The extinction of the dinosaurs has always been an intriguing subject. From theories of a super-volcanic eruption to a deadly disease that wiped out all the dino-species, a lot has been brought up. One theory that has drawn attention over the years is that an asteroid impact killed all the non-avian dinosaurs. While there has been inconclusive evidence to suggest this theory, a group of scientists in Texas may have just found some actual proof of the incident. They found the evidence in the form of asteroid dust inside the impact crater of the supposed asteroid that killed the ancient giants.
Picture this — it is 66 million years ago and a massive impact shakes the Earth, dust clouds cover the sky, there’s no sunlight for weeks, which is followed by global winter. This happened when the asteroid hit the 125-mile-wide Chicxulub impact crater beneath the Gulf of Mexico.
This theory was recently tested through a full chemical ‘fingerprinting’ of the asteroid dust found within the crater. Nearly 3,000 feet of rock core from the crater buried under the seafloor was collected for the study. The comprehensive study analyses the impact, aftermath, and recovery of life after the collision.
It was the element iridium that helped solve the mystery. Rare on Earth, but found abundantly in most asteroids. A spike in iridium in geological layers is one of the reasons behind the asteroid-impact theory.
They believe the dust thrust up by the impact circulated the atmosphere for nearly two decades, and this is how long the extinction of nearly 75% of Earth species, including non-avian dinosaurs, took. The highest iridium concentration was within a 5-centimetre section of the rock core retrieved from the top of the crater’s peak ring.
Additionally, other chemical evidence was also found to confirm the asteroid-impact theory. The full study can be found in Science Advances.