Dome of The Night Sky

In a lab on Little Saanich Mountain, engineers are creating the most sensitive radio receivers on Earth.

In one corner they test a feedhorn antenna, stuck into a wall of sound-dampening foam, by radiating it with a series of inaudible, far-infrared frequencies. In another corner, a finished receiver (photo below right) sits in a sealed case that’s filling up with highly-compressed helium, cooling its components down to minus 269 degrees Celsius – making them so quiet, molecularly speaking, that they can detect the tiniest quivers of electromagnetic activity from distant parts of the universe.

These receivers will record the formation of undiscovered molecules, and the birth of galaxies. They are destined for the 66 dish antennas of the Atacama Large Millimeter Array, a $1-billion international project to create the world’s biggest radiotelescope on a 5,000-metre plateau in Chile, set to become operational in 2012.

“With this, you’ll be able to look right down the throats of black holes,” says Jim Hesser, director of the Dominion Astrophysical Observatory, in his office a few floors above the lab. “It’s a really cool project, so to speak.”

Such mindblowing engineering is just the latest chapter in the DAO’s remarkable history. John Stanley Plaskett (1865-1941, photo left), the founder and first director of the observatory, grew up repairing equipment on his family’s Ontario farm, and eventually ran all the machines used in engineering lectures at the University of Toronto. After obtaining degrees in math and physics, he became an astronomer at the Dominion Observatory in Ottawa, and won worldwide recognition for his studies of binary stars. But he got frustrated by the limitations of Ottawa’s puny (0.381-metre) telescope, and after years of lobbying, in 1913 he got a grant to apply his machinist’s skills to building the observatory of his dreams.

A team of astronomers chose southern Vancouver Island as the location because it had the best atmospheric conditions for starwatching in Canada. The federal government bought the peak of Little Saanich Mountain, and Plaskett ordered the observatory’s huge rotating steel dome from Cleveland and the optical parts of its telescope from Pittsburgh. Horse-drawn wagons carried all the pieces up the slope (photo right), including the telescope’s 1.83-metre mirror, the largest in the British Empire.

Plaskett opened the observatory in 1918, and went to work. In 1922, he announced the discovery of what’s now called Plaskett’s Star (left) – a giant binary star with a combined mass 100 times that of the Sun, and until 2008, the biggest stellar object ever known. In 1929, he achieved even greater fame by accurately measuring the rotation of the Milky Way, calculating that it takes the Sun 220 million years to make one trip around the galaxy.

Plaskett retired in 1935, but the DAO acquired more telescopes, and its astronomers continued to rack up achievements. Andrew McKellar made the first measurement of light from the Big Bang in 1941, and in the 1970s DAO staff ground and polished the 3.6-metre mirror (photo below right) for the Canada-France-Hawaii telescope – the biggest working mirror ever made until the Hubble Space Telescope was launched in 1990. That experience in turn enabled the DAO to develop its Astronomy Technology Research Group, which creates state-of-the-art instruments for observatories worldwide.

In 1995, the National Research Council relocated its Herzberg Institute of Astrophysics to here from Ottawa, and now our mountain with the dome is Canada’s pre-eminent astrophysical research centre, with a staff of over 100 people, managing data from and engineering for at least five international telescope projects. Plaskett’s original telescope is still in use too, making the DAO the oldest active observatory in the country, employed by visiting scientists from around the world.

Indeed, judging by the United Nations of names on the DAO’s directory, it seems astronomy truly is a planet-wide discipline. Hesser, for example, started out in astronomy spending nine years in Chile studying the 14-billion-year development of the Milky Way.

“I’ve realized a dream, learning so much about the world and its different cultures,” says Hesser. Chalk up one more surprising discovery from our observatory on the hill: a shared fascination with the farthest reaches of the universe can help international understanding, right here on Earth.