Space Engine – free 3D space simulation software

Via Ralph Ewig’s blog comes a pointer to the Space Engine, which is a

free space simulation software that lets you explore the universe in three dimensions, starting from planet Earth to the most distant galaxies. Areas of the known universe are represented using actual astronomical data, while regions uncharted by human astronomy are generated procedurally. Millions of galaxies, trillions of stars, countless planets!

Here is a video created by the Space Engine: