Here's the thing about orbits that doesn't get said enough: an orbiting object isn't defying gravity, it's constantly falling — it's just moving sideways fast enough that the ground (or the planet) curves away underneath it at the same rate it's falling toward it. Miss that sideways speed and you don't orbit, you just fall straight down. Overshoot it and you fly off into space instead. Orbiting is the narrow, satisfying sweet spot in between.
The Orbits preset flips gravity from the sandbox's usual "straight down" into "pulls toward a central body," and drops a smaller object nearby with some starting sideways velocity. Because it's a genuine interactive physics simulation and not a looping animation of a circle, you can launch the object at any speed you want and watch what actually happens — a tight fast orbit, a lazy wide ellipse, a spiral straight into the center, or a clean escape off the edge of the screen.
Turn on motion trails and the orbit draws itself as it happens — and if it's not a perfect circle, that's not a bug, that's an ellipse, which is what real orbits (including Earth's, including every planet's) actually are. Watch the object speed up as it swings close to the central body and slow down as it swings out wide — that's the same "closer means faster" rule that governs actual satellites and actual planets, playing out in your browser.
And, same as every preset here: the Knowledge Level slider changes how deep the lesson panel goes. "Falling sideways fast enough that you keep missing the ground" at Curious, Kepler's laws and orbital mechanics once you're at University or Expert. Same central body, same launch, as much gravity math as you want.
Try this
Find the crash speed. Launch the orbiting body slower and slower. At what speed does it stop orbiting and spiral into the center?
Find the escape speed. Now go the other way — launch it faster and faster until it stops orbiting and flies off entirely.
Trace an ellipse. Turn on motion trails and launch at a speed that gives a stretched, oval orbit instead of a circle. Watch it speed up on the close pass.
Go play with it yourself
No signup, no download — it opens straight into the sandbox with this scene already loaded.
Play with it — free →