Sailing Stones

Will a regular stone at your feet intrigue you? Will you be curious to read about a stone? I would not, unless the stone has some mysterious properties or origins (read outer space or earth inner crust).

 Sailing stones are rocks found in the dry mud lake at Racetrack Player in Death Valley National Park, California, which leaves a trail of their movement. There is nothing special about the stones except for the fact that they are moving and leave a trail on the mud. “How do they sail?” – This is the question which puzzles the scientists for four decades.

In 1915, when this phenomenon was first documented, most thought that to be a prank by some locals or park officials. But, later geologists observed and confirmed that this geological phenomenon has no human or animal interference. An article has been published on 1948 in Geological Society of America Bulletin about the sliding rocks/moving rocks (known by these names also) phenomenon.

How does those stones sail? The theories and rumors started feeding the frenzy. All kinds of theories have sprung up right from the supernatural properties of the stones to mysterious spirits moving them to alien intervention.
Extensive experiments were conducted and major progress has been done in 70s. A set of rocks has been identified and given names like Mary Ann, Nancy and Karen and then studied each year. The rock “Karen” has disappeared around 1994 (maybe due to severe winters in 1992 and 1993). It (Karen) has been rediscovered in 1996 by a geologist around 800 meters from its previously observed location.
The most logical amongst the theories after the studies were conducted is – “Stronger Winds or moving ice sheets sail the rocks”. But, the observation/experiments for around a century have shown that rocks as heavier as 700 pounds have been moved for more than 600 feet. The wind speed calculated to sail those kinds of rocks (700 pounds) should be of far greater in magnitude than is observed at the Racetrack Player lake bed. Please take a look at the following pictures for an idea of size of sailing stones.

 

Also, the tracks are not always linear. The tracks take a perpendicular turn in some scenarios. Not all rocks have sailed the same distance. Some of them sailed in completely different directions. (See image below) 

 

Lots of theories have been proposed and lots of experiments were conducted to find the cause of SAILing stones. None has given a satisfactory explanation except for a recent one, which is believed now, unanimously, to be the actual cause of the SAILing stones.
Professor Ralph Lorenz, a planetary geologist at NASA, has proposed that the stones were frozen with ice around them during the colder months and the bottom tip/edge of the stone which would be submerged in icy water for a couple of inches would be prone to soft winds. Once the stone is covered with ice in the muddy soil, it does not totally submerged or totally float. The top portion will float while the bottom which is not fully ice-covered will be touching the soil up to a couple of inches. This greatly reduces the friction between the rocks and the mud surface. With reduced friction and light winds, these stones easily sail leaving their marks on the soil/mud beneath them. Once the frozen areas melt down, those marks left by stone tip were visible to the naked eye and thus the stone has sailed.
The theory by Prof. Ralph Lorenz is also just another theory, until someone proves with a video footage proving or disproving it. But, this theory is the most convincing now since Prof. Ralph Lorenz has tested the theory domestically in his kitchen sink with frozen solid and some ice cold water and the theory holds good in domestic testing in his kitchen table.
You can argue about placing a video camera in the Racetrack Player and record everything and find out the truth. In 2009, an inexpensive time lapse digital camera has been installed and pointed at the Racetrack Playa. But, this phenomenon occurs once in three or four years and should last only tens of seconds, which makes it extremely hard to be captured on a digital camera. In 2013, wind-triggered imagery is being used to greatly reduce the amount of captured digital media and the amount of work one should process post recording them.
In the meantime, the Death Valley National Park officials at Racetrack Player have initiated investigations into the disappearance of a large number of stones from its premises. It is believed that park visitors would have stolen them for some occult beliefs or supposedly divine/magical properties of those stones.
It seems people are still curious about the sailing stones. The people are not ready to hear these theories but love the mysterious part of the ‘sailing stones’ even after convincing theory and proof of concept that it is moved by nature anyway.