It’s Possible That Earth Once Had a Ring Like Saturn—As Astroids Overcame

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All Odds Hitting Only Around Equator: New evidence has been discovered by researchers that casts doubt on the conventional wisdom on the formation of Earth’s ring system 466 million years ago.

This unexpected theory, which was published in Earth and Planetary Science Letters this month, suggests that the Ordovician impact surge occurred during a time of exceptionally strong meteorite bombardment.

The research team located the locations of 21 asteroids strikes on Earth by examining reconstructions of plate tectonics for the Ordovician epoch. Despite the fact that over 70% of the continental crust of Earth is located outside of these latitudes, all of these craters are situated within 30 degrees of the equator—an oddity that cannot be explained by accepted hypotheses.

They think that after a big asteroid passed close to Earth, it created this concentrated impact pattern. The asteroid broke apart owing to tidal forces as it approached the planet (inside what is known as the Roche limit), creating a debris ring around it that resembles the rings that are currently visible around gas giants like Saturn.

Professor Andy Tomkins of Monash University in Australia, the study’s lead author, explained that “over millions of years, material from this ring gradually fell to Earth, creating the spike in meteorite impacts observed in the geological record.” “We also observe that layers of this period’s sedimentary rocks contain exceptionally high concentrations of meteorite debris.”

He speculated that the ring may have thrown a shadow on Earth, obstructing sunlight and causing a major global chilling event known as the Hirnantian Icehouse. “What makes this finding even more intriguing is the potential climate implications of such a ring system,” he said.

It is acknowledged that during this time, which was close to the end of the Ordovician, one of the coldest periods in the last 500 million years of Earth’s history happened.

“Our understanding of how extraterrestrial events may have shaped Earth’s climate is made more complex by the possibility that a ring system could have affected global temperatures,” Prof. Tomkins added.

Since asteroids typically strike Earth at random points, impact craters are evenly spaced across the Moon and Mars, for example. The researchers determined the continental surface area that may retain craters from that era in order to test the hypothesis that the distribution of Ordovician impact craters is non-random and closer to the equator.

They excluded locations that were degraded, buried under sediments or ice, or impacted by tectonic activity. Instead, they concentrated on stable, undisturbed interiors of tectonic plates with rocks older than the mid Ordovician period.

They found areas on several continents that were geologically acceptable by using a GIS (Geographic Information System) technique. It was thought that areas such as Western Australia, Africa, North America, and a few sections of Europe were ideal for crater preservation. All of the impact craters from this time period were located in this area, despite the fact that just 30% of the eligible land area was found to have been near the equator.

There is very little likelihood that this will occur because asteroids should strike Earth randomly at all latitudes, as is the case on the surfaces of the Moon, Mars, and Mercury.

According to Tomkins, “it is highly improbable that all 21 of these craters would form near the equator if they were unrelated to one another.” “Many more craters should be visible at higher latitudes as well,”