David Dunlap Observatory (DDO)

The David Dunlap Observatory is Canada's largest optical telescope with a primary mirror measuring more than 1.88 metres (74 inches) in diameter. Constructed in the 1930s, the Observatory is located in the heart of Richmond Hill, Ontario. The building is 18.6 metres (61 feet) in diameter and the rotating dome weighs 73 metric tons. The telescope itself weighs 21 metric tons (without its primary mirror).

RASC Toronto Centre volunteers manage the Observatory and adjacent Administration building, providing public education and outreach programs to thousands of people each year.

As home to the largest volunteer-managed telescope in the world regularly open for public stargazing, the David Dunlap Observatory provides a model for reuse and repurposing of retired observatories.

Our stewardship has allowed the Great Telescope to remain operational and introduced thousands of visitors to astronomy and the history of space science.

The next step in our journey is the creation of an institution that looks to the future of space science, by encouraging our future scientific leaders. The Observatory will continue to be used for education and public outreach with appropriate upgrading to create a vibrant, interactive experience for public visitors and school groups.

RASC-TC is now actively engaged in discussions with the Town that we hope will lead to a revitalised DDO outreach and telescope operations program for all. The Town will decide on a group that will run the DDO.  RASC-TC wants to be that group. The Town has also decided, in the interest of fairness to all, that no outreach will take place at the DDO until an outreach provider is decided. It is expected that the Town will need the remainder of 2016 to conduct their business with choosing an outreach provider.  If you would like to be a part of the new DDO programs for the 2017 year, contact any Council member.