Astronomy and Astrophysics – Astronomy
Scientific paper
Sep 2006
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2006dps....38.5104h&link_type=abstract
American Astronomical Society, DPS meeting #38, #51.04; Bulletin of the American Astronomical Society, Vol. 38, p.578
Astronomy and Astrophysics
Astronomy
1
Scientific paper
Spokes in Saturn's B ring are rapidly-formed radial markings that have puzzled planetary scientists since their discovery in Voyager images 25 years ago. The most popular theoretical model, due to Goertz and Morfill (1983), postulates that meteoroid impacts into the rings generate clouds of plasma that charge micron-sized dust grains and levitate them out of the ring plane. Recently this model has received two major challenges. First McGhee etal (2005) using HST and later the Cassini imaging team found that spokes are not readily observed when Saturn's rings have a large opening angle as seen from the Sun. The Goertz and Morfill model predicts no such dependence. Second, Framer and Goldreich (2005) showed theoretically that the radial propagation speed of the plasma cloud is limited to about 2km/s, far slower than the >20km/s implied by the rapid formation of some Voyager spokes. Here we present a new model for the formation of Saturn ring spokes that can address the two recent challenges. As with the Goertz and Morfill model, we begin with an interplanetary impact that releases a cloud of dusty ejecta. Some micron-sized debris is immediately visible, but only in a small localized area. In addition, numerous invisible submicron dust grains are also produced. These tiny grains are rapidly accelerated to high speeds by electromagnetic forces, and they are transported both vertically and radially. When they return to the ring plane, the submicron grains strike ring parent bodies at km/s speeds raising clouds of new debris particles at new radial locations; small grains continue this collisional cascade, while micron-sized ones become visible as spokes. We will show that visible spokes form rapidly, as observed, and will discuss how their generation is suppressed by solar radiation pressure.
No associations
LandOfFree
The Collisional Cascade Model for Saturn's Ring Spokes does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The Collisional Cascade Model for Saturn's Ring Spokes, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Collisional Cascade Model for Saturn's Ring Spokes will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1001158