celestia: celestia - 3D space simulation
celestia: 
celestia: Celestia is a free space simulation that lets you explore our 
celestia: universe in three dimensions. Unlike most planetarium software, 
celestia: Celestia doesn't confine you to the surface of the Earth. You can 
celestia: travel throughout the solar system, to any of over 100,000 stars, 
celestia: or even beyond the galaxy.
celestia: Check also http://www.celestiamotherlode.net for lots of celestia 
celestia: add-ons.
celestia: 
celestia: http://www.shatters.net/celestia/