St. Albert aurora-chasers will see some spectacular sights this year as an upcoming solar maximum lights up the night sky.
City residents may have noticed the Northern Lights showing up more often than usual in the night sky in recent months.
“There was a really nice display on the 23rd of March that was apparently a knock-‘em-dead affair,” said St. Albert astronomer and aurora enthusiast Bruce McCurdy, who has seen many photos posted of aurora online in recent weeks.
This was because the sun was nearing a peak in sunspot activity, McCurdy said. More sunspots mean more solar flares and more aurora-causing particles headed Earth’s way.
“We’re probably going to be in for some good auroras in the next one, two, or three years,” he said, especially compared to the last five.
Solar flares spit big gobs of charged particles towards Earth which supercharge atmospheric atoms with energy, said Ian Mann, astrophysicist at the University of Alberta.
Those supercharged atoms shed specific amounts (or quanta, as in quantum physics) of energy to get back to normal, McCurdy said. Those units of energy are released as specific wavelengths of light depending on the atom: oxygen makes green, nitrogen makes dark red, and hydrogen and helium make blue and purple.
Auroras come in many shapes and colours which researchers are still seeking to understand, Mann said. Some are huge, coloured arcs stretching from east to west, while others are wriggling, coruscating ribbons. Some will even pulse on and off irregularly. There’s also the aurora-like phenomenon called STEVE (Strong Thermal Emission Velocity Enhancement), which looks like pink glow or a green picket fence and is caused by friction from electrons pouring into the Earth’s ionosphere.
Solar flares and the aurora are associated with sunspots, which are dark spots on the sun with ultra-strong magnetic fields, McCurdy and Mann noted. Sunspot activity appears to follow an 11-year cycle. When that cycle reaches its maximum, the sun makes lots of flares and Earth sees lots of auroras. A January 2023 study in Frontiers in Astronomy and Space Sciences predicts that the next solar maximum will arrive in late 2023 or early 2024 — about a year earlier than previous predictions— which suggests a busy aurora season in the months ahead.
“We’ve seen some beautiful displays of the Northern lights over the last month or so, and should be hoping to see more of the same, or possibly even more, over the next year or two,” Mann said.
Predicting auroras is a tricky affair as researchers have only a partial understanding of how the sun works, Mann said. The U of A’s AuroraWatch project uses ground-based magnetometers and 10 years of observations to try and forecast auroras, which tend to show up whenever Earth’s magnetic field goes wild. Aurora chasers can sign up for email alerts from the project to know when a nighttime light show may be imminent.
McCurdy said the best way to spot an aurora is to watch the night sky for any strange movements. Get to a darker site or the countryside if you can, as the colours will be more vibrant there. Once you’ve spotted the Northern Lights, expect the show to last anywhere from a few minutes to several hours.
McCurdy said almost everyone he’s met who’s seen the aurora has been impressed by the light show.
“It’s like the whole sky comes alive and is dancing and shimmering with colour.”
International Astronomy Day
St. Albert residents can get a bit of professional help with their aurora-gazing this Saturday from area astronomers as part of International Astronomy Day, which this year falls on April 29.
International Astronomy Day is a celebration of all things space and usually happens around the first quarter moon of spring, said Telus World of Science Edmonton planetarium and space sciences manager Frank Florian. Edmonton and St. Albert astronomers will fan out across the region with their telescopes to help others stargaze on this day.
Florian said this was the first public International Astronomy Day celebration in Edmonton since 2019, so volunteers have planned an extra-big celebration at the Telus World of Science. Members of the Royal Astronomical Society of Canada and Edmonton Rocketry Club will be on hand to talk about their hobbies from noon to 4 p.m., with the society also running a workshop on telescope operation from 2 to 5. The University of Alberta’s AlbertaSat team will also be there to talk about their Ex-Alta 2 satellite, which will soon launch from the International Space Station and monitor forest fires from orbit.
Anyone interested in solar flares can check out the science centre’s solar observatories to get a safe look at the sun’s surface, Florian said. Guests can buy tickets inside the centre to view a documentary on aurora in the Zeidler Dome.
Weather permitting, St. Albert astronomers will set up their telescopes at the southwest end of St. Albert Place from 9 to 11 p.m. on April 29 for public use, astronomer Sharon Tansey said in an email. She encouraged families to come out look at the craters of the moon and the planet Venus, the latter of which will be bright in the western sky.
Visit telusworldofscienceedmonton.ca for details on Astronomy Day at the science centre.
