The yellow-green fireball that pierced Earth’s atmosphere on Sunday night, delighting observers from the UK to the Netherlands, is thought to have partially survived the journey in the form of meteorites, most likely landing just north of Cheltenham.
Fireballs are particularly bright meteors – space matter that burns up as it enters Earth’s atmosphere. Whatever is left of it when it reaches the surface of the Earth is known as a meteorite. They are of particular interest to scientists as they can offer crucial clues about the history of the solar system.
Richard Kacerek, founder of the UK meteor network, a group of amateur astronomers who have been using cameras to record sightings across the UK since 2012, said computer modelling suggested the probable site of the meteor’s impact was just north of the Gloucestershire town.
Roughly 50 tonnes of extraterrestrial material enters the Earth’s atmosphere each year, mainly in the form of sand-sized particles called space dust. In the UK, about 20 meteorites – barely the size of sugar cubes – are estimated to land each year. The last recovered meteorite fall was in 1991 in the village of Glatton near Peterborough.
Brighter fireballs have been sighted in the past, said Kacerek. “What makes this particular fireball really special is that we think that something has actually survived.”
Ashley King, of the Natural History Museum in London, said in a statement: “The video recordings tell us its speed was about 30,000mph, which is too fast for it to be human-made ‘space junk’, so it’s not an old rocket or satellite.
“The videos also allowed us to reconstruct its original orbit around the sun. In this case, the orbit was like an asteroid’s. This particular piece of asteroid spent most of its orbit between Mars and Jupiter, though sometimes got closer to the sun than Earth is.”
Basing their predictions on footage from multiple specialised fireball cameras, the observers concluded that smaller-than-golf-ball sized pieces of dark-coloured fragmented rock pieces would be found, Kacerek said, adding that it was still unclear to which comet the meteor belonged.
“We have already received a few emails from people in the area, saying that they found something interesting,” he added, noting that those sightings still needed to be verified by scientists from the Natural History Museum.
If people come across pieces of meteorite, scientists said, they should first photograph it in place and note the location using their phone’s GPS, but avoid touching it directly. Meteorites are usually rich in iron, but using a magnet could damage the sample – Kacerek suggested picking it up using a clean plastic bag.
The UK public should remember that the lockdown was still in place, and people should not break restrictions to look for meteorites, he cautioned.
One of the biggest draws of examining meteorites is a theory called panspermia: that the chemistry of life exists in space.
Astronomical research has found the building blocks of life in the atmospheres of distant planets and interstellar clouds, and even more complicated compounds in meteorites. Given that life on Earth began at least 3.8bn years ago and the leap from organic chemistry to self-replicating organisms is so vast, some astronomers propose that life might have been delivered by a passing comet.
“It is certainly a theory, but I think it is a very likely theory,” said Kacerek. “We don’t know much about it [the meteor from Sunday] yet. But certainly … setting up a meteor camera, recording the meteorite and then going and pick it up will help answer those questions.”
On Sunday night, Kacerek’s own three cameras did not detect the fireball. “But when I saw the pictures, I said, ‘Holy …’ I knew what it meant,” he said. “Because it meant … that I have to get up at 6 o’clock and talk to media all day.”
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