New Meteor Crater (in Arizona) Info

["Allan Edels" <Edels@email.msn.com>]

All:
    This info is dinosaur related, if you compare this crater to the
Chixilub crater (in Mexico) in size and expected damage for each.

FROM CNN Online:

Study: Space rock that dug Arizona crater melted on impact

July 2, 1999
Web posted at: 12:56 p.m. EDT (1656 GMT)


WASHINGTON (AP) -- Most of the space boulder that smashed to Earth to create
Meteor Crater in Arizona melted upon impact 50,000 years ago and sprayed
molten material in every direction.

A study appearing Friday in the journal Science concludes that an iron
meteor 100 feet in diameter and weighing about 60,000 tons sailed in from
space at almost 45,000 miles an hour and smashed into the desert floor near
Winslow, Arizona.

The collision erupted with the force of a 20 megaton bomb and sprayed molten
rock for miles around the crater, says Elisabetta Pierazzo, co-author of the
study and a researcher at the University of Arizona Lunar and Planetary
Laboratory.

Left behind was a bowl-shaped crater about 4,000 feet wide and 570 feet
deep. It was the first crater on Earth to be identified, by earlier studies,
as being caused by a meteoroid.

Pierazzo and her co-authors used math models and chemical analysis of bits
of the space boulder to determine that about 85 percent of the meteor melted
upon contact. Only the back 15 percent of the 100-foot space rock did not
melt, but, instead, broke into bits of that have been called Canyon Diablo
meteorites.

The melted portion turned into grain-size particles called spheroids that
were spread far and wide by the impact. Only a small bit of the spheroids
and bits of unmelted meteor have been found.

Earlier estimates had put the impact speed of the meteor at about 33,000
miles per hour, but Pierazzo said that the new study confirms the faster
45,000 mile-per-hour speed.

Co-authors of the study included researchers from Rutgers University, the
University of Rhode Island, the University of California, Berkeley, and the
Australian National University in Canberra.

Copyright 1999   The Associated Press. All rights reserved.



Allan Edels