New images of HiRISE high definition imaging in NASA MRO orbiting Mars reveal the erosive ability of wind on the surface of the Red Planet.
In the above snapshot you can see many sand dunes. They have an elongated crescent shape and are called "Barchan dunes". They arise as a result of the continuous operation of the wind, which blows in the same direction.
The orientation of these dunes indicates that the dominant wind blows from right to left (from east to west). The wind constantly moves the grain of sand along the longest slope of the dune, upwards. Small movements on the slope are caused by this movement. When the grains of sand reach a peak, they fall on a steeper and shorter slope, which consequently has no waves. It is the gradual movement of the sand that causes the dunes to shift slowly over time, informs NASA.
Another image taken by the HiRISE camera shows how the erosion of the surface reveals several layers of bright tones, probably bottom sediments, on the surface of Mars.