Annular solar eclipse this month will be partially visible to Canadians — and is one of the last ones we'll see for a while

Canadians will have an opportunity to see an annular solar eclipse later this month — one which is also providing NASA a chance to study our atmosphere in greater detail.

On Oct. 14, the moon will pass in front of the Sun and block its light in one of the last solar eclipses that Canadians will have a chance to see for at least a few years.

“Eclipses are not as rare as people seem to think,” Orbax, a science communicator from the department of physics at the University of Guelph, told CTVNews.ca in a phone interview. “What the rarity is, is us actually lining up to be able to see. So eclipses happen a few times a year, all across the world, but we're often not facing the right direction to be able to see it.”

The last total eclipse visible in Canada was in 2017, Orbax said. This month’s celestial event won’t be a total eclipse, but something called an annular solar eclipse, also known as a “ring of fire” eclipse.

Annular solar eclipses happen when the moon lines up with the Sun at the point of its orbit where it is slightly farther away from the Earth than usual.

“The moon is a little bit further away, it looks to be a little bit smaller, and it actually doesn't block all the light from the sun,” Orbax explained. “And in that case, we see this bright ring around the moon.”

• The information you need to know, sent directly to you: Download the CTV News App

The good news is that some degree of partial eclipse should be visible across the country, with the best view going to those in southern B.C.

The bad news is that the “ring of fire” itself won’t be visible to Canadians. We aren’t in the proper position to see the moon line up perfectly with the Sun. Instead, the partial eclipse will appear for us as if a dark shadow has fallen over the side of the Sun, taking a slice out of it and dimming its overall brightness, Orbax said.

The eclipse will be most striking across the U.S., where scientists at NASA are planning to use the eclipse to study how a sudden lack of sunlight impacts our atmosphere, particularly a layer called the ionosphere.

“All satellite communications go through the ionosphere before they reach Earth,” Aroh Barjatya, a professor of engineering physics at Embry-Riddle Aeronautical University and leader of the mission, said in a recent press release. “As we become more dependent on space-based assets, we need to understand and model all perturbations in the ionosphere.”

WHEN AND WHERE TO SEE THE ECLIPSE

The eclipse will begin around 12 p.m. EDT and last a couple of hours in total.

“So we'll start about noon, you'll see a small blot on the sun, and it will grow till about one when it's about its maximum,” Orbax said. Where he is in Guelph, Ont., the maximum will mean around a third of the Sun is covered. “And then it'll recede again and reveal the entire sun. So it's going to be a bit eerie — you'll have less sunlight.”

In Canada, the more west and the more south you are, the better view you’ll have of the partial eclipse.

The moon will obscure 70 to 80 per cent of the Sun for those in the southeast corner of B.C., with the rest of the province seeing 50 to 70 per cent coverage. The majority of the Prairies will be able to see a 40 to 60 per cent obscured Sun during the eclipse, while the eclipse will range from 20 to 40 per cent coverage for those in Ontario, depending on where they are. The Atlantic provinces will get the least amount of coverage.

“Starting in Vancouver, you'll get about 80 per cent, going all the way to Prince Edward Island, New Brunswick, where you’ll get about 10 per cent coverage,” Orbax said. “So that'll be right across the entire country — going from west to east coast, you'll be decreasing the amount of coverage.”

HOW TO VIEW THE ECLIPSE

Even during an eclipse, it’s never safe to look directly at the Sun. There are numerous ways to view the eclipse, but the naked eye is not one of them, Orbax stressed.

“You can get eclipse glasses, you can get welding goggles, there's all types of filters and ways to look at it safely. But don't just look up with your unprotected eyes.”

A NASA 3D model demonstrates the path that the moon will take across the sky, and broadly what regions of the world will be able to see the eclipse at different times. The eclipse’s roadmap — meaning the slice of Earth from which the eclipse will appear at its fullest coverage as the planet rotates — starts in Oregon and takes a diagonal across the U.S., moving down into Mexico and Central America and then across the northern half of South America before the moon moves out of the Sun’s path.

“There's few things that capture the imagination of humanity like the sun being blotted from the sky,” Orbax said.

