Saturn's Smallest Moon Mimas Hides a Subterranean Ocean

The quest to find extra-terrestrial life in our solar system gains momentum as a distant space body shows potential habitability, with a 12 to 18-mile-deep body of water.

One of Saturn's moons, with a similar appearance to Star Wars Death Star due to its cratered exterior, harbors a subterranean ocean.

Analyzing data from the Cassini spacecraft, which circled Saturn between 2004 and 2017, researchers noted minor variations in the orbit of Mimas. Their findings were published in the journal Nature.

The patterns of its movement and rotation around Saturn indicate the presence of a nascent ocean within Mimas, one that is currently in a state of development.

“If you look at the surface of Mimas, there’s nothing that betrays a subsurface ocean. It’s the most unlikely candidate by far,” said Valery Lainey, an astronomer at the Observatoire de Paris in France.

Mimas is Saturn's smallest moon, with a radius of less than 123 miles (198 km). The team was surprised to find evidence of water beneath its icy surface, but continued studies of its orbit indicated the possibility of an ocean about 12 to 18 miles (20 to 30 km) deep.

According to the scientists' assessments, Mimas' ocean likely developed only in the last two to three million years.

Mimas' orbit is inside those of Saturn's larger satellites such as Enceladus and Titan.

Jupiter's moons Europa and Ganymede are among the bodies of the solar system that boast significant hidden water reserves, placing them among the prime contenders for hosting life within our solar system.

“The existence of a recently formed liquid water ocean makes Mimas a prime candidate for study for researchers investigating the origin of life,” said Nick Cooper, co-author of the study and researcher at the Astronomy Unit of the School of Physical and Chemical Sciences at Queen Mary University of London.

The red planet Mars is a prime location in the search for extra-terrestrial life due to its similarity to Earth.

But the Jupiter Icy Moons Explorer (JUICE) missionodies is embarking on such a task to see if those b could support life. After Cassini's mission around Saturn ended there were plans to send another spacecraft there, especially to explore Enceladus. But such a mission is unlikely to happen soon.