Not to be outdone by Pluto's space slug formation, Mars is offering up its own oddball landscape features in a NASA photo showing a series of sand dunes. The dunes might look like a herd of wriggling worms, but their curved shapes come from exposure to wind.
NASA released the image, taken by the Mars Reconnaissance Orbiter, on Thursday. The crescent-shaped dunes are located in Mars' southern hemisphere. NASA notes these dune formations can occur in craters as well as in open plains.
The worm-like look in the photo is partly due to the direction of the sun. "Here, the steep, sunlit side of the dune, called a slip face, indicates the down-wind side of the dune and direction of its migration," NASA says.