Gaia Sky is a real-time, 3D, astronomy visualisation software which can run on Windows, Linux and macOS.
Gaia Sky is developed in the framework of ESA’s Gaia mission to chart about 1 billion stars of our Galaxy in the Gaia group of the Astronomisches Rechen-Institut (ZAH, Universität Heidelberg).

Gaia Sky supports multiple languages, including English, Spanish and German. Later, the software will support more languages.
Gaia Sky v3.3.0 features:

• Free and open source – Open source and free, and will stay this way. Contribute to the development and translations.
• From Gaia to the cosmos – Move freely through the cosmos or explore the Solar System in a seamless manner!
• Virtual Reality – Visit the whole Universe in VR!
• 6D exploration – Observe star positions but also proper motions and radial velocities, if available.
• Planetary surfaces – Explore surfaces with elevation maps (using tessellation, if available).
• Procedural planets – Procedurally generate planet surfaces, clouds and atmospheres.
• Advanced graphics – Screen space reflections, shadows, HDR, ray-marched distance fields, dynamic resolution, etc.
• 3D-ready – 6 stereoscopic modes: Anaglyphic (red-cyan), VR headset, 3DTV (H and V), cross-eye and parallel view.
• 360 mode – Sperhical (equirectangular), cylindrical and Hammer projections available.
• Planetarium projection mode – MPCDI for real-time usage in multi-projector systems. Ready to produce videos for full domes from the desktop app.
• Gaia – Observe Gaia in its orbit and discover its movement in the sky and its attitude.
• Use your data – Download pre-packed datasets (Gaia eDR3, NBG, SDSS, OCDR2, etc.) or use your own, in VOTable, FITS, CSV and other formats (STIL).
• Real-time filters – Filter any dataset by distance, magnitude, galactic, ecliptic, equatorial coordinates, and more.
• SAMP aware – Use SAMP to interoperate with SAMP-ready software such as Topcat and Aladin.
• Navigate the galaxy – Use your favorite controllers and gamepads to navigate the Galaxy. Piece of cake!
• Camera paths – Record and play camera paths off-the-shelf.
• Scriptable and extensible – Use Python to script and extend the capabilities of the Gaia Sky.
• Internationalised – Translated to English, German, Spanish, French, Catalan, Slovenian and Bulgarian.

For more downloads (Linux,macOS),you can click the link below:
https://zah.uni-heidelberg.de/gaia/outreach/gaiasky/downloads/
Webmaster’s note:
The installation files shared by www.freesoftwaresdownload.org only support Windows 64 bit.