Adler Planetarium

Historic Atwood Sphere

About the Exhibition

Experience the night sky over Chicago as it appeared in 1913 in the Atwood Sphere – Chicago's oldest planetarium. Although the star positions have not changed since then, we can see only a small percentage of these stars in our current night sky due to light pollution. The sphere is seventeen feet in diameter and has 692 holes drilled through its metal surface. These holes allow light to enter and show the positions of the brightest stars in the night sky.

Take a live guided tour of the Atwood Sphere and identify stars and the constellations they form.