Was the Moon-Forming Protoplanet 'Theia' a Neighbor of Earth? (mps.mpg.de) 21
Theia crashed into earth and formed the moon, the theory goes. But then where did Theia come from? The lead author on a new study says "The most convincing scenario is that most of the building blocks of Earth and Theia originated in the inner Solar System. Earth and Theia are likely to have been neighbors."
Though Theia was completely destroyed in the collision, scientists from the Max Planck Institute for Solar System Research led a team that was able to measure the ratio of tell-tale isotopes in Earth and Moon rocks, Euronews explains: The research team used rocks collected on Earth and samples brought back from the lunar surface by Apollo astronauts to examine their isotopes. These isotopes act like chemical fingerprints. Scientists already knew that Earth and Moon rocks are almost identical in their metal isotope ratios. That similarity, however, has made it hard to learn much about Theia, because it has been difficult to separate material from early Earth and material from the impactor.
The new research attempts a kind of planetary reverse engineering. By examining isotopes of iron, chromium, zirconium and molybdenum, the team modelled hundreds of possible scenarios for the early Earth and Theia, testing which combinations could produce the isotope signatures seen today. Because materials closer to the Sun formed under different temperatures and conditions than those further out, those isotopes exist in slightly different patterns in different regions of the Solar System.
By comparing these patterns, researchers concluded that Theia most likely originated in the inner Solar System, even closer to the Sun than the early Earth.
The team published their findings in the journal Science. Its title? "The Moon-forming impactor Theia originated from the inner Solar System."
Though Theia was completely destroyed in the collision, scientists from the Max Planck Institute for Solar System Research led a team that was able to measure the ratio of tell-tale isotopes in Earth and Moon rocks, Euronews explains: The research team used rocks collected on Earth and samples brought back from the lunar surface by Apollo astronauts to examine their isotopes. These isotopes act like chemical fingerprints. Scientists already knew that Earth and Moon rocks are almost identical in their metal isotope ratios. That similarity, however, has made it hard to learn much about Theia, because it has been difficult to separate material from early Earth and material from the impactor.
The new research attempts a kind of planetary reverse engineering. By examining isotopes of iron, chromium, zirconium and molybdenum, the team modelled hundreds of possible scenarios for the early Earth and Theia, testing which combinations could produce the isotope signatures seen today. Because materials closer to the Sun formed under different temperatures and conditions than those further out, those isotopes exist in slightly different patterns in different regions of the Solar System.
By comparing these patterns, researchers concluded that Theia most likely originated in the inner Solar System, even closer to the Sun than the early Earth.
The team published their findings in the journal Science. Its title? "The Moon-forming impactor Theia originated from the inner Solar System."
The Earth may have moved into Theia's orbit (Score:2)
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Re: The Earth may have moved into Theia's orbit (Score:2)
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Oh boy this takes ancestor-guilt to the next level. Like shit, great great great great grandpa (of every race btw) held slaves .. that was bad.. but now you're telling me his great great great great^10 grandpa crashed into a whole fucking planet?
Re: The Earth may have moved into Theia's orbit (Score:2)
It would have been quite spectacular to watch the collision.
Re:The Earth may have moved into Theia's orbit (Score:5, Funny)
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I know you posted that tongue in cheek but the answer is no.
Or more specifically, not unless the explosion was powerful enough to throw that piece of Alderaan into our universe from a parallel one where our laws of physics don't apply (and FTL travel is possible), and parsec is a unit of time. (And events can be retroactively change to determine such pesky details as who shot first...)
Re: The Earth may have moved into Theia's orbit (Score:2)
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That happened in a galaxy far, far away. No way it could make it this far.
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The universe becomes kind of staid when you're practically immortal. ... the Doctor spend most of his time wooing British women.
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That happened in a galaxy far, far away. No way it could make it this far.
Another documentary, Space 1999, would strongly disagree with this assertion. Space might be big, but the moon can be launched away from Earth via nuclear explosions so fast that it will come across an intelligent species every week!
Theia ?? The research team just making up crap (Score:3)
Nice. Exactly what I always thought. (Score:2)
Of course it's nice to see the argument made with substantiation. That's far beyond my ability. But right from the first time I heard the moon origin hypothesis I imagined two rocky planets drifting into each other when clearing their orbits.
The only other thing that seemed plausible was a strike from a rogue planet from somewhere else, but that's just so spectacularly unlikely I never gave it much credence.
*shrug* So, yeah. The thing that seems intuitively right turns out likely to be true. Not a revelatio
In same orbit? (Score:2)
I thought there was an explanation that Theia formed in the same orbit as Earth, each at a Trojan point with the other. This is unstable and eventually they crashed into each other. Is this now considered impossible?