Washington, May 3 : Scientists have come up with a new theory regarding the mass extinction of dinosaurs, attributing the cause to a solar system 'bounce', which might have dislodged the comet that destroyed the species on our planet.
The team of scientists that have come up with the new theory, are from the Cardiff Centre for Astrobiology in the UK.
For their research, the team built a computer model of our solar system's movement and found that it "bounces" up and down through the plane of the galaxy.
As we pass through the densest part of the plane, gravitational forces from the surrounding giant gas and dust clouds dislodge comets from their paths.
The comets then plunge into the solar system, some of them colliding with the earth.
The Cardiff team found that we pass through the galactic plane every 35 to 40 million years, increasing the chances of a comet collision tenfold. Evidence from craters on Earth also suggests we suffer more collisions approximately 36 million years.
According to Professor William Napier, of the Cardiff Centre for Astrobiology, "It's a beautiful match between what we see on the ground and what is expected from the galactic record."
The periods of comet bombardment also coincide with mass extinctions, such as that of the dinosaurs 65 million years ago.
Our present position in the galaxy suggests we are now very close to another such period.
Though the "bounce" effect may have been bad news for dinosaurs, it may also have helped life to spread. According to the scientists, the impact may have thrown debris containing micro-organisms out into space and across the universe.
"This is a seminal paper which places the comet-life interaction on a firm basis, and shows a mechanism by which life can be dispersed on a galactic scale," said Centre director Professor Chandra Wickramasinghe.