Until the 17th century, most educated Europeans considered the orbits of the planets to be on celestial spheres of some unknown matter, nested one within the next. The apparent motions of the fixed stars and planets were accounted for by treating them as embedded in rotating spheres made of an aetherial, transparent fifth element (quintessence), like jewels set in orbs.
I'm just fond of the images. And always amazed/amused by humans creative imaginations.
Design Team Member Rhonda Secrist Thomas made It's in the Cards (see the wide photo below). More info in the blog and/or see the supply list.