Like Saturn, Earth had rings 466 million years ago

The new study found evidence that suggests the Earth may have had a ring system that formed about 466 million years ago. To be precise, at the beginning of the period of meteorite bombardment called Ordovician impact increase.

This hypothesis, published in Earth and Planetary Science Letters, comes from a reconstruction of plate tectonics for the Ordovician period. Scientists recorded the location of 21 asteroid impact craters.

All of these faults are located within 30 degrees of the equator. Although more than 70% of the Earth’s continental crust is outside this region, this anomaly cannot be explained by current theory. The research team believes that this pattern was produced after a large asteroid hit Earth.

As the asteroid passed Earth’s Roche limit, it broke apart due to tidal forces, creating a ring of debris around the planet, similar to the rings seen around Saturn and other gas giants. today.

“Over millions of years, material from these rings gradually fell towards Earth, creating a spike in meteorite impacts seen in the geological record,” said the study’s lead author, Professor Andy Tomkins, from Monash University’s School of Earth, Atmosphere and Environment in Phys.org announced on Friday (20/9/2024).

“What makes this discovery even more interesting is the possible climatic effects of the ring system,” he continued.

Researchers speculate that the rings could cast a shadow on Earth, blocking sunlight and contributing to a global cooling event known as the “Hirnantian Ice House”. This period, which occurred near the end of the Ordovician, is recognized as one of the coldest in the last 500 million years of Earth’s history.

“The idea that ring systems can influence global temperatures adds a new level of complexity to our understanding of how external events can shape Earth’s climate,” said Professor Tomkins.

Usually, asteroids hit the Earth in random places. To investigate whether the Ordovician impact rift distribution was random and closer to the equator, the researchers calculated the surface area of ​​continents that were able to preserve rifts from that time.

They focused on rocks older than the middle of the Order, with the exception of areas buried under sediment or ice, eroded areas, and those affected by tectonic activity. Using a GIS (Geographic Information System) approach, they identified geologically suitable regions on different continents.

Areas such as Western Australia, Africa, the North American Craton, and a small part of Europe are considered suitable for the crater. Only 30% of the eligible land has been determined to be near the equator, but all impact craters from this period have been found in this region.

The impact of this discovery goes beyond modern geological science. Encouraging scientists to rethink the wider impact of celestial events on Earth’s evolutionary history. This also raises new questions about the potential of other ancient ring systems to influence the development of life on Earth.

(land/gas)