John Plaskett looked to the stars

He may have been recognized internationally, but the astronomer called Esquimalt home

By Greg Evans, Municipal Archivist

Our understanding of the cosmos was greatly enhanced by Esquimalt resident Dr. John Stanley Plaskett.

Known in his time as “Canada’s greatest astronomer,” Armit Road was re-named Plaskett Place in 1953, in his honour.

He was born on a farm in Hickson, Ont. in 1865. His father died when John was 16 and after working on the family farm for a time, he began working for the Edison Company (later to became General Electric) in 1886. It was there that he gained his knowledge of electricity and mechanics. This interest would eventually lead to a degree in physics from the University of Toronto. His path was now set for a career in astronomy.

In 1903, he became a member of the Astronomy Division of the Department of the Interior where he helped to design and construct instruments for the new Dominion Observatory in Ottawa. There he designed a new type of spectroscope from which he collected thousands of spectrograms measuring the radial velocities of stars.

In 1910, he proposed that a new giant telescope be constructed so that more effective research in this area could be undertaken. In 1913 federal funding was secured and construction of the new observatory located on Little Saanich Mountain was soon underway.

Inaugurated in 1918, its 1.83-metre telescope was at the time, the largest in the world. Plaskett was appointed as the first director.

Continuing his research with vigour, in 1922, he discovered a binary star – the larger of the two is the most massive known and is named Plaskett’s Star.

Along with Joseph Algernon Pearce he established that our galaxy, the Milky Way, rotates and in time was able to measure its size, mass and rotational speed. Also, he established that it takes 220 million years for our solar system to make one galaxial rotation.

The recipient of numerous national and international awards, Plaskett retired in 1935.

Even after his death in 1941, Plaskett continued to receive recognition. In 1967, a crater on the moon, approximately 80 kilometres in diameter, was named in his honour.

His son, Harry, followed in his footsteps, he too becoming an astronomer of great distinction.

In 1988, the Royal Astronomical Society of Canada and the Canadian Astronomical Society created the Plaskett Medal, awarded each year to the author of the best doctoral thesis in astronomy or astrophysics at a Canadian University.