What I'm thinking is that it was a bolt of lightning that they picked up with their magnetometer, or else a stray radio transmission from earth bouncing off Enceladus' magnetic belt.
The cool thing is that this proves that there is an atmosphere there and there might exist some kind of microscopic life, or even more. Science shows how life can form at the bottom of the ocean or deep under ice or miles underground. If we find Life, in any form on another planet, it answers so many philosophical questions about what life is and how possible it could be somewhere else. I mean, this is SETI's biggest wet dream...a nearby planetoid that may have little amino acids and proteins scattered about? Wicked cool.
I really think that Jupiter, one day long after we are all dead, should be studied for raw materials. Robot probes zipping around, collecting space gold...that'd be killer if you could be a space Pirate