California Institute of Technology[ http://caltech.edu ]
Academic home of NASA's Jet Propulsion Laboratory. Research affiliation: Association of American Universities.

U.S. Navy[ http://navy.mil ]
Official information about the United States Navy.

wolfram.com[ http://wolfram.com ]
The producers of Mathematica, one of the common software packages for advanced mathematics.

Astronomical Society of the Pacific[ http://astrosociety.org ]
News publication, events, education, resources, support, and astro shop in San Francisco.

Sloan Digital Sky Survey[ http://sdss.org ]
A survey that maps one-quarter of the entire sky, determining the positions and absolute brightnesses of more than 100 million celestial objects.

Space Telescope Science Institute[ http://stsci.edu ]
Astronomical research center responsible for operating the Hubble Space Telescope as an international observatory.

The National Maritime Museum[ http://nmm.ac.uk ]
The largest maritime museum in the world covering every aspect of ships and seafaring, in peace and at war, from pre-history to today. The Museum promotes understanding of the history and future of Britain and the sea, the story of time, astronomy and navigation, and of the historic buildings at Greenwich.

Astronomy Today[ http://astronomytoday.com ]
Information and articles on astronomy, space and related topics. Also features a friendly forum and a telescope buyer's FAQ page

Astronomy Net[ http://astronomy.net ]
Resources, searchable forums and searchable lists of organizations providing astronomy services.

Astronomy Online[ http://astronomyonline.org ]
Gives overview of the solar system, the Milky Way galaxy, extrasolar planets, cosmology and astrophotography. Includes images, additional resources, and forums.

Kummer, Jürgen[ http://jumk.de ]
Stellt verschiedene Webprojekte vor.

Department of Astrophysical Sciences[ http://astro.princeton.edu/~mjuric ]
Displays information about the study programs, activities, research, press releases, and the library.

An Atlas of the Universe[ http://atlasoftheuniverse.com ]
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.

Absolute Astronomy[ http://absoluteastronomy.com ]
Facts and statistical information about planets, moons, constellations, stars, galaxies, and Messier objects.