Question: How exactly did Enceladus create the E-ring?

Sheila Kanani answered on 13 Mar 2011:

Great question, so current too 🙂
Until we had the Cassini mission we didn’t know much about Enceladus, and we didn’t know about the E ring! Enceladus is covered in an ice crust and has a liquid water ocean underneath the ice. At the south pole of this moon there are great cracks in the surface of the crust, and through these crack the liquid water can escape.
The E ring is composed of microscopic (rather than macroscopic) particles. In 2005, the source of the E Ring’s material was determined to be mostly ice, with silicates, carbon dioxide and ammonia. Scientists realised that this material was coming from cryovolcanic plumes or the “tiger stripes” of the south polar region of Enceladus.
So Enceladus is continuosly spewing this material out into space and the material is collected up and orbits Saturn due to gravity. Imagine you are Saturn and you are holding a water balloon (Enceladus) with a hole in it, on a piece of string. Start to spin and the water balloon will spin around you. As the balloon goes around you it will release water in a ring formation (the E ring). Saturn is always spinning, Enceladus is always orbiting it, replenishing the E ring all the time, which is why the E ring exists.
This amazing photo shows Enceladus and the plume of material coming from the south pole, embedded in the E ring:
http://apod.nasa.gov/apod/ap070327.html