Neugrund crater

Neugrund is a meteorite crater in Estonia. It is 8 km (5.0 mi) in diameter and is estimated to have been formed in the Ordovician around 470 Ma. The crater is at the bottom of the sea and is not exposed at the surface. Boulders of gneissic breccia found on the coast of Osmussaar, a nearby island, are believed to have been thrown there by the explosion. It has been proposed that the Neugrund crater was created during the Ordovician meteor event when a hypothetical large asteroid transferred directly into a resonant orbit with Jupiter, which shifted its orbit to intercept Earth.

This attractive theory may need to be changed as more recent study puts the age of the impact in the Cambrian (485 Ma-541 Ma).