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.

The chemical composition of a meteorite that was built much like early Earth shows evidence of ample hydrogen necessary to form water.

Researchers say they discovered evidence that early Earth was home to more hydrogen than previously thought, calling into question widely held beliefs about the origins of water and the planet’s evolution.