What is the Moon-Earth collision theory ?

Question

What is the Moon-Earth collision theory ?
2 people in my restauraunt were discussing is , when I went to ask what it is they had left.

Answer 1

The Earth and Moon will never collide. The moon is actually moving farther away and as the Earth slows and it's gravitation weakens, the moon will move farther and farther away. I don't think the moon will be free before the sun becomes a red giant and consumes the inner 3 planets though. The origin of the moon is that a planet about the size of mars collided with a "proto earth" and ejected enough matter to form the moon. The moon was hot and molten at the time and had volcanoes whose lava formed the "seas" on the moon.

Answer 2

This theory (which is believed to be the most likely out of the four theories) is that which a meteor struck the Earth, and all the debris that was dislodged eventually came together through gravity to become the moon.

Another theory states that the moon and Earth were formed simultaneously as the gasses floating through the Solar system formed the planets we all know and love today (except you, Pluto. You suck.), a third theory states that Luna was a small planetoid that got caught in Earth's gravitational field as it was passing, and I forget what the fourth theory states actually. lol

Answer 3

http://en.wikipedia.org/wiki/Giant_impact_hypothesis

it may be that these two were discussing to the giant impact hypothesis. it states that another body about the size of mars formed orbiting the sun at a point trailing earth by 60º. this is one of the five places where the gravitational attractions of earth and sun are equal. about twenty to thirty million years later, this other body caught-up with earth, and the two collided and merged, but the impact threw some material into orbit as a ring. the moon may have formed from this ring of material in as little as one year.

Answer 4

This actually refers to a collision between the early earth and another planet the size of Mars. Huge amounts of debris were thrown into orbit that gradually coalesced to form the moon.