Previous theories held the asteroid that crashed into Earth 65 million years ago and led to the demise of dinosaurs came from the main asteroid belt between Mars and Jupiter and named the remnant of a huge asteroid, known as Baptistina, as a possible suspect.
But data from NASA's Wide-field Infrared Survey Explorer have ruled out the so-called Baptistina family of asteroids, a NASA release said Monday.
"The original calculations with visible light estimated the size and reflectivity of the Baptistina family members, leading to estimates of their age, but we now know those estimates were off," said Lindley Johnson, program executive for the Near Earth Object Observation Program at NASA Headquarters in Washington. "With infrared light, WISE was able to get a more accurate estimate, which throws the timing of the Baptistina theory into question."
Astronomers calculated the original parent Baptistina asteroid broke up 80 million years ago, only half as long ago as originally proposed.
"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 of NASA's Jet Propulsion Laboratory in Pasadena. Calif.