Could the Earth have been seeded with life ...

... from other planets? Quite possibly.

The new research suggests that microbes from other planetary systems, if they existed, could very well have hitched a ride in such rocks – as long as the rocks were large enough to protect the organisms from cosmic rays and the heat of impact. If the Sun was born in a cluster, there would have been time for around 100 life-bearing rocks to be captured by our star before the cluster drifted apart, the researchers say.