Oceans Everywhere?

Scientists using Cassini data see similarities between Saturn's moons Enceladus and Dione.  They see similar ridge structures on both worlds, and while Dione lacks the dramatic geysers of Enceladus, Cassini has detected wisps coming out of Dione.  So, they're wondering-- if Enceladus has an ocean of water inside its ice shell, might Dione?

Indeed, some are beginning to speculate that subsurface water oceans may be common features of small worlds in the outer Solar System-- from some of the moons of the giant planets to Pluto to even the giant asteroid Ceres.