30 seconds that sentenced dinosaurs to their doom

Reptiles would not have been wiped out if asteroid had struck Earth earlier or later

THE asteroid impact that doomed the dinosaurs to extinction had such a devastating effect on Earth by pure chance, scientists say.

If it had struck 30 seconds later – or 30 seconds sooner – it would have caused far less damage and the dinosaurs would probably have survived.

As a result, man might never have become the planet’s dominant species, a BBC documentary reveals tonight. The asteroid struck 66mil- lion years ago 24 miles off the Yucatan Peninsula in Mexico, causing a crater 111 miles wide and 20 miles deep. Scientists who drilled into the crater found the rock was rich in sulphur compounds.

The impact of the asteroid vaporised this rock, filling the air with a cloud of dust similar to that created by a catastrophic volcanic eruption. This blocked out the sun and cooled the planet dramatically – below freezing for a decade – wiping out most life.

Those dinosaurs not killed by fumes, molten rock falling from the sky or tsunamis would have starved as their food ran out. Yet if the asteroid, which is estimated to have been nine miles across and travelling at 40,000mph, had arrived a few seconds sooner or later, it could have landed in deep water in the Atlantic or Pacific.

That would have meant that mostly sea water would have been vaporised, causing far less harm. Instead, the effect of the impact of a comparatively tiny asteroid was magnified catastrophically.

Sean Gulick, professor of geophysics at the University of Texas at Austin, who organised the drilling with Professor Joanna Morgan, of Imperial College London, said: ‘That asteroid struck Earth in a very unfortunate place.’

Professor Morgan said research suggests 100billion tons of sulphates were thrown into the atmosphere, adding: ‘That would be enough to cool the planet for a decade and wipe out most life.’ The Day The Dinosaurs Died is on BBC2 tonight at 9pm.