The book covers the field of solar system astrophysics beginning with basic tools of spherical astronomy and coordinate frames and celestial mechanics. In doing so, the authors have written an entirely unique book that presents an up-to-date overview on all essential topics based on extensive experience in the classroom. The book presents equations and derivations starting from a level that permits one to see the underlying physical ideas. This is the first book on the market that does this. Historical introductions precede the development and discussion in most chapters. The material presented has been updated in the last few months to take advantage of the newer discoveries of the Mars Rover and the Saturn Cassini missions.