80m-year error renews mystery of what killed off the dinosaurs

Efforts to unravel one of Earth’s greatest mysteries – the demise of the dinosaurs – have taken a step backwards after data from a space probe showed up an 80-million-year miscalculation by scientists.

Observations made by Nasa’s Wide-Field Infrared Survey Explorer (WISE) have disproved theories about which asteroid was responsible for the cosmic impact that wreaked havoc on Earth 65 million years ago and ended the Age of the Dinosaurs.

Scientists previously thought that the culprit was a remnant from the asteroid Baptistina, a vast space rock that they believed shattered into mountain-sized chunks when it collided with another asteroid somewhere between Mars and Jupiter 160 million years ago. Gravitational nudges by Jupiter and Saturn, known as “resonances”, would have flung the debris around the solar system before hurling it to Earth.

But the resonance process takes tens of millions of years – and evidence from WISE now shows that Baptistina’s break-up was more recent than previously thought, actually occurring 80 million years ago.

“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, an astronomer working on the project at Nasa’s Jet Propulsion Laboratory, California.

WISE’s latest data has sent experts back to the drawing board to try to pinpoint exactly what asteroid slammed into Earth with a force one billion times more than the US atomic bomb that destroyed Hiroshima in 1946 and where it came from.

“As a result of the WISE science team’s investigation, the demise of the dinosaurs remains in the cold case files,” said Lindley Johnson, head of Nasa’s Near Earth Object Observation Programme.

Evidence of an asteroid impact is based on a 180km-wide crater on Mexico’s Yucatan Peninsula that is believed to have been the starting point for a series of domino-effect occurrences including the toppling of forests around the world, massive wildfires, tsunamis and earthquakes measuring greater than 11 on the Richter scale – forces that destroyed more than half of life on Earth 65 million years ago.

Scientists believe that by examining asteroids in space and assessing their mineral make-up, they may be able to establish where the rock that made the crater originated.

Launched in 2009 and similar in appearance to the Star Wars robot R2-D2, WISE has detected millions of objects including 22 comets and 157,000 asteroids – 1,056 of them pieces from Baptistina.

Joseph Masiero, who led the study, said: “We are working on creating an asteroid family tree of sorts. We are starting to refine our picture of how the asteroids in the main belt smashed together and mixed up.”