Adler Planetarium and Astronomy Museum - Interprets the exploration of the Universe for the broadest possible audience and hosts one of the finest collections of early astronomical instruments in the world.
Discovery of the Perseid Meteors - Article from Sky & Telescope magazine on Edward C. Herrick's discovery of the Perseids in 1837.
Historical Celestial Atlases on the Web - Digital editions of various celestial atlases and maps from the middle of the 15th century to the early 20th century.
History of High-Energy Astrophysics - A list of many important dates in the history of high-energy astrophysics and astronomy in general, with links to further details.
Shapley - Curtis Debate in 1920 - Guide to understanding all facets of the Great Debate between Harlow Shapley and Heber D. Curtis over the scale of the universe. Includes a complete transcript.
Starry Messenger - Focuses on the instruments, people, and themes of early astronomy.
