An orrery is a mechanical model of the Solar System that illustrates or predicts the relative positions and motions of the planets and moons, usually according to the heliocentric model.
Making an orrery like this would probably open a rabbit hole with my kids, but that might not be a bad thing.
For anyone else who might be wondering:
Making an orrery like this would probably open a rabbit hole with my kids, but that might not be a bad thing.