Icy layers and climate fluctuations near the Martian North Pole

The Martian north polar is layered with an ice sheet that is much like the Greenland ice sheet on the Earth. Like that of Greenland, this Martian ice sheet contains many layers that record variations in the Martian climate over time. Sometimes icy layers can be ablated away when the climate is warm. Later the ice sheet can be buried by new ice layers and grow in size again. It's likely that many of these cycles have occurred over the ice sheet's history.

The High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter recorded this image of north polar layered deposits on March 11, 2010.