This full colour textbook provides a comprehensive introduction to galaxies and cosmological models, for undergraduates and amateur astronomers.This well-received textbook has been designed by a team of experts for introductory courses in astronomy and astrophysics. The second edition has been updated to reflect the latest developments and observations and contains features including boxed summaries, a glossary and exercises with full solutions, making it useful for self-study.This well-received textbook has been designed by a team of experts for introductory courses in astronomy and astrophysics. The second edition has been updated to reflect the latest developments and observations and contains features including boxed summaries, a glossary and exercises with full solutions, making it useful for self-study.This well-received textbook has been designed by a team of experts for introductory courses in astronomy and astrophysics. Starting with a detailed discussion of our Galaxy, the Milky Way, it goes on to give a general introduction to normal and active galaxies including models for their formation and evolution. The second part of the book provides an overview of cosmological models, discussing the Big Bang, dark energy and the expansion of the Universe. This second edition has been updated to reflect the latest developments and observations, while still probing the unresolved questions at the forefront of research. It contains numerous learning features such as boxed summaries, exercises with full solutions, a glossary and a supporting website hosting further teaching materials. Written in an accessible style that avoids complex mathematics, and illustrated in colour throughout, this text is suitable for self-study and will appeal to amateur astronomers as well as students.Introduction; 1. The Milky Way - our galaxy; 2. Normal galaxies; 3. Active galaxies; 4. The spatial distribution of galaxies; 5. Introducing cosmology - the science of the Universe; 6. Big banl³