Image: Rock with trail behind it
Cynthia Cheung  /  NASA/GSFC
A roaming rock at Racetrack Playa. Scientists have ruled out animals, gravity and earthquakes as possible culprits for the stones' strange movements.
updated 8/23/2010 6:52:59 PM ET 2010-08-23T22:52:59

A section of California's Death Valley is home to a strange phenomenon: Rocks that litter the landscape seem to move on their own, leaving long trails behind them in the cracked, bone-dry clay.

These wanderings have baffled scientists for more than five decades. Nobody has ever caught a glimpse of the stones actually moving, yet move they must, because the rocks' locations, and the trails they leave behind them, change over time.

A group of young scientists is taking a crack at solving the puzzle of this odd desert area known as Racetrack Playa.

Most of the wandering stones are about the size of a one-liter soda bottle and far heavier, according to Brian Jackson, a NASA scientist who has been studying the area for more than four years.

"You don't expect 20-pound (9-kilogram) rocks to go sliding across the ground very easily, but they seem to do that on occasion," Jackson said.

Jackson said crackpot theories abound to explain the stones' travels across the playa (a term for a dried-out lake bed), which is about 3 miles (4.5 kilometers) long, almost a mile and a half (2 km) across, and preternaturally flat.

"I've definitely heard aliens, magnetic fields, frat boys from UNLV" — the University of Nevada, Las Vegas — "but nothing really plausible," Jackson said. "There's no way it could really be a hoax, because if someone were pushing them you'd see footprints."

Earlier this summer, a group of interns from NASA's Lunar and Planetary Science Academy, a program run by the Goddard Space Flight Center in Maryland, headed west to study the phenomenon. In addition to collecting GPS measurements and myriad other data, the students retrieved instruments that had been buried in the ground three months earlier. The sturdy little instruments they dug up, called hygrochrons, are about the size of a quarter and measure humidity and temperature; they had been planted by NASA researcher Gunther Kletetschka.

The interns plan to publish a paper this year presenting their findings, which so far seem to back up a current theory that during the winter months, ice forms around the rocks, allowing them to slip across the frozen surface of the playa.

Jackson said the data the interns gathered during their expedition confirmed that the playa had been wet and cold enough over the winter to form ice. "So that's encouraging," he said. "That tells us that at least some of the conditions required to move these rocks were met. It's pretty clear these rocks are assisted by ice somehow." Some scientists think algae blooms may play a role, he added.

Besides looking to Racetrack Playa to help solvemysteries on our own planet, researchers are examining the area to better understand conditions on other worlds. Jackson is co-author of a recent study, led by Johns Hopkins University's Ralph Lorenz, comparing the meteorological conditions of the region to those near Ontario Lacus, a vast, liquid hydrocarbon lake on Saturn's moon Titan.

Jackson said the continuing mystery of the moving rocks doesn't bother him and that, in fact, perplexing problems are a boon to science.

"Science is really all about ignorance," Jackson said. "I think the most exciting science is done in places where you don't understand what's going on. Once you're not confused about something, it's time to move on to the next problem."

© 2012 OurAmazingPlanet. All rights reserved. More from OurAmazingPlanet.

Explainer: The 2010 Weird Science Awards

  • Atala et al., PNAS / WFUBMC
    A researcher injects cells from a rabbit's penile erectile tissue into a scaffold (top photo), a procedure which results in a functional rabbit penis (bottom photo).

    That's one small step for rabbit penises, and potentially one giant hop for restorative surgery. An experiment that gave rabbits lab-grown penises capable of fathering offspring won the most votes in's 2010 Weird Science Awards contest. Cells of penile tissue were grown on scaffolds of cartilage. When the creations took on the right shape, they were grafted onto rabbits that had their penises removed. After the transplants, the rabbits were able to breed ... like rabbits. The procedure could someday be used to heal humans as well. The photos at right show an experimenter working on the penile tissue, and an X-ray image of the restored penis.

    Click "Next" to see the nine other Weird award-winners for 2009-2010, and click on the highlighted links to learn more.

  • Fruit bats get kinky

    Image: Fruit bat sex
    Tan et al. / PLoS ONE

    Researchers report that female Chinese fruit bats use oral sex to prolong the pleasure for their partners. The study suggests that there may be an evolutionary advantage to at least some types of kinky sex in the animal world. But can you imagine being the researcher with the job of watching bat porn?

