Dinosaur-killing asteroid didn't ravage earth: Study

London: New research has debunked the theory that the asteroid thought to have led to the extinction of dinosaurs 66 million years ago also caused vast global firestorms that ravaged the Earth.

A team of researchers from the University of Exeter, University of Edinburgh and Imperial College London recreated the immense energy released from an extra-terrestrial collision with Earth that occurred around the time that dinosaurs became extinct.

They found that the intense but short-lived heat near the impact site could not have ignited live plants, challenging the idea that the impact led to global firestorms.

These firestorms have previously been considered a major contender in the puzzle to find out what caused the mass extinction of life on Earth 65 million years ago.

"The findings mean that paleontologists may need to look for new clues from fossils found a long way from the impact to better understand the mass extinction event," said Claire Belcher from the Earth System Science group in Geography at University of Exeter.

The researchers found that close to the impact site, a 200 km-wide crater in Mexico, the heat pulse - that would have lasted for less than a minute - was too short to ignite live plant material.

However, they discovered that the effects of the impact would have been felt as far away as New Zealand where the heat would have been less intense but longer lasting - heating the ground for about seven minutes - long enough to ignite live plant matter.

The experiments were carried out in the laboratory and showed that dry plant matter could ignite, but live plants including green pine branches, typically do not.

IANS