Britannica
Sources used in this answer
How do the moons Pan and Daphnis shape gaps in Saturnās rings?
Created from Britannica articles
using AI.
AI can make mistakes, so verify using Britannica articles.
Saturn
Saturn and its spectacular rings, in a natural-color composite of 126 images taken by the Cassini spacecraft on October 6, 2004. The view is directed toward Saturn's southern hemisphere, which is tipped toward the Sun. Shadows cast by the rings are visible against the bluish northern hemisphere, while the planet's shadow is projected on the rings to the left.
The moons Pan and Daphnis shape gaps in Saturnās rings through their gravitational influence as they orbit within the ring system. Scientists have theorized that small moons, approximately 10 km (6 miles) in size, can clear particles from a region to form a gap through these gravitational effects.1
- Pan: This moon was discovered within the Encke gap of the A ring, where it clears the surrounding material.1
- Daphnis: This moon is located within the Keeler gap, also situated in the outer part of the A ring, where it similarly maintains the gap.1
In this capacity, these moons are considered a type of shepherd moon, a term used to describe any moon that constrains the extent of a ring through its gravitational forces. By orbiting within these gaps, Pan and Daphnis prevent ring particles from accumulating in those specific orbital paths.21