Sunday, February 15, 2009

50,000 Years Ago

Imagine a meteorite 150 feet across and weighing several hundred thousand tons hurtling toward Earth at 26,000 miles per hour.

Now imagine the result of it hitting the rocky plain about 20 miles west of what is now Winslow (AZ). This aerial photo of the result of this impact appears in the Meteor Crater Museum located at the rim of the crater.

There is evidence of Native Americans referring to the crater, but the first written report was not made until 1871 by a scout with General Custer named Franklin. It became known as Franklin’s Hole. In 1891, G.K. Gilbert, chief geologist of the US Geological Survey, concluded that the area had a volcanic origin.

But it was a Philadelphia mining engineer, Daniel Moreau Barringer, who identified the crater as having been formed by a meteorite. He saw the site as a potential source for mining iron ore, convinced that the ore was buried beneath the crater floor. So convinced was he that he filed mining claims and obtained patents and ownership of the two square miles containing the crater.

In 1903, Barringer’s Standard Iron Company searched for the giant iron meteorite. The 10 x 10-foot shaft in the center of the crater was dug by hand to a depth of 200 feet. (Some equipment is still in the crater.) Barringer had been correct regarding the crater’s origin, but he did not know the meteorite underwent total disintegration during the impact through vaporization, melting and fragmentation. There was no iron mass buried beneath the crater floor.

The Barringer family still owns the crater and leases it to the Bar T Bar Ranch, which owns thousands of acres surrounding Meteor Crater.

Our tour guide, Eduardo, led a group of a dozen travelers on a one-mile round trip hike along the rim of the 50,000-year-old crater. This distance covered only a portion of the crater's 2.4-mile circumference. The ruins in the photo are all that is left of the Barringer home, which later became the Visitors' Center. When a wind over 100 mph blew the roof off, the building was abandoned.

In the course of the hike, Eduardo asked all of us to identify our home state. For some reason, we were not surprised to learn that half of the group was from Pennsylvania.

During the hike, we met Harry Augensen from Media, PA. He is a Professor of Physics and Astronomy at Widener University (in Chester, PA) and was here with a group of four students. We talked about some mutual friends on the Widener faculty. Small world.

At the half-mile mark, Eduardo offered to take photographs of anyone interested in standing on the rock overlooking the crater. It made for a beautiful photo--especially from my vantage point.

Originally, the crater was 700 feet deep, but erosion has filled in the crater so that now it is about 550 feet deep. One member of our group said that about 40 years ago he was with a group that hiked to the bottom of the crater. Eduardo acknowledged that such tours were available and pointed out one of the starting points (right) for such a hike. He noted, however, that these hikes have been cancelled for some time.

In addition to its beauty, Meteor Crater has a functional use. From 1964 through 1972, NASA provided extensive science training at Meteor Crater for the Apollo astronauts.

It is said that 20 football fields could fit on the crater floor with two million spectators sitting along the sloping sides watching 20 games being played simultaneously.

Looking in the opposite direction of the immense crater ("the best preserved impact site on Earth") also revealed some beautiful scenes (above)--just on a much smaller scale.

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