Dark Light
This image covers a portion of a typical impact crater in Terra Sirenum at about 40 degrees south latitude on Mars.

At the top of the image, outside the crater rim, there is a mid-latitude mantle, rough in places where ice may have sublimated. Below the crater rim, on the steep, south-facing slope, are gullies. These are erosional features with depositional fans. Some of the gully fans have a bluish color: these are probably quite recent deposits, less than a few tens of years old.

On the floor of the crater (bottom of the full image) are ridges that likely formed from the flow of ice, perhaps a few million years ago.

Image: NASA/JPL/University of Arizona https://www.uahirise.org/hipod/ESP_021699_1405
Related Posts

A Tale of Collapse Terrain

North of Ganges Chasma lies Orson Welles Crater, whose floor contains broken up blocks we call chaotic terrain and which is the source for the major outflow channel Shalbatana Vallis.

Layered Bedrock

This un-named crater in southwestern Arabia Terra contains a treasure! Layered sediments are the key to the puzzle of Martian history. They tell us about the conditions that existed when the sediments were deposited, and how they changed over time.