Dione may not be as famous as Titan or Enceladus, but this Saturnian moon is quietly fascinating. Beneath its icy surface lie strange wispy terrains and ancient scars from unknown forces.

In order of how much water each world has, from the least to the most, the wettest are: Enceladus, Dione, Earth, Europa, Pluto, Triton, Callisto, Titan, and Ganymede. Mimas, a moon of Saturn ...