What Drives Death Valley's Roving Rocks?

Moving rocks refer to a geological phenomenon where rocks move in long tracks along a smooth valley floor without human or animal intervention. They have been recorded and studied in a number of places around Racetrack Playa, Death Valley. The force behind their movement is not confirmed and is the subject of research. The moving rocks have stumped scientists since the 1940s.

Now a student-research project led by NASA's Goddard Space Flight Center has lent support to the idea that, during wintertime, the rocks float down the playa on small 'collars' of ice, which form around the stones when lake water flows down the surrounding hills and freezes on the lakebed.