DINOSAURS - rulers of Earth for 160 million years - all died within days of a giant explosion, scientists said yesterday. An asteroid the size of the Isle of Wight smashed into Mexico with a billion times more force than the Hiroshima A-bomb. A vast fireball swept debris into the atmosphere and within hours day turned to permanent night across the globe. As temperatures plummeted, all the large coldblooded reptiles like T-Rex rapidly died. But that gave small, better adapted warm-blooded mammals a chance to thrive, eventually leading to the evolution of mankind. A panel of 41 experts have re-created the effects of the impact 65 million years ago and have confirmed the theory that it wiped out most life. The panel analysed all the evidence gathered by experts in the past 20 years to explain why the sea and land changed so rapidly. Their report is published in the journal Science. Dr Gareth Collins, from the Department of Earth Science at Imperial College, London, said: An enormous ball of hot rock and vapour rapidly expanded throwing debris into space. Mirror It would have had the most devastating consequences for life by blocking sunlight and cooling the climate. Ironically this hellish day turned out great for mammals, who had lived in the shadow of the dinosaurs. Dr Joanna Morgan, also of Imperial College, added: If you were taking photographs from a satellite you would have seen the Earth gradually becoming enveloped in a dust cloud and becoming totally enveloped, probably within about two hours. At the surface it would be very dark and also very, very cold. Scientists say its a question of not if but when another huge asteroid smashes into the Earth. But relax... it should happen only once every 100 million years. Dinosaurs ruled the Earth 160 million years before being wiped out in a week. The average gap between giant asteroids striking the earth are 100 million years. While the width of the crater left by the asteroid was 100 kilometres. Mirror