A moon of Saturn that looks suspiciously like Star Wars' The Death Star holds a secret – and it's not the Galactic Empire's favorite space weapon of world destruction.
Mimas, one of the planet's 146 moons, most likely harbors an ocean beneath its icy shell, according to new evidence recently published in the journal Nature.
Although previous research has suggested that the small moon might have water beneath its dull surface, the study, led by astronomer Valéry Lainey of the Paris Observatory, presents the most compelling case yet, contradicting other theories that its interior is solid. This makes Mimas the ninth place in the solar system thought to have soft seas – counting Earth among the lot, of course.
“The existence of a recently formed ocean of liquid water makes Mimas a prime candidate for researchers studying the origin of life,” said Nick Cooper, co-author of the study from Queen's University. Mary of London. in a report.
Galaxy's water worlds could be 100 times more common than previously thought
The tweet may have been deleted
For life to emerge – at least the kind we know of – three key ingredients are needed, according to NASA: energy, organic molecules and water. Mimas is only the latest born a growing list of ocean worlds in the vicinity of the sun. Others include Saturn's moons Titan and Enceladus; Jupiter's moons Europa, Ganymede and Callisto; Triton, Neptune's moon; and Pluto.
The Mimas Ocean surprises many astronomers because it lacks external signs: it has no fractures on the surface, nor geysers spewing water, like Enceladus and Europa, nor a thick atmosphere, like Titan, Lainey said during the study. an interview broadcast live by the SETI Institute this week.
That makes it “one of the most unlikely places” an astronomer could think of to find liquid water — at least at first glance, he said.
Crushable speed of light
“It looks like a cold, very rigid satellite,” he said. “You could say 'boring'.”
NOW the 250 mile wide moon could give astronomers new insight into the earliest, primitive phases of ocean worlds. While Earth's seas are about 4 billion years old — meaning they've been around almost since the planet's formation — Mimas' water might be only 5 to 15 million years old.
“It looks like a cold and very rigid satellite. You could say 'boring'.”
The research team was able to estimate this age using previous data from the Cassini spacecraft on the Moon's tidal interactions with Saturn. The NASA probe explored Saturn and its moons between 2004 and 2017. Importantly, by observing oscillations and slight changes in the moon's orbit, scientists were able to conclude the existence of a hidden ocean.
This information also helped them estimate its depth. Lainey's team combined Cassini's observations with computer simulations to determine that an ocean must lie about 12 to 18 miles beneath the crust.
Mimas is “one of the most unlikely places” an astronomer could think of to find liquid water, at least at first glance, said French astronomer Valéry Lainey.
Credit: NASA/JPL/Space Science Institute
During the SETI Institute interview, the French astronomer explained why there would then be no trace of water in the gigantic Mimas ship. Herschel Craterits most defining and “Death Star”-like feature.
On the one hand, the crater is shallower than the sea. But there is another reason.
“It is also clear that Herschel Crater arrived well before the ocean itself,” Lainey said.