This spectacular false color Voyager 2 close-up image of Saturn's ring system was taken with three separate filtersultraviolet, blue, and greenon August 23, 1981, from a range of 3 million km. The resulting combined image shows that the C ring, which appears slightly blue, and the B ring, which has a yellow tint, could have different trace element compositions from each other.
Source: NASA JPL, Frequently Asked Questions about Saturn's Rings, Image ID: saturn32.gif
"Spokes" are strange dark radial features as long as 20,000 km that move in curious patterns on the B ring. The spokes have been observed on both sides of the ring plane, and are thought to be microscopic grains that have become electrically charged and are floating above and below the ring plane. Since the spokes rotate at the same rate as Saturn's magnetic field, it is thought that interactions between these hypothesized charged grains and the magnetic field of the planet cause the observed motion.
Source: NASA JPL, Frequently Asked Questions about Saturn's Rings, Image ID: saturn20.gif
This drawing shows a comparison of the four known planetary ring systems, indicated here by solid circles, plus their associated satellites in a view that has been scaled to a common planetary equatorial radius. The density of cross-hatching suggests the relative optical depths of different ring components. Synchronous orbit is indicated by a dashed line; the fluid tidal breakup (Roche) limit for a density of 1000 kg/cubic meter is indicated by a dot-dashed line.
Source: National Academy of Sciences, An Integrated Strategy for the Planetary Sciences, 19952010, Image ID: Figure 4.5