Globe science reporter Ivan Semeniuk answered readers’ questions this week about one of the biggest astronomical events of the decade: the April 8 solar eclipse. Ivan recently recounted the story of viewing his first solar eclipse in 1979 and the excitement eclipse chasers are feeling as Monday approaches, and also wrote a viewing guide on how best to watch it.
Readers from across Canada asked Ivan questions ranging from how to watch the eclipse safely with children to what Canadians will see depending on their location. And most importantly, how to know when to look up.
Here are some highlights – questions have been edited and condensed for clarity.
Why do so many people travel around the world to watch solar eclipses? And where are you seeing the eclipse?
Ivan Semeniuk: Once you’ve seen one total eclipse you won’t have to ask, believe me! It’s quite an experience. A very rare and special way to appreciate nature on a grand scale. This time around I will be trying to watch the eclipse in Canada. My default is to be in the Fort Erie area but I will be watching the weather forecast and may adjust to improve my chances of a clear sky.
What are some alternatives to eclipse glasses if we’re not able to secure a pair? Can I look at the eclipse through my phone?
IS: The phone will saturate if you are pointing it at the sun and will show you a white blur. The field is also too wide to see the shape of the sun. A better way is projecting through a small hole (about 2-3 mm) onto a white card. If you hold the hole up close to the card you will only be looking at the outline of the hole, but as you pull back about 1.5 metres or so, you will start projecting an image of the sun. So, if the sun is a crescent, you will see a little crescent on your screen. You can use anything with small holes, like a pasta strainer or a piece of pegboard, and get the same cool effect.
A total solar eclipse is coming to Canada. Is your heart prepared?
Is viewing the eclipse through the screen of a welder’s helmet safe?
IS: It is only safe to use welder’s glass (which also comes in plastic versions) if the number of the glass is Shade 14. A lower number does not provide sufficient protection. So check the glass inside the helmet to make sure it’s 14 (you may have to remove it to find the number. If you don’t see a number, I would err on the side of caution and not use it).
Any advice on letting small children look through glasses?
IS: Small children should watch with adult supervision. The key thing is to make sure they are not looking at the sun without protection. It’s also good practice to look down when you put your glasses on and then look up to the sun, not the other way around.
From eclipse glasses to pinhole projection, Globe science reporter Ivan Semeniuk explains what parents need to know to enjoy the stellar event with their kids. The eclipse is April 8 and will be visible from a large swath of eastern Canada.
The Globe and Mail
How do we know when to put our eclipse glasses on, and how do we know when it’s over?
IS: This is a great question. You should be wearing special protection any time you look directly at the sun, whether the eclipse is happening or not. The reason the special eclipse glasses are needed is not because the eclipse produces something harmful to your vision, but because it is always dangerous to stare at the sun. Exactly when the partial eclipse starts will depend on where you are. In southern Ontario, for example, it’s 1:58 p.m. in Leamington, but 2:12 p.m. over in Cornwall. The total eclipse occurs at 3:13 p.m. and 3:25 p.m. at those two places, respectively. You can find a listing for most locations in North America here.
Will the eclipse still be visible in other parts of Canada, like B.C., Alberta or Saskatchewan?
IS: This eclipse will be partial in western Canada. But as you go westward, less and less of the sun will be blocked by the moon. So Winnipeg will see the sun about 50 per cent obscured but Vancouver only about 15 per cent. Other western cities fall between. The consolation prize is that the next total eclipse in Canada will be in 2044 and it passes directly over Calgary. Twenty years may seem like a long time from now but many of us in the east have been waiting for this eclipse for 45 years!
If I’m not in the viewing path, do I need special glasses to look outside?
IS: You will need protection to view the sun in these locations because a portion of the sun’s surface is always visible. In Toronto the sun will narrow to a very slender crescent and almost – but not quite – disappear at the peak of the eclipse. Around this time, the surroundings will become noticeably darker. If you are inside the path of totality, the sun will momentarily be completely hidden behind the moon’s silhouette and, if the weather is clear, the sun’s wispy outer atmosphere, called the corona, will be visible. Sadly, Toronto will miss that part.
If I fly my Learjet up to Nova Scotia will I see the total eclipse of the sun? Asking for the wife of a close friend.
IS: There actually was a total eclipse in Nova Scotia just a few months before Carly Simon’s song with that famous lyric was released in 1972. In this case, the jet will have to make it all the way to Newfoundland, or else the effort (wait for it) will be in vain.