We keep finding life on Earth in more and more surprising and hostile environments but it remains the case that no matter where it emerges life seems to require at least three things; certain essential chemicals, an energy source and a liquid. 

In the case of life on Earth that liquid is water but could another liquid work as well?

What about Methane? Well it just so happens that there are methane lakes on Titan.

So could Saturn’s largest Moon harbour life, but not as we know it Jim?

Dr Nick Lane is Professor of Evolutionary Biochemistry in the Department of Genetics, Evolution and Environment at University College London