An iron arrowhead discovered near Lake Biel, probably in 1873, recently surprised researchers at Switzerland’s Paul Scherer Institute and the Natural History Museum in Bern.
In February 2021, after many failed attempts, the arrowhead was successfully identified as being of meteoric origin. Analysis showed it had a high nickel content, something indicating it was made from meteoritic iron.
Archaeological objects made from meteoritic iron are extremely rare. In the whole of Eurasia and Africa, only 55 meteoritic iron objects from 22 sites are known. 19 of these objects come from the tomb of Tutankhamun in Egypt, leaving only 36 others.
The next question for researchers was: where did the meteorite iron come from? This question was answered this week using Muon analysis, and the results were surprising.
Around 170,000 years ago, a meteorite with a diameter of around 4 metres and a weight of 250 tonnes showered the nearby town of Twannberg and an area with a radius of 15 kilometres with countless pieces of iron. The resulting meteorite strike, the largest in Switzerland and one of the largest in Europe, left at least 2,000 iron fragments.
Given the proximity of the arrowhead and the Twannberg meteorite strike, it would make sense to assume the arrowhead was made from a piece of it. However, that appears likely to be wrong.
When a Muon Spin Spectrometer was used to analyse the composition of the arrowhead its material matched most closely with fragments of iron from a meteorite that struck the earth in 1500 BC in Estonia, roughly 2,500 kilometres away.
Press release (in English)