On the tidal environment of an outwardly migrating F ring

Saturn’s F-ring is a unique narrow ring that lies radially close to the tidally disruptive Roche limit of Saturn for water ice. Significant work has been done on the system that shows it to be one of the most dynamic places in the Solar System. Aggregates fortunate enough to form constantly battle against the strong tidal forces of Saturn and the nearby moons Prometheus and Pandora, which act to gravitationally stir up ring material. Planetary rings are also known to radially spread, with the outer ring edge migrating outwards. As the F ring lies at the edge of the main rings, we investigate the effect of an outwardly migrated F ring and its interaction with Prometheus. For each model with decreasing local tidal environment, an increase in maximum number density of particles at the channel edges is observed. In the same locations as particles with maximum number densities, radial velocity dispersion's are observed to fall below escape velocities of a 150m icy moonlet (<10 cm s^(-1)), and are gravitationally unstable with Toomre parameters Q<2. Additionally, in locations of the ring where Q<2 is observed, more particles are seen to fall below or close to critical values as the radial location of the ring increases.