“If you have an armchair interest in science, or you just happen to have young ones near and dear to you who are super interested in astronomy and space, this is a perfect opportunity to take an afternoon and to go and to learn a little something new.”

DO ECLIPSES AFFECT OUR ATMOSPHERE? NASA TO USE ECLIPSE TO FIND OUT

Those living near the White Sands Missile Range in New Mexico might see another strange sight in the sky when they aim their eclipse glasses at the sky on Oct. 14 — the tell-tale white streaks of three scientific rockets, sent out to investigate the eclipses’ shadow.

The Atmospheric Perturbations around the Eclipse Path (APEP) mission is aiming to figure out what happens to the ionosphere, a layer of the atmosphere more than 80 kilometres up from the ground in which the air becomes electric. When sunlight interacts with this layer, the UV is able to separate electrons from their atoms to create clouds of charged particles, many of which will recombine into neutral atoms as the Sun sets.

But in an eclipse, sunlight vanishes over a small portion of the land all at once, only to reappear again relatively quickly.

“If you think of the ionosphere as a pond with some gentle ripples on it, the eclipse is like a motorboat that suddenly rips through the water,” Barjatya said. “It creates a wake immediately underneath and behind it, and then the water level momentarily goes up as it rushes back in.”

It may not sound like a big issue, but instruments including GPS and communications satellites detected the atmospheric changes during the total solar eclipse of 2017. Researchers want to be able to understand what is going on in the ionosphere to ensure that any potential issues that future eclipses might cause can be planned for.

To get a full picture, the three rockets will be launched one after the other, with around 35 minutes in between each to get an idea of before peak eclipse, during the peak and after it. Instruments on the rockets will measure changes in electric and magnetic fields, as well as density and temperature.

“Rockets are the best way to look at the vertical dimension at the smallest possible spatial scales,” Barjatya said. “They can wait to launch at just the right moment and explore the lower altitudes where satellites can’t fly.”

TOTAL SOLAR ECLIPSE COMING NEXT YEAR

This partial eclipse will be one of the last opportunities for a while for Canadians to experience an eclipse. But it’s not the last – on April 8, 2024, there will be a total eclipse, which will be visible in parts of Canada.

Eastern Canada will get the best view of the April eclipse as its path takes it through southern Ontario and then across the Atlantic provinces. Those in the Niagara region in Ontario will get to see the eclipse at full coverage, with the Sun totally blotted out at around 3 p.m.

“This is a traditional total solar eclipse. So the moon will be big enough to block the entire sun,” Orbax said.

It’ll also be visible in the U.S., providing a second opportunity for the APEP project. They will be relaunching their rockets again on April 8 next year, helping to round out their measurements to see how widespread the atmospheric impacts are during an eclipse.

After April, Canada won’t have a good view of a solar eclipse for a while, Orbax said.

“We have a few partial eclipses coming up in the next decade or so, but those are with very small coverage. Your next full, total eclipse after April is going to be like 20 to 25 years.”

According to timeanddate.com, which tracks eclipses, the next partial solar eclipse visible in Canada will be in 2029, and after April 2024, we won’t have a total eclipse that is visible across a wide swathe of Canada until August 2044.

Although we’ll have to wait until April to see the last big eclipse for a while, the annular solar eclipse is far from the only thing to see in the sky this month.

According to Orbax, who creates monthly stargazing guides, this October is a big month for observing fascinating occurrences and objects in the sky.

International Observe the Moon Night is being held Oct. 21, a night in which moon lovers worldwide gather in local events to gaze at the moon together. Jupiter and Saturn will also be large in the sky early in the evening for the duration of the month, he said, while Saturn’s rings will be visible through a telescope.

“We also have two meteor showers coming up this month, Draconids and the Orionids,” he said. “We are looking at Oct. 8 to 9 is the peak of the Draconid meteor shower, coming up this weekend, and Oct. 20 and 21 is the Orionid meteor shower. These are named as the constellations that they appear to radiate from, so the Draconids look like it's coming from Draco the dragon and the Orionids look like it's coming from Orion.”