Caelium Alpha




Caelium Alpha is a digital orrery sandbox.

An orrery is a model of the solar system; small worlds you can carry with you. Make your own little planetary system orrery by adding planets, moons, and adjusting properties. Then marvel at the possibilities in the universe :)

There are 2 editions of Caelium Alpha: LD38 Edition and Post-LD Edition. LD38 Edition was made in 72 hours for the 38th Ludum Dare game jam. That edition has strange bugs and little features. It is highly recommended to play the Post-LD Edition, which has the bugs fixed, and more features. Both editions are avaliable for download on (link below).


  • Start off with a star and adjust its properties (radius, color, etc.)
  • Add planets to the star, and adjust their properties
  • Add moons to each planet, and adjust their properties
  • Automatic padding between every astronomical body, fully adjustable
  • Properties include color, radius, padding, axial speed (rotation), and orbital speed (revolution)
  • Guarantee that most stars spawned will have a unique name
  • Planet and moon names are based off stars (just like real exoplanets)
  • Stars, planets, and moons will spawn with random surface texture (not adjustable at this time)


  • WASD: Move
  • Shift: Hold down to move faster
  • R: Zoom In
  • F: Zoom Out
  • 4: Reset Zoom
  • Right Click: Select a Star or Planet (or deselect by right clicking nothing)
  • Esc: Quit


Post-LD Edition on

Info and Ratings on Ludum Dare