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KStars vs Gaia Sky: catalog facts
KStarsGaia Sky
Free

Free and open source from the KDE community.

Free

Free and open source under the MPL-2.0.

Windows, macOS, Linux Windows, macOS, Linux
  • Sky simulation with up to 100 million stars, plus comets and asteroids
  • Observation planner and calculation tools such as conjunction prediction
  • Uses real scientific catalogs including Gaia star data
  • Handles around a billion objects in real time
  • The large feature set takes time to learn
  • Some information and imagery features rely on internet resources
  • Large datasets need significant download space and capable hardware
  • Aimed at scientific exploration rather than a guided planetarium experience
Downloadable app Downloadable app
Open source Open source
License not stated License: MPL-2.0
No account needed No account needed
Not stated if it works offline Not stated if it works offline

Checked September 23, 2026

Checked October 1, 2026

Catalog facts only. Anything “not stated” is unconfirmed. Check full listings for details.