Why Pallene has a ring, not an arc

Resonance makes the difference.

Published 2026-10-23

In 2006 Cassini discovered a faint dust ring sharing Pallene’s orbit.^[1]

Source

Its particles are blasted off Pallene by meteoroid impacts.^[1]

Arcs elsewhere

Methone, Anthe and Aegaeon have arcs instead. Because they are in resonances, their ejecta stays locked in the same resonance and forms an arc.^[1]

Pallene is free

Pallene is not in resonance, so its dust spreads into a complete ring about 2,500 km wide.^[1]

Numbered citations link to the sources list on the Pallene overview page.