Using the Magnetospheric Imaging Instrument NASA's Cassini spacecraft scientists have been able to produce the best observations of the magnetic field of Saturn. From these observations you are able to clearly see the plasma and radiation belts (the bit us radio astronomers are interested in). Like in the case of Jupiter it is one of the planet's moons that produce a main source of the plasma in the ring current (in the case of Jupiter this is Io) - for Saturn this comes from the gas vented by geysers on the moon Enceladus.
This is an artist's concept of the Saturnian plasma it shows Saturn's embedded "ring current," an invisible ring of energetic ions trapped in the planet's magnetic field. Credit: NASA/JPL/JHUAPL
