Nasa's Cassini space probe is about to search for signs of life on Enceladus – a tiny, ice-covered moon next to Saturn.
Just 310 miles in diameter, Enceladus is around a seventh of the size of Earth's moon, and is constantly ejecting a plume of icy spray from an ocean on its surface, making it possible for the Cassini space probe to work out its chemical composition without actually touching down.
On its most recent mission a month ago, Cassini identified the presence of water on Enceladus, which first shed light on the possibility of alien organisms thriving there. Check out this video Nasa created following the fly-by:
But this time, it will delve even deeper into the icy plume, giving it unprecedented insight into the chemical composition. It will come within 30 miles of the surface of the south polar region, where the spray is ejected through fractures on the moon's surface.
The US space agency isn't searching for actual aliens, but for the key signs the environment is habitable enough for them to survive. One of the key chemicals it will look for is hydrogen.
Curt Niebur, Cassini program scientist at Nasa's headquarters in Washington, said:
This incredible plunge through the Enceladus plume is an amazing opportunity for Nasa and its international partners on the Cassini mission to ask, “Can an icy ocean world host the ingredients for life?”