It also stretched scientific credulity that the interior of a moon as small as Mimas could be warm enough for an ocean to remain unfrozen.
“I was saying Mimas can’t have an ocean, but what I was really saying was, for Mimas to have an ocean would really challenge our intuition about Mimas.
The suggestion of a Mimas ocean comes from measurements by NASA’s Cassini spacecraft, which orbited Saturn from 2004 to 2017.Mimas’s orbit is tidally locked with Saturn: The same side of the moon always faces the ringed planet, just as we on Earth see only one side of Earth’s moon.
That suggested either the core of Mimas was stretched out in the direction of Saturn or there was an ocean.
“There isn’t anything about Mimas’s surface that says ‘ocean’ or ‘high heat flow,’ unlike Enceladus.”