History of Solar System formation and evolution hypotheses is captured by the Sun and planets form from it. In this there were 6 original planets, corresponding to 6 point-masses in the filament, with planets A and B, the 2 innermost, colliding, the former at twice the mass of Neptune, and ejecting out of the Solar System, and the latter at 1/3 the mass of Uranus, and splitting into Earth and Venus. Mars and the Moon are former moons of A. Mercury is either a fragment of B or an escaped moon of A. The collision also produced the asteroid belt and the comets. T.J.J. See was an American
Solar eclipses on Uranus Umbriel, Titania and Oberon—are large enough and near enough to eclipse the Sun. All other satellites of Uranus are too small or too distant to produce an umbra. At its distance from the Sun, the Sun's angular diameter is reduced to a tiny disk about 2 arcminutes across. The angular diameters of the moons large enough to fully eclipse the sun are: Cressida, 6–8'; Desdemona, 6–7'; Juliet, 10–12'; Portia, 9–13'; Rosalind, 4–5'; Belinda, 6–8'; Puck, 6–8'; Miranda, 10–15'; Ariel, 20–23'; Umbriel, 15–17'; Titania, 11–13'; Oberon, 8–9'. Solar eclipses on Uranus Solar eclipses on Uranus occur when any of the natural