Four propeller-shaped gaps in one of Saturn's main rings are the latest evidence that a shattered moon produced the planet's dazzling hoops. The discovery supports the theory that a comet or asteroid struck a large, icy Saturn moon about 100 million years ago and that the distributed debris formed rings. They cover a region broader than the distance between the Earth and its moon.
Note: To comment, Science News subscribing members must now establish a separate login relationship with Disqus. Click the Disqus icon below, enter your e-mail and click “forgot password” to reset your password. You may also log into Disqus using Facebook, Twitter or Google.