Scientists may have found evidence that Earth was once surrounded by rings. Here’s what we know.
Researchers have found evidence that suggests Earth may have had a ring systemformed about 466 million years ago, at the beginning of a period in which many meteorite impacts occurred.
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This hypothesis, published in Earth and Planetary Science Letters, derives from reconstructions of plate tectonics for the period Ordovicianowhich detect the locations of 21 craters. All of these craters are within 30 degrees of the equator, despite more than 70 percent of Earth’s continental crust lying outside this region, an anomaly that conventional theories fail to explain.
Did the Earth have rings?
Scientists believe a large asteroid had a close encounter with Earth. When the asteroid passed I enter the Roche limit of the Earth, i.e. within the minimum distance from the center of the planet at which a celestial body can orbit without fragmenting, has shattered due to tidal forces, forming a ring of debris around the planet. Very similar to the rings we see today and other gas giants.
What happened next
“Over millions of years, material from this ring gradually fell back to Earth, creating the peak in meteorite impacts seen in the geological record,” said the study’s lead author, Professor Andy Tomkins, of the School of Earth, Atmosphere and Environment at Monash University. “We also see that layers in sedimentary rocks from this period contain extraordinary amounts of meteorite debris. What makes this discovery even more intriguing are the potentials of such a ring system,” he said.
How the climate would have changed if the Earth had rings
Researchers hypothesize that the ring may have cast a shadow on Earth, blocking sunlight and contributing to a significant global cooling event. This period, which occurred towards the end of the Ordovician, is recognized as one of the coldest of the last 500 million years. “The idea that a ring system may have influenced global temperatures adds a new level of complexity to our understanding of how extraterrestrial events may have shaped Earth’s climate,” concluded Professor Tomkins.
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