A hunt is under way for the remains of a suspected meteor that was seen shooting across British skies.
Astronomers desperately want to track down any remnants of the space rock in the hope it could yield secrets about the birth of the Earth and solar system.
It was last spotted over the UK above Devon and there has been speculation it could have landed in Normandy, France - or perhaps in the Bay of Biscay.
Most meteors are only the size of tiny pebbles and burn up when they enter the Earth's atmosphere but this one was big enough for some to survive. It is thought to be about the size of a fist.
Even the slowest meteors travel at 10 miles a second - which is much faster than a speeding bullet.
Dr Marek Kukula, public astronomer at the Royal Observatory in Greenwich, has said any remnants could be worth more than their weight in gold.
"Our own origins are locked up in these pieces of rock. They are pristine material from the beginning of the solar system and hold the ingredients of life. They are a real treasure-trove," he told The Independent.
Police forces and astronomy websites found themselves inundated with sightings after a "bright light" and "orange glow" were spotted on Saturday evening.
The Met Office said it believed it had been a meteorite and the Royal Observatory at Greenwich said it was probably part of a meteor shower.
A brightness of magnitude -6 is required to be seen in daylight and according to the International Meteor Organisation only one in 12,000 reaches magnitude -8.
The Kielder Observatory in Northumberland reported the sighting as a "huge fireball" travelling from north to south over Northumberland at 9.41pm, and rated it at magnitude -9.
Its director Gary Fildes, who has been an astronomer for 30 years, said: "I've never seen anything like that in my life."
He has said it will be difficult to determine where the meteor came from. "Trying to nail down the origin of the object will not be easy. It's open to conjecture."
Strathclyde Police was "inundated" with calls about a bright object in the sky across the west of Scotland.
Durham Police received calls from concerned members of the public who believed it might have been an incident involving an aircraft.
The American Meteor Society website was also swamped with dozens of Britons logging sightings.
Michelle Thornton, from Birmingham, wrote that it was "the most amazing thing I have seen in the night sky in ages - outstanding".
Another user, Brandi, from Stirling, at first thought it was a firework and wondered if it was a missile after it "changed direction".
"We wondered if it was a missile. The tail was longer than any astral body I have ever seen and the colour between the head and tail was very distinct.
"The head was bright - warm colours - and the tail was much longer. We thought it was a firework because it stuttered out and seemed to fade, but we did not hear the bang.
"It then reappeared as it continued across the sky, seemingly changing directions slightly - as if around a 15 degree corner.
"It then also seemed to go lower down in the sky and then passed out of our vision after another 10 seconds or so.
"It still looked orangey-red in the distance as it left our vision, but we could not see the tail from that angle."
David Whitehouse, fellow of the Royal Astronomical Society , told The Times: "It might well have survived landing. You hope for a farmer who has found a piece of rock in a turnip field."