Natural modern art on Mars

A piece of Mars: Abstract modern art? No, these are north polar dunes almost completely covered in winter frost (mostly CO2 ice). It’s early spring in this image, and the dark sand underneath the ice is only just beginning to peak out from under the ice cover. The ice looks a little yellow because some dust from the atmosphere has settled on the ice. Soon the ice will sublimate away and reveal the spectacular dark dunes. (ESP_024876_2590, NASA/JPL/University of Arizona)