History of Solar System formation and evolution hypotheses (we've known, of course, since 1965, that it doesn't), very slow, accelerated, and finally, daily rotation. He explained the differences between inner and outer planets and inner and outer moons through vortex behaviour. Mercury's eccentric orbit was explained by its recent expulsion from the Sun and Venus' slow rotation as its being in the "slow rotation phase", having been expelled second to last. The Tom Van Flandern model was first proposed in 1993 in the first edition of his book. In the revised version from 1999 and later, the original Solar System had 6 pairs of twin planets each fissioned
Formation and evolution of the Solar System times render their formation highly implausible. The two are instead thought to have formed in orbits near Jupiter and Saturn, where more material was available, and to have migrated outward to their current positions over hundreds of millions of years. The migration of the outer planets is also necessary to account for the existence and properties of the Solar System's outermost regions. Beyond Neptune, the Solar System continues into the Kuiper belt, the scattered disc, and the Oort cloud, three sparse populations of small icy bodies thought to be the points of origin for most observed comets. At their distance