Posted by tourdemars to Mars Express at August 24, 2004 01:40 PM

These images, taken by the High Resolution Stereo Camera (HRSC) on board ESA's Mars Express spacecraft, show a Martian crater with a dune field on its floor. In arid zones on Earth, these features are called ‘barchanes’, which are dunes having an asymmetrical profile, with a gentle slope on the wind-facing side and a steep slope on the lee-side. The dune field shown here suggests an easterly wind direction with its steeper western part. The composition of the dune material is not certain, but the dark sands could be of basaltic origin.