Mystery image: animal, vegetable, or astronomical?

Mars’ Russell Crater is streaked with dunes, themselves marked with the dark trails that dust devils leave behind as they streak across the scored landscape exposing the dark underlayer. In the winter, the dunes are covered with carbon dioxide frost�dry ice�which thaws by sublimating directly from solid to gas. This photograph was made by the HiRISE camera aboard the Mars Reconaissance Orbiter.

[via NASA]