What was the name of the planet that collied with earth that ultimately crated the Moon?

Answer 1

Bearing in mind that this is a theory, that there is no certain proof that a planet the size of Mars or so collided with the infant Earth to create the Moon, the proposed name for this hypothetical planet is Theia.

Based on very limited information - moon rocks collected by six Apollo missions, and not much else - the currently accepted theory of the origin of the Moon is that a planet (perhaps the size of Mars) which had perhaps formed near the Earth or at least near its orbit, finally collided with it. The impact reshaped the Earth, may have caused its spin, and possibly caused Earth's 23.5 degree axial tilt. The planet, named "Theia", may have merged with the Earth (or parts may have ricocheted away) and substantial portions of the Earth's crust were blasted back into space. Over millions of years, the debris and rocks left over from the remains of Theia and the matter blasted away from Earth into space coalesced to form the Moon.

Did this really happen? Good question! The math seems to work out, and the lunar samples seem to indicate that moon rocks were at one time Earth rocks; or at least, they came from the same source. Of course, it was about 4 BILLION years ago, and both the Earth and the Moon have been steadily bombarded by other meteors all the years since.

Answer 2

The Earth, very early in it's formation collided with a Mars sized planet called Theia.

Answer 3

That planet, or more aptly "planetoid" has been named Theia.

Answer 4

Luna (the Moon).