The University of Chicago

373 W. Geneva St, Williams Bay WI 53191 (Latitude 42 34.2, Longitude -88 33.4)
Look Through a Large Telescope at the Moon, Saturn, Nebulae, Star Clusters and More at Yerkes Observatory!

From season to season the evening sky changes slowly and reveals many different celestial wonders visible with, and without, optical aid. Every month during the year, on select weekday and weekend evenings, Yerkes Observatory offers observing sessions with our 24-inch diameter reflecting telescope, weather permitting, for participants who are age 10 and up.

All July 2014 observing dates are sold out. Our August public observing dates will be posted here on or about July 25th.

Summer public observing events at Yerkes are very popular and sell out quickly. Space on each tour is subject to availability. All sessions are limited to 12 participants and last approximately two hours.

The cost to participate is $30 per person, payable the evening of the event. Reservations are required and can be made by email at Please include your email address and cell phone number with the number of people in your party. The tour organizer will send a return email confirmation promptly that includes additional information and instructions pertinent to your event.

Scheduled event dates are removed from these listings as quickly as possible after they sell out. Other dates in July not shown in the listings above are not available for public observing due to previously scheduled, private, Observatory events. We do not schedule public viewing for about four evenings before and four evenings after full moon due to excessive sky brightness. Full moon in July occurs on the 12th.

Participants must be physically fit and able to climb 40 steep, winding stairs from the ground floor of the building to the observing dome of the 24-inch reflector. Sensible shoes are required (no high heels, flip flops, open-toed sandals, etc.).

We begin each program with a brief introduction to the night sky with the unaided eye. Binoculars can help to enhance your stargazing experience at Yerkes, but are not necessary. During summer evenings from the dark sky environment at Yerkes you may see superb views of planets, constellations, hundreds of stars, an occasional meteor, the Milky Way and artificial satellites.

For information about regularly scheduled Saturday tours, weekday tours, and other events, please click here.