That is No House Station | by Brian Koberlein

NASA/JPL

Mimas is a small moon of Saturn, about 400 km in diameter. It’s floor is dominated by Herschel crater, which supplies the moon a passing resemblance to a fictional area station. Because of this it’s typically utilized in memes and jokes, however Mimas is definitely an attention-grabbing puzzle.

Mimas has a really low density, not a lot increased than water. It will appear that Mimas consists virtually totally of water ice. It’s fairly near Saturn, orbiting simply outdoors the planet’s rings. So shut that it’s tidally locked with Saturn, in order that just one facet faces the planet. It additionally appears to be totally frozen strong. There is no such thing as a proof of any geyser exercise, and its floor is closely cratered not like different moons like Enceladus. And therein lies the thriller.

Enceladus is extra distant from Saturn, however does exhibit geysers and ice flows. Thus Enceladus maintains liquid water in its mantle. That is regarded as resulting from tidal heating, the place Saturn’s gravity stretches and compresses the moon barely, which retains it heat. This impact is much like squeezing a lump of clay in your arms, which causes it to get heat. Mimas is nearer to Saturn, and its orbit is extra elliptical. Mimas can also be oblate (it’s wider at its equator than it’s from pole to pole), so it ought to expertise tidal heating much more than Enceladus.

So why is it frozen strong? We aren’t positive. In truth some have known as this puzzle the Mimas check, since any mannequin that may clarify the liquid water in Enceladus should additionally clarify why Mimas is frozen strong.