July 11, 2008 11:44 PM Subscribe
An Interactive Space Simulator
"Smash planets together, introduce rogue stars, and build new worlds from spinning discs of debris. Fire a moon into a planet or destroy everything you've created with a super massive black hole. You can simulate and interact with our solar system: the 8 planets,160+ moons, and hundereds of asteroids, the nearest 1000 stars to our Sun, and our local group of galaxies." [31Mb, Windows only, sorry, but see inside for similar Mac and Linux apps]
If you're keen and you're not an XP or Vista user, you'll probably like Stellarium
[Linux, Mac or Windows] and Celestia
[Linux, Mac or Windows] [previously
] as well, which are less physics simulation and more 'fly through the universe' brain food, but heaps of fun, too.