Gravity & Orbits
Launch stars, planets and moons and watch real orbits form under Newton's law of gravity.
This is real Newtonian gravity, not an animation. Pick a preset or drag on the canvas to launch a body, then read off its mass, distance, orbital speed and Kepler period in real units.
Bodies: 0 · Time: 0.00 yr
Drag to launch a body
Presets
Selected body
Tap a body to see its mass, distance, speed and orbital period.
SystemStable
Energy drift: 0.000%
Constants & sources
G = 4π² AU³·M☉⁻¹·yr⁻²
1 AU = 1.496×10¹¹ m
1 M☉ = 1.989×10³⁰ kg
1 AU/yr = 4.741 km/s
T² = a³/M (Kepler)