Some might say it’s paranoid to think about an asteroid hitting Earth and wiping us out. But the history of life on Earth shows at least 5 major extinctions. And at least one of them, about 65 million years ago, was caused by an asteroid.
The asteroid that struck Earth about 66 million years ago and led to the mass extinction of dinosaurs may have hit one of the worst places possible as far as life on Earth was concerned. When it struck, the resulting cataclysm choked the atmosphere with sulphur, which blocked out the Sun. Without the Sun, the food chain collapsed, and it was bye-bye dinosaurs, and bye-bye most of the other life on Earth, too.
The asteroid thought to have killed the dinosaurs smashed into the Earth with a billion times more energy than the atomic bombs dropped on Hiroshima and Nagasaki. Many believe the impact caused a mass extinction, wiping out the dinosaurs on land and numerous lifeforms in the oceans. But one of the difficulties in knowing exactly whether and how this happened is that the Chicxulub crater left by the asteroid is buried below a thick layer of sedimentary rock.