This new edition is an unrivalled source of information and images covering the whole of modern astronomy. Its 130 articles written by experts form an absorbing panorama of information arranged by topic. Almost every page of the Atlas is richly illustrated with colour photographs, maps, and detailed diagrams. This reference book commences with a survey of the Sun and the solar system, followed by the stars and the Galaxy, and concludes with the extragalactic universe and cosmology. For this edition there are entirely new sections on the planets Venus, Neptune and Pluto, solar system debris, black holes and collapsed stars, active galaxies, galaxy clusters and cosmology. Many photographs have been replaced by improved images from modern telescopes, including the Hubble Space Telescope. An elaborate 24-page glossary and index has been added to increase the ease with which this sumptuous and lavish encyclopedia can be used for quick reference. There are substantial changes throughout the section on the Solar System. The material on Venus is re-written, to take account of the spectacular Magellan mission. The Mars chapter now includes the Phobos results. In the outer solar system new results on the satellites of Jupiter and Saturn are included, as well as new photographs from the Hubble Space Telescope. There is also a new chapter on planetary climate change. The section on stars and the Galaxy now includes chapters on astrometry and protoplanetary systems, as well as many modifications to the existing texts on evolved stars.