The sailing stones have been a source of fascination and speculation since the mid-1900s.
Deep in the heart of Death Valley National Park, a seemingly barren dry lakebed hides one of Earth’s most peculiar phenomena: the mysterious sailing stones of Racetrack Playa. These rocks, some weighing up to 700 pounds (320 kilograms), have puzzled scientists for decades as they leave long tracks across the cracked desert floor, moving without any visible force pushing them.
The sailing stones have been a source of fascination and speculation since the mid-1900s. The rocks, which can drift across the flat, dry surface of Racetrack Playa for distances up to 1,500 feet (460 meters), leave behind distinct grooves in the ground. The question baffling researchers for years was simple: How were these massive stones moving?
Cracking the Mystery: How the Stones Really Move
It wasn’t until 2013 that researchers finally observed the rocks in motion, thanks to a high-tech experiment. Scientists fitted 15 stones with motion-activated GPS and monitored them using a time-lapse camera. The surprising discovery? A rare combination of rainfall, ice, and wind moves the rocks across the desert.
The study, published in 2014, showed that when a thin layer of ice forms overnight after rainfall, it acts as a slick surface under the rocks. As the morning sun melts the ice, large floating panels form and, with a push from the wind, shove the stones along the playa at speeds of 7 to 16 feet per minute (2 to 5 meters per minute).
These conditions are rare, which explains why the stones can sit in one place for years or even decades before moving. The data also shed light on why some stones show parallel tracks or synchronized movements, with sharp turns occurring when the ice breaks apart.
