Saturday, May 23, 2009

Crater of Death

This is the profile of an extraterrestrial mass murderer: one whose existence was denied by scientific orthodoxy for nearly two decades, but has now been tracked down. 65 million years ago a 15km wide asteroid hit the Earth. In 1978 Walter Alvarez, a Nobel-prize-winning physicist, and his son Luis, first proposed the outrageous idea that a meteorite strike blasted the dinosaurs into extinction, taking with them half of life on the planet.

Their theory was hotly disputed. Now the irrefutable evidence is rolling in. Martin Belderson's dramatic film retraces the hunt for evidence for the hidden 'smoking cannon': the crater left by the impact 65 million years ago. In 1991 it was found, buried beneath the coastline of the Yucatan Peninsula, Mexico. The central crater is at least 180km wide and nearly 20km deep. The outer impact rings may stretch to 300km in diameter, making it the largest crater produced in the inner solar system in the last four billion years. But did it cause extinction?

The fossil record seemed to show a gradual decline and extinction of animals like the dinosaur before the line of the impact. The in-fighting forced many scientists to re-examine their fossil beds. What they discovered has overturned the orthodoxy and led to a new understanding of how extinction works, and why some species survived whilst others vanished. Alvarez, father and son, have finally been vindicated.

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