AbsoluteAstronomy.com - Facts and statistical information about planets, moons, constellations, stars, galaxies, and Messier objects.
Astronomical Applications Department, U.S. Naval Observatory - Computes the position, brightness, and other observable characteristics of celestial bodies, as well as the circumstances of astronomical phenomena. Site has extensive information on astronomical phenomena, calendars, and related topics.
Astronomical Optical Interferometry - The use of multiple telescopes to produce high resolution images - commonly used at most modern observatories. A literature review article.
Astronomy Facts and Trivia - Fun facts and trivia relating to astronomy, space, science fiction movies. Most trivia items are submitted by users.
Astronomy for All - Extensive index full of graphics and illustrations about stars, the Solar System, cosmology and Galileo.
Astronomy Net - Resources, searchable forums and searchable lists of organizations providing astronomy services.
Astronomy Today - Articles on astronomy, cosmology and space exploration, with a regularly updated sky guide and the latest space news.
AstroWeb - Astronomical Internet resources by the Space Telescope Science Institute.
An Atlas of the Universe - Contains 3D maps of the universe zooming out from the nearest stars to the scale of the galaxy and out to the surrounding superclusters and finally to the scale of the known universe.
Beyond Earth - Everything Not on Earth - We provide info about the beginning of universe and solar system. About the planets, quasars, the Milky Way, black holes. Life of a star, etc. Travel in space and extraterrestrial beings.
Infrared Astronomy - All about infrared astronomy from NASA's infrared astronomy center: Discovery of infrared, what is infrared and infrared astronomy, history, the infrared universe, gallery, activities, discoveries, missions and a lot of links to IR astronomy sites.