Planets in a Box

Planetary collision simulator

Planets in a Box is a PC planetary-collision simulator. You set up bodies in space, start the simulation, and watch gravity pull particles of rock and iron together as they collide, heat up and break apart. You can recreate the giant-impact scenario for the Moon, with a Mars-sized body striking the early Earth, or set up your own collisions and planetary systems.

Set up impacts

Before a collision, change the bodies’ masses, impact angle, speed, core size and spin. Choose a grazing hit-and-run or a head-on impact, or start with a rotating cloud of dust and watch it collapse into a planet, with clumps left in orbit. You can also start from empty space, add planets, the Moon or custom bodies, and arrange them in orbit.