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General Astronomy/Formation of the Moon

< General Astronomy

One theory is that the Moon came from the Earth. It is theorized that a Mars sized object struck the Earth tossing huge amount of the mantle up into space. While much of this fell back to Earth some of the matter collected together and formed the Moon. This theory is supported by evidence that the Moon has the same composition of Earth's mantle and the same three isotopes of oxygen that Earth has.