"The Facts on File Dictionary of Astronomy, Fourth Edition contains approximately 3,700 entries that cover a broad spectrum of disciplines within the fascinating field of astronomy." "Revised and expanded by more than 200 new terms, the volume reflects advances in astronomy, particularly in spectroscopy, photometry, and particle physics." "New entries include: Atacama Large Millimeter Array; Big Ear Radio Telescope; Jicmarca Radio Observatory; magnetars; SKA; and zodiac constellations." "More than 100 line drawings and 10 detailed tables illustrate many complex concepts and theories, and extensive cross-references guarantee that no user will waste time searching for the right definition."--BOOK JACKET.