Evidence of Hydrothermal Activity on Enceladus, Hypotheses for Silica and Methane plumes Options

[stevesliva]

Enceladus May Harbor Hydrothermal Activity

Silica detected by the CDA doesn't have a plausible genesis other than water supersaturated with silica cooling.

Methane detected by INMS could be explained by methane being produced faster than it can be bound up in clathrates.

[TheAnt]

Hydrogen (1%) detected in plumes from Enceladus.
This show two things to us, one is that the water have contact with a rocky ocean floor, and that it's very likely to be ongoing hydrothermal activity.
Hydrogen could be an energy source powering secondary processes, then again, according to one hypothesis based on the orbits of Saturn's moons, Enceladus might be a rather young world of an age of about 100 million years.
Sky & Telescope have featured this also.

(Slight edit so one sentence make sense - hurray at least one!)