On Tuesday, the quiet scenery of Northern Alabama was rocked by a thunderous boom from the sky – which in and of itself may not be all that unusual, except there were no storm clouds, and no military aircraft were reported in the area.

At around 1:39 pm local time, the sound, which the Birmingham National Weather Service has hypothesized was likely a sonic boom, could be heard for hundreds of miles.  The NWS took to Twitter almost immediately, admitting to concerned residents that they “don’t have an answer, and can only hypothesize with you” about what it may have been.

If it wasn’t an aircraft, the NWS postulated, the next most likely candidate would have to be a meteor.  Military aircraft have strict regulations on when and where they are permitted to enter supersonic speeds when flying over inhabited stretches of American soil, and no civilian aircraft since the Concorde has been capable of breaking the sound barrier.  Further, the Leonid Meteor Shower is expected to reach its peak around November 17th or 18th, so Occam’s Razor would seem to dictate that it had to have been an early meteor, streaking across the Alabama sky at supersonic speeds.  Mystery solved, right?  Well, maybe not.

Bill Cooke, the head of NASA’s Meteoroid Environment Office (MEO) at the Marshall Space Flight Center in Huntsville, Alabama, is perhaps the man most qualified to determine if what’s been dubbed “the ‘Bama boom” was actually the product of a stray meteor swinging through early to announce the Leonid Meteor shower’s arrival.  According to him, the boom was not a meteor.  He instead posits that it may have been caused by the aforementioned supersonic aircraft possibility, a large ground explosion, or potentially a bolide – which is a large meteor that explodes in the upper atmosphere, but not tied to the forthcoming meteor shower.