Researchers theorize that the Moon formed when a protoplanet, called Theia, struck Earth billions of years ago. They also say the alien planet's remains are hiding deep within Earth's mantle.
Researchers with Arizona State University's (ASU) School of Earth and Space Exploration published a paper titled "Giant Impact Origin For The Large Low Shear Velocity Provinces," which says mysterious continent-sized formations are hiding under the Pacific Ocean and Africa, are, in fact, remnants of Theia.
The impact, approximately 4.5 billion years ago, is thought to have transformed Earth's surface into a sea of magma and may be responsible for ejecting enough planetary debris to create the Moon.
Qian Yuan, the lead researcher behind the new report, studies geodynamics at ASU, explained that "the left-over Theia mantle materials may have sunk to the bottom of Earth's mantle and caused the Large Low Shear Velocity Provinces (LLSVPs)."
Yuan told Bussiness Insider the collision preserved parts of Theia's mantel in the Earth's mantel - this could only be due to the alien planet's mantel is denser.
He said those pieces are "millions of times larger than Mount Everest in terms of volume."
Researchers said the LLSVPs are 1.5% and 3.5% denser 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 chunks of Earth's crust sank into the mantle and joined them, contributing to the blobs' growth over time, Yuan said.
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.
But scientists have figured out that plumes of hot rock and magma from some Icelandic and Samoan volcanoes came from these blobs. By analyzing this magma's makeup, researchers can glean insight into the composition of these mysterious buried chunks. According to a 2019 study, some elements in the volcanic plumes date back to about 4.5 billion years ago — when Theia supposedly hit Earth. - Bussiness Insider
Yuan's findings will soon be published in the journal Geophysical Research Letters. The research may finally offer some proof of the LLSVPs that lurk deep within the Earth and the Moon's formation.
Read the report here: