The blue dot at the center is the Earth, and next to it are the center of the deferent and the equant point.

The equant point is connected to the center of the epicycle by a faint blue line.

The blue dot on the epicycle is Saturn.

The outermost circle represents the celestial sphere, which carries the mean Sun and the projection of Saturn.

Tap on the canvas (or press Space) to start/stop the animation.

Use the sliders (or ASZX buttons) to adjust the speed and the trail length.