Neugrund crater
Template:Short description Template:Infobox terrestrial impact site
Neugrund is a meteorite crater in Estonia. It is Template:Convert in diameter and was previously estimated to have been formed in the Ordovician around 470 Ma, with later research revealing a possible Cambrian origin (around 535 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.<ref>Template:Cite Earth Impact DB</ref> 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.<ref name=Nature1>Template:Cite journal</ref><ref>Template:Cite journal</ref><ref>Korochantseva et al. "L-chondrite asteroid breakup tied to Ordovician meteorite shower by multiple isochron 40Ar-39Ar dating" Meteoritics & Planetary Science 42, 1, pp. 3-150, Jan. 2007.Template:Dead link</ref>
This attractive theory may need to be changed as more recent study puts the age of the impact in the Cambrian.<ref>Template:Cite journal</ref>