The rare Winchcombe meteorite contains water similar to that found on Earth

  • The Winchcombe meteorite is a rare find, with a hydrogen isotopic ratio similar to that of water on Earth.
  • Recovering a meteorite within 12 hours of arrival means it’s about as authentic a specimen as we can get without going to space.
  • Eleven percent of the meteorite’s weight comes from Earth-like water, sparking scientists’ curiosity about the implications for Earth’s early formation.

The discovery of a meteorite within 12 hours of its crash turned out to be a scientific boon for researchers studying the hydrogen composition of this visitor from outer space. One pound of carbonaceous chondrites was plowed in the English town of Winchcombe in February 2021. What’s most special about it, according to scientists? The ratio of hydrogen isotopes in rocks is very similar to that of water on Earth.

“One of the biggest questions for the scientific community is how did we get here? This analysis on the Winchcombe meteorite gives insight into how Earth gets its water, the source of so much life,” Luke Daly, lecturer at the University of Glasgow and author of the first meteorite paper published in Science advances, in a press release. “Researchers will continue to work on this sample for years to come, uncovering more secrets in the origins of our solar system.”

Key to the research was the fact that specialists from 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 plucked from the driveway and surrounding area and taken to London’s Natural History Museum, away from any environmental impacts that could alter its analysis.

“Winchcombe’s rapid recovery and processing makes it one of the most primitive meteorites available for analysis, providing scientists with a tantalizing glimpse through time into the original formation of the solar system 4.6 billion years ago,” Ashley Key, senior curator of Natural History and co-author on the paper, says in the article. press release. Estimates vary, but the Earth is about 4.5 billion years old.

The meteorite provides a glimpse of a rare carbonaceous chondrite, a highly silicate rock that contains approximately 2 percent carbon by weight. It is the first of its kind to be discovered in the UK. After imaging and chemical analysis, the researchers determined that it contains 11 percent extraterrestrial water by weight. Most of the water is trapped in minerals resulting from chemical reactions between fluids and rocks on the asteroid from which the meteorite originated – during what scientists believe was the first formation of our solar system.

By measuring the ratio of hydrogen isotopes in the water, the team found that it is very similar to the composition of water on Earth. It also contains extraterrestrial amino acids, or prebiotic molecules that are key to creating life. Because the meteorite was largely unmodified by Earth’s environment due to its rapid recovery, the researchers believe their findings support the theory that carbonaceous asteroids played a major role in bringing the ingredients for life — such as water — to early Earth. This makes the Winchcombe meteorite markedly different from more common icy comets, which do not have a chemistry matching Earth’s water.

According to the paper, “Direct links between carbonaceous chondrites and parent bodies in the solar system are rare.” “The Winchcombe meteorite is the most accurately recorded carbonaceous chondrite fall. Its pre-atmospheric orbit and age of cosmic ray exposure confirm that it reached Earth shortly after being ejected from a primitive asteroid.”

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

“We are still very fortunate to have such an important meteorite fall in the UK,” Natasha Almeida, curator of meteorites at the Natural History Museum and co-author on the paper, says in a press release. “The combination of this rapid recovery, careful assembly and Winchcombe’s continued treatment in a nitrogen atmosphere means that this incredibly new specimen will remain one of the most pristine meteorites in collections worldwide.”

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