SpaceEngine

SpaceEngine is a 3D astronomy program and game engine developed by Russian astronomer and programmer Vladimir Romanyuk. Using real astronomical catalogs and procedural generation, it builds a three-dimensional planetarium that shows the entire universe. You can travel in space in any direction and at any speed, and jump forward or backward in time. It uses pseudo-random numbers to procedurally create all kinds of planetary systems, nebulae, or galaxies.