Spirograph modeling orbit precession

Use spirograph art to model how orbits go through precession (the orbit slowly rotates around the central body).
Lessons activity is in
  • spirograph set
  • ballpoint pens
  • paper

We usually think of the orbit of a body in space to be fixed, but 'apsidal precession' of orbits (slow rotation of the orbit path) has been observed - see image here:…

Most planets in the solar system have apsidal precession, but at a very slow rate, so their orbits are almost stationary.

Show students orbit precession images. Note that drawings of precession are highly exaggerated - the actual shift on each orbit is very small and only observed after watching an orbiting body for many years.

Lunar precession of the Moon around Earth image:…
Also animations of lunar precession at

A star, called S2, orbiting Sagittarius A* (the black hole at the centre of the Milky Way) has been observed for 27 years to notice precession:…

Students make art with a spirograph to model the patterns made by precession of orbiting bodies.

Grades taught
Gr 4
Gr 5
Gr 6