Fake Image: Fri Sep 19, 2:13 AM ET In this image provided by NASA Thursday Sept. 18, 2008, shows the north polar layered deposits of Mars form a layered stack of dusty ice up to 3 kilometers (2 miles) thick. Newly posted images from more than 1,000 observations by the high resolution camera on NASA's Mars Reconnaissance Orbiter reveal details as small as a desk. The differences from layer to layer in this image are thought to reflect differences in the climate of Mars that existed when the layers were formed. The section of the layered deposits that is exposed on this cliff face is unusual in that, as well layers of dusty ice, there are also layers of sand present. Small structures, called cross-beds, visible in the sandy layers indicate that each layer was originally a dune field that only later became covered with ice. Some of this sandy material is being removed from the cliff face and is forming new dunes at the foot of the cliff.(AP Photo/NASA - JPL - University of Arizona)