Moons at Work

moons_at_workSaturns rings are divided into distinct bands. The Saturnian moons Prometheus and Pan are both caught “shepherding” their respective rings in this image (click the image to embiggen it). Through their gravitational effect on nearby ring particles, one moon maintains a gap in the outer A ring, and the other helps keep another ring narrowly confined.

Prometheus (86 km across) and its partner Pandora (not seen here), maintains the narrow F ring seen at the bottom left in this image. Pan (28 km across) clears the Encke gap in as it moves along the gap’s center. The other bright dot near the inner edge of the Encke gap is a star in the background.

Image Credit: NASA

Rings and Moons

Image Credit: NASA

The large moon in the background is Titan, Saturn’s largest moon. The moon in the foreground is Dione with some of its surface features visible. The small moon to the right of rings is Pandora. There’s a fourth moon in the picture. Look closely at the dark gap in the rings. The tiny speck is the moon Pan.