A sonic boom that shook homes and rattled windows was reported by thousands of residents across several counties on Wednesday night.
The Ministry of Defence (MoD) confirmed to the BBC that RAF Typhoon fighter aircraft, which travels faster than the speed of sound, took off from Coningsby, but did not explain why.
Several residents from Northampton, Stamford and Cambridge reported on X, formerly known as Twitter, that their house shook during the boom.
On Facebook Joe Lucas said his house “rumbled” while Stuart Hewitt-Hall described the “exciting” noise as “almighty”. Another resident said it was “a scary moment”.
Carline Upex wrote: “Just starting to drift on the sofa, thinking I should go to bed even though it’s only 9.30pm. Then one very large, loud bang followed by the whole lodge shaking, had me worried my gas tank had exploded! Only to here a fighter jet a few moments after.”
Helen Davey said: “Haven’t been so frightened before! Sonic boom over Bourne tonight made everyone think there had been a huge explosion! All the buildings shook.”
— Retro32 (@TheRetro32UK) August 30, 2023
A spokesperson for the MoD said: “RAF Typhoon fighter aircraft from RAF Coningsby were launched from Quick Reaction Alert this evening.
“The RAF is responsible for policing UK airspace and would prefer not to cause any disturbance to those on the ground, however, the safety and security of the nation remains paramount.”
“QRA are launched to intercept unidentified aircraft because the aircraft cannot be identified by any other means, i.e. the aircraft is not talking to civilian or military air traffic control, has not filed a flight plan and/or is not transmitting a recognisable secondary surveillance radar code.”
In March a sonic boom was heard across London as RAF jets scrambled to escort a flight to Stansted Airport after itspilot lost contact.
The plane, heading from Iceland to Nairobi via Southend, successfully landed at the airport safely.
A sonic boom is caused when planes fly faster than the speed of sound, which at ground level is around 761mph.
When travelling at this speed, also known as Mach 1, the aircraft displaces the air and creates pressure waves that become compressed and then released in a shock wave.
As long as the aircraft is flying at Mach 1 it will generate continuous sound waves, known as a boom carpet.
An aircraft flying at 20,000 feet would create a sonic boom cone 20 miles wide.