Name: Earth contains buried chunks of an alien world that are 'millions of times larger than Mount Everest,' research suggests
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Earth contains buried chunks of an alien world that are 'millions of times larger than Mount Everest,' research suggests

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Two crossed lines that form an 'X'. It indicates a way to close an interaction, or dismiss a notification.An icon in the shape of a person's head and shoulders. It often indicates a user profile.Redeem nowGet the latest on the culture &amp; business of sustainability — delivered weekly to your inbox.Something is loading.If you were to peer deep under Earth's crust, you'd spot two giant blobs of rock cupping the planet's core like a pair of hands.The source of these mysterious continent-sized formations — one under the Pacific Ocean, the other under Africa —has baffled geologists for four decades. that the massive rocks are fragments of tectonic plates that got trapped under their counterparts.But according to , their origin may be otherworldly.A group of scientists from Arizona State University suggested the blobs are remnants of a "Mars-sized planetary embryo" named Theia, which struck Earth in its infancy 4.5 billion years ago. The impact is thought to have turned Earth's surface into a sea of fiery magma and caused it to shoot out enough planetary debris to create the moon.&nbsp;Qian Yuan, the lead researcher behind the findings, studies geodynamics at ASU. He thinks that following the ancient collision, parts of Theia may have sunk and gotten preserved deep in our planet's mantle — the semisolid layer between Earth's crust and core, he said.Those pieces are "millions of times larger than Mount Everest in terms of volume," Yuan told Insider.&nbsp;Geologists discovered these chunks — their technical name is large low-shear-velocity provinces — by sending seismic waves down into the planet. Under both Africa and the Pacific Ocean, the speed of these seismic waves slowed to a crawl, suggesting an area of rock denser than its surroundings. The animation below, based on a , shows the size of these areas.According to Yuan, these blobs are between 1.5 and 3.5% more dense than the rest of Earth's mantle, and hotter.If the planet Theia was rich in iron and highly dense, Yuan's models showed, any pieces of it that broke off when it hit Earth would have sunk deep into our planet's mantle. There, they could have accumulated undisturbed, rather than getting mixed into the rest of the mantle.It's also possible denser sank into the mantle and joined them, contributing to the blobs' growth over time, Yuan said.&nbsp;Figuring out what these slabs are made of is challenging. Their deepest parts are 1,800 miles under our feet, in the part of the mantle closest to Earth's outer core. They're 621 miles (1,000 kilometers) high and two to three times wider than they are tall.&nbsp;But scientists have figured out that plumes of hot rock and magma from some Icelandic and Samoan volcanoes . By analyzing this magma's makeup, researchers can glean insight into the composition of these mysterious buried chunks. According to a , some elements in the volcanic plumes date back to about 4.5 billion years ago — when Theia supposedly hit Earth.The idea that the impact between a tiny planet and Earth helped form the moon has been around for . But a problem with that hypothesis is that scientists haven't found any evidence of Theia's existence. suggested that's because Earth's and Theia's cores fused together. Another idea, posits that when the planets collided, both were "almost completely vaporized," Yuan said. According to that thinking, Earth became a rapidly spinning mass of molten and vaporized rock called a synestia, then . Part of that spinning mass became the moon, and Theia was no more.A third theory — called the "hit-and-run," according to Yuan — is that Theia just glanced off Earth, and chunks of one planet, or pieces from both, combined to form the moon. But the moon's composition matches Earth's almost exactly, which suggests it contains very little of Theia.Yuan's new findings, which will soon be published in the journal Geophysical Research Letters, may finally offer proof that Theia was in our solar system billions of years ago.Sign up for notifications from Insider! Stay up to date with what you want to know.Subscribe to push notificationsAn icon in the shape of a lightning bolt.Keep readingTwo crossed lines that form an 'X'. It indicates a way to close an interaction, or dismiss a notification.

Two crossed lines that form an 'X'. It indicates a way to close an interaction, or dismiss a notification.An icon in the shape of a person's head and shoulders. It often indicates a user profile.Redeem nowGet the latest on the culture &amp; business of sustainability — delivered weekly to your inbox.Something is loading.If you were to peer deep under Earth's crust, you'd spot two giant blobs of rock cupping the planet's core like a pair of hands.The source of these mysterious continent-sized formations — one under the Pacific Ocean, the other under Africa —has baffled geologists for four...

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Aylin Woodward

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Earth contains buried chunks of an alien world that are 'millions of times larger than Mount Everest,' research suggests

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