A volunteer meteorite-hunter made an incredible discovery in March this year while scouring an English field and pleading to the spirit of his late father for assistance.
Derek Robson found one of the oldest, rarest space rocks in humanity’s possession partially buried in a horse’s muddy hoofprint. This 4.6-billion-year-old hunk of olivine and phyllosilicates had apparently fallen to Earth a few weeks earlier after traveling from some distant point beyond Mars.
Now scientists at Loughborough University, in central England, are gently probing the fragile, two-inch rock. The meteorite’s uncontaminated insides could surrender vital clues about some of the deepest mysteries of our solar system’s early history.
They might help us understand how life evolved on Earth. They might even confirm a theory about the formation of our sun and the planets around it, including our own. “There is huge potential to learn about ourselves and our solar system,” Sandie Dann, a chemistry professor at Loughborough University who is part of the analysis team, said in a statement.
The hunt that turned up Robson’s meteorite began back in February, when a larger space rock—itself once part of a faraway asteroid—blazed across the night sky over Winchcombe, 60 miles south of Loughborough. Some of the biggest chunks of that meteor embedded themselves in a farmer’s sheep pasture and a suburban driveway.
Chunks of that rock, the first meteorite to land intact in the United Kingdom in around 30 years, are already under study at universities all over the world. In the weeks following the Winchcombe impact, scientists and volunteers scoured the landscape under the meteor’s path, hoping to find additional fragments.
The follow-on search was important. Impact can contaminate a meteorite with sheep poop or asphalt or some other Earth material, so the more samples you gather, the better your chance of finding a clean one. When it comes to the science of space rocks, the more the merrier.
Robson had witnessed the Winchombe meteor streaking overhead and was eager to join the hunt, he said. He teamed up with the East Anglian Astrophysical Research Organisation and together they searched around the town of Woodmancote.
“It was exhausting at times,” Robson told The Daily Beast. “The areas were vast, and after two weekend searches, I felt it was going to be impossible. We were all disappointed and disheartened.”
Robson’s dad died a few years ago. “On occasions at times of need, I call out to my dad,” he said. “In this field, I shouted out, ‘Come on, Dad, help me find a meteorite!’ Within less than half an hour, I walked up to this dark blue-black stone embedded in the mud soil.”
It had all the hallmarks of a meteorite. A coal-like surface. Glassy bits. It was apparently a chunk of the same rock that had scattered fragments across Winchcombe. Robson and the other volunteers carved out a heavy cube of dirt containing the meteorite and shipped it off to Loughborough University, where Robson has friends and colleagues.
Initial analysis revealed that the Woodmancote meteorite, possibly like the Winchcombe fragments, is special. “The internal structure is fragile and loosely bound, porous with fissures and cracks,” Shaun Fowler, a specialist in optical and electron microscopy at Loughborough University, said in a statement.
Most importantly, it’s weirdly pristine. Younger meteorites—those resulting from the apocalyptic collisions that occurred as our solar system was forming—bear the scars of that calamity.
The Woodmancote rock has none of those scars, meaning the asteroid that produced it apparently predates our solar system’s birth. “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,” Fowler said.
Dann, Fowler and other scientists have begun scrutinizing the meteorite using a dizzying array of methods and instruments. Dann rattled off a few, including “vibrational spectroscopy to identify functional groups, powder x-ray diffraction to identify different mineralogical phases and elemental analysis to determine the relation proportions of the chemical elements within the sample.” The university invited Robson to join the analysis project.
One thing the Loughborough University team is looking for is evidence of amino acids. These acids, which can survive for billions of years inside meteors, form the proteins that are found in all living things. The acids are, in other words, the building blocks of life. Scientists lump them in the broader category of “prebiotics.” That is, the stuff that comes before biology.
“We think that asteroids and comets could have delivered some key molecules through impacts, which potentially led to the emergence of life on Earth,” Audrey Coutens, an astrophysicist at the University of Bordeaux in France, told The Daily Beast. “Analyzing the chemical composition of this meteorite is consequently a way to know what molecules were possibly delivered by asteroids.”
The trick is to find meteorites that sheared off those pre-Earth asteroids, and then find prebiotics inside of them. The Winchcombe meteorite could be just the thing to connect our own planet’s dizzying array of life to the very ancient space rocks, 5 billion years old or older, that might have sparked evolution.
To be clear, amino acids have turned up in other meteorites. But every time scientists find these prebiotics in some old space rock, they have to ask themselves—was the acid there before the rock hit Earth? “It is important to be mindful that terrestrial contamination can be possible,” Dann told The Daily Beast.
Every new meteorite is a fresh opportunity to use new analysis methods and instruments and get cleaner results. If Robson and his colleagues can pinpoint amino acids in their space rock, they could add another data point to the global effort to understand how life on Earth evolved.
But at least one scientist team said the Loughborough University researchers should set their sights higher. Lots of folks are looking for amino acids in meteorites. Fewer are looking for polymers, which are groups of bonded amino acids.
Finding a polymer inside the pre-Earth Winchcombe meteorite “would imply that this polymer formed at the point the solar system was accreting,” Julie McGeoch, a Harvard University biochemist, told The Daily Beast.
McGeoch and her husband and frequent collaborator Malcolm McGeoch have a theory: that polymers can form a lattice-like structure in the vacuum of space. “This could have been one of the very first very dense materials to form in the universe,” Malcolm told The Daily Beast.
These lattices could trap other molecules as they meander across the cosmos. Slowly growing over eons, these lattices might form the cores of stars and planets.
Yes, amino acids in some very old rock might point to the origins of life. But polymers in the same old rocks could point to the origins of, well, nearly everything. Including the planets that might harbor life and the stars that warm those planets. “We think that that is most important,” Julie said.
The McGeoch team has found its polymer in two meteorites so far. Julie said she’s eager to speak to the Loughborough University team and see if some kind of collaboration is possible. Maybe the Winchcombe rock has polymers, too.
Dann said that the processes she and her colleagues are using to find amino acids should also detect polymers. “But we are not looking for them, specifically,” she added.
Robson stressed that the Loughborough team is in touch with experts at Sheffield University who could specifically look for polymers. “We would be certainly wanting to know if any of them are present,” Robson said.
The Winchcombe meteorite might harbor clues to the origins of life and related clues to the mysterious processes that formed stars and planets. Both inquiries have merit. The problem is that some of the processes scientists use to analyse a meteorite destroy part of the meteorite.
You might have to bake it. Or shatter it. Or grind it into powder. In other words, the Winchcombe space rock, all two inches of it, is a finite resource. So scientists have to prioritize their investigations while awaiting the fiery arrival of the next primordial meteorite. Whenever that might be.