Celestia

Speaking of astronomy, the following programme is recommended on the NCHENZ site:

"An excellent, free download open source program runs in planetariums… it is called Celestia. If your computer is not too old and your graphics card is more than 256K then this should work very well on your computer. This page will take you to the Educational version download, which has had activities programmed and documented for it. And, yes, those activities and worksheets are downloadable too. It pays to print out the overview to give you a starting point, and this will help you learn to navigate without too much overload. There is also an updated full version, and extra models and objects that can be uploaded – including spacecrafts from real life, and fiction ie. Star Wars, Star Trek."

http://www.shatters.net/celestia/
http://www.celestiamotherlode.net/