Where did the moon come from and how was it formed? It's a question scientists have been scratching their heads for decades.
According to the widely accepted "giant impact" hypothesis, the Moon formed billions of years ago when a planet the size of Mars called Theia collided with Earth, losing a large chunk in the collision.
Now, researchers from the University of New Mexico say in a new article published in Nature Geoscience to believe to have found the remains of Theia buried under the lunar surface.
There is a major drawback to the impact hypothesis (as discussed at length by numerous scientists over the course of many years). It is the fact that although the oxygen isotopes in moon rocks collected during NASA's Apollo missions look a lot like those found on Earth, they are strikingly different from those found on other objects in our Solar System.
So how could the Moon be largely made up of the remains of Theia, as many models have predicted?
Despite the very small odds, Terra and Theia may have originally had similar compositions, but were then mixed beyond recognition. A fascinating possibility that makes the study of the "moon planet" even more interesting. Yes, I know it is a satellite and not a planet, but I like hybridization.
In their research "space" , New Mexico scientists examined oxygen isotopes in a range of different types of lunar rocks, collected from a variety of altitudes. They found that the deeper the origin of the rock, the heavier the oxygen isotopes than those found on Earth.
Is a piece of Theia on the moon?
"Clearly, the distinct isotopic oxygen composition of Theia has not been completely lost with the homogenization due to the giant impact," the researchers wrote in their paper.
“These data suggest that the deep lunar mantle may have undergone less mixing. So physically represent the results of the impact of the moon planet with Theia "said the research scientist and co-author Zach Sharp in a note.
This means that the oxygen isotopes did not mix completely during Theia's impact with Earth. In conclusion, in short, the planet Theia may still have come from outside the Solar System before impacting Earth.