This is probably an elementary question for most, but can anyone explain how saturn's moon 'Pan' maintains the gap in saturn's ring in which it orbits (the Encke gap).
My intuition is that the moon's gravity should be attracting ring particles from both sides of the gap as it orbits (thereby closing the gap) and not pushing them away to keep the gap clear.
Should the little moonlet not be continually accreting ring material as it orbits?
I've seen a NASA image in which another ring shepherd (Prometheus) is clearly pulling in material from the f-ring.
Would be grateful if anyone can explain in layman's terms how the process works with Pan.