The story of the Chinguetti meteorite is a very elusive mystery.
According to reports, this piece of 4The 5-kilogram (10-pound) stony ironstone was photographed in 1916 from the top of a huge 100-meter-wide (328-foot) iron mountain in Africa and is thought to be a massive meteorite.
Despite several searches, the existence of this larger parent meteorite has never been confirmed. Now, a team of researchers is tracking it down again.
If it exists, the iron mountain would represent the largest meteorite on Earth for some distance – scientists at Imperial College London and the University of Oxford in the UK hope to find it using maps of magnetic anomalies such as large pieces of iron.
First, the smaller meteorite block was first discovered by the French consul, Captain Gaston Ripert, who said he was blindfolded by a local chief and guided to the "Iron Mountain".
Chinguetti meteorite.
Fragments of the Chiengeti meteorite. （claire h/flickr/cc-by-sa-2.0）
The meteorite was named after the city of Chiengeti near Mauritania in northwestern Africa. Until the 90s of the 20th century, all subsequent attempts to find this huge iron mountain failed to find the place where Ripert was taken.
What's more, a 2001 study concluded that, based on chemical analysis of the metal, fragments of iron in stone iron could not have come from a volume greater than 16 meters of substance.
Is Captain Ripert lying? Or just got it wrong?
Maybe it's neither, the latest researchers say. For example, the absence of an impact crater may be the result of a meteorite entering at a very low angle before hitting the ground.
Meteorite map. 
The team has identified areas where Iron Mountain may be located. (Warren et al., Arxiv, 2024).
Past searches may have yielded nothing, either because the Iron Mountain was covered in sand, or because the instruments used were inaccurate, or because the search area was in the wrong place according to Ripert's vague instructions. Scientists say in a new article that these are all possible.
Perhaps most interestingly, Ripert specifically described a feature on the Iron Mountain. The captain described that he had found extracted metal "needles" from smaller meteorite samples, but without success.
The authors speculate that these ductile structures may be nickel-iron phases known as "Thomson structures." Without hearing about it in 1916, it is unlikely that Ripert could have fabricated such observations.
For the first time, researchers here used digital elevation models, radar data and interviews with local camel riders to narrow down the area where Ripert might have been taken according to reports from his half-day journey.
Guided by the height of the sand dunes that could obscure the massive meteorite, the team identified areas of interest and asked the Mauritanian Ministry of Petroleum, Energy and Mines to provide airborne magnetic survey data for these locations. So far, no one has been able to access this data.
Another option is to scan the area on foot in search of long-lost meteorites, although this can take weeks.
"However, if the result is negative, the interpretation of the Ripert story will remain unresolved, and the question of the ductile needles and the coincidental discovery of the medium-iron meteorite will still remain," the researchers wrote. ”。