There's a subsurface ocean deep within Dione, one of Saturn's moons, says data from the Cassini mission.
In a study published in the journal Geophysical Research Letters, researchers from the Royal Observatory of Belgium detailed that, for gravity data acquired from recent flybys carried out by the Cassini spacecraft to make sense, Dione will have to have a crust floating atop an ocean situated 62 miles from the moon's surface and wrapping around a massive rocky core.
It has been established that Saturn's other moons, Enceladus and Titan, have oceans beneath their icy crusts and this new study is suggesting Dione could also be an ocean world.
"A future orbiter hopping around Saturn's moons could test this prediction," said Antony Trinh, a co-author for the study.
Ocean worlds are icy planets or moons with subsurface oceans. So far, there are three orbiting Jupiter, three for Saturn, and Pluto also holds the possibility of being an ocean world.
According to the researchers, the subsurface ocean in Dione has probably existed as long as the moon so it offers a long-lived zone habitable for microbial life. Attilio Rivoldini, also a co-athor for the study, adds that contact between Dione's ocean and rocky core is crucial, pointing out that rock-water interactions offer not only key nutrients but also an energy source, which are both needed to start life.
In August, NASA revealed that the Cassini spacecraft was able to detect a canyon network flooded with liquid hydrocarbons for the first time in Titan. The discovery was based on data gathered by the mission during a flyby in 2013. During this event, Cassini's radar instruments were focused on channels branching out from the Ligeia Mare, the large northern sea on Titan.
These branching channels appeared dark on radar images, similar to how seas rich in methane on Titan looked, and this led scientists to believe that they contain liquid as well. There was the chance at first that the dark material could just be saturated sediment but further analysis using Cassini's radar showed that scientists are indeed looking at fluid-filled channels.
In July, another study revealed that a chemical trail has been discovered on Titan, indicating the high plausibility that the Saturn moon could harbor alien life. in fact, it's possible that prebiotic conditions may already be in place, thanks to the hydrogen cyanide produced when sunlight hits Titan's dense and toxic atmosphere.
As an organic chemical, hydrogen cyanide can react with itself or with other molecules, forming long chains called polymers in the process.
