On February 28, 2021, a fireball crossed the UK skies, leaving behind fragments of a meteorite near the town of Winchcombe, Gloucestershire. It was the first meteorite to land in the UK in 30 years, and the hunt was on. Scientists found these celestial fragments very quickly, immediately removing them from Earthly contamination. This meant they could be analyzed almost as if they were samples collected directly from an asteroid. Now, they are providing new insights into the early Solar System.
The meteorite is already classified as one of the rarest types. In a new paper, a team from the Natural History Museum, London and the University of Glasgow conducted the first laboratory analyses of the meteorite and found that the space rock contains about 10 percent water by weight and it is remarkably similar to Earth's water. This suggests that this class of meteorites, known as carbonaceous chondrites, must have played a crucial role in bringing water to our ancient planet.
“Carbonaceous chondrites are incredibly reactive and rapidly degrade in Earth's atmosphere, changing their original mineralogy and composition. But for Winchcombe, it had almost no time to react with Earth's environment, so we know that everything inside it is 100 percent extraterrestrial including the 10 percent water it contains,” study author Dr Luke Daly from the University of Glasgow told IFLScience.
And it’s not just water. The sample also had evidence of important carbon and nitrogen-based molecules. Among them, there were amino acids, the building blocks of proteins. These, together with water, are believed to have played a key role in the evolution of life on Earth. Winchcombe is a rare type of carbonaceous chondrite known as a CM, with only 15 of them on record.
“Life as we know it needs two key things to have a chance at emerging: water and organic molecules like amino acids – the Winchcombe meteorite has both," Dr Daly explained to IFLScience. "Winchcombe is the best evidence so far that CMs likely were a key source of water for Earth, as the water inside it is quite close in composition to that of the Earth as well as being rich in organics – and because Winchcombe was recovered so fast we know it hasn't been changed by its time on Earth. Winchcombe and other CMs are essentially a one-stop shop for everything a growing planet needs if it has ambitions of developing life.”
The incredibly fast recovery of the object was possible thanks to the UK Fireball Alliance, 16 cameras, and plenty of public reports that allowed researchers to quickly track where the object had fallen, which turned out to be onto someone's driveway.
“What was also really surprising was the fireball data which suggested that Winchcombe had no right to have survived coming through our atmosphere. We were incredibly lucky to have any meteorites on the ground at all," Dr Daly told IFLScience.
"The meteorite before it hit Earth's atmosphere was really small, only originally about the size of a basketball, and if it had come it at a slightly different angle or slightly slower or faster would have completely burnt up in the atmosphere."
“The rapid retrieval and curation of Winchcombe make it one of the most pristine meteorites available for analysis, offering scientists a tantalising glimpse back through time to the original composition of the Solar System 4.6 billion years ago,” co-author Dr Ashley King of the Natural History Museum said in a statement.
If you're in the UK, samples of this extraordinary meteorite are on public display in several locations, including the Natural History Museum, London.
The paper is published in Science Advances.