The meteorite hit a road in the Gloucestershire town of Winchcombe last February and is believed to hold clues to where the water in Earth’s vast oceans came from. About 12% of the sample was made up of water, and it offers a lot of insight as it was the least contaminated sample collected, according to Ashley King, a researcher in the planetary materials group at the Natural History Museum. “The composition of this water is very, very similar to the composition of water in Earth’s oceans,” he told the British Science Festival. “It’s really good evidence that asteroids and bodies like Winchcombe contributed very significantly to Earth’s oceans.” Dr King also confirmed it was the first time a meteorite containing extraterrestrial water – albeit encased in minerals – had fallen in the UK, in the historic town of Cotswold. He explained that because the 0.5 kg meteorite was recovered quickly, within about 12 hours, it was not contaminated by water and materials on Earth. He continued: “We always try to match the composition of water meteorites and other extraterrestrial materials with the composition of water on Earth. “For most meteorites, the challenge we face is that they’re just contaminated, whereas with Winchcombe we actually know that it really isn’t contaminated, so that’s good evidence.” Image: Fragments from the meteorite that landed in Winchcombe last year Dr King continued: “One of the big questions we have in the planetary sciences is where did the water on Earth come from? And one of the obvious places is either through comets that have loads and loads of ice in them, or from asteroids. “There’s always a debate—were comets the primary source, were asteroids the primary source?” But he explained that data from missions to comets suggests they don’t match water on Earth well, adding: “The composition of the water at Winchcombe matches much better, so that would mean asteroids – carbonaceous asteroids – were probably the main source of water in the inner solar system, on Earth.” Read more: ‘Bright fireball’ that lit up night sky across parts of Britain was space debris, experts say Dr. King continued: “We had a hint that some asteroids are a good match for Earth. “But now we have a meteorite that’s really fresh that we know hasn’t been modified and it confirms the same story.” Speaking at De Montfort University, which hosts the festival, Dr King revealed that the analysis suggested the meteorite came from an asteroid somewhere near Jupiter. It is believed to have formed about 4.6 billion years ago and took about 300,000 years to reach Earth. As it stands, there are about 65,000 known meteorites on Earth. The meteorite found at Winchcombe is the first known carbonaceous chondrite to be found in the UK and the first to be recovered across the country in 30 years.
