The alienlike beauty of this image, taken by a camera aboard NASAs Mars Reconnaissance Orbiter (MRO), may seem to portend some Martian artists. Alas,the ridges and ripples are evidence of Martian sand dunes. The brighter features represent two classes of so called aeolian bedforms within Proctor Crater. The ripples, research has shown, are composed of fine sand or fine sand coated with coarser sand and granules. And the larger, darker bedforms are dunes composed of sand, possibly derived from basaltic, or volcanic, rock (and hence the darker color). Ripples tend to move slower than dunes. Because of this, over time, ripples get covered with dust, possibly explaining the bright tone visible here. The image was taken by the MROs High Resolution Imaging Science Experiment (HiRISE) on Feb. 9, 2009.