Nasa has announced the discovery of a global ocean beneath the surface of one of Saturn’s moons, giving rise to the possibility that it may host extraterrestrial life.

The agency has announced that, using visual imagery of the moon, that can confirm there is an ocean beneath the surface.

In 2005 the Cassini orbiter - a combined effort between Nasa, the European Space Agency and the Italian Space Agency - spotted plumes of water vapour escaping from cracks in Enceladus’s moon, and since then the agency has been working to discover more about the moon and the potential for life within.

Flybys by the Cassini mission spotted that the moon has a slight wobble, and after years of analysis of this the team has determined that the magnitude of this wobble “can only be accounted for if its outer ice shell is not frozen solid to its interior, meaning a global ocean must be present,” Nasa says.

And the presence of water gives hope that there may be life present.

"If the surface and core were rigidly connected, the core would provide so much dead weight the wobble would be far smaller than we observe it to be," said Matthew Tiscareno, a Cassini participating scientist at the SETI Institute, Mountain View, California, and a co-author of the paper which announces the findings.

"This proves that there must be a global layer of liquid separating the surface from the core," he said.

Space commentator Leo Enright spoke with Newstalk Breakfast this morning and told Ivan: “Where there is water there may be life.

“If there is water it’s warm enough, it’s not frozen.

The discovery is “very exciting news,” Leo told us.

Image: A global ocean is now believed to be under the surface of Saturn's moon Enceladus (Credit: NASA)

What keeps the ocean from freezing “remains a mystery,” Nasa says, with one suggestion being that the gravitational pull could be creating tidal forces that generate a lot more heat on the moon than was previously thought.

Cassini is due to make another flyby on October 28, going as close as 30 miles above the moon’s surface – its deepest ever dive into the moons active plumes of icy material.

Leo also discussed Elon Musk’s plans to nuke Mars, and how people misunderstood them, and a school project across Ireland that will have seen Irish schoolkids eagerly checking in on the effects of the Chilean earthquake this morning.

Listen: Life on a moon of Saturn?