Here is the essential companion to Welcome to the Universe, a New York Times bestseller that was inspired by the enormously popular introductory astronomy course for non-science majors that Neil deGrasse Tyson, Michael A. Strauss, and J. Richard Gott taught together at Princeton. This problem book features more than one hundred problems and exercises used in the original course--ideal for anyone who wants to deepen their understanding of the original material and to learn to think like an astrophysicist. Whether you're a student or teacher, citizen scientist or science enthusiast, your guided tour of the cosmos just got even more hands-on with Welcome to the Universe: The Problem Book. * The essential companion book to the acclaimed bestseller* Features the problems used in the original introductory astronomy course for non-science majors at Princeton University* Organized according to the structure of Welcome to the Universe, empowering readers to explore real astrophysical problems that are conceptually introduced in each chapter* Problems are designed to stimulate physical insight into the frontier of astrophysics* Problems develop quantitative skills, yet use math no more advanced than high school algebra* Problems are often multipart, building critical thinking and quantitative skills and developing readers' insight into what astrophysicists do* Ideal for course use--either in tandem with Welcome to the Universe or as a supplement to courses using standard astronomy textbooks--or self-study* Tested in the classroom over numerous semesters for more than a decade* Prefaced with a review of relevant concepts and equations* Full solutions and explanations are provided, allowing students and other readers to check their own understanding