Enceladus is the 6th largest of Saturn’s Moons. Given the number of orbiting objects around Saturn, including the ring system, determining the true number of moons proves difficult. There are currently 62 orbiting satellites around Saturn but only 13 of them have a diameter larger than 50 km (~30 miles)
Enceladus is of a particular interest because when Voyager 1 first reached Saturn, very little was known about many of its moons. What was discovered were giant geysers that erupted into space nearly 300 miles from the surface! These geysers were measured later by the Cassini spacecraft to contain mostly water vapor as well as molecular nitrogen, methane, and carbon dioxide.
So far only the moons, Io, Triton, and Enceladus have been observed that have active eruptions.
Enceladus continues to be a focus for Astronomers as perhaps underneath the miles of thick ice, liquid water most likely exists. As shown by the diagram, this is what scientists believe is going on under the thick ice surface of Enceladus.