Anthe's Arc

Saturn's ring-and-moons system keeps getting more complex - or, rather, we keep learning more details of its structure. Earlier in its mission, Cassini found that Mimas holds a bright arc in place along the faint G ring, an arc that travels along the ring as Mimas orbits. Later it showed us that Pallene has a thin ring of its very own. Now, Cassini has confirmed that other moons (Anthe, pictured here, and Methone) have arcs - incomplete rings.

Those three little moons - Anthe, Pallene, Methone - orbit between Mimas and Enceladus, and Anthe and Methone's orbits are in resonances, perturbed by Mimas. This may be why they have arcs instead of a complete ring like Pallene.

(as always, see Cassini's page for more details)