Moons of Uranus hinder its ring formation

New simulations suggest that the size of Uranus' rings is controlled by its five major moons, which can eject significant amounts of dust out of the Uranian system. The interactions between the moons and the rings, particularly when they are in "mean motion resonances," can truncate the size of Uranus' ring system. The moons Miranda and Ariel have the greatest influence, severely truncating the rings at a distance of 4.3 planetary radii. The research also suggests that the rings may have been larger and brighter in the past but have been diminished by the moons' scouring effect.