New findings: Two asteroids, not one, might have ended the age of dinosaurs

In a new groundbreaking study, the catastrophic asteroid impact, which led to the extinction of the dinosaurs 66 million years ago, may not have been an isolated incident. Researchers have identified a second significant asteroid that struck Earth around the same time, potentially exacerbating the environmental conditions responsible for the dinosaurs' demise.

Published in Nature, the research focuses on the Nadir crater, an underwater formation discovered off the coast of Guinea. This crater, measuring over 8 km in diameter, is believed to have formed from an asteroid approximately 400-500 meters wide. The space rock impacted Earth at an incredible velocity of 72,000 km/h, likely occurring between 65 and 67 million years ago. While this asteroid was smaller than the one that created the Chicxulub crater in Mexico, its effects were still considerable.

Dr. Uisdean Nicholson, a marine geologist at Heriot-Watt University in Edinburgh, initially found the Nadir crater in 2022. However, the full extent of the impact was not understood until recently, when advanced 3D seismic imaging technology allowed scientists to explore the crater's geological features. This imaging revealed that the asteroid's impact triggered intense seismic activity, liquefying sediments beneath the ocean floor and resulting in widespread landslides and faults. The collision also generated a massive tsunami, estimated to have been over 800 meters tall, sweeping across the Atlantic Ocean.

The Nadir crater's remarkable preservation offers a rare glimpse into the geological consequences of such impacts. Dr. Nicholson referred to the new imaging as “exquisite,” highlighting that while approximately 20 marine craters are known worldwide, none have been examined with such detail. The findings indicate that the damage from this impact extended for thousands of square miles beyond the crater's immediate vicinity.

Though researchers are still uncertain about the exact timing of this asteroid's strike, its discovery raises fascinating questions regarding the possibility of multiple impacts occurring in quick succession at the end of the Cretaceous period. The Chicxulub impact, known for its role in the mass extinction event, created a much larger crater measuring 160 km in diameter.

The Nadir impact is likened to the 1908 Tunguska event, when a smaller 50-meter asteroid exploded above Siberia, causing significant destruction. In contrast, Dr. Nicholson explained that the Nadir asteroid would have produced an immense fireball that, if it had struck Glasgow, would have been visible from as far as Edinburgh, potentially igniting vegetation in its path.

As scientists further analyze the Nadir crater using high-resolution 3D data from geophysical sources, they are eager to deepen their understanding of impact events and the conditions they create in marine environments. Dr. Nicholson emphasized that this research represents the first opportunity to explore the inner workings of an impact crater in such detail, providing valuable insights for future studies.