Riddle of the late night rumblings that caused a sonic boom in Norfolk
09:46 11 August 2011
Mystery surrounds what made the earth tremble across Norfolk in a bizarre late-night phenomenon
Meteorites are fragments of rock and metal which have fallen from space.
Asteroids are different shaped rocks which orbit the sun. When two asteroids collide a meteorite is formed and breaks away from the original rock.
Once separated, the meteorite is captured by the Earth’s gravity reaching speeds of more than 11.2km per second.
As it reaches the Earth’s atmosphere it slows down due to friction, gas and glow.
A meteorite is commonly known as a shooting star (meteor), the only difference is a meteorite survives the passage through the Earth’s atmosphere and has an impact.
Although their paths are random, meteorites nearly always fall in the ocean.
Experts and amateurs alike believe a sonic boom – triggered by a meteorite or aircraft – caused strange tremors to shake homes and spook pets.
The rattling was reported by people across the county, including Norwich, North Walsham, Gayton, Belton, Cringleford and South Lopham at about 10.30pm on Tuesday.
Jonathan Larter, from Sprowston, said: “I was just going to bed and the house started shaking and doors rumbling as if the wind was blowing through the windows, but they weren’t open. I thought it was a ghost outside knocking on my door because I live near a cemetery.”
Alan Sharman, from City Road, Norwich, added: “My French doors rattled rather loudly at 10.30-ish. It actually sounded like someone was trying to get in. It woke me up a bit.”
Experts quickly dismissed the possibility of the movement being caused by an earthquake as their equipment did not pick up any seismic activity.
Glen Ford, a seismologist with the British Geological Survey, said: “From the descriptions and the lack of seismic information ,it sounds like it could have been a sonic boom.”
Mr Ford said sonic booms can be caused by aircraft or meteorites. And in a bizarre coincidence some people reported seeing a meteor over the skies of Norwich just before the tremor started.
Dominic Hyde-Smith, 44, spotted “a streak of fire” land south of the city while on his way home to Hempnall.
“It just shot down in a split second,” he said. “Rather than a shooting star, this went straight down towards the ground.”
Meanwhile, RAF Marham staff said aircraft were not out on Tuesday but planes from RAF Lakenheath were reported to have been on exercise.
Do you have a theory about what made the earth tremble? Email firstname.lastname@example.org