14th January 2010.
Sand dunes can often be seen on the floors of Martian craters, trapped in by the crater walls. These dunes can show incredible patterns and formations, sculpted by the Martian winds.
In this incredible photo taken by the Mars Reconnaissance Orbiter on 28th of December 2009, the dunes are very similar to each other, with thin bands of redder coloured material on the north east sides. Boulders also litter the ground between the dunes in this amazing 1.2 kilometere wide scene from the floor of a crater in Noachis Terra, west of the Hellas Impact Basin. This linear formation is the result of the changing wind directions.