Mystery solved. Giant asteroid killed the dinosaurs, say scientists

A new scientific study claims to have found the definitive answer as to what killed the dinosaur - Chicxulub asteroid.






The coldest of cold cases is now officially solved.

A team of scientists has agreed on a cause of death in the extinction of the dinosaurs 65.5 million years ago: a gargantuan asteroid that slammed into the Earth in Yucatan, Mexico.

"The world changed immediately due to the effects of this impact, and things were really, really bad for at least a decade afterward," Jim Melosh, professor of earth and atmospheric sciences at Purdue University and one of the authors of the study, told the Daily News. "We think that during that time, 90% of life on the planet died."

Even apex predators like the Tyrannosaurus rex were no match for the 7.5-mile-wide asteroid, the impact of which was a billion times more powerful than the Hiroshima atomic explosion, according to the report by 41 scientists, published in Friday's issue of Science.

The asteroid strike created a perfect storm of death and destruction, said Melosh. All life within a half-continent was almost immediately wiped out in the blast – and then things really got bad.

"It was the global effects that did everything in," said Melosh. "The impact blasted out the crater at full speed. Debris blasted up in the sky like ballistic missiles, raining back down into the atmosphere, caused a burst of heat equal to 10 noonday suns, probably blistering the skins of dinosaurs and causing wildfires."

The devastation didn't stop there: The Chicxulub asteroid hit "an unusually lethal site," rich in sulfur, said Melosh. When that sulfur combined with water vapor in the sky after being blasted upward, it created clouds that blotted out the sun for about a decade – and rained sulfuric acid.

The dinosaurs never had a chance.

The 41 scientists who collaborated on the paper found that chemical analyses of soil samples and fossils provided the smoking gun, so to speak. Data showed an almost uniform layer of rock with high concentrations of iridium, coinciding exactly with the period of the massive impact. Iridium is an element found in higher concentrations in meteors.

The paper contends that all other theories regarding the demise of the dinosaurs, including the massive volcanic eruptions in India during that period, should now be rendered extinct.

"The world was a pretty busy place at the time of the dinosaurs' extinction – some scientists have had trouble with the deus ex machina concept of an extraterrestrial object falling from the sky [and causing the extinction,]" said Melosh. "[But] the evidence is so overwhelming."



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