Rock Solid Link: Asteroid Doomed the Dinosaurs

THE WOODLANDS, Texas ? Scientists have debated for two decades whether a giant space rock wiped out the dinosaurs or if some other catastrophe did the deed.

Now, a blue-ribbon panel of scientists has banded together to support the link between the Chicxulub asteroid impact crater in Mexico?s Yucat?n Peninsula with the mass extinction of dinosaurs and the majority of life on our planet 65 million years ago.

?It is an international consensus. They are saying that there?s a rock solid link between the Chicxulub impact event and the K-T boundary mass extinction,? said David Kring, a Senior Staff Scientist and geologist at the Lunar and Planetary Institute in nearby Houston.

The K-T boundary refers to a layer of iridium-rich clay that marks the end of the Cretaceous period 65 million years ago. Iridium is a chemical element commonly found in asteroids and comets and the K-T boundary has been held up as the tail-ending tale of an asteroid impact that snuffed out the dinosaurs.

It was Kring, nearly 20 years ago, that announced the discovery of shocked quartz and other evidence of a huge, out of the sky wallop from a mile-deep (1.6 km) drill hole into a buried crater on the Yucat?n Peninsula of Mexico.

Kring and his team named the crater Chicxulub for a Mayan village above the center of the crater. That Mayan word means ?tale of the devil,? which Kring thought an ideal name for a dinosaur-killing asteroid impact.

?Nineteen years ago I thought the case was pretty solid,? Kring said. ?The international community has been poking at this for nearly two decades,? he told SPACE.com during the 41st Lunar and Planetary Science Conference (LPSC) being held here this week.

In fact, that announcement ? with co-authors William Boynton and Alan Hildebrand ? was made at the LPSC in 1991.

Combining all available data

Now, fast forward to this week.

A team of over three dozen scientists from around the world will report on their consensus in Science magazine on Friday.

Lead author of the paper, Peter Schulte, Assistant Professor at the University of Erlangen in Germany, said in a press statement: ?Combining all available data from different science disciplines led us to conclude that a large asteroid impact 65 million years ago in modern day Mexico was the major cause of the mass extinctions.?

Kring said that with any extraordinary discovery there is a natural interest in confirming it?that?s the scientific method.

?You need to have a testable hypothesis and you need to confirm it with multiple lines of evidence,? Kring added. ?What?s important is for the international community to have that opportunity to review the data and make up their own minds.?

Tenets of geological sciences

?We saw the very same thing with the concept of plate tectonics ? which we all now accept,? Kring said. ?But the concept of an impact mass extinction hypothesis is as revolutionary?and there are going to be people who just are not going to accept it.?

Kring noted that there are specialists in the historical importance of scientific ideas that have compared and contrasted the impact mass extinction hypothesis and its impact on the tenets of geological sciences.

?They have concluded that it is actually, fundamentally, a larger shift, a bigger change, than the theory of plate tectonics,? Kring said.

So it?s not surprising, Kring added, that there will be those in the unconvinced camp. That said, there is a huge consensus reflected and represented by the Schulte-led paper in Science magazine, he concluded, published coincident with this year?s Lunar and Planetary Science Conference.

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Leonard David has been reporting on the space industry for more than five decades. He is past editor-in-chief of the National Space Society's Ad Astra and Space World magazines and has written for SPACE.com since 1999.