What ingredients are needed for life beyond Earth?
Nasa believes one of Saturn's moons, known as Enceladus, may now be the single best place to look for life beyond Earth.
The discovery was made through Nasa's Cassini probe, which flew close enough to examine the icy moon.
Maggie Aderin-Pocock, space scientist and researcher at University College London, tells Radio 4's Today the moon has the "three key ingredients for life to exist," we just need to find out if it actually does.