A meteor that crashed in 2021 in the city of Winchcombe, United Kingdom, contained water that perfectly matched that of the Earth. This reinforces the idea that rocks from space brought key chemical components, including water, to the planet early in its history, billions of years ago.
The meteorite is considered the most important recovered in the United Kingdom.
The scientists who published the first detailed analysis say it yielded fascinating ideas.
More than 500 grams of blackened remains were collected from the gardens and local fields where it fell, after a Giant fireball will light up the night sky. The shredded remains were carefully cataloged at the Natural History Museum (NHM) in London and then they lent to teams in Europe.
The water represented until the 11% of the weight of the meteorite, and contained a very similar ratio of hydrogen atoms to water on Earth. Some scientists say that Earth, in its youngest stage, it was so hot that it would have expelled much of its volatile contents, including water.
That the Earth has so much water today (70% of its surface is covered by oceans) suggests that there must have been a later addition. Some say this could come from a icy comet bombardment, but their chemistry doesn’t add up.
However, carbonaceous chondrites (Winchcombe-like meteorites) certainly do. And the fact that the parts of the meteorite will recover less than 12 hours later of crashing means that it had absorbed very little terrestrial water, or indeed any contaminants.
“All the other meteorites were compromised in some way by the terrestrial environment,” study co-author Ashley King of the NHM told BBC News.
But Winchcombe’s is different because the speed with which it was picked up.
“This means that when we looked at it, we knew that the composition we’re looking at takes us back to the composition at the beginning of the Solar System, 4.6 billion years ago.”
“Excluding the search for rock samples from an asteroid with a spacecraft, we could not have a more pristine specimen.”
Scientists who examined the carbon- and nitrogen-containing organic compounds of the meteorite, including its amino acids, obtained an equally clean image. This is the kind of chemistry that could have been the raw material that allowed biology to begin on Earth primitive.
The new analysis also confirms the origin of the meteorite.
The camera images of the fireball allowed the researchers to determine a very precise trajectory. calculating backwards, They found out that the meteorite came from the outer asteroid belt between Mars and Jupiter. The Winchcombe material recently sold at auction for more than 120 times its weight in gold.
Further investigation revealed that it broke off from a larger asteroid, presumably in some collision.
Later, it took between 200,000 to 300,000 years to reach Earthas revealed by the number of particular atoms, such as neon, created in the meteorite material through the constant irradiation of high-speed space particles, or cosmic rays.
“0.2-0.3 million years seems like a long time, but from a geological perspective, it’s actually very fastsaid Helena Bates, from the NHM.
“The carbonaceous chondrites have to get here quickly or they won’t survive, because they’re so crumbly, they’d just break off.”
The scientists’ first analysis, in this week’s issue of the journal Science Advances, is just an overview of the Winchcombe meteorite’s properties. A dozen articles will be published soon more on specialist topics in an issue of the journal Meteoritics & Planetary Science.
“Researchers will continue to work on this sample for years to come, revealing more secrets about the origins of our Solar System,” said study co-author Luke Daly of the University of Glasgow.
By Jonathan Amos
BBC News World
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