Moons of Uranus Moons of Uranus Uranus is the seventh planet of the Solar System; it has 27 known moons, all of which are named after characters from the works of William Shakespeare and Alexander Pope. Uranus's moons are divided into three groups: thirteen inner moons, five major moons, and nine irregular moons. The inner moons are small dark bodies that share common properties and origins with Uranus's rings. The five major moons are massive enough to have reached hydrostatic equilibrium, and four of them show signs of internally driven processes such as canyon formation and volcanism on their surfaces. The largest of
History of Solar System formation and evolution hypotheses stars and clusters and the star-clouds of the Milky Way", which proposed that the planets formed in the outer Solar System and were captured by the Sun; the moons were formed in thus manner and were captured by the planets. This caused a feud with Forest Moulton, who co-developed the planetesimal hypothesis. A preview was presented in 1909 at a meeting of the ASP (Astronomical Society of the Pacific) at the Chabot Observatory in Oakland, Cal., and newspaper headlines blared "Prof. See's Paper Causes Sensation" (San Francisco Call) and "Scientists in Furore Over Nebulae" (San Francisco Examiner). Our current knowledge