Kepler attempt to associate the six known planets with the five Platonic Solids [La tentative de Képler d'associer les six planètes alors connues aux cinq solides platoniciens].
In 1595, Johannes Kepler found that each of the five Platonic Solids
could be inscribed and circumscribed by spherical orbs, nesting these solids, each encased in a sphere and then associated to the six known planets (at that time...).