Latest international research: Astronomical evidence shows there may be an underground ocean on Mimas. Further studies of Mimas may provide a better understanding of how this icy world formed.
The ocean lies about 20-30 kilometers deep beneath the ice shell. simulations suggest that it emerged 25 million to 2 million years ago, so signs of this underground ocean have not had time to leave traces on the surface. The authors of the paper concluded that the results of this study indicate that recent processes on MimAs may be common in the early formation stages of other icy planets.