Cassini Data Aiding Theories on Origin Of Saturn's Rings

摘要

Oddly shaped gaps found in Saturn's rings hint at the existence of long-sought "moonlets" and support the theory that the rings are the broken remains of an icy moon shattered long ago in a violent collision, according to scientists who have been studying data gathered by NASA's Cassini spacecraft in orbit around Saturn. Scientists think a comet or asteroid collided with one of Saturn's moons about 100 million years ago. Such an impact would have created debris in a range of sizes, but until now, scientists only had evidence for chunks of rock that were kilometers in diameter and smaller particles that were about 20 kilometers across or less. The medium-sized moonlets — so named because their size would be between that of a moon and smaller particles — predicted by theory were missing.