New Evidence That the Moon Was Created In a Massive Collision 155
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."
Re:Doesn't anyone think... (Score:4, Informative)
A mars size rock hits the earth, that would create enough heat to melt the rocks and send them into space as a big liquid ball. Those crazy astronauts that play with their drinks show in microgravity that liquid will prefer to be in a sphere shape. So a chunk of liquid rock the size of the moon over Thousands/Millions of years of slowly cooling down would take the shape of a sphere.
Now the moon isn't a perfect sphere, that is because it is spinning while it was cooling and those other gravitational forces shifting it, and once an awhile getting pounded by some other rocks.
Sorry was that a troll?
Re:Old news? (Score:5, Informative)
You insensitive clod! The invisible pink unicorn is a demon implanted into the minds of credulous cretins by the Flying Spaghetti Monster to test our faith! Obviously the FSM, his spaghetiness be praised, was the one who created the moon by spontaneously generating a meatball and applying his large-body creation sauce to it. o one listen to parent - he is a deluded fool.
Re:Doesn't anyone think... (Score:5, Informative)
You can read about the reason for the moon's spherical shape here:
http://en.wikipedia.org/wiki/Hydrostatic_equilibrium#Planetary_geology [wikipedia.org]
It's fairly straightforward, nothing at all like Quantum mechanics.
Re:Further, I'd suggest... (Score:3, Informative)
Pangaea, Pangæa, or Pangea (play /pænËdÊ'iËÉ(TM)/ pan-JEE-É(TM);[1]) was a supercontinent that existed during the late Paleozoic and early Mesozoic eras, forming about 300 million years ago[2] and beginning to rift around 200 million years ago
The Moon is thought to have formed nearly 4.5 billion years ago, not long after the Earth.
Re:Size of Earth? (Score:5, Informative)
Considering it took a Mars-sized object to cause the collision event, and that a pretty substantial amount of mass would have been blasted away at escape velocity, I'm not sure the veracity of your math.
Of course, you might be roughly right, but probably not for the reasons I think you're implying...
Re:Doesn't anyone think... (Score:5, Informative)
I suppose you're a troll as well, but to hell with it, I'll bite.
Any celestial body large enough to have a sizable gravity (I am sure there's a threshold formula somewhere, but CBA to check) will take, in time, a spherical shape because of... GRAVITY! (applause in the background)
http://www.pa.msu.edu/sciencet/ask_st/031198.html [msu.edu]