Celestia - a free 3D space simulation

"Celestia is a free real-time space simulation that lets you experience our universe in three dimensions. 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"

Screenshots of this are VERY good. You can download from here, where the author has thoughtfully placed Mandrake & SuSe rpms.