This comprehensive Encyclopedia covers the full history of astronomy from its ancient origins in Africa, South America, the Middle East and China to the latest developments in astrophysics and space-based research. The initial articles, which are largely organised chronologically, are followed by numerous thematic historical articles on the constituents of the Solar System, types of stars, stellar evolution, active galaxies, cosmology and much more. These are followed by articles on tools and techniques, from the history of spectroscopy to adaptive optics. The last part of the Encyclopedia is devoted to the history of ground and space-based telescopes and observatories, covering the full spectral range from gamma-rays through the optical waveband to radio waves. Informative and accessibly written, each article is followed by an extensive bibliography to facilitate further research, whilst consistent coverage from ancient times to the present makes this an ideal resource for scholars, students and amateur astronomers alike.