Creation of the Uranus rings and dust bands

VOYAGER observations of the extended hydrogen exosphere of Uranus and of the σ Ring and its shepherds set an upper limit to the age of the σ Ring of 6 × 10⁸ years. Unless we are seeing Uranus at a special time in its history, this requires a continuing process to create the ring material. We propose that the moons, rings and dust now visible in the Uranus system are created by the diminution of larger objects by meteoroid impacts. A Monte Carlo calculation shows that the largest surviving fragments of the original precursor satellites are in the size range of the new satellites observed by Voyager near the rings. The current bombardment rate is sufficient to create all the observed rings and dust bands. The observed and inferred components of the Uranus ring system fit a power-law size distribution with index of ~3. We predict that the material in Neptune's ring system has a similar size distribution.