Evidence of Protoplanet Found On Moon

mrspoonsi (2955715) writes 'Researchers have found evidence of the world that crashed into the Earth billions of years ago to form the Moon. Analysis of lunar rock brought back by Apollo astronauts shows traces of the "planet" called Theia. The researchers claim that their discovery confirms the theory that the Moon was created by just such a cataclysmic collision. The accepted theory since the 1980s is that the Moon arose as a result of a collision between the Earth and Theia 4.5bn years ago. It is the simplest explanation, and fits in well with computer simulations. The main drawback with the theory is that no one had found any evidence of Theia in lunar rock samples. Earlier analyses had shown Moon rock to have originated entirely from the Earth whereas computer simulations had shown that the Moon ought to have been mostly derived from Theia. Now a more refined analysis of Moon rock has found evidence of material thought to have an alien origin.'

Comments

Skeptics

[Dan East]

And the rest of the article discusses the skepticism of this "evidence". To sum it all up, the evidence is the different ratios of oxygen isotopes found between 3 moon rocks and Earth. Most experts are saying the difference in the ratios should be much, much larger, because of how different the ratios of isotopes are in meteorites and other outer solar system bodies. The difference between the earth and moon is so small that other theories are just as likely for explaining it. The counter argument is that maybe all of the inner planets have the same ratios of oxygen isotopes as one another, and it was an inner planet that struck Earth and basically everything involved was made of the same stuff so the differences are small.

I think that until we have actually measured the ratios from Mecury or Venus, we can't assume that every inner planet is exactly the same in that regard, and thus the "evidence" this study has found is actual evidence one way or another. The only thing we know for certain is all the extraterrestrial material we have analyzed so far from the rest of the solar system has had very different ratios of the isotopes, and so this evidence requires a whole new theory about the homogeneousness of the solar system to be true.

Re:Skeptics

[C0R1D4N]

Considering the nature of the impact it is also possible that most of Theia is here on Earth under the Pacific or something while the moon is made up more of jettisoned Earth pieces. Or that the original Theia pieces make up the core/underground bits of the Moon with a tasty Earth frosting.

Re:Skeptics

[Charliemopps]

The impact simulations kind of rule that out. I'd say the sample size is a real issue though. Also, there are quite a few assumptions that I'd say are questionable. We've no idea where this protoplanet came from. It could have been from outside the solar system... or it could have been part of earth at one time, jettisoned in a previous impact and came back for revenge. The fact that we have as much information as we do blows my mind. Science is amazing.