Explore the Universe in this detailed space simulation
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 using OpenGL. Unlike most planetarium software, the user is free to travel about the Universe.
This package contains a minimal frontend for Celestia. There is a separate package that provides a frontend that integrates with GNOME.