Saturn’s moon could harbour alien life: Mimas may have a hidden ocean buried beneath almost 20 miles of ice, study finds

  • Mimas is a small moon with a crater so large it gives appearance of Death Star 
  • Astronomers say it could be hiding an ocean beneath its icy cratered surface 

One of Saturn‘s moons could be hiding an ocean beneath its icy cratered surface which may provide an abode for life, researchers suggest.

Mimas is a small moon but has a crater so large it gives the appearance of the Death Star space station from Star Wars.

Astronomers have long believed it has a solid core because nothing has been observed on the surface of the moon to indicate it has a subsurface ocean.

But a new study – made possible by data from a crashed spacecraft – suggests otherwise.

NASA‘s Cassini, a spacecraft sent to study Saturn, spent two decades in space which included tracking Mimas’ orbit.

Mimas is a small moon but has a crater so large it gives the appearance of the Death Star space station from Star Wars

Mimas is a small moon but has a crater so large it gives the appearance of the Death Star space station from Star Wars 

The spacecraft was destroyed in 2017 when it made a purposeful plunge into Saturn’s atmosphere.

But new analysis of its data indicates that Mimas’ position and orbit is best explained as being influenced by an internal ocean rather than having a solid core.

The researchers, from the Observatoire de Paris, calculate that the ocean lies beneath an icy shell approximately 20-30km deep, is less than 25 million years old and is still evolving.

The discovery, published in the journal Nature, is likely to trigger a ‘thorough examination’ of mid-sized icy moons throughout the Solar System.

In an accompanying comment piece Matija Ćuk, a research scientists at the SETI Institute in California, and Alyssa Rhoden, from the Southwest Research Institute in Colorado, said: ‘The detection of liquid water oceans under the icy surfaces of outer Solar System moons suggests that these moons could provide abodes for life under conditions that differ markedly from those on Earth.

One of Saturn 's moons could be hiding an ocean beneath its icy cratered surface which may provide an abode for life, researchers suggest

One of Saturn ‘s moons could be hiding an ocean beneath its icy cratered surface which may provide an abode for life, researchers suggest

‘There are many implications of Mimas being an ocean world. The idea that relatively small, icy moons can harbour young oceans is inspiring.

‘The findings will motivate a thorough examination of mid-sized icy moons throughout the Solar System.

‘The Solar System will always have surprises in store, and researchers must be open enough to new ideas and unexpected possibilities to recognise them.’

Dr Nick Cooper, honorary research fellow at Queen Mary University of London, said: ‘Mimas is a small moon, only about 400 kilometres in diameter, and its heavily cratered surface gave no hint of the hidden ocean beneath.

‘This discovery adds Mimas to an exclusive club of moons with internal oceans, including Enceladus and Europa, but with a unique difference: its ocean is remarkably young, estimated to be only five to 15 million years old.

‘The existence of a recently formed liquid water ocean makes Mimas a prime candidate for study, for researchers investigating the origin of life.’

SATURN: THE BASICS

Saturn is the sixth planet from the Sun and the second-largest planet in our solar system after Jupiter.

It is regarded as the ‘jewel of the solar system’ with its sunning rings.  

It is not the only planet to have rings but none are as spectacular or as complicated as Saturn’s.

Like Jupiter, Saturn is a massive ball made mostly of hydrogen and helium, with some heavy elements.

Its core stretches out to cover 60 per cent of the radius of the world.

It is similar to the rest of the planet, but made of a ‘slush’ like material of gasses, metallic fluids, rock and ice. 

The farthest planet from Earth discovered by the naked eye, Saturn has been known since ancient times. 

The planet is named for the Roman god of agriculture and wealth, who was also the father of Jupiter. 

While planet Saturn is an unlikely place for living things to take hold, the same is not true of some of its many moons.

Satellites like Enceladus and Titan, home to internal oceans, could possibly support life. 

Facts and figures 

Distance from Sun: 1.434 billion km

Orbital period: 29 years

Surface area: 42.7 billion km²

Radius: 58,232 km

Mass: 5.683 × 10^26 kg (95.16 M⊕)

Length of day: 0d 10h 42m

Moons: 82 with formal designations; innumerable additional moonlets