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
Satellite system (astronomy) the smallest natural satellites. Known satellite systems of the Solar System consisting of multiple objects or around planetary mass objects, in order of perihelion: Natural satellite systems, particularly those involving multiple planetary mass objects can have complex interactions which can have effects on multiple bodies or across the wider system. Ring systems are collections of dust, moonlets, or other small objects. The most notable examples are those around Saturn, but the other three gas giants (Jupiter, Uranus and Neptune) also have ring systems. Studies of exoplanets indicate that they may be common around giant planets. The 90 million km (0.6