Scientists speculate that asteroids colliding with Earth delivered water—an essential building block of life—but new research suggests the planet didn't need the delivery.

All that said, the findings can’t confirm the terrestrial life theory beyond a doubt. There’s still a chance hydrogen-heavy meteorites helped us along. Still, the new evidence makes a strong case that ancient Earth had the ability to form water all on its own—no space rocks needed.

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.