2024 was an amazing year for astronomical events across Canada. In particular, though, three made headlines like no other — the total solar eclipse, the strongest solar storm in 20 years, and the comet of the century.
The April 8 Total Solar Eclipse
On the 8th of April, 2024, the Sun, Moon, and Earth lined up in a perfect syzygy, resulting in a total solar eclipse.
Throughout the day across North America, this alignment projected the Moon’s shadow onto Earth’s surface, which followed a path from the west coast of Mexico, northeast through the United States, and across eastern Canada before ending over the north Atlantic Ocean.
Most of Canada was able to see a partial eclipse on that day, with the Moon covering more of the Sun, the closer you were to the direct path of the Moon’s shadow. However, along a narrow corridor from southwestern Ontario to Gander, Nfld, known as the Path of Totality, observers experienced the incredible sight of the Moon completely blocking the Sun.
(NASA/Keegan Barber)
Besides the amazing view of the solar corona, totality brought some surprises as well, as several large ‘prominences’ were visible just beyond the edges of the Moon.
Prominences, also known as ‘filaments’ are giant arcs of solar plasma, lifted high above the Sun’s surface by powerful magnetic fields. Sometimes, one of these arcs can erupt from the Sun, expanding out into space as a coronal mass ejection. A CME that passes Earth often results in bright displays of the Aurora Borealis, aka The Northern Lights.
WINTER ASTRONOMY: Heads up! A total lunar eclipse will shine across Canada late this winter season
The strongest solar storm in 20 years (and more!)
Speaking of the Northern Lights, just over one month after the solar eclipse, night skies across Canada and the United States erupted with light and colour.
Early in the morning on Wednesday, May 8, the Sun blasted out an extreme X-class solar flare. In its wake, an enormous CME was seen erupting directly towards Earth. At least two more coronal mass ejections followed, catching up to the initial one to form a dense solar storm.
The solar flare and coronal mass ejection from May 8, 2024 are shown in these two snapshots from the Solar Dynamics Observatory and the Solar and Heliospheric Observatory. (NASA, NASA/ESA)
Two days later, on Friday, May 10, this solar storm swept past Earth, sparking the strongest geomagnetic storm in over 20 years. The auroras visible from this event were seen all across Canada and far south into the United States. There were also reports of aurora being spotted along the northern horizon from the Caribbean and the Yukatan Peninsula.
While an event like this hadn’t been seen since Halloween 2003, this would not be the last aurora display in our skies this year.
Bright Northern Lights were also seen in mid-August, and then again in early October.
The Aurora Borealis over Lambton, QC, on October 6, 2024. (UGC/Alex Dostie)
If you missed out on these events, don’t worry. The Sun is now in its period of maximum activity (“Solar Maximum”) and will remain so for at least the next year. Thus, there will most certainly be more opportunities to see the Northern Lights in the months to come.
TIPS AND TRICKS: How to get the most out of auroras, meteor showers, and other night sky events
The “Comet of the Century”
One of the somewhat unexpected ‘hits’ for this year was Comet Tsuchinshan-ATLAS.
First spotted in January 2023, astronomers had already plotted the comet’s course through the inner solar system and around the Sun. Thus, it was no surprise that it would be visible in our skies during the Fall of 2024.
What was unexpected, though, was just how brightly it would show up!
Comet 2023 A3 (Tsuchinshan-ATLAS) on October 17 (left) and 18 (right). (Tree and Dar Tanner/Team Tanner)
While astronomers can plot a comet’s course with precision accuracy, these icy remnants from the solar system’s formation are notoriously unpredictable in other ways.
Specifically, it is very difficult to know, in advance, how active any particular comet will become, and also whether or not it will survive its journey around the Sun. Several comets have generated a lot of hype on their approach, but then broke apart and vapourized, ultimately disappointing astronomers and night sky enthusiasts alike. Comet ISON from 2012-2013 was a good example of this. At the time, it promised to be the “Comet of the Century” (the best comet seen in 100 years), but then shattered and disappeared after it rounded the Sun.
There were high hopes for Comet Tsuchinshan-ATLAS throughout the first part of 2024. It was a visitor from the Oort Cloud, the vast cloud of large comets that surrounds our solar system, that was on a journey that may have already spanned millions of years just to reach us.
These hopes were initially confirmed just before perihelion (its closest distance to the Sun), as it showed up brightly in predawn southern hemisphere skies. The astronomical community held its collective breath as the comet disappeared into our sunlit skies during perihelion, and anxiously waiting for its return in the western sky after sunset.
When it did, it likely exceeded all expectations, becoming a rare naked-eye visible comet, and blowing us away with a tail roughly 40 times longer than the width of the Full Moon!
While we’ll never know when we’ll see another one, Comet Tsuchinshan-ATLAS very well may live up to the title “Comet of the Century”.