spacetoday.net: New rings, moons found around Uranus

Posted: Fri, Dec 23, 2005, 10:31 AM ET (1531 GMT)
Uranus ring discovery (STScI)

Astronomers have discovered a pair of new rings and accompanying moons that they believe constitutes a second ring system for the distant planet. Using the Hubble Space Telescope, astronomers detected the rings in 2004 and confirmed their presence in images from Hubble earlier this year; they were later able to detect them in a reexamination of Voyager 2 images taken when the spacecraft flew past the planet in 1986, as well as in recent Keck Observatory images from Earth. One of the new rings shares its orbit with Mab, a newly-discovered moon 20 kilometers across. The moon may supply material for the ring when collisions knock dust from its surface. Both rings are much farther from the set of nine rings previously known to orbit the planet.