The sky darkened not once, but twice. The extinction of the dinosaurs, one of the most dramatic events in Earth's history, may have been caused by a double asteroid impact. New evidence from the seabed off Guinea is rewriting the story of that fateful day 66 million years ago.
A team of researchers has revealed the secrets of a submerged crater that could be the “smoking gun” of a second asteroid, the culprit along with the infamous Chicxulub of wiping out 75% of life on Earth. This discovery (I link it to you here) not only sheds new light on the extinction of the dinosaurs, but forces us to reconsider our planet's vulnerability to cosmic threats.
An impact that changes history
The story of the extinction of the dinosaurs has always been fascinating, but now it has a new, incredible chapter. Imagine the scene: 66 million years ago, a gigantic asteroid approaches the Earth. Its impact will be devastating, but it is not alone. A second celestial body follows it, ready to deliver the final blow to a planet already on its knees.
This scenario, which until recently was unthinkable, is becoming increasingly plausible thanks to recent discoveries. The team of researchers led by Weisdean Nicholson, geoscientist of the Heriot-Watt University in Scotland, has uncovered convincing evidence of the existence of a second impact crater, named Nadir.
“The asteroid responsible for Chicxulub is much larger than what we propose for Nadir,” Nicholson explained. “We would expect about 10.000 times more energy released by Chicxulub. So the Nadir impact would have been eclipsed by Chicxulub.”
Evidence of the Cosmic One-Two Punch That Caused the Dinosaurs to Extinct Hidden in the Seafloor
The Nadir crater, with its 8,5 kilometers in diameter, lies silent under 400 meters of marine sediments off the coast of Guinea. Its discovery was made possible by using sophisticated three-dimensional seismic data, which allowed researchers to “see” through layers of rock and sediment.
Analysis of this data revealed surprising details about the crater's formation. The asteroid is estimated to have hit Earth at a speed of about 72.000 km/h, triggering earthquakes of such intensity that they liquefied seafloor sediments throughout the surrounding area.
But the real surprise came when researchers dated the crater: 66 million years old, exactly the same time as the Chicxulub impact. This temporal coincidence has opened the way to new theories about the extinction of the dinosaurs.
Double hit
The discovery of Nadir Crater raises fascinating questions about the nature of the event that led to the extinction of the dinosaurs. Three main hypotheses:
- A large asteroid broke apart as it approached Earth, resulting in two nearly simultaneous impacts.
- A collision in the asteroid belt hurled multiple cosmic projectiles toward Earth.
- The two impacts are a pure, albeit unlikely, coincidence.
Whatever the truth, one thing is certain: the extinction of the dinosaurs was an even more catastrophic event than previously thought.
The immediate consequences
Nicholson's team also simulated the immediate effects of the Nadir impact. The results are nothing short of shocking:
“The earthquakes caused by the impact liquefied sediments beneath the seafloor across the plateau,” Nicholson said, “and caused massive underwater landslides.”
But that's not all. Simulations suggest that the impact generated a tsunami at least 800 meters high. A wave of that magnitude would have devastated the coasts of much of the planet, contributing significantly to themass extinction which followed.
The future of research
The story of the extinction of the dinosaurs is far from being completely written. Nicholson's team has already submitted a request to drill into the seabed and retrieve sediment samples from Nadir Crater.
These samples could provide crucial information about the force of the impact and its immediate effects on the surrounding environment. They could also contain traces of extraterrestrial material, definitively confirming the asteroid origin of the crater.
Dinosaur Extinction: A Lesson from the Past for the Future
The Earth, this research shows once again, is vulnerable to asteroid impacts, and the consequences can be catastrophic. This awareness underlines the importance of monitoring programs of potentially dangerous celestial objects and the search for strategies for planetary defense. The extinction of the dinosaurs reminds us that the fate of entire species can be decided in a cosmic instant.
The history of life on Earth is written in rocks, fossils, and, as we have discovered, craters hidden beneath our oceans. Each new discovery brings us a little closer to understanding our past and, perhaps, protecting our future.
