Giant asteroid killed off dinosaurs 66,038,000 million years ago: study [View all]

[Playinghardball]

Scientists said Thursday they are a step closer to proving the death blow for dinosaurs 66 million years ago was a gigantic comet or asteroid that struck near Mexico.

Although a catastrophic impact has long been thought to be involved earlier work left doubts about just when the object, estimated at some six miles (10 kilometers) in diameter, struck in relation to when dinosaurs disappeared.

But in a study out Thursday in the US journal “Science,” researchers used updated techniques to get a more precise date for the impact — 66,038,000 million years ago — which they said was accurate within 11,000 years.

“When I got started in the field, the error bars on these events were plus or minus a million years,” said paleontologist William Clemens, a UC Berkeley professor emeritus who was not directly involved in the study.

The researchers also updated their estimate for the time the mass dinosaur extinction, and found that the date was within the same margin of error — in other words, at around the same time as the asteroid impact.

“We have shown that these events are synchronous to within a gnat’s eyebrow,” said Paul Renne, of the Berkeley Geochronology Center at the University of California, Berkeley.

“The impact was clearly the final straw that pushed Earth past the tipping point,” he said.

More at: http://www.rawstory.com/rs/2013/02/07/giant-asteroid-killed-off-dinosaurs-66038000-million-years-ago-study/