Hi Jen & All,
Back in Feb this year I was in Arizona. My son, Andrew, and I visited a number of landmarks in that state. The Grand Canyon helicopter flight was unreal.
That hole took a long time to excavate.
But the one that really gave me goose bumps was the Barringer Meteorite Crater. 750 feet deep and 4000 feet diameter in seconds.
176 million tons of rock was shifted.
http://www.youtube.com/watch?v=_M2X99D_RLY
http://www.meteorcrater.com/eventsfun/exptheimp.htm
From memory the meteor was about 150 feet diam and weighed around, I quote:
Scientists now believe that the crater was created approximately 50,000 years ago. The meteorite which made it was composed almost entirely of nickel-iron, suggesting that it may have originated in the interior of a small planet. It was 150 feet across, weighed roughly 300,000 tons, and was traveling at a speed of 28,600 miles per hour (12 kilometers per second) according to the most recent research. The explosion created by its impact was equal to 2.5 megatons of TNT, or about 150 times the force of the atomic bomb that destroyed Hiroshima.
Its amazing to see it in real life. I've been there. I say go see it yourself if you ever can do.
Cheers Marty