Mysterious booms have been sounding across the globe this year, but nobody can seem to work out exactly why.
One of the latest occurred in northern Alabama on Nov. 14 and was heard across more than 10 counties, WBMA reports.
It sounded like "a propane tank just exploding. I looked, and I didn't see nothin' sailing through the air," Dawn Stanton told WBMA.
Listen to the scary sound caught on video in the player below.
Birmingham's office of the National Weather Service had no explanations for the loud phenomenon and could only hypothesize it was a sonic boom from an aircraft or a meteorite from the ongoing Leonid shower.
Re: loud boom heard: we do not see anything indicating large fire/smoke on radar or satellite; nothing on USGS indicating an earthquake. We don't have an answer, and can only hypothesize with you. 1) sonic boom from aircraft; 2) meteorite w/ current Leonid shower?
— NWS Birmingham (@NWSBirmingham) November 14, 2017
However, NASA expert Bill Cooke quickly shut down the Leonid meteor theory.
"Leonids never penetrate low enough into Earth’s atmosphere to produce sounds audible on the ground," Cooke wrote. "As new data become available, our meteor scientists and their colleagues will do further analysis to triangulate and better characterize the energy of the event, which may provide more clues."
Those clues don't seem to have materialized yet in the intervening 10 days since the "Bama Boom." Cooke's working theories are that the noise came from a bolide (a meteor that explodes in the atmosphere), a large supersonic aircraft or a ground explosion.
The New York Post reported on Thursday that 64 locations around the world have experienced similar, mysterious sounds this year, including in Michigan and in St. Ives, Swansea and Yorkshire in the United Kingdom.
Then, of course, the people of the internet began theorizing ...
Can we all agree that the Bama Boom yesterday was just Eleven opening the portal to the upside down? Get your nail bats ready guys, we have a demegorgon to kill. pic.twitter.com/R1jccWFOe8
— Anna Blackwell (@AnnaH_Blackwell) November 15, 2017