The Dominion Observatory was founded in 1905 in Ottawa, Ontario. The impetus for Canada’s first government observatory came from the Geological Survey of Canada, which had a pressing need for a service that could supply precise temporal and spatial coordinates for its mapping and topographic surveys. In those days, only observatories were capable of providing such a service.

William Frederick King, Chief Astronomer for the Department of the Interior, played a key role in setting up the new observatory. He became its first Director and equipped it with a 35-centimetre telescope, the largest ever installed in Canada.

The first mandate of the observatory was to determine and distribute the exact time to the rest of the country. King confided this task to Robert Meldrum Stewart, the astronomer who went on to become Director from 1923 to 1946. In those days, it was necessary to monitor the path of reference stars on a regular basis in order to precisely determine the time. More specifically, it was necessary to know the exact moment when certain stars passed their highest point in the sky (the meridian); these were known as “transit times”.
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The Dominion Observatory was founded in 1905 in Ottawa, Ontario. The impetus for Canada’s first government observatory came from the Geological Survey of Canada, which had a pressing need for a service that could supply precise temporal and spatial coordinates for its mapping and topographic surveys. In those days, only observatories were capable of providing such a service.

William Frederick King, Chief Astronomer for the Department of the Interior, played a key role in setting up the new observatory. He became its first Director and equipped it with a 35-centimetre telescope, the largest ever installed in Canada.

The first mandate of the observatory was to determine and distribute the exact time to the rest of the country. King confided this task to Robert Meldrum Stewart, the astronomer who went on to become Director from 1923 to 1946. In those days, it was necessary to monitor the path of reference stars on a regular basis in order to precisely determine the time. More specifically, it was necessary to know the exact moment when certain stars passed their highest point in the sky (the meridian); these were known as “transit times”.

Due to the conscientious observation of transit times for many stars, and to the acquisition of a high precision clock in 1929, Stewart gradually established a network of clocks throughout Ottawa’s federal government buildings. A signal from the observatory’s clock was electronically transmitted to the buildings; in this way, about 700 clocks in Ottawa were able to display precise time by 1930. After 1941, this time service was extended to the entire country and the Dominion Observatory became the official supplier of time for Canada.

In order to fulfill its second mandate – to provide spatial coordinates for the country – the Dominion Observatory set out to determine the precise position of 3,162 stars in the sky. This was accomplished by recording 28,000 astronomical observations from 1911 to 1923. A new project was launched in 1923, and the positions of another 1,368 stars were measured until 1950.

The first speaking clock of the Dominion Observatory.These data – combined with the knowledge of exact time – allowed longitude, latitude and elevation to be calculated with precision for many points across Canada.

As part of its responsibility to the Geological Survey of Canada, the Dominion Observatory was also entrusted with a third mandate: to collect seismic, gravimetric and magnetic geophysical data.

Among the noteworthy events that marked the history of the Dominion Observatory were the apparent discovery of “Planet X” in 1928, the determination of the solar rotation as a function of latitude in the 1930’s, and the discovery of numerous meteor impact sites in Canada.

Scientific institutions in Canada were reorganized in 1970 and the responsibilities of the Dominion Observatory were transferred to the National Research Council of Canada (NRC). The observatory ceased its activities and the building became the headquarters for the NRC. In 1974, the telescope was moved to the Helen Sawyer Hogg Observatory of the Canadian Museum of Science and Technology where it remains to this day.

© 2006 An original idea and a realization of the ASTROLab of Mont-Mégantic National Park

Black and white photo of the Dominion Observatory

The Dominion Observatory

Pierre Lachaîne

© Pierre Lachaîne


Black and white photo of the first speaking clock of the Dominion Observatory

The first speaking clock of the Dominion Observatory.

Canadian Science and Technology Museum/Dominion Observatory

© Canadian Science and Technology Museum/Dominion Observatory


The Mont-Mégantic Observatory was opened in 1978 near Sherbrooke, Quebec. It was created to promote university-level astronomy education in Quebec, to provide qualified astronomers with state of the art research equipment, and to promote astronomy among French Canadian citizens.

The telescope is equipped with a 1.6-metre mirror that weights one metric ton; the entire structure weighs 24 tonnes. The Mont-Mégantic Observatory houses the largest telescope in eastern North America, and the fourth largest in Canada after those of the David Dunlap Observatory in Toronto (1.88 metres), the Dominion Astrophysical Observatory in Victoria (1.83 metres), and the Rothney Astrophysical Observatory (1.8 metres). Although not the biggest, the state of the art instruments attached to the Mont-Mégantic telescope make it the most powerful telescope in Canada.

