Active Sand Abrasion in the Northern Polar Region of Mars
Science Theme: Aeolian Processes
The large dune field which surrounds Mars' North Polar cap is actively being modified by the wind, with dunes moving at rates of a meter or more per year. This image shows that the blowing sand is also abrading the ice-rich ground over which the dunes migrate. Clearly visible is a linear texture on the interdune surface that is oriented north-northeast to south-southwest. This orientation matches that of the horns and slipfaces of the barchan dunes, which together indicate migration from the north-northeast to the south-southwest. The linear texture is visible, albeit subtly, on the surrounding ground surface. The texture is more apparent in the wind-etched topography as a series topographic high and lows, with the directional trend. Further inspection shows that the topographic highs contain boulders, which may be ice rich. Most of the sand abrasion probably occurs within the topographic troughs, accentuating topography and abrading away boulders, leaving remnant rocks on the highs.
This shows that sand abrasion is actively modifying the surface in Mars' northern latitudes.

Acquisition date:              17 April 2012
Local Mars time:               14:25
Range to target site from satellite :          319.7 km (199.8 miles)
Original image scale range:          32.0 cm/pixel so objects ~96 cm across are resolved.
Sun about 37° above the horizon
Northern Summer