With a diameter of 1,123 kilometres, Dione is the 15th largest moon in the solar system. It takes this moon 2.7 Earth days to complete a full orbit around the ringed planet, at a distance of around 377,400km. Mysterious craters and a wispy surface have led scientists to ponder whether there could be an ocean underneath Dione’s surface. Because the back side of Dione is more heavily cratered than the front, it’s also thought that a collision may have spun the moon around 180 degrees!