How the sailing stones of death valley were moving on its own?

The sailing stones of death valley national park, California ​was one of the ​unanswered mystery that have confused the scientist for a long time.The stones found in the death valley weighs more than 300 kg and they were found moving on a day to day basis leaving a long trail. Multiple stones moved along a same directions making angles showed that they were moving because of same action.

It was even considered as superstitious behavior until the mystery is resolved.

The mystery came to end in January 2014, when US scientist finally found that this happens as a result of thin sheet of ice formed below the stones during night. This made the stones drift(move) in the direction of the wind. 


How did they crack this case?

Scientists have placed a customized motion activated GPS and camera to understand the strange behavior.

Technology always helps. :)