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 System Identified dwarf planets include the asteroid Ceres and the trans-Neptunian objects Pluto and Eris. In addition to these two regions, various other small-body populations, including comets, centaurs and interplanetary dust clouds, freely travel between regions. Six of the planets, at least four of the dwarf planets, and many of the smaller bodies are orbited by natural satellites, usually termed "moons" after the Moon. Each of the outer planets is encircled by planetary rings of dust and other small objects. The solar wind, a stream of charged particles flowing outwards from the Sun, creates a bubble-like region in the interstellar medium