Uranus after Voyager 2 and the origin of the solar system

The discoveries made by the Voyager 2 spacecraft at Uranus in January 1986 are discussed in the light of the modern Laplacian theory for the formation of the solar system. The most important confirmation by Voyager was the discovery of 2 new satellite groups near orbital radii 2 1/2 R_U and 3 1/2 R_U (R_U = Uranus' equatorial radius), as first predicted in 1977. The discovery that the densities of the Uranian satellites are consistent with these bodies having condensed in a single compositional class, consisting of anhydrous rock, NH₃ ice and CH₄.6H₂O clathrate hydrate in normal solar proportions, confirms the hypothesis that the chemistry of all planetary/regular satellite systems are accounted for by a single choice of the turbulence parameter, namely β = 0.107±0.001. The implication of the Voyager data for the origin of comets is also discussed.