This completely rewritten new edition begins with an historical perspective of the place of the solar system in the universe. Evidence from meteorites is used to describe how the planets were formed and the giant planets are considered in the light of the discovery of new extrasolar giants. Other chapters discuss satellites, comets, centaurs, asteroids and why Pluto is not a planet. Explanations on why Earth and Venus turned out so differently, and how Mars and Mercury are the survivors of many similar bodies, are also discussed. The formation of the Moon in a giant impact leads to an assessment of the importance of collisions and impacts in the solar system. It is concluded that our solar system is the end product of many accidental and chance events. This leads to the philosophical discussion of whether planets like our Earth are likely to be found elsewhere in the universe.