Flash! A couple of minutes later, boom! Double boom even.

Within minutes, various Facebook community groups across the Lower Mainland—particularly in Metro Vancouver, and even more particularly in the Tri-Cities (Coquitlam, Port Coquitlam, Port Moody)—started to come alive with vague references to an explosion.

It was Tuesday evening, March 3, a gloomy, rainy night. At around 9:15 p.m., residents in the areas mentioned above may have experienced the flash and boom events, in some cases accompanied by rattling windows and doors, even houses shaking.

Although I didn’t hear anything unusual myself, others in my Port Coquitlam house did notice, in hindsight, a sort of distant thunder-like sound that they described as briefly shaking a window or two.

I happened to be working on posting a weather satellite photo to a Facebook group when a Port Coquitlam group posting popped up with the vague line: “Did anyone hear that noise just now?”

These sorts of posts occur frequently, and I usually don’t pay them much heed. This time, however, the initial post was quickly followed by others—so much so that within a couple of minutes I began thinking of a bigger picture.

Was it a local event? The repeated references to an explosion had me thinking of a house gas explosion, or perhaps a tank car in the Port Coquitlam CPKC rail yard. A breakthrough came when I began noticing posts on X from outside the immediate area. Immediately I knew this was a more distant event. Several posters also referenced a two-minute gap between seeing a bright flash and hearing one, or possibly two, explosion-type sounds.

Yes, we’ve heard distant sounds in Metro Vancouver before. Under exceptional conditions, Mission residents claim to be able to hear Stanley Park’s Nine O’Clock Gun. And the sharp crack of Mount St. Helens erupting in 1982 was heard in this region. Neither of these, however, was representative of the sound heard March 3, and certainly neither had the accompanying widespread flash.

I was now fairly sure this was an atmospheric event, and certainly not a thunderstorm. An off-the-cuff calculation, using 330 metres per second as the speed of sound, suggested the sound originated about 40 kilometres away. For me, the most likely explanation was a meteor—possibly a meteorite—or space debris. The latter I ruled out, as such debris tends to move more slowly and is usually not accompanied by a single bright flash, or even two flashes, as some observers described.

Around five minutes after the first posts appeared in my local community group, I replied to one poster with the words “Likely a meteor.” To provide some backup to my quick conclusion, I consulted the Grok AI service built into X. By this point—about 10 minutes after the initial reports of the flash and boom—Grok had a definitive conclusion. It also backed up its assessment by pulling in data from the American Meteor Society (AMS) from a pending reports file. Such reports become permanent records once verified by a human.

That pretty much clinched it. All that remained was to nail down details about the meteor—size, speed, direction, that sort of thing—which would come from overnight analysis of data from automated sensors, along with additional citizen observations logged by the AMS.

As it turned out, one of Earth’s primary weather satellites, GOES-18—a geostationary satellite positioned about 36,000 kilometres above the equator south of Hawaii and tasked with monitoring the eastern Pacific, including B.C.—spotted the meteor as a point flash at 9:10:20 p.m., just 20 seconds after 9:10. That effectively gave us a timestamp.

This GOES-18 capture was first noted by Whidbey Island weather watcher and aspiring meteorologist Jonathan Pulley. He posted an image sequence showing the flash at 9:46 p.m. He also reported receiving accounts of either the flash or the boom from a wide area stretching from Port Townsend, Washington, to Kamloops, further reinforcing the conclusion that this was a meteoric event given the large distance between those locations.

Meteor? Fireball? Bolide? By morning, NASA was ready with an analysis incorporating witness observations from the AMS and data from GOES-18. The agency used the term “fireball.” A fireball is an exceptionally bright meteor. A bolide is a meteor—or fireball—that explodes with a sonic boom, sometimes producing fragments, called meteorites, that make it to the ground.

NASA’s analysis noted that the object entered the atmosphere and became visible at an altitude of 98 kilometres over Coquitlam, travelling at about 120,000 km/h. Yes, you read that right.

It continued slightly east of north and exploded at roughly 65 kilometres above Greenmantle Mountain, about halfway between Mount Garibaldi and Port Douglas at the northern tip of Harrison Lake — roughly 40–50 kilometres north of Maple Ridge and Mission.

It was this tremendous speed that produced the energy behind the boom and flash—the equivalent of roughly 10 tons of TNT. The object itself likely had a mass of about 75 kilograms and a diameter of roughly 40 centimetres, typical for a space rock originating from the asteroid belt.

John Cassidy, an earthquake seismologist with Natural Resources Canada, told The B.C. Catholic in an interview that the multiple booms reported by some observers could be consistent with multiple blast points as the object broke apart. It could also represent separate sonic and blast booms, with the blast boom being the louder of the two.

All told, the “Coquitlam bolide” made for an interesting event on an otherwise typically rainy southwest B.C. winter evening. As for meteorite fragments, the potential landing area is extremely remote. Stay tuned.Follow me on X (@PeterVogel) or on Bluesky (petervogel.bsky.social).

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