Program Details: Open to the public

Astronomy Day at CU

Every year for the past decade, Sommers-Bausch Observatory and Fiske Planetarium have opened their doors to the public for a free, day-long CU Astronomy Day celebration. The Saturday date varies from year to year, but is usually held during the last two weeks in April shortly before school lets out. Activities begin around noon and continue through the late evening hours.

Activities at the Observatory include explorations of the electromagnetic spectrum, general astronomy activities and demonstrations, and hands-on astronomical observations. During daylight hours, members of the Boulder Astronomy and Space Society help budding young astronomers learn about amateur astronomy and what kind of telescope to buy. After dark, there is stargazing (weather permitting) with both the BASS and Observatory telescopes.

Fiske Planetarium offers a variety of displays, activities and demonstrations including rocket launches, live talks, starshow mini-presentations, Science on a Sphere explorations of the Earth and the solar system, and concludes each year with a special evening planetarium presentation. Local amateur and professional astronomy vendors are also present.

This is a public program. For more information, please visit the program website.


On Campus

  • Fiske Planetarium & Science Center
  • Sommers-Bausch Observatory

Program Partners

Supporting This Program

  • Astronomy Magazine
  • Boulder Astronomy & Space Society
  • CU Astronomy Club
  • Celestron Telescopes
  • Fiske Planetarium
  • Sommers-Bausch Observatory

Sponsoring Units

Arts & Sciences, College of

  • Astrophysical & Planetary Sciences, Department of

Program Contact

Fabio Mezzalira
Manager, Sommers-Bausch Observatory

Program Categories


  • Education (K-12)
  • Physical Sciences
  • Physics
  • Recreation/Entertainment
  • Science
  • Space Sciences
  • STEM (Science, Technology, Engineering, Math)

Program Types:

  • Community Event
  • Exhibition
  • Public Lecture/Demonstration
  • Public Performance


  • Children & Youth (outside school)
  • Families
  • General Public
  • Students - Elementary School
  • Students - High School
  • Students - Middle School

We do our best to accurately represent CU Boulder’s outreach programs and services, but they are subject to change and may no longer be active in a community. Please contact the program directly for current information.