The northern lights may shine across Canada overnight tonight

Eyes on the overnight sky for a chance to see the elusive Northern Lights!

On Saturday, September 16, a huge filament of solar matter broke off from the Sun and was blasted off into space. Known as a coronal mass ejection (CME) or solar storm, this cloud of charged particles moves outward through the inner solar system throughout the weekend.

These three panels taken by NASA/ESA’s Solar and Heliospheric Observatory’s coronagraph instrument on Saturday, September 16, 2023, show that the coronal ejection is expanding away from the Sun. The Sun is represented by a small white ring inside the black circle, and the cloud growing around it is the CME. Because it forms a “ring” around the Sun, space weather scientists call it a “corona” (CME). Credit: NASA/ESA

NOAA’s Space Weather Prediction Center expects this “corona CME” to pass near Earth on Monday evening or very early Tuesday morning (Eastern time). As a result, forecasters issued a G2 geomagnetic storm warning throughout the night. According to spaceweather.com, NASA expects the solar storm to arrive later, indicating that there is some uncertainty in the timing.

in the pictures: Spectacular aurora borealis appear across Canada during a solar storm

If CME follows NOAA’s forecast, the aurora is expected to push southward into central Quebec, the northern Great Lakes, and the central prairies around midnight EDT, with increased activity likely in the few hours before dawn. Based on this timing, aurora watchers across the prairies will likely be in for the best show tonight.

Alternatively, if the solar storm arrives at the time NASA expects, we could miss the show entirely. Aurora activity usually occurs on the dark side of the planet, or at least that’s where it can be seen (the sky is too bright during the day for us to pick out the exact colors of the aurora). Therefore, if the storm arrives late enough, the only people who will see the aurora borealis during the next day will be those who live in northern Siberia.

What is a geomagnetic storm?

Space weather phenomenon. Credit: NASA

The Sun is a very active star. They emit a continuous stream of charged particles called the solar wind. It also goes through a cycle of waxing and waning activity every 11 years, triggering solar flares and spewing enormous clouds of solar plasma (CMEs) into space during its most active periods.