66 million years ago a six-mile-wide
asteroid larger than Mount Everest is tall
slammed our planet with the force
of ten billion atomic bombs,
unleashing giant fireballs, crushing tsunamis, continent-shaking earthquakes, and suffocating darkness.
This was the cause of the Cretaceous Paleogene extinction event,
which drove the dinosaurs extinct
almost overnight, or so we thought.
Prior to the ascent of the asteroid hypothesis, researchers have proposed other explanations for the dinosaurs' demise.
Gluttony, protracted food poisoning, terminal chastity, acute stupidity, even death by boredom.
Those fell by the wayside when in 1980 a Nobel prize-winning physicist found iridium,
a hard silver-gray element that lurks in
the bowels of planets including ours,
deposited all over the world and approximately the same time that, according to the fossil record, creatures were dying en masse.
Mystery solved! An asteroid had crash-landed into Earth, spewing pulverized rock dust around the globe, and wiping out most life-forms.
It's a great story - one many of us learned as children - but is it the truth?
Some scientists present an alternate scenario - the Deccan volcanism hypothesis - which posits that eruptions from the Deccan Plateau in India,
over the course of 350,000 years, are the true culprit.
Ash, toxic elements, and gases from eruptions would have blown around the world,
poisoning creatures and their food supply.
The belches of sulphur would have initially cooled the climate, then drenched the earth in acid rain,
ravaging oceans and destroying vegetation that land animals needed to survive.
Carbon dioxide and methane would have eventually raised temperatures by as much as 46 degrees Fahrenheit,
acidifying oceans and making them inhospitable to plankton.
Once these microscopic creatures disappear from the base of the food chain, the larger marine animals follow.
The Earth's oceans flora and fauna did not show signs of recovery for more than three hundred thousand years,
a time period that coincides with
the duration of the Deccan Traps.
The dinosaur wars, a battle between proponents of the asteroid impact theory and the Deccan volcanism theory, remains heated.
After nearly 40 years of arguing, each side still cannot agree on fundamental facts like how rapidly much of Earth's life disappeared.
Ultimately consensus may be the wrong goal.
Some scientists argue that controversy produces progress, pushing experts to take on more sophisticated
questions.
Whether or not Deccan caused the mass extinction, its eruptions illuminate how our current environment may react to man-made pollutants.
If Deccan was responsible, the volcanism theory casts our current level of environmental contamination in a more terrifying light.
