Create a solar system, throw worlds into each other, or watch a thousand rings find their balance. Every body participates in Newtonian gravity.
Explore
Drag empty space to orbit the camera. Right-drag to pan. Scroll or pinch to zoom. Click a body to inspect it; double-click to follow it.
Experiment
Change mass, velocity, temperature, or composition. Add an orbital companion or use Place & launch: drag from a launch point to set velocity. Move mode repositions a body in the world’s XY plane.
Keep your discoveries
Save locally, export JSON, capture a PNG, or scrub recorded history. Undo and redo restore entire edit snapshots, including the time of the edit.
What this model means
Leapfrog N-body gravity, optional Barnes–Hut approximation, conservative mergers, and explicit sandbox fragmentation. Thermal response is a zero-dimensional equilibrium model. Rings drawn on planets are decorative; ring-scenario particles are physically simulated. Surfaces and black-hole accretion graphics are procedural illustrations, not measured maps or relativistic ray tracing.
Initial orbital phases are illustrative, not NASA ephemerides. This independent, clean-room implementation does not load Universe Sandbox files or reproduce its proprietary simulation engines. Read the included science and architecture documents for equations and limitations.