North Polar Layered Deposits and Dunes in Chasma Boreale

This image shows a steep, layered slope and flatter, dune-covered plains in Mars’ north polar region. The layers are composed of varying contents of water ice and dust.

On Earth, icy layers like these in Greenland and Antarctica are important because they contain a record of past climate conditions. By looking at the detailed sequence of polar layers on Mars, scientists hope to be able to discover the types of variations that Mars’ climate may have experienced. The lowest section in the stack of light layers is noticeably darker because of the presence of dark, sandy material. Erosion of this dark material is thought to provide the sand making up the large dunes on the plains.

Several exceptionally well-developed barchan (crescent-shaped) dune forms up to approximately 50 meters (160 feet) across are present in the center of the image.

Written by: Patrick Russell   (29 October 2008)

More info and image formats at

Image: NASA/JPL/University of Arizona