Produced by: Tarun Mishra
A new study suggests that Earth might have had a ring system around 466 million years ago, potentially formed during a period of unusually intense meteorite impacts known as the Ordovician impact spike.
Published in *Earth and Planetary Science Letters*, the study examines the spatial distribution of 21 asteroid impact craters on Earth, alongside plate tectonic reconstructions from the Ordovician period.
Researchers noted that all studied craters are located within 30 degrees of the equator. This localized impact pattern, unusual given that over 70% of Earth’s continental crust lies outside this region, points to the presence of an ancient debris ring.
Scientists believe a large asteroid may have passed very close to Earth, crossing its Roche limit. Tidal forces would have torn the asteroid apart, possibly forming a debris ring around Earth, similar to those around gas giants like Saturn.
Over millions of years, fragments from this debris ring likely fell to Earth, creating a spike in meteorite impacts. This pattern is visible in geological records from the period.
The study found unusually high levels of meteorite debris in sedimentary rock layers from this time, further supporting the idea of an Earth ring system slowly dispersing its material over time.
The ancient ring could have cast a shadow on Earth, blocking sunlight and contributing to global cooling. This period coincides with the "Hirnantian Icehouse," one of Earth’s coldest intervals in the last 500 million years.
Researchers are now considering whether Earth could have experienced more than one ring system throughout its geological history, adding new dimensions to the study of extraterrestrial impacts on Earth’s climate.