Panspermia is the idea that asteroids seed life through space Stocktrek Images, Inc. / Alamy Stock Photo

Life finds a way – perhaps even across the stars. It may be possible for organisms to travel all over the galaxy by hitching a ride on a fast-moving rock in a phenomenon called galactic panspermia. In this way, just a few inhabited worlds could spread life throughout the Milky Way.

In October 2017, astronomers spotted the first interstellar object we have ever seen come through our solar system, called ‘Oumuamua. That was the first concrete proof that rocks can be tossed out …