Around 66.03 and 66.04 million year ago, the cretaceous-paleogene extinction wiped out about 75 percent of the world’s species, including almost all the dinosaurs. Scientists now believe that there is evidence the world’s atmosphere had been shifting and that the impact from the asteroid was the coup de grace that did them in.
The asteroid was in 9 miles wide and released 420 zettajoules of energy — two million times stronger than the world’s largest nuclear detonation.
“The impact was clearly the final straw that pushed Earth past the tipping point,” said researcher Paul Renne. “We have shown that these events are synchronous to within a gnat’s eyebrow, and therefore the impact clearly played a major role in the extinctions, but it probably wasn’t just the impact.”
The Earth’s climate had been changing already. “These precursory phenomena made the global ecosystem much more sensitive to even relatively small triggers, so that what otherwise might have been a fairly minor effect shifted the ecosystem into a new state…. the impact was the coup de grace.”
Landing in the ocean, it would have made gigantic tsunamis, and also blotted out the sun with a massive dust cloud. This is the most solid confirmation we have that it was indeed an asteroid that killed the dinosaurs.