Racetrack Playa is one of the most mysterious features of Death Valley National Park. The sailing stones move across the desert landscaping with no gravitational powers. Some of these rocks weigh just ounces, while others weigh several hundred pounds. According to the National Park Foundation, nobody has ever witnessed these stones moving. The rocks leave behind trails, making it obvious there has been movement.
Movements of the Sailing Stones
The rocks and surrounding mountains are made of syenite and dolomite. The force of erosion is responsible for the movement of the stones. Once reaching the surface, the rocks move in a horizontal direction. The pathway is recorded by the tracks. According to Live Science, the trails are a maximum of 1,500 feet. Straight tracks are left by rocks with rougher surfaces, while smooth rocks wander.
The first time the movement of the sailing stones was captured by scientists was in 2014. Time-lapse photography showed the movement is caused by the ideal combination of wind, water, and ice. A small pond was created by the rain in 2014. The pond froze during the night, then thawed over the next day. As the sheet of ice began to break, the stones were pushed forward.
This is a popular scientific explanation for the movement. Another explanation is the rocks are moved by a combination of bacteria and wind.
The NASA Exploration
In 2014, NASA and the Scripps Institution of Oceanography announced the mystery of the sailing stones had been solved. Richard Norris and James Norris claim the motion results from thin ice covering the lake bed. Light winds break up the ice once the morning sun appears. The ice panels then push the rocks, resulting in movements and tracks on the floor of the desert.
The investigation started in 2011. The result was the Slithering Stones Research Initiative. Once a weather station was established, the men added 15 stones with GPS attached. One GPS unit was placed in the Racetrack Playa. The GPS included a battery pack. Time-lapse photography captured the movements on the 4th and 20th of December, 2013.
The camera showed the sailing stones moving over the playa at three to five meters or 15 feet per minute. The movements of numerous stones were revealed. This was the first time in history the movement of the stones was observed. On December 20th of 2013, the biggest rock movement observed consisted of 60 different rocks. From December of 2013 through January 2014, some rocks moved a total of 224 meters.
Sheet of Ice
According to the men, they determined the cause of the phenomena by watching the stones’ movement. This was different than the previous scientific explanation of thick ice, or powerful winds on the surface resulting in the movement of the sailing stones. The researchers determined a sheet of ice between three and six millimeters in thickness covering the playa pool melted in the morning sun.
Light winds traveling four to five meters per second broke up the ice. The floating panels of ice pushed numerous rocks at extremely low speeds, an average of two to five meters each minute. The trajectories of the rocks were determined by the water moving beneath the ice and the velocity and direction of the wind. Movement can only be seen in the sailing stones once in every period of two to three years.
The majority of tracks left by the rocks remain for approximately three to four years. The type of tracks left are dependent on whether the bottoms of the rocks are smooth or rough.
Visiting Death Valley
Visitors interested in seeing the sailing stones of the Racetrack Playa actually moving should drive two miles to the south of the Grandstand area designated for parking. There is no precise location to see the movement because the location is consistently changing. The best option is usually walking to the southeastern corner approximately one-half of a mile.
Visitors need to be careful not to disturb the actual rocks, or the tracks left behind. There is a lot of mud in the playa after it has rained. When the area is wet, it is easy to leave unintentional footprints behind. Driving on any unestablished roads has been prohibited.
Death Valley sailing stones are still confusing both scientists and visitors today. Scientists are convinced they have determined the reasons behind the mysterious movements. Numerous individuals visit Death Valley every year to see this amazing phenomenon.