Most of what we know about Saturn comes from close-range rendezvous with the planet using spacecraft. The first man-made object to visit Saturn was the Pioneer 11 in 1979, followed by the Voyager 1 and 2. Right now, the Cassini spacecraft is heading toward Saturn and will arrive in 2004.
One of the most odd and puzzling discoveries of Saturn's rings is the radial spokes as first confirmed by the Voyager (first seen by amateur astronomers). The spokes represent the spokes on a wheel, but are much less uniform and for the most part, temporary. It seems that they are composed of the same material as Saturn's rings and are the result of electrostatic and magnetic activity, in conjunction with the planet's magnetic field. They are found in the B-ring of Saturn and seem to constantly form and dissipate. The true nature of this phenomenon still remains a mystery.