What would life on other planets look like? Forget the little green men, alien life is likely to be completely unrecognisable - we haven't even discovered all the life on our own planet.This visionary book offers some of the most radical but scientifically accurate thinking on the possibility of life on other planets ever conceived. Using broad principles of Earthly biology and expanding on them laterally, Cohen and Stewart examine what could be out there.Redefining our whole concept of what 'life' is, they ask whether aliens could live on the surface of a star, in the vacuum of space or beneath the ice of a frozen moon. And whether life could exist without carbon or DNA - or even without matter at all. They also look at 'celebrity aliens' from books and films - most of which are biologically impossible. Jack Cohen is an 'alien consultant' to many writers, advising what an alien could and couldn't look like. (E.T. go home - you do not pass the test).But this book is as much about the latest discoveries in Earthly biology as well as life on other planets. It's a serious yet entertaining science book, as you'd expect from the bestselling authors of The Science of Discworld.