, even in the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shown here. South polar layers were eroded to provide this spectacular view, but later the materials were almost uniformly covered with a material that, when the image is viewed at full resolution (click on image, above), has become cracked. This picture is located near 82.0°S, 72.4°W, and covers an area about 3 km (1.9 mi) wide. Sunlight illuminates the scene from the upper left.