The Town in a Crater
A medieval German town sits inside a giant crater, and its church is built of stone studded with tiny diamonds.
What was reported
Nördlingen, a walled medieval town in Bavaria, lies in the middle of the Ries, a round, flat basin about 25 km across. For centuries it was thought to be the remains of a volcano.
In 1960 the American geologists Eugene Shoemaker and Edward Chao found coesite, a form of quartz made only under enormous pressure, in the local rock, proving the basin was an impact crater. The town's St. George's Church is built from suevite, a rock formed in the impact, which holds countless microscopic diamonds.
Explanations offered
An asteroid roughly a kilometre across struck about 15 million years ago, and the crater slowly filled and wore down into today's basin. NASA trained Apollo astronauts there in 1970 to recognise impact rocks. The diamonds are far too small to be worth anything.
- When
- Proven in 1960
- Where
- Nördlingen, Bavaria, Germany
- Witnesses
- The geologists Eugene Shoemaker and Edward Chao
- Status
- Explained
Famous cases are real, widely reported events. Each file sets out what witnesses said and the explanations that have been offered, without taking a side.