Earth may have once sported a Saturn-like ring system after an encounter with an asteroid, scientists reveal. According to a new study, over 450 million years ago, during a period of intense meteorite bombardment, the planet may have briefly had rings akin to Saturn.
Researchers examined 21 asteroid craters dating back to the “Ordovician impact spike” 466 million years ago and noted that these craters were concentrated in a narrow band of land near the equator. This was unusual as typically asteroid impacts are dispersed randomly, as seen on the moon and Mars. The scientists speculate that this unique impact pattern near the equator could have been caused by a large asteroid coming into close proximity with Earth in the distant past.
In a study published in the journal Earth and Planetary Science Letters, scientists theorised that this massive asteroid disintegrated due to tidal forces, forming a debris ring around Earth, similar to Saturn’s rings. Over millions of years, debris from this ring would have fallen to the planet, resulting in an uptick in meteorite impacts during that geological period.
Moreover, scientists suggest that this ancient ring may have had climate implications by casting a shadow on Earth. By blocking sunlight, the ring could have contributed to a significant global cooling event known as the “Hirnantian Icehouse,” one of the coldest periods in the last 500 million years. This cooling phenomenon occurred despite high levels of carbon dioxide in the atmosphere, puzzling researchers.
The study sheds new light on how cosmic events may have influenced Earth’s climate in the past. Scientists calculated the regions across continents capable of preserving craters from that era and found that only certain areas such as Western Australia, Africa, North American Craton, and parts of Europe were suitable for the preservation of such structures. Despite only 30% of the land area being near the equator at that time, all impact craters were situated in this region.
The researchers likened the likelihood of this event to tossing a three-sided coin and getting tails 21 times. They estimated the probability of this impact crater distribution resulting from random impacts to be 1 in 25 million, suggesting a rare and significant cosmic event.
This study provides valuable insights into how Earth’s climate and geological history may have been influenced by celestial events, offering a new perspective on the planet’s ancient past.