People in different places across the globe have heard mysterious booming sounds this year, leaving experts baffled as a concrete reason for the phenomena is yet to be established.
The terrifying loud sounds, nicknamed "Bama Boom", have been heard in various regions ranging from the Middle East to the East Midlands to Australia while the majority of the noises have been recorded in America's eastern coast.
In 2017, similar booms have been reported in 64 locations, including Michigan, Lapland, St Ives, Swansea and Yorkshire, with the latest one reported from the US state of Alabama and Idaho last week.
Despite being widely reported, the booms remain to be a mystery for experts, with suggested causes reportedly ranging from supersonic aircraft to meteors exploding in the Earth's atmosphere.
A loud boom heard in Alabama on November 14 got the attention of the Birmingham National Weather Service, which suggested that the sound was probably caused by either a sonic boom from an aircraft or a meteorite from the Leonid shower, a prolific meteor shower associated with the comet Tempel–Tuttle that peak in the month of November.
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
Has anyone heard a loud explosion in west Blount County? We’ve recieved several calls between Spunky Hollow Rd and Cannons Crossing. Law Enforcement is currently patrolling the area.— Blount County 9-1-1 (@BlountCounty911) November 14, 2017
However, Bill Cooke, head of NASA's Meteoroid Environment Office, told ABC 3340 that the boom could have been caused by a supersonic aircraft, a ground explosion, or a bolide -- a large meteor that explodes in the atmosphere, but not related to the Leonid shower.
The strange noise was also picked up by the US Geological Survey, whose data suggests that the boom was not resulted from an earthquake.
A day after the Alabama incident, multiple people in Idaho also heard a similar boom while its cause and location still remain unclear.
On October 10, residents in Cairns, Queensland heard a similar boom, leading many to suggest that it probably came from a meteorite, a gas bottle explosion, or a military plane.
Two weeks later, another boom was heard over the Eyre Peninsula in South Australia at the same time when a blue meteor passed across the sky.
"It just got bigger and bigger and it was just this big flash across the sky and there were sparks coming off it," Lisa Watson, a local resident, told News Corp.
NASA's Cooke, meanwhile, said that meteor scientists at the federal space agency will continue to examine new data to determine the cause of the baffling booms.