What life might be like in alien oceans.
Recent discoveries have led astrobiologists to think that moons are the most promising places for alien
life to exist in our Solar System. And now several major space missions are being planned over the next
decade to search for hints of life there.
Unlike our neighbouring planets, some of the moons have plenty of liquid water. Jupiter’s moon, Europa,
for example, is thought to contain more liquid water than all of Earth's oceans combined. This water –
and any life in it – is protected from space radiation and asteroid impacts by a thick layer of kilometersdeep surface ice.
The discovery of plumes of water shooting up from Saturn’s moon Enceladus and Europa have suggested
they could have warm interiors that can support liquid oceans, heated not by the Sun, but by an internal
dynamo powered by radioactive decay in their cores or by tidal heating generated by the gravitational
attraction of the planets that they orbit.
There is now evidence for water oceans on several moons, including Europa, Enceladus, Callisto and
Ganymede. One study published this June estimates that the Enceladus ocean is around one billion years
old. Others have suggested it may be billions of years old – plenty of time for life to evolve.
Adapted from: http://www.bbc.com/future/story/20190926-what-life-might-be-like-in-the-alien-oceans