You can download the latest official versions of the Celestia program for various platforms: Download - Celestia

is a powerful, free, and open-source real-time 3D astronomy program that allows you to explore the universe far beyond the confines of Earth. Unlike standard planetarium software, Celestia functions as a space simulator, giving you a "point-and-goto" interface to fly through the solar system, visit over 100,000 stars, and explore distant galaxies. Where to Download Celestia

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