Marble

Marble is a water moon with what seems to be half of its oceans frozen.

Marble is one of, most likely many, moons of a Saturn like gas giant called Glumo, and has a orbit that doesn't go with the ring like other moons do, which might suggest that Marble was caught by Glumo.

It most likely has an atmosphere.

It might have life if it's not too cold. It appears in the ksp 2 trailer.