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Researchers think that water, ice, and wind work together to move the stones. In this photo, the students dig up small sensors called Hygrochrons, which had been buried three months before the interns arrived and recorded temperature and humidity data electronically. Photo credit: NASA/GSFC/Maggie McAdam To read a feature story on the Racetrack Playa go to: <a href="http://www.nasa.gov/topics/earth/features/roving-rocks.html" rel="nofollow">www.nasa.gov/topics/earth/features/roving-rocks.html</a> <b><a href="http://www.nasa.gov/centers/goddard/home/index.html" rel="nofollow">NASA Goddard Sp…
