Planet formation and the evolution of the Solar System

The Capture Theory gives planet formation through a tidal interaction between a condensed star and a protostar within a dense embedded stellar cluster. Initial extensive and highly eccentric planetary orbits decay and usually round-off in circumstellar material captured from the protostar. Collapsing protoplanets leave behind a circumplanetary disk within which satellites form by an accretion mechanism. Many properties of exoplanets-orbits very close to and very far from stars, highly eccentric orbits, planets around binary stars, the proportion of stars with planets and spin-orbit misalignments are explained in terms of this model. It is proposed that the initial Solar System contained six major planets, the existing four plus Bellona of mass 2.5 M-J and Enyo of mass 1.9 M-J, where M-J is Jupiter mass. The products of a collision between the two additional planets explain many features of the Solar System-the larger terrestrial planets, Mars and Mercury and their characteristics, the Earth-Moon relationship and the Moon's surface features, the formation of asteroids, comets and dwarf planets, the formation of the Kuiper Belt and Oort Cloud, the relationship between Neptune, Pluto and Triton, the characteristics of ice giants and isotopic anomalies in meteorites. All the mechanisms involved in these processes are well understood and occur in other astronomical contexts.