New Evidence That the Moon Was Created In a Massive Collision

derekmead writes "New evidence that the giant impact hypothesis is correct: A paper published today in Nature shares findings of a chemical analysis of Moon rocks that shows fractional differences between the makeup of the Earth and Moon that most likely were caused by the collision between Earth and a Mars-sized planet around 4.5 billion years ago. Although the two are quite similar, it's been previously shown that Moon rocks lack volatile elements, which suggests they may have evaporated during the incredibly intense heat and pressure created during an impact event. But if the hypothesis that light elements actually evaporated from Moon rocks during their formation is correct, you'd expect to find evidence of elements being layered by mass — heavier elements would condense first, and so on. That process is known as isotopic fractionation — a concept central to carbon dating — and the Washington University team's results suggest they found exactly that (abstract). They compared the blend of zinc isotopes in Moon rocks and Earth samples, and found that the Moon rocks held slightly higher proportions of heavier zinc isotopes. If the Moon was indeed once part of Earth — which has been shown by extensive modeling (PDF) — the difference in the balance of zinc profiles would most likely be explained by lighter zinc isotopes evaporating away following a collision."

Comments

Re:Old news?

[Kittenman]

Who DOESNT think the moon was caused by a collision, outside of a few Creationists?

Tut. Look back at the past. I used to be a lot more into astronomy than I am now, and back in the 70s/80s, the thought that the moon was caused by a collision was not laughable, but looked at askance. One thought was that if there was a helluva collision, why wasn't the rest of the planet shattered into fragments (much like the poor chaps in the gap between Mars and Jupiter...). I took the "both formed together, dual planet" thesis as the latest there was 'til I read Bill Bryson (god help me...) in his book "A short history of nearly everything", or some such title.

Every theory is blindingly obvious and unquestionable, 'til someone proves it isn't. T. H. Huxley read Darwin's "Origin of Species" and thought it stupid of him (Huxley) not to have thought of it. Same here ..