Celestia 1.5.0 is an open-source 3D space simulator and astronomy program. 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. Celestia comes with a large catalogue of stars, galaxies, planets, moons, asteroids, comets, and spacecraft. The program is available for Linux, Mac OS X, and Microsoft Windows.