What size meteorite does it take to wipe out life?
ABCNEWS.com T U C S O N, Ariz. The disaster was foreshadowed by a light in the distant sky that grew more brilliant as the iron meteorite, half the size of a football field, plunged through the atmosphere toward the Earth. Northern Arizona looked much different than the dry, desert wasteland of today. Some 50,000 years ago, long before the first humans arrived, streams flowed through the wooded lands. The wetter landscape provided lush grazing for the elephant-like mastodons, the prehistoric ground sloths and the camels, horses and bison that called that part of the Colorado Plateau home. All that changed in a instant when the meteorite slammed into Earth carving out a mile-wide crater. The impact sent 2,000 mile-an-hour winds blasting across the land, literally ripping out by the roots everything from large trees to blades of grass. Every creature and every plant within two or three miles died instantly. Large animals close to the impact were vaporized. Those a little farther away die
