APOD 3.6

2012 February 22  
A Sailing Stone in Death Valley 

Death Valley is a desert valley located in California and oddly enough has a very low fatality rate. After doing some research, I found Yellowstone National Park has had 14 more fatalities than Death Valley. In fact, its name stems from the lack of vegetation and life that the oppressive heat causes.


The dried lake-bed known as Racetrack Playa is a completely flat salt flat that features a few large stones (featured above). The "sail stones" are not easily movable by normal, human means; however, Earth uses its natural forces to scoot these 300 kilogram rocks along. Through a combination of wind and a slippery surface, caused by recent rainfall, can shift these rocks on a scale that no human eye can discern. Much like man celestial objects in our nighttime sky, these rocks need additional, non-human equipment to track their motion.