Universe Sandbox Wiki

Most objects in Universe Sandbox have a simulated composition, a list of materials that make up the object and their relative amounts. The composition of an object will affect its temperature, appearance, and other simulated characteristics.

Currently, four materials are simulated by Universe Sandbox:

  • Iron
    • The densest of the materials, Iron is displayed at an object's core in the cutaway view at the top of the Composition tab.
  • Silicate
    • Represents rock, and is the second-most dense of the materials.
  • Water
    • The second-least dense material
  • Hydrogen
    • The least dense material, Hydrogen is the top later in the cutaway view at the top of the Composition tab. Star objects are composed of 100% Hydrogen.

Related Properties & Settings[]


  • Each material is listed in the Material Composition section at the top of the Composition tab of an object's properties panel. For each material, the total mass of that material is displayed, as well as its relative amount compared to the other materials, in the form of a percentage. The percentage of all the materials in an object will always add to 100%.


  • Organics & Carbon Dioxide were materials that existed in prior versions on Universe Sandbox, but have been removed.
  • In the May 2022 Blog, it's stated the Universe Sandbox developers are planning on adding new materials to the game, such as Carbon Dioxide, Helium and Methane. It's also stated that Methane will be used to simulate methane lakes such as the ones on Titan in real life.