Nasa has given details on how it hopes to find life on Jupiter's moon Europa in a mission launching in the 2020s that will seek to determine if the satellite is habitable.
It is thought that beneath Europa's icy surface there is an ocean sitting on a rocky bed punctured by hydrothermal vents that could circulate heat and nutrients.
"After five billion years with conditions like that, it could be a very habitable place," said Jim Green, director of NASA's planetary science division, at a news conference. "We believe the environment is just perfect for the potential development of life."
If life of any description is discovered, it will surely be the biggest news in our entire human history.
"If we do find life or indications of life that will be an enormous step forward in our understanding of our place in the universe," Green added. "If there's life in the solar system and in Europa in particular, it must be everywhere in our galaxy and perhaps even in the universe."
Hydrothermal vents on Earth are teaming with life, so there is certainly a chance that organisms of some kind persist on Europa's.
The spacecraft Nasa is creating for the mission will use nine different instruments to determine whether the moon is habitable, though it will have no "life detectors" as such, with 'life' as we define it being somewhat difficult to confirm with certainty given what an unknown quantity any extra-terrestrial creatures would be.