Scientists have found new evidence that a massive comet trail may have caused climate upheaval on Earth more than 12,000 years ago. Tiny particles detected in ocean sediment cores suggest that dust from a large comet entered the atmosphere around the beginning of the Younger Dryas event, leading to an extended period of cooling.
The Younger Dryas occurred about 12,900 years ago and lasted for about 1,200 years, causing temperatures in the Northern Hemisphere to plummet by up to 18 degrees Fahrenheit. Researchers previously proposed that cold freshwater lakes pouring into oceans or impacts from a disintegrating comet could have triggered this event.
However, no direct evidence of an impact crater has been found at the start of the Younger Dryas. The new study, published in PLOS One, provides indirect evidence through the detection of tiny metallic particles and other materials that are common in comets and meteorites.
The researchers found similar particles in ocean sediment cores from Baffin Bay, which suggests that a comet or asteroid may have exploded inside the atmosphere shortly before the Younger Dryas began. This would have released dust into the atmosphere, causing a short-term “impact winter” and leading to an extended period of cooling.
While the study does not directly confirm the impact hypothesis, it provides new insights into the possible causes of the Younger Dryas event. Further research is needed to confirm this proposal, and the team plans to test other ocean cores for similar particles in the future.
Source: https://www.livescience.com/planet-earth/massive-comet-trail-may-have-transformed-earths-climate-more-than-12-000-years-ago-tiny-particles-suggest