The Massive Mystery of Saturn’s Rings
Astronomers have produced the best measure yet of the planet’s signature bands.
Saturn has confounded scientists since Galileo, who found that the planet was “not alone,” as he put it. “I do not know what to say in a case so surprising, so unlooked-for, and so novel,” he wrote. He didn’t realize it then, but he had seen the planet’s rings, a cosmic garland of icy material.
From Earth, the rings look solid, but up close, they are translucent bands made of countless particles, mostly ice, some rock. Some are no larger than a grain of sugar, others as enormous as mountains. Around and around they go, held in place by a delicate balance between Saturn’s gravity and their orbiting speed, which pulls them
