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In Racetrack Playa in Death Valley, California, hundreds of rocks — some weighing as much as 700 pounds — seem to have been dragged across the ground, leaving synchronized trails that can stretch for hundreds of meters. Though many phenomena were speculated (hurricane-force winds, dust devils, slick algal films, thick sheets of ice), no one knew what caused the movement — until a team of researchers got to work using rocks tagged with GPS devices and a high-resolution weather station.
Watch the video to see the rocks move, and read more about the research.
