STARS Foundation- http://www.starsfoundation.org/kids/s_kids.html
A place for teachers and students can go to learn about astronomy. Color the universe, take a quiz about the solar system, or get homework help.
NASA KIDS - a nasa site dedicated to kids - http://kids.msfc.nasa.gov/
There are lots of space-related activities at the official 'NASA for Kids' web site. Find out about the space shuttle. Print out some cool images to color, plus information and games about Space, Science, Rockets, Astronauts and the Solar System.
Walk the Solar System - http://www.exploratorium.edu/ronh/solar_system/
Amazing Space - http://amazing-space.stsci.edu/
Collection of web-based activities designed for classroom use, but made available for everyone to enjoy.
StarChild: A Learning Center for Young Astronomers - http://starchild.gsfc.nasa.gov/docs/StarChild/StarChild.html
Offers an interactive gaming and entertainment center for kids who wish to learn more about the solar system, the universe, and space.
Satellite Tracking and Prediction - http://www.heavens-above.com/
See the space station, the space shuttle and many other satellites from your back yard.
Powers of 10 - http://www.powersof10.com/
Discover the relative size of everything in the universe. Beginning with a 1 metre square, each successive page jumps back 10 times until you are a billion light years away. Lots of good activities and information. Based on the Eames film of the same name.
re-create Galileo's Telescope - http://es.rice.edu/ES/humsoc/Galileo/Student_Work/Astronomy95/
Students at Rice University explain how they re-created the telescope that Galileo used to make the first ever magnified views of the stars and planets... and all for less than 30 dollars.
Eyes on the Sky, Feet on the Ground - http://hea-www.harvard.edu/ECT/the_book/index.html
This collection of children's online astronomy activities, is a product of the Smithsonian Astrophysical Observatory. Designed for grades 2 to 6, it contains hundreds of fun explorations into astronomy as a classroom tool for learning how to theorize, experiment, and analyze data.
Cassini Kid's Page - http://saturn.jpl.nasa.gov/cassini/english/kids/
Spacecraft Cassini is on its way to Saturn. Download the parts and instructions to build a paper model of the Cassini space probe. Find Saturn in the sky and discover more about this exciting adventure in space.