RESIDENTS all over the east of England were startled to hear a large boom noise at lunchtime.
From Kings Lynn to Kent, people have taken to social media to ask what was that noise that shook the teacups on Tuesday morning.
Sources have suggested it might have been a RAF Typhoon travelling over the area.
A RAF spokesman said: “The RAF can confirm Quick Reaction Alert Typhoon aircraft were launched this afternoon from RAF Coningsby to intercept a civilian aircraft that had lost communications; subsequently, communications were re-established, the aircraft was intercepted and safely escorted to Stansted.
“The Typhoon aircraft were authorised to transit at supersonic speed for operational reasons.”
What causes a sonic boom?
When an aircraft approaches the speed of sound (768mph or 1,236km/h), the air in front of the nose of the plane builds up a pressure front because it has “nowhere to escape”, said Dr Jim Wild of Lancaster University.
A sonic boom happens when that air “escapes”, creating a ripple effect which can be heard on the ground as a loud thunderclap.
It can be heard over such a large area because it moves with the plane, rather like the wake on the bow of a ship spreading out behind the vessel.
This also occurred in June and December 2019.