What causes a sonic boom?
The MoD has said a loud bang heard across much of England on Thursday night was a sonic boom caused by one of two Typhoon aircraft responding to an emergency call.
The jets were scrambled and authorised to go supersonic after a small civilian helicopter had emitted an emergency signal.
Dr Jim Wild from Lancaster University explained to the BBC how and why a sonic boom happens.
13 Apr 2012
- From the section Science & Environment