Moon capture is the world rule by which a light body that comes near a much heavier one is caught into orbit around it, becoming its moon. It reaches further than Accretion, so a body close enough to be caught but not to merge ends up circling instead. Neither body may already be a moon, and a body with moons of its own is not caught. A collision's fragments near a large planet can become new moons this way.
MOON CAPTURE
NOTE> STATUS reference note.