  • Is the future trying to avert our doom?

    Image: LHC
    Martial Trezzini  /  AP

    Why did it take so long to get the world's most powerful particle-smasher up and running? Two scientists suggested it might be because the Large Hadron Collider was about to create phenomena so catastrophic that the future sent a cosmos-altering signal back in time to disrupt its operation. The research wasn't taken all that seriously when it came out, and since then the LHC was restarted without incident.

  • Octopus builds mobile home

    Image: Octopus
    R. Steene

    It sounds like a spin-off from "The Little Mermaid" or "Spongebob Squarepants": An octopus builds a mobile home under the sea by stacking up coconut shells. It moves in ... and then it carries the whole heap across the seafloor. "It was an extremely comical sight," said marine biologist Julian Finn, who spotted the behavior off the Indonesian coast. "I never laughed so hard underwater." Let's just hope those clever cephalopods don't develop opposable thumbs. That won't be such a laughing matter.

  • Researchers clone dogs that glow

    Image: Dog
    Seoul National University  /  AP

    Awww, how cute! South Korean scientists cloned a litter of genetically engineered dogs that glow red under ultraviolet light. Like an earlier experiment involving glowing cats, this isn't aimed at creating glow-in-the-dark pets. Rather, it's a proof of concept for procedures that could help develop treatments for genetic diseases in humans. If you can add the coding to make fluorescent protein, maybe you can add the coding to fix a genetic flaw.

  • Gay penguins make good dads

    Image: Penguins
    Focke Strangmann  /  AP

    German zookeepers in Bremerhaven had a problem on their hands when penguin parents rejected one of their eggs. To solve it, they placed the egg in a nest shared by two male penguins. The pair is one of three same-sex couples that have tried to mate at the zoo. The males incubated the egg for 30 days and continued to care for the chick after it hatched. Homosexual behavior has been documented in many animal species. "Sex and coupling in our world don't always have something to do with reproduction," the zoo said.

    Video:'s Dara Brown reports on the gay penguin parents.

  • Huge blob lies deep beneath Nevada

    Image: Crossing the Great Basin
    J.D. West / Silverheels Photography

    You wouldn't know it by driving through the Great Basin in Nevada, but researchers have detected a huge blob of highly compressed rock that is dripping like honey, extending from a depth of about 47 miles to at least 310 miles beneath the surface. The blob is 30 to 60 miles across, scientists say. But don't worry, Nevadans: This blob isn't expected to cause earthquakes - or rise up and destroy Las Vegas.

  • Nude 'Mona Lisa' surfaces

    Image: Mona Lisa
    Museo Ideale Leonardo Da Vinci

    Art historians have long suspected Leonardo da Vinci painted more than one version of his famous "Mona Lisa," and now a painting with much more Mona has surfaced. The painting, which portrays its subject nude from the waist up, had been hidden for almost a century within the wooden walls of a French cardinal's library. Experts are looking into whether this particular work, now on display in the Tuscan town of Vinci, was actually painted by the master.

  • Galileo's fingers and tooth found

    Image: Galileo's finger

    Was that any way to treat a genius? Back in 1737, Galileo Galilei's admirers removed three fingers, a vertebra and a tooth from the astronomer's body when his corpse was being moved to a new tomb. The vertebra and one of the fingers were recovered soon afterward, but the whereabouts of the tooth and the other two fingers were a mystery. Recently, however, the relics turned up in a container that was auctioned off to a private collector. Now the Galilean body parts, including the finger shown at right, will be put on display at the Museum of the History of Science in Florence.

  • Fragrances pay tribute to dead celebs' DNA

    Spotlight On Marilyn
    Hulton Archive  /  Getty Images file

    Let's get one thing straight: MyDNAFragrance's "Antiquity" line of perfumery will not make you smell like Marilyn Monroe did when she was alive, and certainly not like her mortal remains. Rather, the "Marilyn" fragrance is mixed up from ingredients that are coded to capture the "essence" of the movie star's mitochondrial DNA. Other scents pay tribute to Albert Einstein, Joan Crawford, Katharine Hepburn, Michael Jackson and Elvis Presley. The company behind the scents says the process is "very scientific," but others might well conclude that the whole exercise smells like a gimmick.

    Click here for the 2009 Weird Science Awards


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