EVENT LOG
REPLAY
buffer 0 frames
Each scenario loads a ready-made system. You can edit anything once it is running.
Everything here also works from the command palette: press / and type what you want.
Version 3 · physics: direct N-body, Leinhardt & Stewart collision scaling, Roche and tidal heating, Jeans escape.
Speed. The readout says how much simulated time passes per real second. Above ×10⁶ the integrator may not keep up; the SIM-LIMITED chip appears when it slows down.
Collisions. Slow impacts merge; grazing ones can skim past (hit-and-run); fast ones erode or shatter bodies into fragments and debris. Big impacts melt crusts into magma oceans.
Roche limit. Inside it, tides tear bodies apart and fragments can't re-merge, so rings form. Black holes do this to whole stars: a tidal disruption event.
Accretion cross-section. Real planet formation takes millions of years. This slider inflates collision radii so you can watch it in minutes; set it to ×1 for physical behavior.
Black holes. Anything entering the capture zone is swallowed. Infalling gas heats into a glowing accretion disk, and the hole's luminosity tracks how fast it feeds.