The Engine of Space

Imagine for a moment. An space simulation that not only lets you explore the universe in three dimensions, from planet Earth to the most distant galaxies but also these areas of the known universe are represented using actual astronomical data, while regions uncharted by astronomy are generated when they learn more about our universe. Millions of galaxies, trillions of stars, countless planets all available for boundless exploration. You can land any planet, moon or asteroid and watch alien landscapes and celestial phenomena. Best part is the small space the program takes and it does not set you're PC on fire. I highly recommend it to those who love exploration and space, it has certainly given inspiration for some story ideas.

http://en.spaceengine.org