NASA's Curiosity rover reaches Martian sand dunes

PASADENA, Calif., Dec. 11 (UPI) -- NASA's Curiosity rover is continuing its trek up Mount Sharp. Recently, the Mars rover reached a series of sand dunes covering a lower portion of the layered Martian mountain inside Gale Crater.

The dunes are dark in color and high in stature, some of the crests towering up to two stories. Images snapped by Curiosity reveal the ripples of one dune dubbed the "High Dune," as well as a pair of fresh wheel marks.

Any marks left by the rover likely won't last long. Satellite observations suggest the crests of Mars' dunes move as much three feet annually.

The dunes imaged by Curiosity are part of a larger group called "Bagnold Dunes," which blanket the northwestern flank of Mount Sharp.

Friday marks Curiosity's 1,222nd day on Mars, or 1190 sols -- the duration of a solar day on Mars.

Since landing on Aug. 6, 2012, the rover has drilled, dug, driven and photographed a variety of outcroppings and other geological features on Mars. The rover's current mission is to document higher elevations of Mount Sharp.