Giant impact theory for formation of Moon garners more evidence

Analysis of lunar rocks brought back by the Apollo missions shows they have heavier forms of zinc - a telltale sign of the impact billions of years ago.

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Although it's rather obvious that the GIT is really the only feasible and realistic model of the formation of the Moon that we currently have it's good to see its evidence base expanding. Further confirmation of it all should make Dawn's visit to Ceres in a few years time all the more interesting as we'll get the chance to view the type of celestial object responsible for such an impact.

...so, I've read the article.
I wouldn't mind finding the original source though, which I'm assuming has or will be published in a reputable journal somewhere.

isn't it equally conceivable that the concentration of zinc could be due to meteoric impact, rather than necessarily stemming from the "collision of a Mars-sized object with an early-earth"? That would seem vastly more likely to me.

I can't imagine a Mars-sized object colliding with earth without significant impact (uh... figuratively, not literally) upon the earth, its orbit and trajectory, and yet we simply don't see that...

not least of all the fact that the moon simply doesn't seem to fit the necessary criteria to be a product of this planet in geological terms, zinc or no zinc.

reply to post by Awen24


Consider that we've no evidence of what Earth's orbital placement was pre-impact.

Earth's orbit may have been closer to, or further from the sun before the impact. The orbit may have been more or less erratic above/below the ecliptic, and/or with a deeper or more shallow orbit around the sun.

Further, there's been 4.5 Billions of years for Earth's orbit to stabilize from the the event such that modern humans have only been around a mere dust speck of time to observe Earth's transit around the sun to any accuracy.

Originally posted by Awen24
...so, I've read the article.
I wouldn't mind finding the original source though, which I'm assuming has or will be published in a reputable journal somewhere.

isn't it equally conceivable that the concentration of zinc could be due to meteoric impact, rather than necessarily stemming from the "collision of a Mars-sized object with an early-earth"? That would seem vastly more likely to me.

I can't imagine a Mars-sized object colliding with earth without significant impact (uh... figuratively, not literally) upon the earth, its orbit and trajectory, and yet we simply don't see that...

not least of all the fact that the moon simply doesn't seem to fit the necessary criteria to be a product of this planet in geological terms, zinc or no zinc.

edit on 17-10-2012 by Awen24 because: (no reason given)

What criteria does it not fit? It is already scientifically proven that the composition of rocks on the moon is identical to that on Earth. The only logical reason for that is they both share the same origins. Your post really shows a lack of understanding of what happened.

So if you find that a sample has the same oxygen isotope composition as one from Earth, then it’s very likely the sample came from our world.

Previous research has established that the oxygen isotope composition of lunar samples is indistinguishable from that of Earth.

www.wired.com...

However, a comparative analysis of titanium from the moon, Earth and meteorites, indicates the moon's material came exclusively from Earth.

news.discovery.com...

It is as close to 100% as you can get the Moon comes from Earth. The problem is we should see a mixture of Earth and Theia isotopes, and we don't. So the question is not where did the Moon come from, it's proven it's from Earth. It is how did it get there if there was no impact. We don't know, perhaps a glancing blow rather than an impact. If there was an impact why does the moon only have Earth material? It shouldn't.