Quirks & Quarks·Bob McDonald's blog

Canada a leading force behind the most powerful telescopes for a century

Since 1918, we've built some of the most powerful eyes on the skies.

Since 1918 we've built some of the most powerful eyes on the skies

The observation dome which holds the 100-year-old, 1.8-metre Plaskett Telescope at the Dominion Astrophysical Observatory in Victoria, B.C. (National Research Council of Canada)

May 3, 2018, marks the 100th anniversary of the first light through the Plaskett telescope at the Dominion Astrophysical Observatory in Victoria, B.C. It was the largest operating telescope in the world at the time, and started a tradition of this country building large astronomical instruments that continues today.

John Stanley Plaskett was the astronomer who convinced the government to build the 1.83-metre telescope that is named in his honour.

He became the first director of the DAO and used the 42-ton instrument to make the first measurement of the rotation rate of our Milky Way Galaxy, which he found takes about 220 million years to turn once.

He also discovered that most of the stars in our galaxy are binary systems — two stars orbiting each other.

Plaskett was dedicated to public outreach and made sure that the telescope was open to the public by providing tours and hosting star parties, which still continue to this day. And the telescope, while far from the world's largest by today's standards, still contributes cutting edge astronomical  observations.

Unpacking the 1.88-metre mirror at the Dunlap Observatory in 1935. (Virtual Reference Library)
Canada has a long tradition of building large telescopes.

The David Dunlap Observatory just north of Toronto opened in 1935 and is almost an exact duplicate of the Plaskett with a slightly larger mirror of 1.88 metres (Of course the Toronto telescope had to be bigger).

Canada partnered with France and the United States in 1979 to open the Canada-France-Hawaii Telescope on top of Mauna Kea in Hawaii.  While it's 3.6-metre mirror was not the largest in the world, the telescope was still the most powerful thanks to a sophisticated CCD camera, with a resolution that would not be beaten until the Hubble Space Telescope was sent into space.

Gemini North (left) in Hawaii, and Gemini South (right) in Chile. Canada is a major partner in the twin Gemini telescope project. (Mailseth, Denys, cc-by-sa-3.0)
In the 1990's, Canada joined a consortium of countries including the U.S., U.K., Argentina and Chile to build the twin Gemini North and South instruments,  with one in Hawaii and the other in Chile so both hemispheres of the sky can be covered.

It is a little know fact that the first astronomical observatory ever built in North America was erected in Nova Scotia in 1765 and since then this country has built than 25 instruments around the world and in space.

And this investment has paid off scientifically, where over the last century, Canada has been among the top five countries in the world when it comes to astronomical publications and citations..

Rendering of the James Webb Space Telescope, which will launch in 2020. (NASA/Northrop Grumman)
That tradition continues into the future with the construction of the enormous Thirty Metre Telescope, which is planned to be built in Hawaii. And Canada is even involved in the new James Webb Space Telescope, which will be the largest telescope ever sent to space.

All this is to say that Canada does great science, which most Canadians may not know.

So let's celebrate a century of staring at the stars and figuring our our place in the universe.


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