The University of Chicago

373 W. Geneva St, Williams Bay WI 53191 (Latitude 42 34.2, Longitude -88 33.4)
Dome structure

The birthplace of modern astrophysics
Yerkes Observatory is a facility of the Department of Astronomy and Astrophysics of the University of Chicago. It was established in 1897 on Geneva Lake in Williams Bay, Wisconsin. Until the mid-1960's, Yerkes Observatory housed all of the Department's activities. Today the 77-acre, park-like site in southeast Wisconsin provides laboratory space and access to telescopes for research and instruction.
Yerkes Observatory occupies a unique niche for the educational and the scientific community. It bridges several important perspectives in formal and informal education. The history of astronomy and astrophysics of the observatory is a solid foundation for introducing all the important topics in current research as well as the practice of observational astronomy. There is a huge range of opportunities for learning. Because of Yerkes' historical context, the world of professional and student astronomers and astronomy educators is drawn to the observatory. These communities learn from one another, build relationships, and create programs, which result in enriched experiences and learning opportunities for young and diverse members of our society.

Yerkes Observatory is open for free public tours  every Saturday throughout the year. We also offer group tours or special programs.

Upcoming Events

  • Regular Saturday Tours
    Yerkes Observatory is open for free public tours every Saturday throughout the year. Programs begin at 10:00 a.m., 11:00 a.m., and Noon. We will be open for regular Saturday tours December 27 and January 3. Occasional repairs to the exterior of Yerkes Observatory from Spring through Fall of 2014 are not expected to interfere with weekday or Saturday tours.

    For more information, click here
  • New Weekday Tours
    We offer daytime tours similar to those on Saturday on some weekdays, dependent on tour guide availability. 30-minute tours for up to five people are $25, plus $5 per additional person. To schedule a tour, email: or call 262-245-5555, Extension 880. Be certain to include your cell/telephone number and email address.
  • Observe through a Big Telescope
    Throughout the year, weather permitting, Yerkes Observatory offers evening observing sessions for adults and kids aged twelve and up. Participants look at a variety of fascinating celestial objects through a large, modern 24-inch diameter telescope....

    For more inormation, more...
  • Public Star Party
    As the seasons change, so do whichever planets, stars, and constellations happen to be visible. Yerkes Observatory is hosting a public star party on Saturday, April 11 from 7:30 to 9:30 p.m. 

    To learn more about this events and register, click here
  • 2015 Yerkes Astrophysics Academy for Young Scientists (YAAYS) Camps
    Every year, Yerkes Observatory scientists and educators offer a variety of summer camps revolving around STEM topics (Science, Technology, Engineering, and Math). The aim of Yerkes Observatory summer camps is to involve students in STEM based exploration to build a sense of confidence solving problems using the practices of science and engineering in an atmosphere that is active, engaging, and fun.

    For more info and applications, click here

The education programs are made possible in part through SOFIA Outreach at Yerkes Observatory.

University of Chicago Press release: Middle schoolers to explore sky with robotic telescopes

Yerkes Study Group (YSG)
The Yerkes Study Group was formed to explore the best use of Yerkes Observatory as a future site for a regional center for science education. To download the final report (pdf file) of the YSG click here
Yerkes Obs