This book will acquaint readers with the basics of astronomy, methods for studying planets and constellations, tell about the evolution of the Sun and stars, quasars and much more. The series "Polymath" is a universal reference publication, which conveniently and clearly presents the main achievements of all areas of knowledge. Fascinating and accessible thematic material includes information of a high scientific level and contains a large number of tables, diagrams, photos, drawings, which greatly facilitate the assimilation of the material by schoolchildren and applicants. The books in this series are indispensable for students; in addition, they contain a huge encyclopedic material necessary for any educated person.