The Botjes planetarium is a fully operational model of the solar system completed in 1868. It is on display in North Hall.

To learn more about the planetarium, click on the detail of interest in the image or select a topic from the list below.

Site Map:

• Why build a planetarium?
• Orbits of the planets
  • Botjes' table of planetary data
• Motions of the sun and moon (years and months)
  • Botjes' description of sun and moon motions
• The celestial sphere: diurnal motion of the stars
• Time of day
• Day of the week
• History of the Botjes planetarium
  • 1896 Newspaper report: arrival in North America
  • 1992 Newspaper report: arrival at Calvin College
• Mechanism and restoration
• Another planetarium
• Directions to visit the planetarium

Calvin observatory home page