to believe that the ring system may be relatively young and did not form at the same time as Uranus. The particles that make up the rings may be remnants of a moon that was broken by a high-velocity impact or torn up by gravitational effects. To date, two new rings have been positively identified. The first, 1986 U1R, was detected between the outermost of the previously known rings - epsilon and delta - at a distance of 50,000 kilometers (31,000 miles) from Uranus's center. It is a narrow ring like the others. The second, designated 1986 U2R, is a broad region of material perhaps 3,000 kilometers (1,900 miles) across and just 39,000 kilometers (24,000 miles) from the planet's center. The number of known rings may eventually grow as a result of observations by the Voyager 2 photopolarimeter instrument. The sensor revealed what may be a large number of narrow rings - or possibly incomplete rings or ring arcs - as small as 50 meters (160 feet) in width. The individual ring particles are not very reflective, which explains why some have remained unseen. At least one ring, the epsilon, was found to be gray, an unusual color. This ring is surprisingly deficient in particles smaller than the approximate size of a beach ball - the average ring contains smaller dust sized (relatively) particles. This may be due to the atmospheric drag from the planet's extended hydrogen atmosphere, which may siphon smaller particles and dust from the ring. The sharp edge of the epsilon ring indicates that the ring is less than 150 meters (500 feet) thick and that particles near the outer edge are less than 30 meters (100 feet) in diameter. Important clues to Uranus's ring structure may come from the discovery that two small moons - Cordelia and Ophelia - straddle the epsilon ring. This finding hints that small moonlets may be responsible for confining or deflecting material into rings and keeping it from escaping into space. Astronomers expected to fi...
