There is a new version available of the Space Engine simulation program:
SpaceEngine – a free space simulation program that lets you explore the universe in three dimensions, from planet Earth to the most distant galaxies. Areas of the known universe are represented using actual astronomical data, while regions uncharted by astronomy are generated procedurally. Millions of galaxies, trillions of stars, countless planets – all available for exploration. You can land any planet, moon or asteroid and watch alien landscapes and celestial phenomena. You can even pilot starships and atmospheric shuttles.Version 0.9.7.1 released!
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For more such sims, see the HobbySpace Simulations section.