ORBITARIUM — A Personal Observatory

Create 3D planetary systems, experiment with gravity and complete eight orbital challenges. Local, offline, no accounts.

Build a small collection of worlds. Change one thing. Watch a different sky emerge. ORBITARIUM opens a full-tab 3D observatory from the browser toolbar. Create planetary systems, inspect individual worlds and experiment with a bounded Newtonian gravity model. It does not replace your New Tab page, so it can coexist with FLIPFOLIO. A SYSTEM THAT RESPONDS Up to 32 bodies participate in pairwise softened gravity. Change mass, position, velocity and collision radius; add worlds with a circular-velocity starting helper; or use the X–Z velocity pad for direct changes. Planets are not attached to preset animated tracks. Collisions combine bodies using a simplified mass- and momentum-preserving merge rule. FIVE STARTING SYSTEMS Explore The Aurora system, A dance for two, Around a quieter world, The scattered garden, or a blank system with a central star. Rotate the view, fit the system, zoom in and follow a world. Procedural planetary surfaces, illumination, rings and trails are rendered locally with WebGL. EIGHT HANDCRAFTED EXPERIMENTS Repair an almost-circular orbit, arrange a rendezvous, tune a binary, keep a moon, redirect a visitor, preserve a belt, tilt an orbit and build a system of your own. Each experiment has a finite, explicit observation period and an actual completion condition. Sandbox play remains open after the experiments. TRY ANOTHER OUTCOME Keep up to ten recent checkpoints and twelve archived systems. A checkpoint restores the stored physical state rather than pretending that reversing time can undo a collision. Export/import a portable .orbitarium system file. Imported systems become sandbox worlds; they do not award experiment completion. TIME UNDER CONTROL Pause, single-step or request ¼×, 1×, 4×, 12× or 32× simulation time. The calculation budget limits work per animation frame. On a slower machine, simulated time slows instead of silently increasing the integration step. Time does not continue when the page is hidden or closed. MODEL AND HARDWARE LIMITS This is an exploratory game, not a scientific prediction or mission-planning tool. Units are normalized; gravity is softened; collisions merge bodies. It does not simulate general relativity, atmosphere, climate, life, fluid dynamics or whole galaxies. Visual radii are enlarged for readability; rings, halos, surface textures and background stars are decorative. Future paths cover only a finite simulated horizon. Success over a mission interval is not a guarantee of indefinite stability. WebGL support is required for 3D viewing. Economy, Balanced and Detailed modes adjust rendering resolution without changing physics. Context-loss handling pauses the model and attempts to restore the renderer. Performance depends on the device, scene and requested speed; 32× is a requested rate, not a guarantee on every computer. PRIVATE BY DESIGN No account, analytics, cloud simulation or automatic uploads. Keep exported system files as backups; browser data can be removed by uninstalling, clearing data or device failure. One tab edits the local workspace at a time when browser locking is available. A storage warning means persistence has not been confirmed.