A predator-prey model for moon-triggered clumping in Saturn's rings

► Cassini UVIS occultations show clumping in Saturn's F ring and at the B ring edge. ► This indicates aggregation and disaggregation triggered by Prometheus and Mimas. ► A simple model reproduces the phase lag of the clumps. ► Rare events that cause the aggregates to accrete can recycle ring material.