In their previous book, Astronomy: Principles and Practice, the authors presented the principles and practice of astronomy. This book describes the universe as revealed by the application of those methods. Although the work has been published in two separate volumes, it was conceived as one book, written to fulfil the need of a preliminary science course or a liberal arts course at first year university level. This third edition contains additions reflecting the advances of knowledge in astronomy, which have been achieved by the use of spacecraft.