Excellent resource for these science topics: earth, space, weather, and ocean. Contains a wealth of articles, diagrams, and activity ideas, plus several animations and a teacher page with links.

A great resource site, but its value is not immediately apparent from the home page. Explore the site to find PowerPoint presentations, well-organized earth science lesson plans for grades K-12, contests and games for kids, printable diagrams, and links to more earth science sites.

A fun and friendly introduction to physical geography! Topics include earth structure, atmosphere, hydrosphere, biosphere, bio-geo-chemical cycles, and climates. Also includes online quizzes.

Online lessons complete with diagrams and other visual aids. Each lesson is supplemented with printable and hands-on activities that correspond with information provided on the site.

Online modules and activities on a variety of earth science topics, from seasons and weather for young children, up through water quality and the "UV Menace" for upper grades.

Information on the environment, those working to protect it, the origins of life, and a great section on the "Earth at a Glance". Also has an extensive links section.

Current events as it relates to the earth and the environment. Choose from these "channels":  sustainable economy, ecosystems, sci & tech, energy, water, conservation, food, and wildlife.

Everything you could wish for to teach or to learn about volcanoes! Includes detailed information, aerial photos and mini-movies, volcano history, current eruptions, and even links to volcano-related online adventures. Also includes teacher resources such as lesson plans.

Everything a kid could ever hope to know about earthquakes, from the US Geological Survey. Maps of recent quakes, quake history and geology, puzzles, games, and other activities. Also includes science fair project ideas related to earthquakes.

A fun way to supplement lessons on meteorology or natural disasters! Includes full color maps, charts, and diagrams, a chronological list with brief descriptions of each event, and global extremes of temperature and precipitation.

A fun site from the US Environmental Protecion Agency, with links to lessons, games, and other activities on the environment, air, water, plants and animals, and related topics. There is a separate site for high school students.

Home page of the country's biggest and best-informed space science website! There are sections for younger children, for older students, for educators, and for the general public. Also check out the Space Science Education Resource Directory.

Great interactive site with many online exhibits and interactive modules. Collect space trading cards, plan a mission to the Hubble space telescope, construct a galaxy, or plan a lesson on one of the featured space topics.

A nice user-friendly site with information on the planets, their moons, space travel & exploration, and more. Also includes news, an astronomy dictionary, and lesson plans and other resources for teachers.

Updated information on the current locations of planets and other celestial destinations, as well as other sky maps and space science information. Includes a "beginners guide" to skywatching and online puzzles.

A colorful site with much timely information. News, informational articles, image galleries, and more.

Several customizable animated simulations including solar system, horizon, sun/moon, comets, and jovian system. Each needs Java enabled in order to run. Also includes a short glossary.