Traditionally, giant space rocks colliding with Earth are seen as a bad thing for life. That's certainly true now, but the primordial Earth of 3 billion years ago was a different place. A team from Harvard University studying an ancient impact known as S2 has discovered evidence the event may have given life a leg up.

The space rock that slammed into Earth 66 million years ago at the end of the Cretaceous Period caused a global calamity that doomed the dinosaurs and many other life forms. But that was far from the largest meteorite to strike our planet.

Some billions of years ago, Earth was a very different place. Long before life appeared on Earth, countless meteorites rained down on it. One such impact, known as the S2 event, occurred about 3.26 billion years ago and has left behind a trail of clues about our planet’s early history.