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 Mars-sized planet called Theia collided with Earth, losing a large chunk in the crash.
Now, researchers at the University of New Mexico say in a new paper published in Nature Geoscience to believe to have found the remains of Theia buried under the lunar surface.
There is one major drawback to the impact hypothesis (as discussed at length by numerous scientists over many years). It's the fact that even though oxygen isotopes in lunar rocks collected during NASA's Apollo missions closely resemble 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 very small odds, Earth and Theia may have originally had similar compositions, but then became mixed beyond recognition. A fascinating possibility that makes the study of the "moon planet" even more interesting. Yes, I know it's 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, compared to those found on Earth.
Is a piece of Theia on the moon?
“Clearly, Theia's distinct oxygen isotopic composition was not completely lost with homogenization due to the giant impact,” the researchers wrote in their paper.
“These data suggest that the deep lunar mantle may have undergone minor mixing. Therefore physically represent the results of the impact of the planet moon 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 could still come from outside the Solar System before impacting Earth.
