This rare meteorite contains Earth-like water and could explain where our oceans came from

• The Winchcombe meteorite is a rare find, with a hydrogen isotope ratio similar to that of water on Earth.
• Recovering a meteorite within 12 hours of its arrival means it is as pristine a specimen as possible without going into space.
• Eleven percent of the meteorite’s weight comes from Earth-like water, puzzling scientists about the implications of Earth’s early composition.

Picking up a meteorite within 12 hours of crashing has proven to be a scientific boon for researchers investigating the hydrogen composition of this space visitor. The pound of carbonaceous chondrite was plowed up in the English town of Winchcombe in February 2021. Its most spectacular feature, according to scientists? The hydrogen isotope ratio of rock is surprisingly similar to that of water on Earth.

“One of the biggest questions posed to the scientific community is how did we get here? This analysis of the Winchcombe meteorite provides insight into how the Earth got water, the source of so much life,” said Luke Daly, a professor at the University of Glasgow and author of the first paper on the meteorite published at Scientists progress, said in a press release. “Researchers will continue to work on this specimen for years to come, unlocking more secrets about the origins of our solar system.”

Key to the research was the fact that specialists around the world could begin investigating the Winchcombe meteorite within days of its fiery fall from the sky. Less than 12 hours after entering Earth’s atmosphere, chunks of rock were ripped from an alley and surrounding area and taken to London’s Natural History Museum, away from any environmental effects that could alter its analysis.

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“The rapid recovery and preservation of Winchcombe makes it one of the most pristine meteorites available for analysis, giving scientists fascinating insight into the original composition of the solar system 4.6 billion years ago,” said Ashley Key, senior curator at the Natural History Museum. and the journal’s co-author, says in a press release. Estimates vary, but the Earth is about 4.5 billion years old.

The meteorite offers a glimpse of a rare carbonaceous chondrite, a high-silicate rock containing about 2% carbon by weight. It is the first of its type to be discovered in the UK. After imaging and chemical analysis, researchers have determined that it contains 11% extraterrestrial water by weight. Most of the water is trapped in minerals created by chemical reactions between fluids and rocks on the asteroid from which the meteorite originated, during what scientists believe is the oldest formation in our solar system.

By measuring the ratio of hydrogen isotopes in water, the team discovered that it closely resembles the composition of water on Earth. It also contains extraterrestrial amino acids or prebiotic molecules essential for the creation of life. Because the meteorite was unaltered by Earth’s environment due to its rapid recovery, the researchers believe their findings support the theory that carbonaceous asteroids played a key role in providing the ingredients for life. – like water – on the primitive Earth. This makes the Winchcombe meteorite particularly different from the more common icy comets, which have no chemistry to match Earth’s water.

“Direct links between carbonaceous chondrites and their parent bodies in the solar system are rare,” according to the paper. “The Winchcombe meteorite is the most accurately recorded carbonaceous chondrite fall. Its pre-atmospheric orbit and age of exposure to cosmic rays confirm that it arrived on Earth shortly after its ejection from a primeval asteroid.

Combining camera footage of its trajectory from the UK Fireball Alliance – which aims to recover fallen meteorites as soon as possible – with chemical analysis of the meteorite, researchers believe Winchcombe broke away from an asteroid’s surface near Jupiter and traveled to Earth in the last million years.

“We are still in shock at our luck to have such a large meteorite fall in the UK,” Natasha Almeida, meteorite curator at the Natural History Museum and co-author of the paper, said in a statement. hurry. “The combination of such rapid recovery, careful collection and our continued preservation of Winchcombe in a nitrogen atmosphere means that this incredibly fresh specimen will remain one of the most pristine meteorites in collections around the world.”