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.

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.

Experts from the University of Oxford now think that the rocky material which built our planet had the elements it needed to make water without any help.