Space & Astronomy

Evidence of proto-planet 'Theia' found deep inside Earth's mantle

By T.K. Randall
November 2, 2023

Image: Earth Cutaway
Credit: CharlesC / CC BY-SA 3.0 (adapted) While the exact circumstances that brought about the formation of the Moon have long been debated, today most scientists tend to subscribe to a theory known as the Giant Impact Hypothesis which suggests that the Moon formed from the debris created by a cataclysmic impact between the early Earth and a proto-planet named Theia approximately 4.5 billion years ago.

Definitively proving that this happened, however, has long proven a challenge because nobody has been able to find any direct evidence that Theia ever actually existed.

Now, though, that could be set to change thanks to a new study of two mysterious 'blobs' of material previously discovered at the bottom of the Earth's mantle near the core.

These 'blobs' are much hotter and denser than the surrounding material and for years scientists have been left scratching their heads over how they came to be there.The answer, it turns out, might just kill two birds with one stone.

According to CalTech geodynamics researcher and study lead author Qian Yuan, these 'blobs' may in fact be the evidence of Theia that scientists have been searching for.

"Simulations of the Giant Impact suggest that at least some intact pieces of Theia's mantle may have persisted in the Earth's mantle throughout Earth's history," the study authors wrote.

While the research doesn't prove the hypothesis outright, it does add significant credence to the idea that the Moon really did form from what was left behind after Theia collided with the Earth.

Evidence of this mysterious proto-planet, it seems, may have been right beneath our feet all along.

Source: CBS News

Tags: Moon, Theia, Earth