The sailing stones of Death Valley’s Racetrack Playa are a remarkable geological phenomenon involving heavy boulders that mysteriously glide across a completely flat desert landscape, leaving long, winding tracks in the hard-baked clay. For over a century after their initial documentation by a prospector in 1915, these moving rocks baffled geologists, prompting various supernatural, magnetic, and high-wind theories. The mystery was finally unraveled in 2014 by a team of scientists who discovered that the rocks move through a highly specific combination of rare weather events. During winter rains, a shallow pond forms on the playa, which freezes at night into thin sheets of "windowpane ice." As the morning sun fractures the ice into large floating panels, even light breezes of around ten miles per hour can drive these ice sheets forward, gently pushing boulders weighing up to hundreds of pounds across the slippery, waterlogged mud. To study this sensitive phenomenon without disrupting the protected national park environment, researchers successfully utilized custom-made rocks embedded with motion-activated GPS trackers and miniature weather stations. These trackers revealed that the rocks move at incredibly slow speeds of just a few inches per second, explaining why the movement had gone unseen for generations. The stones themselves originate from the surrounding mountains, where erosion and freeze-thaw cycles cause chunks of dolomite, limestone, and syenite to splinter off and tumble onto the desert floor, creating a diverse geological mosaic of varying shapes, sizes, and colors. While Death Valley is the most famous site for this phenomenon, sailing stones also occur in other arid regions sharing the same unique environmental criteria, such as Nevada's Little Bonnie Claire Playa and the Altillo Chica lagoon in Spain. Because the flat clay surfaces are highly fragile, visitors are urged to avoid walking on the basins when damp, as footprints can bake into the ground and permanently alter the natural landscape and stone pathways. ⁠Listen Ad-Free on Patreon. ⁠ For just $3 per month, you can get ad-free versions of Fun Facts Daily, Who ARTed and Art Smart. Head over to ⁠https://www.patreon.com/cw/FunFactsDailyPod⁠ if you are interested. Want to learn more? Head over to my website www.funfactsdailypod.com and be sure to listen to my other podcasts Who ARTed: Weekly Art History for All Ages or Art Smart. For family fun, check out my son's podcast Rainbow Puppy Science Lab The image used in the episode cover art came from Adobe's stock photos. Fun Facts Daily is an Airwave Media Podcast. If you are interested in advertising on this or any other Airwave Media show, email: [email protected] Learn more about your ad choices. Visit megaphone.fm/adchoices