Live 2D orbit view

The yellow planet is stationary. The blue planet moves under gravity from the fixed planet.

Running

Stationary planet Orbiting planet Motion trail

Variable sliders

Change values anytime, then press reset to restart from the selected distance and velocity.

Stationary planet mass 5000 More mass creates stronger gravity and faster possible orbits.

Orbiting planet mass 50 Changes force, energy, and visual size. Acceleration depends mainly on the fixed planet.

Gravity strength G 1.00 Higher G pulls the orbiting planet inward more strongly.

Start distance 260 The orbiting planet starts this far to the right of the fixed planet.

Start velocity 4.38 Tangential starting speed. Try lower for crashes and higher for escape paths.

Time scale 1.00× Speeds up or slows down the simulated time step.

Trail length 900 Set to zero for no trail, or increase for long orbit paths.

View zoom 1.00× Zoom the camera without changing the physics.

Show vectors Auto follow

How the simulator works

This model uses Newtonian gravity in two dimensions. The stationary planet is locked at the center, while the orbiting planet updates its velocity and position every animation frame.

F = G × M × m / r²

For a near-circular orbit, use the Stable Orbit button or set velocity close to √(G × M / r).