The Sailing Stones of Death Valley

In the Racetrack Playa, a dry lakebed in California’s Death Valley, heavy rocks mysteriously move across the completely flat desert floor on their own. For decades, they left long, parallel trails behind them, baffling scientists and sparking wild theories about aliens and magnetic fields. In 2014, the mystery was finally solved using time-lapse cameras. During rare winter rains, a thin layer of water freezes on the lakebed. As the morning sun melts the ice into large, floating panels, even a light breeze can push the ice against the rocks, slowly sliding them across the muddy floor to leave their signature tracks.