The Younger Dryas is once again a topic of debate following new discoveries in Baffin Bay, near Greenland. A possible cosmic impact has been identified in ocean sediments, which contain iridium and platinum, as well as impact microspheres that indicate the passage of a comet. NASA suggests that this event goes beyond glaciation and is directly related to changes in the Earth’s climate.
This scenario might sound like science fiction
Picture in your mind a scenario that sounds like science fiction: Earth, a warming planet, sees its glaciers slowly melt, and life starts to adapt to new conditions. Until, suddenly, all changes. This is due to the nation that temperatures drop dramatically, about 10°C, and the planet comes in “winter mode,” a period that lasts more than a thousand years. This event, named as the Younger Dryas, happened about 12,800 years ago and stills a great mystery to this day. So much so that, for a long time, the explanation was easy: the melting glaciers dumped large volumes of freshwater into the oceans, weakening ocean currents and interrupting the transport of heat to the Northern Hemisphere.
A sudden freeze and another theory
Well, the respond to the Younger Dryas enigma may lie further away than we concieved… not just in the melting ice sheets, but in the begining. To comprehend the impact of this achievement, we need to go back in time and look at what was occuring on Earth. After more than 7,000 years of ongoing warming, the planet entered an extremely rapid cooling phase. What caused this abrupt change? We will explained right here.
The most widely accepted principles until then suggested that melting glaciers had dumped large volumes of freshwater into the oceans, interfeing the ocean currents that transport heat northward. But what no one would be able to explain was the speed of the cooling, about a year. How could something so drastic takes place so quickly? It was then that investigators wondered: what if this cooling wasn’t just a result of the melting ice, but had been caused by something external? By something that has its origin on space?
Clues in the dust: Did a comet spark Earth’s sudden deep freeze?
It was then that a team of scientists took the decision to investigate deeple about ocean sediments collected from Baffin Bay, close to Greenland, and their findings were unexpected. They identified small metallic particles, rich in elements such as platinum, iridium, nickel, and cobalt. These elements are not common on Earth but plentiful in comets and meteorites. Even more memorable, they found impact microspheres, which are small mineral bubbles that form by the times materials melt under intense heat, a happening that can takesplace when a comet disintegrates upon impact with the atmosphere.
It’s worth recalling that these particles block solar radiation, causing an “impact winter.” This is a temporary blockage of the sun that could have drastically reduced temperatures, so quickly that Earth was plunged into a long period of cooling. In other words, this happening would have destabilized the planet’s conditions, impacting ecosystems and the civilizations that were just starting to form (much like this vast anomaly affecting America).
When comets rewrite the climate
And no, this achivement isn’t just an interesting detail from the past… Here are several of the lessons we can learn from this discovery:
- Rewriting climate ideas: The Younger Dryas, previously seen as an event mainly caused by ice melt, can currently be seen as the result of a union of terrestrial and cosmic factors.
- Comets as agents of modification: Comets are not just celestial bodies that are far away from Earth. They have the power to modify, the course of Earth’s history, as confirmed by dust detected in the sediments of Baffin Bay.
- Lessons for nowadays: Even though the impact that caused the Younger Dryas took place thousands of years ago, it has been as a warning for the incoming time. Current technology for following near-Earth objects is critical to ensuring our safety.
Even though research into the Younger Dryas is far from complete, these achievement underlines that the reason of one of the planet’s greatest climate changes may have come from space. The comet that exploded over Earth, releasing cosmic dust, may have been the catalyst for a centuries-long global cooling. That’s the main reason we need to keep vigilant, in specific now with this 1.9-billion-year-old megablast hurtling toward Earth.
