Melty dunes

A Piece of Mars: With all due apologies to followers of the show Coupling, I have to call these things “melty dunes”. This link shows what a crisp dune should look like. The dunes in this 600×450 m (0.37×0.28 mi) scene, however, have rounded crests and sand that seems to have ponded around the bottom of the dunes. These are common at high southern latitudes on Mars. (HiRISE ESP_039610_1150, NASA/JPL/Univ. of Arizona)