Hyperion as a Dust Source in the Saturnian System

Abstract

We argue that Hyperion may act as a reasonably effective source of dust in the Saturnian system. Hypervelocity impacts of interplanetary grains and of dust particles from the outermost moon Phoebe should produce impact ejecta from Hyperion’s surface, an appreciable share of which would escape into the planetocentric orbits. Though the particles would initially be locked in a strong 4:3 mean motion resonance with Titan so that encounters with this satellite would be prohibited, the solar radiation pressure and especially plasma drag force destroy the resonant locking. Once the resonance is broken, the orbits become unstable and experience multiple close approaches to Titan. Using numerical integrations, we performed a statistical study of the grain trajectories and found that most of the grains larger than ~ 5 μm will finally collide with Titan, smaller particles down to ~ 1 μm will escape out of the system, and still smaller (submicrometer) particles will rapidly collide with Saturn. First order estimates of the dust influx to Titan are also made; they show that the upper limit of the income rate of the Hyperion particles is comparable with the direct influx of interplanetary grains.