English Dictionary

shepherd moon

noun

A small moon that orbits near the outer edges of a planetary ring or within gaps in the ring. The edge of the ring remains sharply defined owing to the gravity of shepherd moons.

The shepherd moon orbits around the planet.

意味（1）

A small moon that orbits near the outer edges of a planetary ring or within gaps in the ring. The edge of the ring remains sharply defined owing to the gravity of shepherd moons.