Long exposure to capture star trails circling around the North Star, Polaris, at the "Racetrack," a remote desert playa (dry lake bed) in Death Valley National Park, famous for its mysterious moving rocks that, under just the right conditions, slide across the mud leaving behind tracks that remain for years. Current theories suggest the rocks are moved by high winds when the playa is slick from rain. Death Valley National Park, California, USA January 2007.