Slices of space rock reveal watery secrets

摘要

SOME meteorites that fell to Earth relatively recently may have contained liquid water within the past million years. This means space rocks might have delivered water to our planet's surface throughout its history rather than just early on.Many scientists suspect that meteorites once brought water to Earth. But previous analysis of the rocks suggests chemical reactions inside them involving liquid water ceased billions of years ago. So there was a question mark over whether they lost their water long ago.