Saturn’s rings are one of the solar system’s most iconic features, but Earth may have once had something similar. In a recent paper in *Earth & Planetary Science Letters*, researchers suggest that Earth might have had a ring system around 466 million years ago, which could explain several geological puzzles from that era.
The Case for Earth’s Rings
Around 466 million years ago, there was a surge in meteorite impacts on Earth, leaving behind many craters. Limestone deposits across Europe, Russia, and China from this period contain debris from meteorites, showing they were exposed to space radiation for much less time than today’s meteorites. Additionally, several tsunamis during this time have left behind unusual sediment patterns.
Researchers believe these events may be connected, possibly linked to a ring of debris around Earth.
Crater Patterns
Scientists identified 21 meteorite craters from this high-impact period, and when they mapped them using tectonic plate models, they noticed that all of these craters were located near the equator. Under normal circumstances, impacts would occur randomly across the planet, similar to what we see on the moon and other planets.
This unusual pattern suggests that the debris likely came from a single asteroid that broke up during a close encounter with Earth, raining fragments down over millions of years, mostly near the equator.
How Rings Form
Rings around planets like Saturn form when a smaller object passes too close to a larger one and gets torn apart by gravity. The debris eventually forms a ring, and over time, some of this material falls back to the planet, creating impact craters—usually near the equator.
Researchers believe a similar event occurred on Earth, with an asteroid breaking up and forming a temporary debris ring. The debris would have eventually fallen to Earth, explaining the crater pattern and other geological anomalies from that period.
Possible Impact on Climate
Earth’s ring may have also influenced the planet’s climate. The ring, located around the equator, would have shaded parts of Earth’s surface. This reduction in sunlight could have caused global cooling, which coincides with the dramatic drop in temperatures around 465 million years ago and the onset of the Hirnantian Ice Age—the coldest period in the last 500 million years.
The next steps for researchers are to model how such a ring might have formed, dispersed, and impacted Earth’s climate, potentially providing new insights into this ancient period of planetary history.
