Rocky Fingers on Mars

This image shows the wind eroded deposit in Pollack Crater, on Mars, called ‘White Rock’. Captured by THEMIS VIS camera during the Southern Fall season.

Detailed studies of these fingers now indicate a more mundane possibility: volcanic ash. Studying the exact color of the formation indicated the possible volcanic origin. The light material appears to have eroded away from surrounding area, indicating a very low-density substance. The stark contrast between the rocks and the surrounding sand is compounded by the unusual darkness of the sand. The featured picture was taken with the Thermal Emission Imaging System on the Mars Odyssey, the longest serving spacecraft currently orbiting Mars.

via APOD