A recent study from the University of Oxford challenges the long-held theory that Earth's water was delivered by asteroid impacts. The research suggests that the building blocks of Earth contained sufficient hydrogen to produce water from the planet's formation.
The team analyzed a rare meteorite, LAR 12252, an enstatite chondrite with a composition similar to Earth's early building blocks (4.55 billion years ago). Using X-ray spectroscopy, they found hydrogen, in the form of hydrogen sulfide (H₂S), strongly bound to sulfur compounds within the meteorite's mineral structure. This suggests the hydrogen was original to the meteorite, not a result of contamination.
The findings indicate that Earth formed with enough internal hydrogen to generate its water. This implies that habitable planets may depend more on their initial formation material than on later asteroid impacts. The hydrogen content in enstatite chondrites like LAR 12252 offers an alternative explanation for Earth's water, potentially increasing the likelihood of finding liquid water, and thus life, on other planets.