One of the most fascinating whodunits in the history of this planet is the extinction of the dinosaurs 65 million years ago. One explanation for their disappearance involves the impact of a six to ten mile wide object - an asteroid - with Earth. A huge underground crater discovered beneath the Yucatan Peninsula of Mexico is thought to be the mark left by the impact of this object.

Such an impact would equal the force of 60 million modern atomic bombs. Initially, a two-mile high wall of fire and vaporized rock would emanate from the impact, plus 100-foot tidal waves, earthquakes and hurricane-force winds. Soot and dust thrown into the air would darken and cool the entire planet for months or years. Once the dust settled, carbon dioxide left in the air by the impact may have led to decades or centuries of global warming.

Fossil records indicated that more than 70% of all plant and animal species went extinct. It may have been the last straw for the dinosaurs, which were likely on the way out anyway. This ancient catastrophe opened the door for the Age of Mammals, and thus, in a way, for us.