NASA

Scientists may have solved the mystery behind one of the five mass extinctions in Earth's history – a time 65 million years ago at the end of the Cretaceous period when a meteor struck the Earth and wiped out dinosaurs and nearly every living creature on the planet. The reason? A blanket of soot cast the Earth into darkness for up to two years, according to a new study.

What they found: Using a sophisticated climate supercomputer, researchers modeled what may have happened when a meteor hit the planet and found such an impact would likely create raging global wildfires and toss a blanket of soot into the atmosphere, thereby keeping more than 99% of sunlight from reaching the surface of the Earth for up to two years.

Why did the dinosaurs die?

  • With the Earth in darkness for that long, photosynthesis would stop; temperatures would plummet by more than 30 degrees Fahrenheit for several years; and the protective ozone layer would be depleted.
  • This creates a deadly combination that the researchers say could have led to mass extinctions and the end of the dinosaurs.
  • Geological evidence shows that the Cretaceous mass extinction event occurred at the same time that a very large asteroid hit Earth in what is now the Yucatan Peninsula.
  • What the new computer model shows is how such a collision would trigger other events in its wake that drastically altered Earth's climate.

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