arXiv.org e-Print archive Available to the public, this archive started with physics papers, and now includes math, non-linear science, computer science, and quantitative biology. Authors submit material, often from conference proceedings, and often before print publication. (Cornell University, National Science Foundation)
Asteroid Watch, NASA Jet Propulsion Laboratory This site provides up-to-date information about asteroids, orbits of near-earth objects, and space missions, as well as basic facts about the origin of asteroids and comets and how close they come to Earth.
CERN Document Server CERN publications including articles, pre-prints, books, proceedings, presentations, periodicals, and multimedia. CERN is the European Council for Nuclear Research (in French, Conseil Européen pour la Recherche Nucléaire).
Fermi National Accelerator Laboratory Fermilab is a U.S. Department of Energy national laboratory dedicated to particle physics. This high-energy physics laboratory, home of the Tevatron particle accelerator, has reports on the latest research on particle physics. Used by scientists around the world.
HubbleSite 30 years of Hubble Space Telescope discovery
PhysLink ‘Physics and astronomy online'. A comprehensive physics and astronomy online education, research and reference website.
PhysOrg Science, physics, and technology news and information; provides forums, discussions, and experts to help on scientific problems/questions.
PhysicsWorld
This meta-site provides access to just about every major Web resource including The Living Encyclopedia of Physics, job postings, scholarships and grants, conference calendars, graduate programs, student societies, free downloadable physics software, companies, instrumentation, consulting firms, patent information and more.
Science agencies in U.S. government -- a list of representatives of the Science.gov Alliance, the interagency that governs Science.gov (a metasearch of 60 databases and over 2,200 scientific websites to provide users with access to more than 200 million pages of authoritative federal science information including research and development results).
European Southern Observatory Not limited to Europe, this site features international astronomical news through images, videos, blogs, audio-video podcasts, and more.
Sloan Digital Sky Surveys (SDSS) Detailed three-dimensional maps of the universe, with deep multi-color images of one third of the sky, and spectra for more than three million astronomical objects.