Celestia vs Sky Tonight

Celestia is free, open-source software for visualizing space in 3D. It simulates objects ranging from planets and moons to star clusters and galaxies, which can be viewed from different positions in space and at different times. Solar system positions and movements are calculated in real time, and users can choose the rate of motion. Celestia also works as a planetarium: users can travel to celestial worlds, land on their surfaces, and see solar system objects in the sky. Add-ons expand the catalogues with objects, high-resolution textures, 3D models, spacecraft, and fictional objects. Celestia is licensed under the GNU General Public License and is available for Android, iOS, Linux, macOS, web, and Windows. The browser option is a lite version. Installation routes differ: Android versions are offered through Google Play, GitHub APK, and alternative markets; Apple versions are on the App Store, with a direct GitHub download for macOS. Windows users can use the Microsoft Store or sideload a GitHub version. The latest stable original-project release for Linux is listed as source code.

Sky Tonight has no write-up on Specifiction yet; its figures are above.