Galileo mistook Saturn's strange markings for a pair of moons. Other early astronomers thought the planet spat out giant clouds of vaporous breath that clung close by; still others suggested that Saturn was shaped like an egg and that two black blotches on its surface made it look like a double-handled cup.
It was Christiaan Huygens who first realized that Saturn's odd "appendages" might in fact be a ring, which he supposed was a solid, shiny strip. Still cautious about this conclusion, however, he hedged his bets by publishing his idea in the form of an anagram. At the end of his 1656 pamphlet announcing his discovery of Saturn's moon Titan, Huygens added a coded message that, unscrambled, read: "It is surrounded by a thin flat ring, nowhere touching, and inclined to the ecliptic." Not until the end of the nineteenth century did James Clerk Maxwell correctly suggest that a solid ring would shatter under the gravitational strains of orbit; he concluded that the ring must consist of a dense collection of countless separate small particles, all orbiting Saturn the way the planets orbit the sun.
Today the sprawling, sparkling Saturnian rings continue to surprise astronomers lured into their beguiling maze. During the past ten years, for example, many scientists have been forced to abandon the long- established notion that the rings of Saturn are as ancient and enduring as the solar system itself. It now appears that the rings could not have formed along with the planet 4.5 billion years ago. Rather, they are a recent addition no more than 100 million years old. Furthermore, the same processes that created them are already sowing the seeds of their destruction. This makes the rings a passing fancy that will disappear before the next 100 million years go by. In all likelihood Saturn has fathered several generations of rings over the course of its lifetime.
Once considered unique, Saturn's rings now represent merely the most spectacular specimens of a cosmic species known to circle every giant world--from Jupiter's diffuse, dusty halo to the narrow, dark hoops of Uranus to the demi-rings that appear to trace a line of dashes around Neptune. The presence of so many different systems suggests that rings sprout as a normal part of a giant planet's life cycle.
"I'm interested in all the ring systems," says Jeffrey Cuzzi of NASA's Ames Research Center in Mountain View, California, who was drawn to his work by the confounding beauty of Saturn's rings. "I like to think of them as a family. Everybody is an individual, yet because of the resemblances, you can understand each one better by knowing something about the others."
