Science

You've likely never seen a total solar eclipse. Here's where and how to watch April's upcoming show

On April 8, the moon’s shadow will glide across a narrow part of Canada, producing one of nature’s greatest spectacles: a total solar eclipse. If you think you've seen one before, you probably haven't, as these eclipse experts reveal the beauty and awe of the experience.

A total solar eclipse is a 'spiritual' experience, says one eclipse chaser

White streamers emanate from a black disk.
A total solar eclipse — when the moon entirely covers the sun — creates an amazing visual experience, as seen here. The streamers are part of the sun's corona, the outermost part of the its atmosphere. (Alan Dyer/AmazingSky.com)

On April 8, the moon's shadow will glide across Mexico, into the United States and finally into Canada, producing one of nature's greatest spectacles: A total solar eclipse.

But if you want to see it, you'll likely have to travel to eastern Canada — and into a very narrow path that stretches from southern Ontario, through Quebec into New Brunswick, P.E.I. and Newfoundland. (In Nova Scotia, only the Meat Cove area will experience totality.) 

Total solar eclipses occur when the moon passes in front of the sun, blocking out its light. The path of that shadow is extremely narrow, which is why most people have likely never seen one.

"People … think that solar eclipses are extremely, extremely rare," said Fred Espenak, a retired NASA astronomer and the agency's lead eclipse expert. "The rare part of total solar eclipses is that they're only visible from a very small fraction of the Earth's surface, typically less than about one-half per cent of the Earth's surface for a given total solar eclipse."

Given that, the average for any one spot on Earth to see a total eclipse is about once every 375 years, he explained. And that's why most people haven't experienced a total solar eclipse.

However, many people have likely experienced a partial solar eclipse, where it looks like something has taken a bite out of the sun. That's because the visibility of those is far wider. For next month's eclipse, outside of that narrow path of totality, the rest of the country will experience a partial eclipse in some form. 

But seasoned eclipse chasers say there's a very big difference between a partial and a total solar eclipse.

Espenak, who has seen 24 total solar eclipses, said a partial eclipse is lovely, but there's nothing like a total.

"People have to understand that even if someone may have seen a partial eclipse, they think that's the whole thing. It's just a degree of a percentage," he said. "They saw a 50 per cent partial or an 80 per cent partial — that 80 per cent is as good as a total. Well, it's not. 

"Seeing a partial eclipse is like getting five out of the six numbers in the Powerball. To win the jackpot, you've got to get all six numbers. And to win the jackpot with eclipses, you've got to be 100 per cent."

A 'spiritual' experience

Jay Anderson, a former meteorologist with Environment and Climate Change Canada and an avid eclipse chaser, said the experience of standing in the moon's shadow is unforgettable. 

"The eclipse itself is the marvel: the prominences, chromosphere, the corona, all of which are parts of the solar atmosphere that suddenly pop into view that average person wouldn't see.

A black disk shows a ring of light.
The diamond-ring effect of 2017's total solar eclipse, seen from Salem, Ore. (AP Photo/Don Ryan)

"And the temperature drops and the shadow comes in," he said, "and you're looking up at the sun and you're watching that last little bead [of light] squeeze off, and you get the diamond ring, and — whomp — you're into that darkness. But you're seeing the corona appearing before the sun is completely covered.

"Then when it's over, there's a lot of hugging and shouting, and a few tears and marriage proposals sometimes."

Espenak feels the same way. "For some people, it's almost a spiritual experience," he said. "It's a humbling experience, in my opinion. It gives you a sense of man's place in the universe. And you realize just how small and inconspicuous we really are, and insignificant."

Safety first

It's why Espenak is also frustrated with some school boards opting to make April 8 a P.A. day, or keep the children indoors.

The Toronto District School Board, for one, cited safety concerns, as the eclipse would fall around the end of the school day, when students and staff would be heading home.

"Getting the chance to see a total eclipse is such an incredible educational opportunity that I think it's criminal negligence to lock kids up in schools," he said.

He acknowledged that it takes some preparation, but he said it could have provided for a good learning experience leading up to the event — teaching children about how and why eclipses happen, proper safety practices and more.

A child looks up wearing disposable eclipse glasses with 2017 written on them.
A young spectator looks skyward during a partial eclipse of the sun on August 21, 2017 at the Cradle of Aviation Museum in Garden City, New York. (Bruce Bennett/Getty Images)

"Seeing something like this could could inspire some hidden passion for studying the sciences. It doesn't have to be astronomy, but just experiencing something beautiful in the natural world."

Eye safety is of the utmost importance, whether you're in the path of totality or will see the partial eclipse. The best and easiest way to protect your eyes is to purchase eclipse glasses, which are widely available from astronomical organizations, science centres and online astronomy stores.

It's important to ensure they are ISO-compliant, with ISO 12312-2. Try to avoid purchasing elsewhere, as in 2017, there were many fakes that still contained the ISO number. Looking directly at the sun without protection could permanently damage your eyes.

WATCH | A solar eclipse can cook your eyes: How to watch safely: 

A solar eclipse can cook your eyes: How to watch safely

3 years ago
Duration 4:36
A solar eclipse can seriously damage your eyes. Using eclipse glasses is just one safety tip for viewing the total eclipse.

The only time it is safe to take off your eclipse glasses is when the moon has totally covered the sun. All other times, you must wear eclipse glasses. The only caveat is that people should already have them or should order them soon, as places are beginning to sell out.

Anderson — who's also seen 24 total solar eclipses — and Espenak both feel that once someone experiences a total solar eclipse, it will just feed their desire to see more of them.

"Every eclipse is different," said Anderson.

ABOUT THE AUTHOR

Nicole Mortillaro

Senior Science Reporter

Based in Toronto, Nicole covers all things science for CBC News. As an amateur astronomer, Nicole can be found looking up at the night sky appreciating the marvels of our universe. She is the editor of the Journal of the Royal Astronomical Society of Canada and the author of several books. In 2021, she won the Kavli Science Journalism Award from the American Association for the Advancement of Science for a Quirks and Quarks audio special on the history and future of Black people in science. You can send her story ideas at nicole.mortillaro@cbc.ca.