Ordovician meteor event

The Ordovician meteor event was a time when many more space rocks, called L chondrite meteorites, fell to Earth about 467.5 million years ago during the Middle Ordovician period. This lasted for around 40 million years. We know about this event because scientists found many pieces of these meteorites preserved in rocks from Sweden and other places.

A study from 2019 suggests that this increase in space rocks might have happened when a huge space rock, about 150 kilometers wide, broke apart. This rock used to orbit in the asteroid belt between Mars and Jupiter. When it broke up, pieces were sent toward Earth, causing more impacts.

Some scientists think this rain of space rocks may have helped life on Earth grow more diverse during a time called the Great Ordovician Biodiversification Event, though others are not sure. A newer study from 2024 looked at craters made by these impacts and found they were mostly near Earth's equator. This makes scientists think the space rocks might have come from a big asteroid that broke apart close to Earth, creating a ring of debris that later fell to the surface. Some even wonder if this ring might have helped cause a time of cold weather called the Hirnantian glaciation.

Possible craters

Locations of possible craters related to the event