DIY Planet vs Space Crash Simulator

Create all kinds of planets and see them grow.

Space Crash Simulator models planet collisions the way scientists do. Every planet, moon and star is built from thousands of particles and simulated with SPH (smoothed particle hydrodynamics), the method researchers use to study giant impacts such as the one thought to have formed our Moon. Nothing is scripted: gravity, pressure and heat decide what happens, so every collision plays out differently. SET UP YOUR OWN EXPERIMENT Place up to 8 bodies, choose their size, density, spin and velocity, and see the predicted orbits before you press play. Watch an impact melt a crust, fling debris into orbit and gather it into a new moon, which gets its own trail so you can follow it. OCEAN TIDES An Earth with real oceans: tens of thousands of water particles that respond to the Moon’s gravity. Watch tides flow around the continents, change the Moon’s mass, distance and orbit, and send asteroids into the sea to see the waves they make. GALAXY COLLISIONS Collide two galaxies and watch their stars and gas swirl into tidal tails and bridges before the cores merge into one. MORE TO EXPLORE Protoplanetary disk mode: watch planets form from a disk of dust around a young star Rings, and moons torn into rings by tides inside the Roche limit Black holes with gravitational lensing and accretion disks Heat, lava and cooling crusts after impacts Shapes beyond spheres: cubes, walls, tori, hollow spheres, and your own drawings with the Shape Painter Sample models to collide: Phobos, a Saturn V, a Dyson sphere, the Moai and more Your own photos as planet textures Particle count, accuracy and timescale adjustable to your device PREMIUM No ads, 20 save slots, and a 3D model importer (.glb, .gltf, .obj, .stl, .zip): turn your own models, with their colors and lights, into particle bodies and see how they hold up in a collision. Developed by the creator of Solar System Simulator.