Richmond Hill David Dunlap Observatory Turns 90!

RICHMOND HILL – This year marks the 90^th anniversary of the Richmond Hill David Dunlap Observatory (RHDDO). Since opening on May 31, 1935, the RHDDO has been home to Canada’s largest telescope and a centre for astronomical discovery, education and community programming. 

To celebrate the anniversary, residents are invited to explore the night sky, discover the cosmos and learn about the history of this unique site through exhibitions across the site.   

• Saturday, May 31: Bring your binoculars or telescope, a flashlight and folding chair for a Stargazing Party in Observatory Park. Learn to read star charts and pick up basic observing techniques from local astronomy enthusiasts. The Administration Building is open for self-guided tours at 8:30 p.m. and stargazing begins at sunset!
• Saturdays and Sundays: Drop by from 1-5 p.m. for self-guided tours of the RHDDO’s historic Administration Building and Observatory Dome
• All Summer Long: Visit a new exhibit of artifacts and historic materials from the Dunlap Institute for Astronomy and Astrophysics, University of Toronto on display in the Administration Building’s library 

Come celebrate 90 years of stargazing, science and community connection! Plan your visit, sign up for programs and learn more at RichmondHill.ca/DDO. 

Quote
“Richmond Hill’s David Dunlap Observatory is one of our most treasured and recognizable landmarks. For 90 years, it has helped people discover the wonders of the universe and continues to inspire new generations of stargazers, scientists and explorers. I’m extremely proud of its legacy and invite you to come and discover the magic of the night sky at this historic site!”

- Mayor David West 

Did You Know… 

Ongoing restoration projects — including recent dome repairs and a new pedestrian bridge now under construction — are part of the City’s vision to transform the RHDDO into a destination park and national landmark for future generations to enjoy. 

RHDDO Timeline

• 1800s: Observatory property is a farmstead
• 1932: Jessie D. Dunlap purchases land for the University of Toronto Observatory
• 1935: Dome and Administration Building open
• 1972: DDO astronomer Charles Thomas Bolton presents direct evidence of the black hole Cygnus X-1
• 2017: 40 hectares of parkland, the Observatory Dome with the original 1.88 metre telescope and the Administration Building transferred to Richmond Hill ownership
• 2019: RHDDO is designated a national historic site
• TODAY: 15,000+ participants enjoy our astronomy programs annually