Listen: Was Earth's Oldest Rock Found on the Moon?
"Today's episode is brought to you by listerine ready tabs small discrete tabs, the transform from a solid to a liquid just to switch and swallow no sink required to get that just brushed clean feeling, and they pack a huge punch up to four hours of fresh breath, and the confidence that goes with it on the go wherever life takes you to a surprise meeting a date you want to freshen up for or just from one event to another try listen ready tabs today. Find them near the mouthwash. Welcome to brain stuff from how stuff works. Hey, brain stuff, Lauren Bogle bomb here on February six nineteen seventy-one. Be late astronaut Alan Shepard the commander of NASA's. Apollo fourteen mission was taking a walk on the moon. He and fellow space traveler, Edgar Mitchell were out gathering rocks around a depression called cone crater to quote shepherd himself. Many of these were hand sized grab samples, but the pair took home some larger mementos to one basketball sized rock collected by Shepard earned itself. A nickname big Bertha officially known as lunar sample one four three two one big Bertha weighs about nineteen pounds. That's nine kilograms making it the largest rock that Apollo fourteen brought back to earth and the third largest collected by any of the Apollo missions. Although shepherd found big Bertha on the moon that may not be where it story began. The rock is a Brescia a hodgepodge of geologic fragments called clasps which are held together by cement like mix. A newly published hype. Office says that part of big Bertha formed billions of years ago right here on planet earth. In fact, despite the lunar connection this could represent the oldest earth rock ever discovered. Big Bertha's origins were the focus of a study that was published in January in the journal earth and planetary science letters the paper's authors include an international team of geo. Scientists who looked the moon rocks procured by Apollo fourteen including lunar sample, one four three two one for the most part the classes on this famous Brescia are dark gray. But there's also a lightly colored one that catches the eye. It's made a fell site a kind of all Cannock rock that contains the minerals feld Spar end quartz. The light grade class which is two centimeters that's point seven inches across is loaded with tiny zircon crystals as well many cons contain vital information about what the environment was like when and where they formed close inspection of zircon and big Bertha's light. Patch showed that the crystals were produced by cool oxygen, rich magma. Yet molten rock of the sort doesn't exist anywhere near the moon's surface defined some you'd need to travel more than one hundred miles. That's one hundred sixty two kilometers below the surface of the moon where Shepard and Mitchell found big Bertha. So how did these cons and the class? They belong to end up on the surface of violent impact was probably involved when a meteorite or asteroids smacks into a planet or moon, it can transport material that's buried deep under the crest up to the surface. And as noted earlier big Bertha was found near an impact crater. So case closed, right? Well, maybe not cone crater and expanse measuring about two hundred and fifty feet that seventy six meters. Deep and a thousand feet or three hundred and four meters wide was created roughly twenty six million years ago. Scientists thinks that the violent episode that left this depression behind would have failed to dredge up geologic material lying more than forty five miles or seventy two kilometers underneath the moon. A big Bertha's fell site classed. Could have originated deepen a lunar magma pocket. But it doesn't seem likely. The study authors think different scenario is way, more plausible around twelve miles or nineteen kilometers blow planet earth surface. There's a supply of cool oxidized magma. This is exactly the kind of raw material that probably made his cons on big Bertha's light patch. And by the way, they're con crystals. Have a helpful habit of preserving uranium isotopes? Those can be used for radio metric dating a process that tells us the fell site classed is four point zero to four point one billion years old, but both of these clues together and a potential timeline of events emerges. According to the policies championed in the study, some of that cool oxidized magma lying deep under earth's continental crust hardened into this class between four point zero and four point one billion years ago. We know that our planet was besieged by meteorites in those days a process that by the way created a lot of old Granitz. Repeat impacts would have driven the class ever closer to the surface until finally a projectile hit the earth with enough force to launch the fell site clear out into space. It's estimated that four billion years ago. Our moon was around three times closer to earth than it is right now, the far flung class might have bridged the gap and settled on the moon, but around that time meteorites from space also harassed the moon and approximately three point nine billion years ago. One of these impacts could partially melted. The class and driven it under the lunar surface where it merged with other classes and became part of Brescia then twenty six million years ago, the asteroid strike that gave birth to the cone crater could set big Bertha free propelling it to the spot where Alan shepherd came and grabbed it up one historic day in nineteen seventy-one if the fell site class really did have terrestrial origin. Then ironically enough, it might be the oldest known rock from planet earth. There's a four point zero three billion year. Old rock from Canada's Northwest. Territories that's comparable in age and over in Quebec, the greenstone belt is at least three point nine billion years old out in the Jack hills of Western Australia. Scientists have located circum- that formed roughly four point three seven billion years ago, but these crystals seemingly detached from their original rocks at some point big Bertha's fell site, classed and zircon seemed to have formed simultaneously. This episode was written by Mark van Cini and produced by Tyler clang for I heart media, and how stuff works for more on this and lots of other far flung topics. Visit our home planet. Testif- works dot com. This is April and Cassidy, we're the host of the podcast dressed the history of fashion and this season, we traveled throughout history and around the world to bring you more of the fascinating stories from behind the clothes. We wear we traveled a central Asia tiller all about the resist dyeing technique known as e Kat and to Paris to learn all about the legacy of Christian Dior. We also spore the history of a whole host of topics from plus size fashion or the clothing choices of colts listening to subscribe on apple podcasts or the iheartradio app or wherever else you get your podcast."