public alpha now available


Universe Sandbox ²

What is Universe Sandbox ² ?

Universe Sandbox ² is a physics based space simulator.


Create, destroy, and interact on a scale you've never before imagined.


Shoot asteroids at the Earth or cause a run away greenhouse effect. Rip apart the rings of Saturn or blow up the Sun.


OS Logos

For Windows, Mac, and Linux.


Requires free Steam account.


For full system requirements and other information, see the FAQ.




Windows, Mac, Linux

What does alpha mean?

Universe Sandbox ² is still alpha software. We're not done fixing many of the issues and improving it. There remain many bugs, and you, the early access user, will help us uncover even more. Buying-in early means you won’t have to wait to explore the many new and exciting features that are already in place, but know that all of the final polish won’t be there yet.






What's New?

Earth & Moon Collision

Awesome Collisions

Epic, mind blowing collisions of massive planetary bodies that can be simulated at almost any speed.



Climate Simulation

Watch sea ice grow and recede with the seasons because of the tilt of the Earth: change the tilt and change the seasons. Or move the Earth further from the Sun and freeze the entire planet.

Learn more...



Add carbon dioxide to a planet's atmosphere to heat it up. Then add water...


Deform the Surface

Impact planets with asteroids and comets and leave behind massive, molten craters.

And more...

  • Material System - build planets out of Hydrogen, Iron, Rock, & Water
  • Stellar evolution & supernovae
  • Solar flares & volatile trails
  • Procedurally generated
    stars and planets
  • Light-warping black holes
  • Simulated dark matter





Universe Sandbox ² Gameplay Video

Demonstration of Universe Sandbox ² Alpha 7

Collision Tests in Universe Sandbox ² Alpha 7




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Who's Making It?

Dan Dixon

Project Lead & Creator

Christian Herold

Developer & Code Architect

Georg Steinröhder

Developer & Shader Wizard

Thomas Grønneløv

Numerical Physics Developer

Jenn Seiler

Astrophysicist & Developer

Naomi Goldenson

Climate Scientist & Developer

Collectively we are Giant Army.

Standing on the shoulders of giants...



Chad Jenkins

Developer & Technical Artist

Jared Meier

Operations & Support