These layers formed as a mix of dust, water ice and frost settled on the martian ground over time. Each layer holds valuable information about Mars’s history, telling the story of how the planet’s climate has changed over the past few million years.

In martian winter, the layers are topped by a thin cap of dry ice (carbon dioxide ice) a couple of metres thick. This cap completely disappears to the atmosphere each martian summer.

This image comes from the Mars Express High Resolution Stereo Camera (HRSC). Two steep banks, or escarpments, cut vertically through the frame. These mark the boundary between the aforementioned layered deposits (which stretch out of frame towards the pole, right) and the vast, sweeping dune fields covering the lower terrain of Olympia Planum (to the left).

Click on the image below to explore the region and discover more about the different features you can see.