Rock fragment found in field turns out to be 4.6 billion year old meteorite



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A small fragment of rock found lying in a field in Gloucestershire in the UK may not have looked like much to the casual passer-by, but it could contain vital information about the formation of the solar system – and its origins of life itself.

This is because it did not form here on Earth, but comes from somewhere beyond the orbit of Mars. Expelled by gravitational interactions or a collision between asteroids, the fragment tumbled through the vastness of space to eventually pierce our atmosphere to land on Earth in the form of a meteorite.

What is known as the Winchcombe meteorite may not be an ordinary meteorite. Scientists are now carrying out analyzes to determine its composition, hoping to learn more about its origin and formation.

“The internal structure is brittle and weakly bonded, porous with cracks and fissures,” said microscopist Shaun Fowler of Loughborough University in the UK.

“It does not appear to have undergone thermal metamorphism, which means it has remained out there, beyond Mars, intact, since before one of the planets was created, which means we have the rare opportunity to examine a piece of our primordial past. “

The small fragment, which is part of the same meteorite that fell at Winchcombe in March, is about 4.6 billion years old, roughly the same age as the solar system. This means that it formed from the same cloud of dust and gas that gave birth to the Sun and the planets.

While the planets in the solar system have since undergone significant events and transformations, the Gloucestershire meteorite somehow trailed without concern in the asteroid belt between Mars and Jupiter. Its low aggregate construction means it has not undergone compaction due to repeated collisions.

That is, until he lands in England. Its arrival caused a sensation – not only was it the first meteorite to be recovered from the continent in 30 years, but it turned out to be a rare species, known as carbonaceous chondrite.

This means that it is a rocky meteorite, rather than iron, made up mostly of carbon and silicon. These materials are less likely to survive the rigors of atmospheric entry than iron rocks; this is why carbonaceous chondrites are rare.

The blackened piece of space rock will undergo a series of analyzes, including electron microscopy, vibrational spectroscopy, and X-ray diffraction. These techniques will help reveal the physical structure of the rock, as well as what it is done. A little is already known, but scientists are looking for hidden details.

“Most of the meteorite is made up of minerals such as olivine and phyllosilicates, along with other mineral inclusions called chondrules,” Fowler said.

“But the makeup is unlike anything you might find here on Earth and potentially unlike any other meteorite we’ve found – possibly containing chemistry or physical structure never before seen in other meteorite samples. recorded. “

Less than five percent of all meteorites recovered on Earth are carbonaceous chondrites, but they are highly sought after: They are rich in organic matter, and scientists believe they may contain clues to the origin of organic matter here. on earth.

Other such pieces of space rock have provided tantalizing clues to the origins of the building blocks of life, as well as water, but with so little evidence available for study, researchers want more. .

“Carbonaceous chondrites contain organic compounds, including amino acids, which are found in all living things,” said astrochemist Derek Robson of the East Anglian Astrophysical Research Organization (EAARO), who found the meteorite. .

“Being able to identify and confirm the presence of such compounds from material that existed before Earth was born would be an important step in understanding how life began.”

The team’s analysis is in progress.

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