Motorized Planetarium by Trippensee. Trippensee has made this same model for over 50 years. These planetariums are durable and reliable gear and ladder chain driven so that the Earth maintains it’s 23-1/2° axis, revolves around the sun and rotates on it’s axis, all at the same time. The moon revolves around the Earth and keeps it’s one face toward the Earth. Venus also revolves around the sun, and can be positioned by hand, as well, to show phases and where it is located as the morning or evening star.
