A team of researchers at the University of Oxford have uncovered crucial evidence for the origin of water on Earth. Using a rare type of meteorite, known as an enstatite chondrite, which has a composition analogous to that of the early Earth (4.55 billion years ago), they have found a source of hydrogen which would have been critical for the formation of water molecules. Crucially, they demonstrated that the hydrogen present in this material was intrinsic, and not from contamination. This suggests that the material which our planet was built from was far richer in hydrogen than previously thought. The findings, which support the theory that the formation of habitable conditions on Earth did not rely on asteroids hitting Earth, have been published in the journal Icarus.