New ring discovered around Saturn Options

[alan]

The newly discovered ring spans from 128 to 207 times the radius of Saturn – or farther – and is 2.4 million kilometres thick. It was found using NASA's Spitzer Space Telescope, which revealed an infrared glow thought to come from sun-warmed dust in a tenuous ring.

The discovery was announced on Tuesday at a meeting of the American Astronomical Society's Division of Planetary Sciences in Fajardo, Puerto Rico. "This is a unique planetary ring system, because it's the largest planetary ring in the solar system," team leader Anne Verbiscer of the University of Virginia in Charlottesville told the meeting.

The source of the ring's material seems to be Saturn's far-flung moon Phoebe, which orbits the planet at an average distance of 215 times the radius of Saturn. When Phoebe is hit by wayward space rocks, the impacts could generate debris that fills the rings.

http://www.newscientist.com/article/dn1792...und-saturn.html

[volcanopele]

not necessarily. As I pointed out before, for example, Janus and Epimetheus have a similar dust ring at their orbits made of micrometeorite ejecta and they have a prograde orbits around Saturn.

And adding to my list of "Moons with rings at their orbits", I should have also added Pan and Atlas.

[Gsnorgathon]

not necessarily. As I pointed out before, for example, Janus and Epimetheus have a similar dust ring at their orbits made of micrometeorite ejecta and they have a prograde orbits around Saturn.

And adding to my list of "Moons with rings at their orbits", I should have also added Pan and Atlas.

I wasn't very clear there... what I meant was, "might Phoebe's retrograde orbit have something to do with how huge the ring is, by contributing to higher-velocity impacts that would produce more ejecta and/or more widely-scattered ejecta, when compared with the rings formed by impacts on other moons?" But I'm having a hard time figuring out how that might work, anyway.

If Phoebe's a captured TNO, maybe it's just got a higher volatiles concentration, and the ring's a toroidal comet tail.