Most of Earth's water was likely present before the moon-forming giant impact

Most of Earth's water was likely present before the moon-forming giant impact Based on an extensive collection of lunar and terrestrial samples, a new study probing the elusive origins of the moon -- now typically thought to have formed from a collision between a proto-Earth and a solid impactor -- supports theories of a collision with extremely high energy. So high, in fact, that it resulted in nearly complete mixing of materials between the impactor and proto-Earth. https://ift.tt/eA8V8J