This false-color image of the north polar layered deposits has been processed to emphasize color variations. It shows that the color as well as texture or morphology varies from layer to layer. Some of the color variations may be caused by small amounts of water frost on the surface, or they may be due to variations in dust composition within the layered deposits. Such changes in composition may have been caused by volcanic eruptions or local weather phenomena when the layers were deposited.
Overall, it is thought that the polar layered deposits contain a record of recent climate changes on Mars, similar to ice ages on Earth. High-resolution images like this will be useful in the effort to understand the climate history of Mars.
A link to the full HiRISE image that includes this view is online at http://hirise.lpl.arizona.edu/PSP_001738_2670
Image credit: NASA/JPL/University of Arizona