Science sleuths solve the century-old mystery of the discovery of a Martian meteorite

A toxin that makes pigs vomit is the surprising key that unlocked the century-old mystery of the origins of a Martian meteorite, and the possible identity of the black student who discovered it.

In 1931, an unusual stone stored in the Geological Collection of Purdue University in the United States was identified as a perfect example of a meteorite – a piece of space rock blown from the surface of Mars millions of years ago. to be drawn into the earth’s atmosphere.

However, how and when the meteorite – known as the Lafayette – ended up in Purdue’s collection has remained unclear for more than 90 years.

A potential origin story, reported by American meteorite collector Harvey Nininger in 1935, is that a black Purdue University student saw it land in a pond where he was fishing. He picked it up from the mud where it fell and gave it to the university.

Previous attempts to confirm the story have been inconclusive. But now a team of science sleuths have used cutting-edge analytical techniques and archival research to gather enough evidence to suggest this story is true, that it happened in 1919 or 1927, and that one of the four black men could be the student who found Lafayette.

Researchers from the UK, US, Australia and Italy did the detective work, which is published in a preliminary journal article Astrobiology.

The unraveling of the mystery began in 2019, when planetary scientist Dr Áine O’Brien, from the University of Glasgow’s School of Geographical and Earth Sciences, crushed a tiny Lafayette sample and used spectrometry to sophisticated mass to analyze its composition.

She was looking to discover new details about the presence of organic molecules preserved at Lafayette, evidence that could help us learn more about the possibility of life on Mars.

Among the thousands of metabolites revealed by the analysis, Dr. O’Brien noticed one unusually earthbound: deoxynivalenol, or DON. DON is a “vomitoxin” found in F. graminearum, a fungus that contaminates cereals such as corn, wheat and oats. It causes disease in humans and animals when ingested, with pigs being particularly affected.

Intrigued by the presence of a vomitoxin in the Martian meteorite, Dr. O’Brien told colleagues who knew the story of the muddy Lafayette landing. They suggested that crop dust from nearby farmland could have carried DON into surrounding waterways and that Lafayette could have been contaminated with it when the meteorite landed in a pond.

Dr. O’Brien turned to researchers from Purdue University’s Department of Agronomy and Department of Botany and Plant Pathology to learn more about the fungus’ historical prevalence in Indiana’s Tippecanoe County, where Purdue is.

Their records showed it caused a 10-15% drop in crop yield in 1919, and another less pronounced drop in 1927 – the highest prevalence in the 20 years prior to 1931, when the meteorite was identified. With a higher prevalence of the fungus comes a greater likelihood that it will be transported beyond the boundaries of agricultural land.

Analysis of fireball sightings during the same period provided more potential clues to the timing of Lafayette’s landing. Meteorites heat up as they pass through Earth’s atmosphere, causing a glowing fiery trail across the sky. There were reported sightings of a fireball in southern Michigan and northern Indiana on November 26, 1919, and one in 1927 that dropped the Tilden meteorite in Illinois.

Purdue University archivists also searched yearbooks from 1919 and 1927 to find black students enrolled at the time.

Julius Lee Morgan and Clinton Edward Shaw, Class of 1921, and Hermanze Edwin Fauntleroy, Class of 1922, were enrolled at Purdue in 1919. A fourth man, Clyde Silance, was studying at Purdue in 1927. Researchers conclude that it is possible that one of these men found Lafayette, as Nininger’s 1935 origin story suggests.

Dr. O’Brien is the lead author of the article. She said: “Lafayette is a truly magnificent meteorite sample, which has taught us a lot about Mars through previous research.

“Part of what made it so valuable is that it is remarkably well preserved, meaning it had to be recovered quickly after landing, as Lafayette’s origin story suggests. The Meteorites that are left in the elements for a significant length of time have their upper layers eroded, reducing their research value as they collect earth contaminants.

“The unusual combination of Lafayette’s quick protection from the elements and the tiny trace of contamination he picked up during his 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 that we plan to return to Earth after unmanned rover missions to Mars in the coming years.

“I am proud that a century after it reached Earth, we are finally able to piece together the circumstances of its landing and come closer than ever to giving credit to the black student who put it there. found. I’m very glad that one of them was able to be there to see the Lafayette land and donate it to Purdue University.”

The paper’s co-author, Dr Marissa Tremblay, of Purdue’s Department of Earth, Atmospheric and Planetary Sciences, added: “The Lafayette meteorite is very special to Purdue, especially now that we We have a thriving planetary science research group that just celebrated its 10th anniversary.

“These new sightings have helped us demonstrate that Lafayette’s origin story is plausible. Hopefully, this will trigger further historical research, so that one day we can 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 Astrobiology.