Last night, Britons from Aberdeen to Devon were left baffled by a series of mysterious explosions which shook windows and disturbed sleeping children.
Hundreds of Twitter users reported the sounds between around 9pm and 11pm last night, with many describing the noise as sounding like ‘distant fireworks’.
But despite suggestions of RAF jets, meteors and aliens flooding the social media site today, no one has been able to explain what was heard. Even the MoD has said it is stumped.
Now a recording of the ‘loud bangs’, taken by a woman as she sat at home in Croydon, south London, might shed light on what is really behind the unexplained noise.
Some suggested that unusual weather conditions might be the source, but the Met Office today dismissed the claims.
Others on Twitter suggested that it could be traced back to controlled explosions or military exercises. Meanwhile, conspiracy theorists took to social media to claim that aliens were to blame.
Claudia Angiletta said that she was watching TV at home when the unexplained sounds started.
She told MailOnline: ‘I was just at home watching TV when I couldn’t hear the program due to the loud noises. It was very distracting as it went on for ages.
‘I went out to look for fireworks but I couldn’t see anything in the sky. That’s when I recorded the clip to send to my family to see if they could hear the same thing.’
The 27-year-old said that her family, who live roughly seven miles away in Norbury, south London, could also hear the sounds, which lasted for about 30 minutes. She then turned to Twitter to see if anyone could explain what they were.
Many suspected sonic booms similar to ones which shook Kent last month when two RAF jets intercepted a Latvian cargo plane in British airspace.
But a Ministry of Defence spokesman told MailOnline she had no records of any jets being scrambled last night.
The denial only served to fuel an outpouring of Saturday night speculation on social media.
Within minutes Twitter users had started spreading hashtags from the straightforward (#loudbangs) to the slightly melodramatic (#omgwereallgoingtodie).
Many of the reports were picked up by Twitter user Virtual Astronomer, who said space debris re-entering the earth’s atmosphere could have been responsible.
‘Space debris such as old satellites and things can cause sonic booms heard over very large areas,’ he told MailOnline.
‘It’s the same for big meteors or rocks that come in.
‘There are also some rare meteorologic phenomena that can cause rumbling or bangs apart from thunder.
‘The only other explanation could be supersonic aircraft. There was very little wind last night so conditions were perfect for sound to travel very long distances.’
Science writer David Dickinson was among the experts who dismissed the theory.
He told MailOnline that there was one piece of debris from Russian satellite Kosmos 2251 scheduled for re-entry, but said that the timing was ‘not a good fit’ for it to have been over the UK.
He added: ‘I do not think it was a meteor or a piece of space-junk, as the noises mentioned spanned a large segment of time. Plus, unless it was cloudy over the U.K., there would’ve been visual sightings.
Others thought that the loud noises might be due to unusual weather events, such as space weather, electrical storms or ferocious thunder storms.
But the Met Office said today that there had been no reports of such weather last night.
A spokesman told MailOnline: ‘It definitely wasn’t meteorological’.
Other conspiracy theories revolved around whether the noises could be the testing of a secret jet.
Steven Aftergood, a government secrecy expert at the Federation of American Scientists, said: ‘If an aircraft is responsible, then it’s worth noting that it may not be local at all.
‘Because the sound wave that causes the boom can be reflected by the stratosphere, the source of the event could conceivably be hundreds or thousands of miles away from the place where it is heard on the ground.
‘I don’t know how to interpret the sound itself, or whether certain sound patterns would correspond to certain types of aircraft engines.’
Dozens of the reports focused around Croydon, south London, where baffled Twitter users were asking each other what had happened.
The Metropolitan Police said that a fireworks display in Croydon could have been the source.
But that does not explain why other noises were heard in Bedfordshire, Glasgow, North Devon, Leicestershire and West Sussex.
Dave Reed, who lives in Fareham, Hampshire, said his dogs ‘went crazy for a couple of minutes’ after hearing what he had assumed were fireworks.
The noises prompted conspiracy theories and immediate claims of a ‘media blackout’.
Twitter user Carrie Proctor wrote: ‘This is how we’ll find our that WW3 has begun. It’ll be a Twitter hashtag long before any official announcement!’