The meteorite that landed in the English countryside last year was the cleanest ever seen
A meteorite that lit up the sky over an English countryside last year is almost as intact as samples collected by space probes and contains the “right” kind of hydrogen to explain water on Earth, scientists say.
A great furore broke out when a a fireball rattled across the evening sky over SW England on 28th February 2021. Dozens meteor cameras and doorbell webcams picked up the bright streak, and a 1-pound (0.5-kilogram) fragment of the space rock was immediately found in the driveway of a house in the village of Winchcombe, after which the meteorite was later named.
The quick discovery meant the meteorite was barely exposed to Earth’s elements, allowing it to retain its pristine chemical composition. In fact, the composition of the Winchcombe meteorite is so intact that it can almost match samples collected by space probes such as NASA OSIRIS-REx of asteroids in space, researchers said in a new study.
Analysis of this precious rock has yielded fascinating results that seem to support the theory that EarthWater primarily came from asteroids. The Winchcombe space rock contains hydrogen atoms with an isotopic composition quite similar to that of Earth’s water. Isotopes are varieties of the same chemical elements that differ in the number of neutrons in their atomic nuclei. Other possible sources of Earth’s water, such as cometswere found to contain water with different isotopic profiles.
The analysis also revealed that the meteorite must have separated from its parent asteroid relatively recently in the cosmic scheme of things – just 200,000 to 300,000 years ago. Most meteorites, the scientists say in the paper, spend millions of years in interplanetary space before their paths intersect with Earth’s, during which time they are devastated cosmic rays and solar the wind.
By analyzing data from cameras that recorded the Winchcombe meteorite’s cruise through Earth’s atmosphereastronomers managed to reconstruct the rock’s orbit and determine that its parent asteroid is located in the main asteroid belt between orbits mars and Jupiter and not among the near-Earth asteroid population.
The Winchcombe meteorite is a carbonaceous chondritea rare class of meteorites believed to originate from very primitive asteroids that migrated into the main asteroid belt from the outer edges Solar system. Scientists believe that the chemical composition of these asteroids has hardly changed since the birth of the solar system. And that means that, thanks to its pristine nature, the Winchcombe meteorite provides a unique view of these ancient “time capsules”.
In addition to the right kinds of hydrogen, the meteorite also contains organic material of the kind that could have led to life on Earth some 3.5 billion years ago, scientists said in statement (opens in new tab).
All in all, the Winchcombe meteorite was a very lucky strike.
“Direct connections between carbonaceous chondrites and their parent bodies in the Solar System are rare,” the scientists state in the paper. “The Winchcombe meteorite is the most precisely recorded fall of a carbonate chondrite.”
Only four journeys of Carboniferous chondrites through the Earth’s atmosphere have been so well observed that their origin could be determined. Most of the others discovered “are serendipitous finds that lack information about their original region in the Solar System,” the researchers said in the paper.
Study (opens in new tab) a description of the first analysis of this precious rock was published on November 16 in the journal Science Advances.
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