NASA: Asteroid Blamed for Killing Dinosaurs is Innocent

Pasadena - The prime suspect behind the demise of the dinosaurs was off the hook Monday, after NASA revealed the family of asteroids commonly blamed for the extinction probably was not responsible -- and the matter is back in the space agency's cold case files.

While scientists still believe a large meteor crashed into Earth approximately 65 million years ago, leading to the extinction of the dinosaurs, the widely-held Baptistina theory now appears to have been all but ruled out.

Since 2007 it has been widely believed that the giant asteroid Baptistina crashed into another asteroid in the belt between Mars and Jupiter about 160 million years ago, sending shattered pieces as big as mountains flying -- including one that, many millions of years later, hit Earth.

But "as a result of the WISE science team's investigation, the demise of the dinosaurs remains in the cold case files," said Lindley Johnson, program executive for the Near Earth Object (NEO) Observation Program.

WISE is NASA's Wide-field Infrared Survey Explorer, a program that uses infrared to determine the age of things in space. The results threw up new questions around the timing of the Baptistina event.

Scientists established that the Baptistina asteroid actually broke up closer to 80 million years ago, half as long as the 160 million years originally proposed -- meaning the remnants had only 15 million years to get flung down to Earth to cause the extinction of the dinosaurs.

"This doesn't give the remnants from the collision very much time to move into a resonance spot, and get flung down to Earth 65 million years ago," said Amy Mainzer, a study co-author and the principal investigator of NEOWISE. "This process is thought to normally take many tens of millions of years."

The team hopes to use their new data to disentangle different asteroid families and trace their histories -- and hopefully come up with a new suspect in the dinosaur mystery.