For decades, scientists watched in puzzlement as heavy rocks mysteriously carved trails across Death Valley's Racetrack Playa—moving without anyone ever witnessing the motion. Now, thanks to time-lapse cameras, GPS trackers, and a weather station, researchers have finally caught the culprits in action: a few millimeters of windowpane ice and a gentle breeze.

The stones, some heavy enough to require two hands to lift, glide silently across the dried mud when thin sheets of melting ice form beneath them on cold, breezy mornings. As the ice breaks into small rafts and the wind pushes them forward, the rocks ride along like passengers on invisible sleds, leaving their distinctive grooves behind. What seemed like geological magic turned out to be a delicate dance of physics. Read the full story →

Today's takeaway: Sometimes nature's greatest mysteries have the simplest explanations—and patience combined with modern technology can finally reveal what has puzzled us for generations.