Sci-Friday: Meteorite explodes over western Alaska
FAIRBANKS, Alaska (KTVF) -For this Sci-Friday we take a look at a meteorite that exploded last month over western Alaska.
On October 15th, at 7:30 AM, residents from Ruby to Selawik report seeing a bright fireball light up the sky. A security camera in McGrath captured the descent of the object.
"The sky lit up. It was very bright. We saw it. I thought it was closer than it turned out to be. It was going from north to west, and it was going slow so that we had enough time to say, “Oh my god did you see that?,” said Katie Kangas, a bed and breakfast owner in Ruby who saw the event.
David Fee, research professor and head of the infrasound program at the University of Alaska Fairbanks Geophysical Institute explained how an infrasound network on the UAF campus recorded a clean signal of the air-pressure waves produced by the object.
According to Fee, the extra terrestrial object was likely a bolide, a type of fiery meteor that explodes in the atmosphere.
“So these things come in, they’re really energetic, they produce a really loud explosion that people can hear audibly, but they also produce a lot of this low frequency sound. And this one in western Alaska in mid October we actually recorded up to like 700 miles away from the source,” said Fee.
Infrasound is a low-frequency noise, undetectable by the range of the human ear. Scientists detect infrasound signals with over a hundred microphone stations peppered all over Alaska. This technology is used to detect infrasound from sources ranging from exploding volcanos, to the aurora, to meteorites.
“I can say it’s pretty big as far as meteorites go in. We were able to roughly figure out the location of where it was,” said Fee.
Fee and his team were able to determine through the use of stations all over Alaska that the fragments of the meteorite probably landed somewhere north of the upper Innoko River.
“Some folks from NASA contacted me too, and this has happened before. If we detect a meteorite, they’re often interested in trying to find the fragments of it on the ground, which is pretty dang challenging in Alaska. I doubt anyone will find the fragments from this one," said Fee.
Any remaining pieces of the object will have developed a blackened fusion crust as a result of intense friction from atmospheric entry. Now cooled and buried in snow, our guest from the stars has become a permanent resident of Alaska and our planet.
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