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June 21, 2010

Scientific Unknowns: Sailing Stones

On the border of California and Nevada is area of unexplained activity: the Sailing Stones of Death Valley. These are a truly peculiar phenomenon: photographs show that, every once in a while, huge boulders in the Racetrack Playa slide across the ground. No one has ever directly observed this movement. It's a strange phenomenon, which hasn't been observed anywhere else on the planet. Thus, it has been a source of speculation, both scientific and not.

Two of the "Sailing Stones"
On the science side, there seem to be a couple main hypotheses. The most prominent of these is that, during the night, freezing temperatures cause any water in the ground to freeze, forming a thin layer of ice between the boulders and the ground. Strong winds may then push the stones around, leaving shallow trenches and trails behind. Another idea is that, instead of ice, slick, clay-based mud may serve as the lubricant between rock and earth. In either case, it is suggested that, under rare conditions, the force of the wind is strong enough to set the stones in motion, and then continues to propel them hundreds of yards. Variations on this idea have existed since the 1950s, but no one has yet been able to observe the movement of the stones, making a solid call impossible.

An example of a 90o turn by a Sailing Stone
Because the "Sailing Stone" phenomenon is so unusual, and really peculiar, there are also those who believe it has a paranormal or supernatural explanation. After all, how could wind alone, even on a slick surface, move boulders in excess of 250 pounds over hundreds of feet, sometimes even turning at 90o+ angles? Some hint that there are "unseen hands" at work on the Racetrack Playa. Others hint at some connection to Roswell Area 51, the holy site of UFOers and other supernatural conspiracy theorists. A few even suggest that the stones are alive, and move themselves around the valley.

The Sailing Stones are a really bizarre phenomena, and an incredibly rare one. Without more data, it's hard to say what causes their strange behavior. Some scientists have suggested training cameras and other recording equipment on this peculiar valley, in an attempt to actually see what's going on. Until then, though, the moving rocks of Death Valley remain a mysterious curiosity, just another example of how weird and amazing our world can be.


Sources and More Information
The first three articles provide paranormal/supernatural speculation. The last three are scientific articles about the Sailing Stones and the Racetrack Playa.