On the tidal environment of an outwardly migrating F ring

Saturn’s F- ringis a unique narrow ringthat lies radially close to the tidally disruptive Roche limitof Saturnfor 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 forcesof Saturnand the nearby moons Prometheus and Pandora, which act to gravitationally stir up ringmaterial. Planetary ringsare also known to radially spread, with the outer ringedge migrating outwards. As the F ringlies at the edge of the main rings, we investigate the effect of an outwardly migrated F ringand its interaction with Prometheus. For each model with decreasing local tidal environment, an increase in maximum number densityof 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 ringwhere Q<2 is observed, more particles are seen to fall below or close to critical values as the radial location of the ringincreases.