Tonight, Canadians may witness a spectacular show of the northern lights following a series of solar activities. The sun has been active lately, with sunspots emitting magnetic energy and releasing three coronal mass ejections (CMEs) at high speeds toward Earth.
These CMEs, rapidly traveling through the solar wind, are on a collision course with Earth and may potentially merge into what scientists call a “cannibal” CME. When these particles interact with Earth’s magnetic field, they produce the stunning phenomenon known as the northern lights or aurora borealis.
While the northern lights are typically visible in northern latitudes, a strong enough CME could extend their visibility to regions farther south. The National Oceanic and Atmospheric Administration’s Space Weather Prediction Center (SWPC) has predicted a powerful geomagnetic storm tonight and into Friday.
Geomagnetic storms are rated on a scale ranging from G1 to G5. The SWPC anticipates the arrival of combined CMEs around mid-afternoon on June 4, with the potential for up to G3 storm levels thereafter. The forecast suggests that the CME passage could continue into the evening and possibly overnight of June 5.
Although predicting the northern lights’ appearance is challenging, the SWPC expresses a reasonable level of certainty about its arrival on Earth, albeit with uncertainty regarding the intensity. The SWPC mentioned that due to the complex nature of the observed CME circumstances, the intensity is uncertain, with a consensus of up to G3 storm levels and a chance of G4.
The intense northern lights displays witnessed in May and October 2024 resulted from G5 storm levels. To catch a glimpse of the northern lights, several factors must align correctly. The auroral hole through which the CME particles travel should dip south, with a further southward dip indicating wider visibility. Additionally, the storm needs to occur during nighttime for optimal viewing conditions.
For the best viewing experience, individuals are advised to move away from city lights to darker areas. Using a phone to capture photographs of the northern lights, even if they are not visible to the naked eye, is also recommended. Looking northwards is ideal, especially for individuals in southern regions like southern Ontario, where a good vantage point of the northern horizon is essential.
To stay informed about the visibility of the aurora in your location, various apps like Aurora Now can provide real-time information. For a celestial treat, stargazers are encouraged to gaze west after sunset to witness the beautiful conjunction of Jupiter and Venus.