A Field Fragment Is Discovered to Be an Ancient 4.6-Billion-Year-Old Meteorite
A small sliver of granite discovered in a field in Gloucestershire, United Kingdom, may appear insignificant to the casual observer, but it may contain critical information about the genesis of the Solar System – and the origins of life.
That is because it did not originate on Earth, but rather someplace beyond Mars’ orbit. When the component was ejected by gravitational forces or a collision between asteroids, it tumbled across the vastness of space, eventually punching through our atmosphere and crashing to Earth as a meteorite.
What has become known as the Winchcombe meteorite, on the other hand, may not be a typical meteorite. Scientists are now analyzing its makeup in order to learn more about its origins and formation.
“The internal structure is fragile and loosely bound, porous with fissures and cracks,” said Loughborough University microscopist Shaun Fowler.
“It doesn’t appear to have undergone thermal metamorphism, which means it’s been sitting out there, past Mars, untouched, since before any of the planets were created, meaning we have the rare opportunity to examine a piece of our primordial past.”
The little chunk, which is part of the same meteorite that fell in March in Winchcombe, is around 4.6 billion years old – roughly the same age as the Solar System. That is to say, it formed from the same cloud of dust and gas that gave birth to the Sun and planets.
While the Solar System’s planets have since undergone tremendous changes and alterations, the Gloucestershire meteorite was simply hanging around in the asteroid belt between Mars and Jupiter, unmolested. Due to its loosely aggregated construction, it has not been compacted by repeated impacts.
That is, until it reached the shores of England. Its discovery caused a commotion — not only was it the continent’s first meteorite recovery in 30 years, but it also turned out to be a rare type known as a carbonaceous chondrite.
This indicates that it is a rocky meteorite rather than an iron one, consisting mostly of carbon and silicon. Carbonaceous chondrites are less likely to withstand the rigors of atmospheric entry than iron rocks, which explains why they are rare.
The blackened sliver of space rock will be analyzed using electron microscopy, vibrational spectroscopy, and X-ray diffraction. These procedures will aid in revealing the rock’s physical structure as well as its composition. We already know a little, but scientists are on the lookout for additional information.
“The bulk of the meteorite is comprised of minerals such as olivine and phyllosilicates, with other mineral inclusions called chondrules,” Fowler explained.
“But the composition is different to anything you would find here on Earth and potentially unlike any other meteorites we’ve found – possibly containing some previously unknown chemistry or physical structure never before seen in other recorded meteorite samples.”
Carbonaceous chondrites account for less than 5% of all meteorites recovered on Earth, but they are widely sought after because they are rich in organic materials and scientists believe they may carry information about the origins of organic matter on Earth.
Other similar fragments of space rock have offered interesting hints about the origins of life’s building blocks, as well as water, but with so few available for examination, experts are hungry for 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 Organisation (EAARO), who discovered the meteorite.
“Being able to identify and confirm the presence of such compounds from a material that existed before the Earth was born would be an important step towards understanding how life began.”