This article was originally published on The conversation. The publication contributed the article to Space.com’s Expert Voices: Op-Ed & Insights
Monica Grady, Professor of Planetary and Space Sciences, the Open University
As people in the UK started watching the late evening news on Feb. 28, a new news story literally popped up in the night sky. A large and very bright fireball was seen over southern England and northern France at 21:54 GMT. It was recorded by many doorbell webcams, so it was a very well perceived fireball. More importantly, it was also captured by the automated cameras of the UK Meteor Observation Network and similar networks.
Working with colleagues in France and Australia, the meteor watchers determined the fireball’s trajectory and determined where the chunks of meteorite could be located just north of Cheltenham in the UK. Based on their calculations, Ashley King, a meteorite specialist at the Natural History Museum in London, turned to local TV and radio stations for information about unusual black rocks that have fallen from the sky.
Related: Meteorite from the brilliant British fireball is the first in 30 years in England
Among the photos he received was one that caught his eye: a small pile of dust and pebbles in a driveway in the small village of Winchcombe. King asked Open University researcher Richard Greenwood (who lived the closest) to look at the sample. Greenwood was overwhelmed to discover that it was not only a meteorite, but also a very rare species. The UK was lucky – we had a new member to add to our meteorite collection.
Over the next four days, specialist investigators from various British institutions formed teams to systematically search the Winchcombe countryside. The result of their efforts are several stones weighing about 500 g, plus a lot of dust and fragments. The specimens are now in the Natural History Museum.
Precious rocks
Why is this so important? Meteorites are divided into two main groups: primitive and processed. The primitives come from the solar nebula that produced the solar system, and the composition of this original material has been preserved. In contrast, processed samples have been altered by heat. They are of larger bodies and contain information about planetary surfaces and interiors.
The rocks that have fallen over Winchcombe are of the first group – and not only that, they belong to a subcategory known as carbonaceous chondrites – the most pristine (or unaltered) meteorites, with data from the earliest stages of solar system history. They are rich in organic compounds: the molecules that make up the building blocks of life. They also contain miniscule specifications of dust from stars that have died and are older than the sun.
Some of the newly discovered rocks are almost completely black and have no shape, while others are dark gray with irregular, pale patches. Obviously it is a complex meteorite, possibly one that originated from the surface of an asteroid where several pieces of asteroid got mixed up in collisions.
And here’s where it gets a little ironic: Scientists are currently collecting samples from two asteroids in space. About five grams of material collected by Japan’s Hayabusa2 mission from asteroid Ryugu arrived safely in December 2020. Nasa’s OSIRIS-Rex mission is on the return journey of asteroid Bennu with approximately 200 grams of material arriving in September 2023. These missions cost a lot of money, but could help reveal the secrets of the origins of life and the solar system. And then, just out of nowhere, nearly 500g of rock from an asteroid, possibly very similar to Ryugu and Bennu, falls over a part of England.
Next steps
Meteorites in the UK will now analyze the material practically grain by grain. Things have to happen in a series – there are time-sensitive measurements that should be taken within the first month or so of another fall. Meteorites are not radioactive – they do not emit harmful radiation – but they do contain elements that are unstable and disintegrate. And if we can measure the amounts of elements that decay very quickly, we can get valuable information.
We also have to look closely at the organic compounds in the meteorite – there is always a risk of contamination from the earth. So the faster we can analyze the organic matter, the better. The more we can understand about these materials in meteorites, the more we can piece together the chemistry that led to life on Earth. This can give an idea of how widespread that chemistry could be (or have been) in the solar system – and even in the universe.
Searching for a meteorite in a small village and the surrounding fields is usually not dangerous and requires little risk assessment: ask the owners for permission to access their land, follow the country code, remember to close gates and not enter into anything softly. But in the time of a pandemic, everything changes.
The UK government currently prohibits citizens from traveling far from home unless the travel is essential. Was it essential for a group of meteorites to travel to Winchcombe? Yes that’s right. Each had completed fieldwork risk assessments and was allowed to travel by their institutions. They were meticulous in wearing masks and keeping a distance of 2 meters when talking to the locals.
I would have liked to have been involved in the search – although my colleague Sara Russell told me that cleaning the owner’s driveway with a toothbrush stopped working after the first hour. My arthritic knees couldn’t handle that. But I was back on the base, doing something equally important: set machines in motion to get the risk assessment paperwork in order for Greenwood. And as a reward I got to see the first close-up photos of our new family member named “Winchcombe”. It may look a bit like a broken barbecue briquette, but to me it is absolutely gorgeous.
This article has been republished from The Conversation under a Creative Commons license. Read the original article.
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