The winter solstice may be short on sunlight, but Alaskans saw a different kind of illumination Wednesday from a falling meteor seen across Southcentral Alaska.
At about 5:45 a.m., quite a few Alaskans reported they were woken up by a bright flash of light. Some Mat-Su Valley residents said they thought there were high-powered headlights in their driveways. Others took to social media, describing the meteor as amazing and fast, saying it lit up the whole sky. Some also posted video footage from their home security cameras, showing a brilliant blue flare.
National Weather Service Climatologist Brian Brettschneider was among those who found out about the meteor from their doorbell cameras. He got a notification showing footage of a streaking light and a bright flare to the north of his home. Brettschneider said it was clear what the object was — and what it wasn’t.
“It’s not aliens. It’s not anything exotic. These things happen all the time,” he said.
The object in Wednesday morning’s sky was a very bright meteor. Brettschneider said it’s the first time his porch camera has captured one.
“This is the most impressive one I’m familiar with in the area,” he said.
Mark Conde is a physics professor at the University of Alaska Fairbanks. While his specialty is on objects still in space, he is also interested in objects that fall to Earth. Conde said what we’re seeing when a meteor streaks across the sky is a piece of debris. According to Conde, even if a meteor is bright, that debris is typically very small.
“There’s a huge range of sizes… anything from tiny, tiny dust grains to as big as
you want,” he said.
The size estimates shift upward when the meteor makes a sound, however.
Multiple Mat-Su residents reported hearing a low rumble shortly after the meteor was spotted. Most objects burn up when entering Earth’s atmosphere more than 50 miles above the surface. Conde said in order to be heard, a meteor has to be substantial enough to survive into the thicker layers of atmosphere.
“The larger the object, the deeper it penetrates into the atmosphere. In order to be heard, I think it has to get down to maybe 30-40 kilometers altitude,” he said. “And that requires a somewhat bigger object.”
So how big was this meteor? That’s where someone like Mike Hankey comes in. Hankey is the director of operations for the American Meteor Society, a citizen-science organization that collects reports of meteors from eyewitnesses and uses that data to estimate trajectories. He said a size estimate depends on a number of variables.
“It depends on the speed, composition, angle,” he said. “Generally speaking I would estimate this somewhere between a basketball to, like, a grocery cart.”
Given the size and likely source of the meteor, Hankey said some of it likely made it to the ground as a meteorite.
“These larger meteors, like this one you just had, is probably a piece of an asteroid,” he said. “Some of it probably survived. That’s my guess.”
Hankey said the American Meteor Society hopes to receive more witness reports and footage of Wednesday morning’s meteor so that it’s trajectory and possible landing site can be found. The Society’s website can be found at AMSMeteors.org
This story has been updated with additional information about the size of Wednesday’s meteor.