Apollo 11.
To celebrate the 30th anniversary of the landing on the moon, NASA created this site. It includes interviews with the crew; full text of Apollo: Expeditions to the Moon and The First Lunar Landing: As Told By the Astronauts; biographies; documents; multimedia galleries; timelines; Apollo 11 image gallery; panorama photos in Apollo 11 Lunar Service Journal; and Top Ten Scientific Discoveries Made During Apollo Exploration of the Moon.

Astronomy.

Biology.

Chemistry.

Fear of Physics.
Designed for teachers and students in middle and high school, this site contains many different simulations to demonstrate the concepts of physics.

Geology.

HighWire Press.
From Stanford University, this site claims to be the internet's largest archive of free, full-text science articles. Search by author, title, keyword, year and more.

Information Bridge.
From the US Department of Energy, this site provides free public access to full-text documents and bibliographic citations of Department of Energy (DOE) research report literature. Documents are primarily from 1994 forward and were produced by DOE, the DOE contractor community, and/or DOE grantees. Legacy documents are added as they become available in electronic format. The Information Bridge contains documents and citations in physics, chemistry, materials, biology, environmental sciences, energy technologies, engineering, computer and information science, renewable energy, and other topics of interest related to DOE's mission.

Live From CERN.
A series of internet broadcasts designed to raise public awareness and interest in scientific and technological activities, particularly those related to Particle Physics at CERN.

Live Science.
From Imaginova, in partnership with CNN, USA Today, MSNBC, Yahoo, and others, the latest news from the scientific community.

Mars Missions, Year 2000 and Beyond.
Includes a wealth of information on Mars Pathfinder, Mars Global Surveyor, Mars Surveyor 98 and Mars Surveyor 2001.

Mars Odyssey Mission THEMIS.
The Thermal Emission Imaging System (THEMIS) is an instrument on board the Mars Odyssey spacecraft. It is the visual imaging system used to transmit detailed images of Mars back to earth. This site, hosted by Arizona State University, posts these images by topic, such as craters, dunes, storms, etc., and by the "image of the day" from live transmissions.

Near Earth Asteroid Tracking (NEAT).
NEAT is an autonomous celestial observatory located at the USAF/Ground-based Electro-Optical Deep Space Surveillance (GEODSS) site on Haleakala, Maui, Hawaii. It is designed to complete a comprehensive search of the sky for near-Earth asteroids and comets.

Nuclear Files.
This site explores the Nuclear Age and includes basic information about fission and fusion. It includes a timeline of discoveries, biographies, documents, treaties, accidents, ethics, proliferation, and more. For teachers, they offer class exercises, lesson plans, syllabus collections, handouts, study guides, and other resources.

Periodic Table of the Elements.

SciCentral.
First and foremost a gateway to thousands of online resources, grouped by science area (Biological, Health, Engineering, Physical & Chemical, etc.) and then subdivided by resource type (directories, specialized resources, databases, special reports, articles). SciCentral also features a number of diverse Special Features, including Academic Programs, K-12 Science, The Media Room, and a Bulletin Board, among others. Other resources include an internal search engine as well as links to science news wire search engines and science journal meta-sites.

Sue at the Field Museum.
From the Field Museum, this site details "Sue," the largest, most complete, and best preserved Tyrannosaurus rex ever found.