Boulby mine: Underground life gives alien clues
7 August 2013 Last updated at 00:15 BST
Learning whether extraterrestrial life exists is one of the biggest challenges of science - but now Boulby mine in the north east of England could hold the key.
Researchers believe studying the tiny organisms that live there could help them to understand whether life could thrive beyond the Earth.
Professor Charles Cockell, from the UK Centre for Astrobiology at the University of Edinburgh, explains why he has taken his research deep underground.