Book excerpt: Planets come in many different sizes, and with many different compositions, orbiting our Sun and countless other stars. Understanding their properties and interactions requires an understanding of a diverse set of sub-fields, including orbital and atmospheric dynamics, geology, geophysics, and chemistry. This textbook provides a physics-based tour of introductory planetary science concepts for undergraduate students majoring in astronomy, planetary science, or related fields. It shows how principles and equations learned in introductory physics classes can be applied to study many aspects of planets, including dynamics, surfaces, interiors, and atmospheres. It also includes chapters on the discovery and characterization of extrasolar planets, and the physics of planet formation. Key Features Covers a wide range of planetary science topics at an introductory level Coherently links the fields of solar system science, exoplanetary science, and planet formation Each chapter includes homework questions Includes python templates for reproducing and customizing the figures in the book