Gravity Sandbox

Draw a system. Release it into chaos.

Create stars and planets, set their velocity and watch orbits, encounters and mergers. A small universe in your hands.

FR / LAB

Preparing the experiment…

Preparing controls.

01 / THE GESTURE

How to explore

Drag through space to add a body and set its velocity. Or use Add planet. This also works while paused.

02 / THE MODEL

What you are observing

Two-dimensional Newtonian gravity, fixed-step velocity-Verlet integration and short-distance force softening. Collisions merge masses while conserving momentum, not kinetic energy. Arbitrary units, not an astronomical prediction.