Celestia

A real-time 3D space simulator and interactive planetarium. Travel to any planet, moon, star, or galaxy and view it from any point in space and time. Accelerate time, land on alien worlds, and expand the universe with community-made add-ons.

At a glance

• Platform: Windows.
• Genres: Simulation.
• Release date: Jun 22, 2026.
• Steam user reviews: Positive (85% positive).
• Delivered as a Steam library entitlement — activation is handled by Steam.

Minimum

Recommended

System requirements as published by the developer on Steam.

Activate on Steam

• Open the offer above — it takes you to this game's official Steam store page.
• Buy it there, or if you bought a key elsewhere, open Steam and choose Games → Activate a Product on Steam.
• Enter the product code exactly as it was issued to you.
• The game appears in your Steam library — download and play.

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