Scientists explain what happened to the Mount Everest-size asteroid that eliminated the dinosaurs from Earth
Some 66 million years ago, a devastating asteroid strike is believed to have been behind the mass extinction of the dinosaurs.
The fate of the asteroid that’s said to have wiped out the dinosaurs is at the heart of our understanding of how the mass extinction came about.
Dinosaurs dominated the Earth for around 180 million years, until a devastating asteroid strike is understood to have killed off all non-bird species of the animal group around 66 million years ago.
What happened to the asteroid on impact?
Measuring an estimated six miles in diameter, the asteroid is believed to have hit our planet “with the energy of about 8 billion times a World War II-era nuclear bomb”, the geophysicist Sean Gulick told a recent interview with Live Science.
Gulick, a research professor at the University of Texas at Austin, explained to Live Science that the asteroid “basically vaporizes” on impact.
It turned into “a fine dust that ends up in the upper atmosphere and rains down” across the Earth over a period of several decades, he added.
This years-long shower of dust is thought to have brought about what’s known as the ‘iridium anomaly’ - an extremely high, worldwide concentration of the metallic element in a 66-million-year-old layer of rock strata.
“Most widely accepted theory”
Such an abundance of iridium is not known to occur naturally on Earth - and points to an extraterrestrial influence.
In the early 1980s, this led the Nobel Prize-winning physicist Luis Walter Alvarez and his son, the geologist Walter Alvarez, to put forward the theory that an asteroid was behind both the formation of the iridium anomaly and, before that, the extinction of the dinosaurs.
“The Alvarez hypothesis was initially controversial, but it’s now the most widely accepted theory for the mass extinction”, says the U.K. Natural History Museum.
In addition to the tell-tale layer of iridium-rich rock, the asteroid theory is backed up by the existence of a huge crater that also dates back 66 million years, says the Natural History Museum’s Professor Paul Barrett.
The impact site in question - the more than 100-mile-wide Chicxulub crater - is located at the Yucatán Peninsula, in southeast Mexico. “It’s now largely buried on the seafloor off the coast,” Barrett explains.
“Total devastation”
When the asteroid hit, Barrett says, “in the immediate area there was total devastation”.
“A huge blast wave and heatwave went out and it threw vast amounts of material up into the atmosphere.
“It sent soot travelling all around the world. It didn’t completely block out the Sun, but it reduced the amount of light that reached the Earth’s surface. So it had an impact on plant growth.” This left herbivorous species without food - and, as a consequence, deprived carnivores of living creatures to feed on.
“It was a massive event affecting all life on Earth,” Barrett concludes.
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