http://www.stellarium.org/
You have to try this program out. If you don't already lover astronomy I promise this program will change your mind. Must have!
Stellarium is a free open source planetarium for your computer. It shows a realistic sky in 3D, just like what you see with the naked eye, binoculars or a telescope.
It is being used in planetarium projectors. Just set your coordinates and go.
Celestia
http://www.shatters.net/celestia/
Have fun zooming about the universe without having to shell out billions in "gas" money just to break out of the atmosphere.
Unlike most planetarium software, Celestia doesn't confine you to the surface of the Earth. You can travel throughout the solar system, to any of over 100,000 stars, or even beyond the galaxy.
All movement in Celestia is seamless; the exponential zoom feature lets you explore space across a huge range of scales, from galaxy clusters down to spacecraft only a few meters across. A 'point-and-goto' interface makes it simple to navigate through the universe to the object you want to visit.
Celestia is expandable. Celestia comes with a large catalog of stars, galaxies, planets, moons, asteroids, comets, and spacecraft. If that's not enough, you can download dozens of easy to install add-ons with more objects.
Check out the sizable collection of add-ons
http://www.celestiamotherlode.net/
Seriously, pack a bong and fire up one of these programs, you'll have fun.
