Sailing Stones of death valley, California

Sailing stones, sliding rocks, and moving rocks all 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, where the number and length of travel grooves are notable. The force behind their movement is not confirmed and is the subject of research.Some stones make linear turns others make oval turns while others create a wavy shape on their tracks. No one has ever seen them move and nobody knows the speed they move with. The mysterious sailing stones of Death Valley turn while they are sliding through the flat leveled valley and this leaves different tracks behind them. Some stones move further than others over two to five years.