Explanation: How do we know if an Asteroid hit Earth 66 million Years Ago?
There’s massive evidence to suggest that the primary cause of the K-Pg extinction was an asteroid collision, which happened 66 million years ago. The asteroid, 6 miles (10 km) in size, hit the Earth and triggered a series of cataclysmic events, ultimately leading to the extinction of many life forms, including the ancient beasts.
The crater is in the Yucatan peninsula in the Gulf of Mexico and is known as the Chicxulub Impact Basin. It’s enormous, having a diameter of 150 km, and is buried on the seafloor. Its size and chemical composition are suggestive of an asteroid impact. Firstly, a substantial amount of iridium was discovered there. This element, with the atomic number 77 on the periodic table, is mainly found in asteroids/meteorites in huge quantities. Secondly, the dating of the clay layers suggests that the event happened 66 million years ago.
Asteroids or their parts hitting the Earth aren’t uncommon or apocalyptic, but this one was huge and was hurtling through space at high speed. It created a massive crater upon collision and immediately vaporized. There was a huge blast wave and heat wave resulting in materials and soot flying across the Earth’s atmosphere to the other parts of the world. As a result, less sunlight reached the Earth, which impacted plant growth. It created a domino effect, wrecked the food chain, and caused the ecosystem to collapse.
An impact of such a scale affected all living forms on Earth and decimated about 75% of species. The casualty list doesn’t just consist of the dinosaurs. Other life forms, such as planktons, ammonites, and large marine reptiles, among many others, also died out. A long era spanning 186 million years came to an end.
However, other theories suggest that it wasn’t the asteroid alone that killed the dinosaurs. Before the collision, during the Late Cretaceous, the Earth was going through climate change due to volcanic activity, causing problems on a wide scale. Additionally, the continents were drifting and splitting apart, creating larger oceans and changing atmospheric patterns. Some researchers believe that the asteroid’s crash-landing was just the tip of the iceberg, and the dinosaurs started slowly dying out millions of years before that.
To conclude, what happened back then can only be explained by theories based on present evidence, as there can never be eyewitnesses to confirm the exact turn of events. And currently, there’s a vast consensus among the scientific community suggesting that an asteroid hit Earth 66 million years ago, leading to mass extinction.