sky

Celestia – an open-source free space simulation software

Don't you wish you can just fly outside of Earth and into the universe? Explore the other planets and the nearby stars, and maybe even catch a glimpse of a comet or an asteroid? It might not be possible now to tour the Solar System or the universe (unless you are a billionaire!), but you can do this in the comforts of your home right in front of your computer. Celestia is an open-source space simulation software that lets you explore the universe in 3-dimension - stars, galaxies, planets, asteroids and a whole lot more! And the best part? It runs on Windows, Linux and Max OS X.