Recent research indicates that Earth may have once had rings similar to those of Saturn. Scientists believe this ring system was created by the breakup of an asteroid around 466 million years ago. This event coincided with significant meteorite impacts around the planet's equatorial region. Researchers propose that the ring's formation might have contributed to global cooling, potentially leading to the Hirnantian Ice Age, one of the coldest periods in Earth's history.
Evidence from Meteorite Impacts
During this time, Earth experienced a high number of meteorite impacts. The debris from these meteorites has been found in sedimentary rocks in Europe, Russia, and China. These rocks contain meteorite fragments that were exposed to space radiation for a shorter period than typical meteorites. Additionally, multiple tsunamis during this era suggest that these events were interconnected.
Patterns in Impact Craters
Scientists have mapped out 21 impact craters from this period, all located near the equator. Using plate tectonic models, they found that none of these craters were near the poles. Under normal conditions, asteroid impacts would be distributed randomly across the globe, similar to craters on the Moon and Mars. The unusual concentration of craters near the equator led scientists to hypothesise that a large asteroid broke up close to Earth, scattering debris that formed both impact craters and a ring system.
Rings and Planetary Cooling
The potential ring around Earth would have orbited near the equator. As Earth's axis is tilted, this ring could have partially blocked sunlight, contributing to global cooling. This cooling effect might have played a role in triggering the Hirnantian Ice Age, which began around 445 million years ago. Scientists are now working on models to better understand how the ring formed and its impact on Earth's climate.
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