Astronomers at the Royal Observatory of Belgium have come to the conclusion that a subsurface ocean may be hiding under the Saturn moon, Dione. After Titan and Enceladus, Dione is the third of the gas giant’s moon which has now become a possible birthing place for extraterrestrial life.
In the past years, only by analyzing our solar system, we began noticing that liquid water, considered essential for the emergence of life (at least from a human point of view) was not as rare as we thought it to be. We know Mars itself has running water, and, more recently, even the one-time planet Pluto was shown to have water ice on its surface. Chances are there’s a lot more of it in the Universe than we had originally thought.
But what about these cold dark moons, so far away from the Sun’s habitable zone and so close to the dominion of the gas giants? It seems that just as the Sun gives enough warmth to make Earth (and possibly Mars, either in the past or more likely, in the future) habitable, it is these gas giants and their monstrous gravitational pull that provides friction. In turn, the friction provides heat, which helps maintain water liquid on frozen worlds like Jupiter’s Europa.
As for Dione, scientists from the Royal Observatory of Belgium have used data made available by NASA’s Cassini space probe. Their research detected certain gravitational anomalies, that, when accounted for along other features of the celestial body, led them to the conclusion that there might be an ocean hidden under its surface.
Enceladus, the other Saturn moon with a subsurface ocean, has also been studied by the Royal Observatory. Here, the Cassini probe was able to detect the moon’s libration, from which the scientists concluded that the planet’s ocean is much closer to its surface.
As for the possibility of life, scientists say that it depends on the rock-water interaction that takes place on the bottoms of these cold worlds. Only so would sufficient nutrients and sources of energy would form, in order to sustain even the tiniest microorganisms. And since Dione’s ocean is probably as old as the moon itself, the chances that some forms of aquatic life have already sprung there are pretty high.
Image source: Wikipedia