Select a body type, click to place, drag to set velocity
🌍 Earth & Moon
One planet with an orbiting moon
☀️ Solar System
Star with 4 orbiting planets
⭐ Binary Star
Two stars orbiting each other + planet
💥 Chaotic 3-Body
Three equal stars — unstable!
🪨 Asteroid Belt
Star + planet + 20 asteroids
Bodies: 0 · Mass: 0 · Time: 0s
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Solar System Builder — Free N-Body Gravity Simulator
Build your own solar system with this free online gravity simulator. Place stars, planets, moons, and comets, then watch as gravitational forces create orbits, collisions, and chaotic interactions. Our N-body simulation calculates real gravitational physics between every pair of bodies in real-time.