Reflecting the current research in the field, "Worlds Apart" offers a comprehensive introduction to planetary science while training students to look at the universe in a scientific way. Each chapter is devoted to a particular planet or other solar system object and includes descriptions of the methods used by planetary scientists to study them. Complete coverage of planetary surfaces and atmospheres, celestial mechanics, the sun, solar wind, magnetic fields and interplanetary dust is provided. The broad philosophical issues behind planetary science are questioned and comparisons are provided between planetary science and maths and science through algebraic equations and calculus reviews.