For years, scientists believed that the Moon came into existence when a big object called Theia crashed into Earth a very long time ago, around 4.5 billion years ago.
This huge collision broke off a lot of debris from Earth, and all that debris eventually came together to create our Moon. This is the theory many scientists believe in, but not everyone agrees with it.
Now, a group of scientists from the China Academy of Sciences says they’ve found new proof that this theory might be right. They think that larger pieces of Theia might have gotten stuck deep inside Earth, which could be real evidence of that ancient crash, reported Futurism.
Analysis of two large low-velocity provinces (LLVPs)
The scientists studied two big lumps of matter called “large low-velocity provinces (LLVPs)” hidden deep under Africa and the Pacific Ocean. In a recent report published in the journal Nature, they used complicated computer simulations to assess where these lumps might have originated from.
When they simulated a big object like Theia hitting Earth, they determined that it would have melted the upper part of Earth’s mantle. This would have allowed about ten percent of the object to penetrate into the Earth, close to its core.
Afterfwards, these lumps would have been mixed up and become bigger because of the movement of hot material inside the Earth, which we call convection currents. That’s how the two LLVPs came to be.
A study in @Nature suggests that a giant collision between the ancient protoplanet Theia and the proto-Earth about 4.5 billion years ago may have formed distinct regions within Earth’s mantle. https://t.co/lW9Cg0hWb3 pic.twitter.com/yWta3FnIKa
— Nature Portfolio (@NaturePortfolio) November 1, 2023
Before, other simulations showed that only a tiny bit of Theia had melted into Earth. However, this new study suggests that a much larger part of Theia, about ten percent of it, got stuck inside our planet. This makes up around two to three percent of all the matter of which Earth is comprised.
The scientist leading the study, Qian Yuan, who works at Caltech, says that in most simulations of the Moon’s formation, the Moon’s materials mostly come from the thing that hit Earth.
Hence, in the future, when we send missions to the Moon, we can collect rocks from the mantle and compare them to the mantle blobs deep within Earth. If they have the same chemical stuff, it could support this new theory, as reported by Science Alert.
Unsure how much Theia pieces mixed up with Earth’s mantle
While the scientists’ idea is interesting, not all fellow researchers are completely convinced that the two LLVPs are mainly leftovers from the collision that happened 4.5 billion years ago.
Robin Canup, who studies planets and works at the Southwest Research Institute in Boulder, Colorado, believe the scientists’ discoveries are “exciting and provocative.” Nonetheless, she also said it’s still a puzzle how those supposed Theia pieces didn’t get all mixed up with Earth’s mantle over the next 4.5 billion years.
Maxim Ballmer, who works at the University College London, said that he doesn’t think all the material from the impactor would be completely mixed up, but he believes this study might not have considered just how much mixing happened.