Speaker 1: Welcome to brain Stuff from How Stuff Works. Hi brain Stuff,
Speaker 1: Lauren boblebam here. One November afternoon, in residents of fifteen
Speaker 1: Alabama counties were reportedly startled by a loud boom that
Speaker 1: caused some to call nine one one operators in alarm.
Speaker 1: As the National Weather Services Birmingham station tweeted not quite
Speaker 1: a couple hours later, there wasn't any clear explanation for
Speaker 1: the noise. Radar scans and satellite imagery of the region
Speaker 1: didn't show any large fires or smoke from an explosion,
Speaker 1: and the U S Geological Survey didn't spot any signs
Speaker 1: of an earthquake on its seizemic monitoring system. In their tweet,
Speaker 1: the National Weather Service speculated that the sound may have
Speaker 1: been caused by an aircraft or meteor, but said we
Speaker 1: don't have an answer and we can only hypothesize with you.
Speaker 1: A NASA scientist soon knocked down those possible explanations. Bill Cook,
Speaker 1: head of these space agencies Meteoroid Environment office at the
Speaker 1: Marshall Space Flight Center in Huntsville, Alabama, told al dot
Speaker 1: com that he was skeptical that sound could have been
Speaker 1: caused by meteor because there were no reports of anyone
Speaker 1: seeing a fireball. Cook also discounted the possibility that the
Speaker 1: boom had been created by an aircraft, noting that the
Speaker 1: seismic signature is not characteristic of that produced by supersonic jets.
Speaker 1: Boom about six hundred miles or nine and seven kilometers
Speaker 1: to the north in Ontario, Canada, the Elgin Field infrasound
Speaker 1: array picked up an infrasound wave that apparently was linked
Speaker 1: to the boom. It usually takes something pretty big, such
Speaker 1: as a severe storm and avalanche or a rocket launch
Speaker 1: to trigger such a wave. To add to the weirdness,
Speaker 1: less than two weeks later, another similarly unexplained boom was
Speaker 1: heard one morning in the Birmingham area. We spoke with
Speaker 1: James Cooker, director of the Jefferson County, Alabama Emergency Management Agency,
Speaker 1: via email. He said that he heard a double boom,
Speaker 1: although the sound I heard may have included an echo
Speaker 1: caused by the mountains, he said, and Alabama isn't the
Speaker 1: only place where things have been booming lately. Skyquakes as
Speaker 1: they're commonly called, recently have been heard across the US
Speaker 1: in stay ranging from New Jersey to Idaho, as well
Speaker 1: as in places as far away as India, where two
Speaker 1: seaside resort towns were jolted in August by a boom
Speaker 1: so loud that it shattered hotel windows, according to the
Speaker 1: Dacca Tribune. Indeed, as u S Geological Survey scientist emeritus
Speaker 1: David Hill detailed in a article on the subject, mysterious
Speaker 1: booms have been heard for many years in places across
Speaker 1: the world. In Belgium, they're known as MIAs poofer's, while
Speaker 1: the Italians call them bron titi. In the vicinity of
Speaker 1: Lake Seneca and the Catskill Mountains of New York, residents
Speaker 1: have long heard the Seneca guns, a phenomenon that was
Speaker 1: described by author James Fenimore Cooper back in eighteen fifty
Speaker 1: one as a sound resembling the explosion of a heavy
Speaker 1: piece of artillery that can be accounted for by none
Speaker 1: of the known laws of nature. As Hill noted in
Speaker 1: his article, numerous explanations for skyquakes have been proposed over
Speaker 1: the years, including shallow earthquakes that could produce audible sounds
Speaker 1: without noticeable shaking, massive tsunami waves breaking far from shore,
Speaker 1: explosions of methane gas released from the methyl hydrate beds
Speaker 1: sand dunes, shared by avalanches and of course meteors. As
Speaker 1: Hill wrote, meteors penetrating the upper atmosphere could create sonic
Speaker 1: waves that wouldn't reach Earth's surface until after the meteor
Speaker 1: had vanished, so the connection between the two wouldn't be apparent.
Speaker 1: People have also raised the possibility that the booms, or
Speaker 1: at least some of them, might be caused by tests
Speaker 1: a secret U S military aircraft, such as the long
Speaker 1: rumored spy plane that aircraft buffs have dubbed Aurora. However,
Speaker 1: there may not be one single explanation for all the booms.
Speaker 1: Hill explains it is indeed the case that there may
Speaker 1: be several plausible explanations for any given incidents of a
Speaker 1: mysterious booming sound, and that the environment where the sound
Speaker 1: is heard will determine which of the possible explanations are
Speaker 1: the most reasonable. A sound heard in the middle of
Speaker 1: the desert, for example, is not likely due to breaking surf.
Speaker 1: Hill says that most booming sounds are heard over a
Speaker 1: limited range, so reports of clusters of booming sounds separated
Speaker 1: by large distances are most likely coming from multiple sources.
Speaker 1: The exceptions, he says, a main clue the sound from
Speaker 1: a meteorite exploding in the atmosphere high above the Earth,
Speaker 1: a massive volcanic eruption, or an aircraft flying it's supersonic
Speaker 1: speeds for an extended distance. Today's episode was written by
Speaker 1: Patrick Jake Haiger and produced by Tristan McNeil. For more
Speaker 1: on this and lots of other mysterious topics, visit our
Speaker 1: home planet, how stuff Works dot com.