New Rings around Uranus

[Drew]

NASA's Hubble Discovers New Rings and Moons Around Uranus

NASA's Hubble Space Telescope photographed a new pair of rings around Uranus and two new, small moons orbiting the planet.

The largest ring is twice the diameter of the planet's previously known rings. The rings are so far from the planet, they are being called Uranus' "second ring system." One of the new moons shares its orbit with one of the rings. Analysis of the Hubble data also reveals the orbits of Uranus' family of inner moons have changed significantly over the past decade.

"The detection of these new interacting rings and moons will help us better understand how planetary systems are formed and sustained, which is of key importance to NASA's scientific exploration goals," said Dr. Jennifer Wiseman, program scientist for Hubble at NASA Headquarters.

Since dust orbiting Uranus is expected to be depleted by spiraling away, the planet's rings must be continually replenished with fresh material. "The new discoveries demonstrate that Uranus has a youthful and dynamic system of rings and moons," said Mark Showalter of the SETI Institute, Mountainview, California.

Showalter and Jack Lissauer of NASA's Ames Research Center, Moffet Field, Calif., propose that the outermost ring is replenished by a 12-mile-wide newly discovered moon, named Mab, which they first observed using Hubble in 2003.

Meteoroid impacts continually blast dust off the surface of Mab. The dust then spreads out into a ring around Uranus. Mab's ring receives a fresh infusion of dust from each impact. Nature keeps the ring supplied with new dust while older dust spirals away or bangs back into the moon.



http://www.nasa.gov/home/hqnews/2005/de ... pdate.html

[Khaizerex]

This is really interesting stuff. Since nobody had too much information on Uranus except for what they previously analyze from the data. I'm amazed though that they haven't found the second ring system until now. Seems like that should've happened many years ago.

Analysis of the Hubble data also reveals the orbits of Uranus' family of inner moons have changed significantly over the past decade.

Not sure what this could mean, but possibly that the inner moons are headed right toward the planet. That'd be my guess, I think they'll eventually plummet and crash into the planet. But then again, since Uranus is gaseous, I wouldn't presume to know what would happen when that does happen.