Scientists discover remains of a ‘buried planet’ deep within the Earth

A new study of metal ore deep within the moon provides new evidence that Earth’s natural satellite was formed by an ancient planet that crashed into Earth long ago.

This long-theorized interplanetary collision – which scientists believe took place around 4.5 billion years ago – saw a Mars-sized planet called ‘Theia’ slice itself into hot lava fragments as it hit Earth.

Although some of Theia’s planetary remains appear to be buried as dense and massive ‘blobs’ deep beneath Africa and the Pacific tectonic plates, scientists said evidence for where the rest of Theia went after this crash had remained elusive.

But now new data from NASAThe Gravity Recovery and Interior Laboratory (GRAIL) spacecraft has found large tell-tale deposits of titanium-iron ore deep beneath the moon’s surface, indicating that Theia’s other remains did indeed form Earth’s moon.

Beneath the moon’s crust, in the region between the crust and core known as the mantle, NASA’s GRAIL craft discovered two dense areas (pictured above) that correspond to the titanium and iron ‘ilmenite’ deposits that would exist if the ‘planet Theia’ impacted. theory turns out to be correct

Planetary geophysicist, Adrian Broquet from the German Aerospace Center in Berlin called NASA’s GRAIL findings nothing short of “mesmerizing.”

His team’s new paper, published in April in Natural Geosciencestargeting “gravitational anomalies” deep beneath the moon’s surface: dense, heavy particles of matter identified by the GRAIL spacecraft’s sensors.

“By analyzing these variations in the moon’s gravitational field, we were able to look beneath the moon’s surface and see what lies beneath it,” Broquet said.

Beneath the moon’s crust, in the region between the crust and the core known as the mantle, the GRAIL craft discovered two dense areas that correspond to the titanium and iron ‘ilmenite’ deposits said to exist if the Theia impact theory were correct.

After Theia’s likely collision with Earth, and after fragments of this lost planet were buried deep beneath the Earth’s crust, molten lava pools of heavy titanium and iron on the moon’s surface began to sink deeper into the core, lifting lighter rocks pushed.

“Our moon literally turned itself inside out,” says Broquet’s co-author, Jeff Andrews-Hanna, a geophysicist at the University of Arizona’s Lunar and Planetary Laboratory.

Computer modeling by their colleague Nan Zhang of Beijing University in Beijing provided the original framework for their theory that titanium-rich material would exist deep within the moon due to the moon’s origins as pieces of the planet Theia.

“When we saw those model predictions,” Andrews-Hanna said, “it was like a light bulb went off.”

“We see exactly the same pattern when we look at subtle variations in the moon’s gravitational field,” he said, “revealing a network of dense material lurking beneath the crust.”

Back on earth, Two similarly dense and unusual regions at the base of our planet’s mantle – known as Large Low Velocity Provinces (LLVPs) – have also lent credence to the theory that an interplanetary ‘Theia’ collision created our moon.

One LLVP is beneath the African tectonic plate and the other beneath the Pacific tectonic plate, as measured by seismic equipment similar to that used to detect earthquakes.

Their existence was established when geologists discovered that seismic waves slowed down dramatically at a depth of 2,900 km in the two regions, which differed from other parts of the Earth.

Scientists have found new evidence that the moon was formed during a giant impact between Earth and a Mars-sized protoplanet called Theia 4.5 billion years ago. This also buried remnants of Theia deep in the Earth’s mantle (pictured after the collision)

After running a series of simulations, Professor Hongping Deng found that after the moon-forming impact, a significant amount of material from the Theian mantle – about two percent of Earth’s mass – entered the lower mantle (shown in orange in the artist’s impression above)

Scientists believe the material in these LLVPs is between 2 and 3.5 percent denser than Earth’s surrounding mantle.

Last year, researchers led by the California Institute of Technology came up with the idea that these LLVPs might have evolved from a small amount of Theian material that entered the lower mantle of ancient Earth.

To substantiate this, they asked Professor Hongping Deng of the Shanghai Astronomical Observatory to investigate this idea using his pioneering methods in computational fluid dynamics.

After running a series of simulations, Professor Deng discovered that after the moon-forming impact, a significant amount of ‘Theian’ material – about two percent of Earth’s mass – would have entered the lower mantle of the ancient planet Earth.

‘Through accurate analysis of a wider range of rock samples, combined with more refined giant impact models and Earth evolution models, we can infer the material composition and orbital dynamics of the primordial Earth, ‘Gaia’ and ‘Theia’,’ said Deng’s researcher. co-author Qian Yuan, a geophysicist from CalTech who also worked on this project.

Deng and Yuan’s team published their research in the journal Nature late last year.

Broquet said he hopes that future NASA missions to the moon, such as those planned for the Artemis program, will be able to make similar seismic measurements: first-of-their-kind seismic data from the moon to better confirm the Theia collision theory .

“Future missions, such as with a seismic network, would allow better investigation of the geometry of these structures,” he said.