Stellarium, Celestia 3D - for Astronomy Enthusiasts
Stellarium and Celestia 3D are two incredibly good applications for aspiring star gazers. Stellarium renders 3D photo-realistic skies in real-time while Celestia 3D is an awesome 3D astronomy program that allows users to display objects ranging in scale from artificial satellites to entire galaxies in 3D.
Celestia 3D - Explore Universe Using Celestia Space Simulation Application
Celestia is a free 3D astronomy program. Based on the Hipparcos Catalogue, it allows users to display objects ranging in scale from artificial satellites to entire galaxies in three dimensions. Unlike most planetarium software, the user is free to travel about the Universe.