Fully revised and updated, this work presents a thorough, systematic examination of planets, moons, asteroids and comets in our solar system. Treating each body in-depth and with great detail, it begins with discussion of small bodies and moves towards larger bodies as it emphasizes the roles of heat and tectonics in planetary evolution. The outer planets are discussed in order outward from the sun to emphasise the role distance from the sun plays in determining composition. Soundly organized around important themes, this text provides a theoretically based examination that facilitates comparative study of bodies and is accessible to non-specialists.