The discovery of a toxin that makes pigs sick has helped to solve a decade-spanning mystery about a meteorite that fell from Mars.
When the Lafayette meteorite was found in a drawer at the biology department of Purdue University in Indiana, USA, researchers couldn't remember where it had originated from.
There had been a number of theories floating around surrounding its origin. Some said it was donated to the university by a Black student who came across it while fishing in a pond, but nothing had been confirmed, the Mirror reports.
To find out more about the student and where the meteorite had came from, researchers began an investigation.
Geochemist Dr Aine O'Brien, from the University of Glasgow, launched the project two years ago after her team was handed a tiny piece of the meteorite by the Natural History Museum in London.
"Lafayette is a truly beautiful meteorite sample, which has taught us a lot about Mars through previous research," Dr O’Brien said.
"Part of what has made it so valuable is that it’s remarkably well-preserved, which means it must have been recovered quickly after it landed, as Lafayette’s origin story suggested.
"Meteorites which are left out in the elements for any significant length of time have their top layers weathered away, reducing their research value as they collect terrestrial contaminants."
To determine what the meteorite was made of, Dr O'Brien crushed it up into tiny pieces for examination. She was hoping to discover new details about the presence of organic molecules in the meteorite, which could help us learn more about the possibility of life on Mars.
After scrolling through a long list of hundreds of metabolites revealed by her research, Dr O’Brien noticed an unusually earthbound one - deoxynivalenol, or DON.
DON is a ‘vomitoxin’ found in a fungus which infects grain crops like corn, wheat and oats.
It makes human and animals sick, with pigs in particular being badly affected.
Intrigued by her discovery, Dr O'Brien told her colleagues who were also keen to understand the mystery of the meteorite.
They suggested that dust from crops in nearby farmland could have carried DON to surrounding waterways, and that Lafayette might have been contaminated by it when the meteorite landed in a pond.
Dr O’Brien then enlisted the help of researchers at Purdue University’s Department of Agronomy and Department of Botany and Plant Pathology, to find out more about the historic significance of the fungus in Indiana, where Purdue is located.
Their records showed that it caused a 10 to 15 per cent drop in crop yield in 1919, and another less pronounced drop in 1927.
This was the highest prevalence in the 20 years before 1931, when the meteorite was identified. With more fungus, it was more likely that it would be carried beyond the area of farmland.
After examining fireball sightings around that time, more potential clues were revealed regarding the timing of Lafayette’s landing.
Meteorites heat up as they fall through the Earth’s atmosphere, causing a bright streak of fire across the sky.
There were reported sightings of a fireball across southern Michigan and northern Indiana in November 1919, and another in 1927 which dropped the Tilden meteorite in Illinois.
Archivists at Purdue University also looked at yearbooks from 1919 and 1927 to find black students enrolled at the time.
Julius Lee Morgan and Clinton Edward Shaw, of the class of 1921, and Hermanze Edwin Fauntleroy, of the class of 1922, were enrolled at Purdue in 1919. A fourth man, Clyde Silance, was studying at Purdue in 1927.
The researchers conclude that it may be likely that one of these men found the meteorite, as suggested by Nininger’s origin story from 1935.
Dr O'Brien commented: "The unusual combination of Lafayette’s swift protection from the elements and the tiny trace of contamination which it picked up during its brief time in the mud is what made this work possible.
"It’s also a useful reminder of the importance of protecting samples of Martian rock which we expect to return to Earth from unmanned Mars rover missions in the coming years."
Co-author Dr Marissa Tremblay, of the same university, added: "These new observations have helped us demonstrate that Lafayette’s origin story is plausible.
"I hope this sparks additional historical research, so that one day we may give credit to whoever discovered Lafayette."
The team’s paper, titled ‘Using Organic Contaminants to Constrain the Terrestrial Journey of the Martian Meteorite Lafayette’, is published in the journal Astrobiology.
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