Gerber Blueberry Buckle?

Despite being the star closer and better known, the origin of the Moon is one of the most controversial issues, with several theories that try to explain.

The model of the Great Crash, is currently the most accepted theory of lunar formation.

Any theory that explains the existence of the Moon, of course, must explain the following facts:

1. The low density of the Moon (3.3 g / cc) shows no core important iron like Earth.
2. Moon rocks contain few volatile substances (eg water), which implies that the lunar surface had a "baked" additional to that of Earth.
3. The relative abundance of oxygen isotopes in the Earth and Moon are identical, suggesting that the Earth and the Moon formed at the same distance from the sun.
4. The Moon is about 4 000 500 million years, a hundred million years younger than the Earth and other Solar System.

There are several theories about the formation of the moon.

Fission Theory:

This theory proposes that the Moon was once part of the Earth and somehow separated at the beginning of the Solar System. If Earth had rotated enough fast, could have lost to the moon on its surface, and that would explain why the composition of the Moon is similar to the mantle of our planet and not the core.

primitive Earth would separate rapidly rotating material of Ecuador, the future moon.

However, there is evidence it should be noted that initial rapid rotation, and this is not true.

This theory does not explain the "cooking" additional lunar materials.

The capture theory:

This theory proposes that the moon formed elsewhere in the Solar System, and was later captured by the gravitational field of Earth. The different chemical composition makes this possible, but against this that the catch in the orbit that is currently highly unlikely.

Nor has an explanation for the "cooking."

Condensation Theory:

This theory proposes that the Moon and the Earth condensed from the same nebula that formed the solar system, and when condensed, it became a rotating around each other. However, if well formed, should have the same composition and structure (iron core) also does not explain the "cooking."

The Great Collision Theory

This is currently the most accepted theory, with a Mars-sized object colliding with Earth, at the time that they were packing. This material ripped from the mantle, many return to Earth, and the larger piece to the moon formed. Computer simulations

put this scenario as entirely possible, as you can see in the video below.

You can see that as the collision is "side", most of Earth's core remains intact. This makes the composition of the Moon is more similar to Earth's mantle, and in fact has almost the same density and chemical composition.

The current orbit is compatible with this event, and also explains the "cooking" additional lunar materials. It also explains why the materials of the moon is a hundred million years younger.

Just this theory has its problems, for example, the Moon should be built with materials from the proto-Earth mixed with material from the impactor. However, the amount of oxygen is almost equal to that of Earth.