Celestia

Celestia is a real-time 3D astronomy software program that was created in 2001 by Chris Laurel. The program allows users to virtually travel through the universe and explore celestial objects that have been catalogued. Celestia also doubles as a planetarium, but the user is not restricted to the Earth's surface, like in other planetarium software such as Stellarium. Celestia can display objects of various scales using OpenGL.

Celestia is available for AmigaOS 4, Linux, macOS, Microsoft Windows, Xbox, iOS, and Android. It is free and open source software released under the GNU General Public License.

Celestia's development stopped in 2013, with the final release in 2011. Since then, some of its development team went to work on celestia.Sci, a cosmological visualizer featuring more realistic rendering of galaxies and planets, gravitational lensing, and many other scientifically accurate enhancements, but there have been no updates on the progress of the program since 2020. The original creator of Celestia, Chris Laurel, created Fifth Star Labs shortly after Celestia's development stopped, and began working on an iOS-only planetarium app called Sky Guide. In late 2016, the official Celestia forums were restored, and development restarted under a new development team. As of 2018, beta testing builds of version 1.7.0 are available, as well as the bugfix releases 1.6.2 and 1.6.3, which were released in 2020 and 2023 respectively. Celestia was ported to mobile devices in 2020, and it continues to receive updates and experimental beta versions.

Celestia is available for download from its main website, celestiaproject.space, but it can be obtained from a large multitude of free software websites as well. Between 2001 and May 2017, the former central distribution site SourceForge counted approximately 12 million downloads.