Mars is famous for its volcanoes, canyons and ancient river valleys, but some of its most active geology happens in slow motion, powered by air. Over time, strong gusts can loft sand grains that ping and scrape at exposed surfaces, gradually carving landscapes the way a sandblaster etches metal.
Recently, the European Space Agency's (ESA) Mars Express orbiter captured this image of a series of yardangs near the Eumenides Dorsum mountain. The ridges all lean the same way, slanting and curving in from the lower left of the frame, which ESA noted reflects the direction of the prevailing wind in this region.