The Mont-Mégantic Observatory.The project to construct a large observatory in Quebec was launched in 1971 by professors Gilles Beaudet and George Michaud of the University of Montreal. Laval University in Quebec City joined the venture in 1974 and a partnership agreement was signed in 1975. The federal and provincial gove Read More
The Mont-Mégantic Observatory was opened in 1978 near Sherbrooke, Quebec. It was created to promote university-level astronomy education in Quebec, to provide qualified astronomers with state of the art research equipment, and to promote astronomy among French Canadian citizens.

The telescope is equipped with a 1.6-metre mirror that weights one metric ton; the entire structure weighs 24 tonnes. The Mont-Mégantic Observatory houses the largest telescope in eastern North America, and the fourth largest in Canada after those of the David Dunlap Observatory in Toronto (1.88 metres), the Dominion Astrophysical Observatory in Victoria (1.83 metres), and the Rothney Astrophysical Observatory (1.8 metres). Although not the biggest, the state of the art instruments attached to the Mont-Mégantic telescope make it the most powerful telescope in Canada.

The Mont-Mégantic Observatory.The project to construct a large observatory in Quebec was launched in 1971 by professors Gilles Beaudet and George Michaud of the University of Montreal. Laval University in Quebec City joined the venture in 1974 and a partnership agreement was signed in 1975. The federal and provincial governments approved the project in 1976, and construction started the same year. The service building was completed in 1977, and the observatory several months later in 1978.

René Racine joined the project in 1973 and became Director in 1976, the same year he left the University of Toronto to work at the University of Montreal. He remained Director until 1997 when he retired, with the exception of a short period from 1980 to 1984 when he took on the role of Director at the Canada-France-Hawaii Observatory.



The 1.6-metre telescope of the Mont-Mégantic Observatory.The observatory was involved in many research projects over the years, the most important of which concerned the relationship between galaxy dynamics and their abundance of chemical elements, the interactions between luminous stars and the interstellar medium, and the polarimetry of young stellar objects.

A dynamic instrument program also accounts for a large part of Mégantic’s productivity. In 1982, Jean-René Roy, along with Yvon Georgelin and Jacques Boulesteix, designed a new Fabry-Perot interferometer for the observatory, and other pieces of equipment followed.

In 1991, for example, the observatory became the first in Canada to use an infrared camera. Named MONICA (for MONtreal Infrared Camera), it was designed by Daniel Nadeau and René Doyon of the University of Montreal. The site at Mont-Mégantic is particularly favourable for infrared astronomy because interference radiation levels are very low during the long cold nights in winter (sometimes even lower than the levels at Mauna Kea in Hawaii).

In 1996, the Mont-Mégantic ASTROLab, an astronomy activity centre, opened its doors to the general public. The centre hosts interactive displays, a high definition movie, multimedia presentations and access to two public observatories during open house astronomy evenings. Visitors can also tour the observatory and its 1.6-metre telescope during the day.

In 1999, a major 3-year renovation program was started. First, the dome of the 1.6-metre telescope was repaired and equipped with a ventilation system. Then, in 2000, the observatory was linked to universities by fibre optics. A year later, the telescope controls became fully computerized and a new bonnet (the interface that allows instruments to be coupled to the telescope) was installed. Following this, a number of new state of the art instruments were also added to the telescope.

Asteroid 4843 is named in honour of the observatory.

© 2006 An original idea and a realization of the ASTROLab of Mont-Mégantic National Park

Colour photo of the Mont-Mégantic Observatory

Mont-Mégantic Observatory.

Sébastien Giguère

© ASTROLab/Mont-Mégantic National Park


Colour photo of the Mont-Mégantic Observatory in the winter

The Mont-Mégantic Observatory.

Sébastien Giguère

© ASTROLab/Mont-Mégantic National Park


Colour photo of a telescope

The 1.6-metre telescope of the Mont-Mégantic Observatory.

Sébastien Giguère

© ASTROLab/Mont-Mégantic National Park


Colour photo of the ASTROLab of the Mont-Mégantic National Park with northern lights

The ASTROLab of the Mont-Mégantic National Park.

Sébastien Giguère

© ASTROLab/Mont-Mégantic National Park


Colour photo of the Mont-Mégantic Observatory at night

The Mont-Mégantic Observatory.

Sébastien Giguère

© ASTROLab/Mont-Mégantic National Park


Learning Objectives

The learner will:
  • identify recent contributions, including Canada’s, to the development of space exploration technologies;
  • describe in detail the function of Canadian technologies involved in exploration of space;
  • draw a solar system with all its components;
  • establish the link between atoms and light using different instruments.

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