Ubuntu founder Mark Shuttleworth spent about $20 million to go into space, and he never got farther away from Earth than a few hundred miles. Using three free software programs, you can look at and virtually travel to places millions of miles away without leaving your GNU/Linux desktop or paying a dime.

Stellarium is a real-time 3D photo-realistic nightsky renderer. It can generate images of the sky as seen through the Earth's atmosphere with more than one hundred thousand stars from the Hipparcos Catalogue, constellations, planets, major satellites and nebulas.