It seems that the largest meteorite in the world disappeared in 1916. Why can't we find it? Science alert

story Chinguetti meteorite It is a very compelling mystery.

The 4.5-kilogram (10 lb) iron rock was reportedly taken from the top of a giant 100-meter (328 ft)-wide iron mountain – suggested to be a massive meteorite – in Africa in 1916.

Despite numerous searches, the existence of this larger parent meteorite has not been confirmed. Now, a team of researchers is back on track.

If it exists, this iron mountain would represent the largest meteorite on the planet by some distance – and scientists from Imperial College London and the University of Oxford in the UK want to use maps of magnetic anomalies (such as large clumps of iron) to try to find it.

To start at the beginning, the smaller piece of meteorite was originally recovered by French consular official Captain Gaston Ripert, who said he was blindfolded and directed to the “Iron Hill” by a local chief.

The meteorite was named after the nearby city of Chinguetti Mauritania, northwest Africa. All subsequent attempts to find the giant iron mountain of which it was originally a part, until the 1990s, were unable to find the place to which Ribert was transported.

What's more, 2001 study It was concluded that part of the stony iron mesosiderite It could not have come from a block larger than 1.6 metres, based on chemical analysis of the mineral.

Was Captain Ripert lying? Or simply wrong?

Perhaps neither, as the latest researchers who undertook the task of finding the Chinguetti meteorite say. For example, the lack of an impact crater may be the result of the meteorite falling at a very low angle before hitting the Earth.

Previous searches may have yielded nothing because the Iron Mountain was covered in sand, or because the tools used were not precise, or because the search area was in the wrong place based on Ripert's vague instructions. These are all possibilities, say scientists in a new paper.

Perhaps most interesting is that Ripert specifically described a feature on Iron Hill. The captain described finding long metal “needles” that he tried to remove with blows from the smaller meteorite sample, but was unsuccessful.

The authors of the paper speculate that these soft structures could be phases of nickel iron known as “Thomson structures.” This was unheard of in 1916, and it is unlikely that Ripert would have made up such a remark.

For the first time, researchers here used digital elevation models, radar data, and interviews with local camel riders to narrow down the areas to which Ribert may have been transported, based on his report of a half-day trip.

Using sand dune heights that could hide the giant meteorite as a guide, the team identified areas of interest and requested aeromagnetic survey data for these sites from the Mauritanian Ministry of Petroleum Energy and Mines. To date, access to that data has not yet been granted.

An alternative approach is to scan the area on foot for the long-lost meteorite, although this could take several weeks.

“If the result were negative, the explanation for Ribert’s story would remain unresolved, and the problems of flexible needles and the chance discovery of mesosiderite would remain.” He writes Researchers.

The researchers' new findings have not yet been peer-reviewed, but can be accessed on a preprint server arXiv.