Saturn's ring system has a very sharp outer edge because
A) particles at the edge have a 7:6 orbital resonance with a pair of co-orbiting moons that lie just outside the rings.
B) the edge marks the Roche limit.
C) of a pair of shepherding moons.
D) Saturn has a thicker atmosphere than Earth.

Question

Quizplus · Accepted Answer

The correct answer is A because the particles at the edge of Saturn's ring system have a 7:6 orbital resonance with a pair of co-orbiting moons that lie just outside the rings. This resonance prevents the particles from moving beyond the outer edge of the ring system.

Saturn's Ring System Has a Very Sharp Outer Edge Because