With this newly revised 9th edition of FOUNDATIONS OF ASTRONOMY, Mike Seeds' goal is to help students use astronomy to understand science and use science to understand what we are. Fascinating and engaging, this text illustrates the scientific method and guides students to answer these fundamental questions: "What are we?" and "How do we know?" In discussing the interplay between evidence and hypothesis, Seeds provides not just facts, but a conceptual framework for understanding the logic of science. The book vividly conveys his love of astronomy, and illustrates how students can comprehend their place in the universe by grasping a small set of physical laws. Crafting a story about astronomy, Mike shows students how to ask questions to gradually puzzle out the beautiful secrets of the physical world. Mathematics is incorporated into the text (and in separate sections for easy reference), but the book's arguments do not depend on mathematical reasoning, keeping even math-averse students engaged. The revision addresses new developments in astrophysics and cosmology, plus the latest discoveries, including evidence of a new world beyond Pluto and new evidence of dark energy and the acceleration of the universe. Students are also provided with an online assessment tool, called AceAstronomy. Designed specifically to help students prepare for tests and exams, AceAstronomy improves conceptual understanding by providing a personalized learning plan based on a pre-test diagnostic.