A GTA professor says the upcoming major eclipse is quite literally a “once-in a lifetime event” as the last time it happened in the Toronto region was 1925 and the next one is expected to be in 2144.

“It’s an once-in-a-lifetime event,” Robert Cockcroft, McMaster University astronomy and physics professor told CTV News Toronto on Thursday. “It’s when you get the perfect alignment between the moon and the sun, and it’s just a coincidence they appear on the same side of the sky.”

“The sun is about 400 times bigger than the moon, but it’s also 400 times further away from the earth so they appear the same size so that allows periodically for the moon to cover the sun.”

A total eclipse in and of itself is not an especially rare occurrence, Cockcroft noted. In fact, it happens once every 18 months or so in various parts of the world, he said.

“If you are willing to travel to an eclipse, it's not that rare of an event. You can get to see one every one or two years,” he said. “But for the eclipse to come to you is what makes it rare. That's what makes it an once-in-a-lifetime thing.”

In Ontario, a total eclipse happened in 1979, but it could only be seen in the northern parts of the province. Paul Delaney, astronomer and professor at York University, chased the eclipse to Brandon, Manitoba, where it was also visible.

“I have seen three total solar eclipses and that was my second one,” he told CTV News Toronto. “It was by far the coldest. It was February and it was chilly on the roof of Brandon University, but the skies were clear. My master’s thesis was based on my observation of the sun that day.”

Back in 1925, when the last total eclipse took place in the Toronto region, Delaney said historical records show there was “surprisingly” large amounts of public engagement thanks to the Royal Astronomical Society of Canada, which was in full swing at the time, and the University of Toronto.

“The eclipse took place shortly after a very famous solar eclipse in 1919, which basically verified the theory of relativity,” Delaney said. “So there was a lot of interest around solar eclipses in the early part of the century, even though we didn't have social media and so on.”

“The Royal Astronomical Society of Canada and the University of Toronto were very, very engaged in making sure the public is safe,” he said.

The eclipse on Monday will happen at around 2 p.m., experts say. The whole occurrence takes abut two and a half hours.

“The thing that everyone is excited about is that 90 seconds in the middle at 3:18 p.m. when totality happens,” Cockcroft said. “All this excitement and work for these 90 seconds.”

The complete blocking of the sun by the moon will cause darkness for a short period of time.

Depending on the conditions and how clear the skies are at the time of the eclipse, he said, the first thing that will be noticed during totality is the solar corona, a white haze around the sun.

Delaney said he is trying to be hopeful about the weather and skies on Monday, and has been monitoring the weather forecast every hour for the last week.

“The snowstorms that you had earlier this past week in Toronto, if that had been forecast on Monday, I would have been terribly disappointed,” he said. “At the moment the forecast is iffy and so I'm quietly optimistic.

“But you have to take it with a grain of salt. Whenever you chase eclipses, solar or lunar. You've got to be prepared for failure from the weather.”


In 2017, a partial eclipse was visible in the Toronto area, but only around 70 per cent of the sun was covered. Monday’s eclipse is expected to have 99.9 per cent coverage.