[meteorite-list] Thousands of Meteorites May Have Fallen in Canadian Meteorite Fall

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Mon, 22 Dec 2008 13:54:50 -0800 (PST)
Message-ID: <200812222154.NAA18347_at_zagami.jpl.nasa.gov>

http://www.ctv.ca/servlet/ArticleNews/story/CTVNews/20081222/meteorites_earth_081222/
10,000 meteorites touched down in Sask.: scientist
CTV.ca
December 22, 2008

The sheer number of meteorite fragments that touched down on Nov. 20 in
Saskatchewan -- first lighting up the sky in a dramatic light show
witnessed by people across the prairies -- may have set a new Canadian
record.

Rather than just one space rock hitting the ground, as first thought,
the bounty appears to consist of thousands of meteorite fragments,
according to the team that has co-ordinated the recovery.

The group, organized by the University of Calgary, has recovered more
than 100 meteorites from the site southwest of Lloydminster, on the
border of Alberta and Saskatchewan, and says many more are still out there.

Volunteer searcher Ellen Milley, who is pursuing her master's at the
University of Calgary's geoscience department, found the first meteorite
fragments on Nov. 27.

U of C planetary scientist Alan Hildebrand said in a written statement
there are roughly 2,000 meteorites of 10 grams or more, per square
kilometre, in the northern part of the field where the fragments were
found.

Altogether, he calculated, there are likely more than 10,000 meteorites
on the ground in the area.

"The last day that the search teams were out, it snowed all day and we
still found five meteorites which is ridiculous. It shows just how many
are out there," Hildebrand said.

The area where the meteorites were discovered is being called Buzzard
Coulee, after a valley near the hamlet of Lone Rock, Sask., where Milley
found the first fragments.

The largest meteor fall previously on record occurred when hundreds of
fragments were recovered near Bruderheim, Alta. in 1960.

Hildebrand said the November event could easily surpass those numbers.

"I think that the number of individual meteorites that will be recovered
for Buzzard Coulee will easily set the Canadian record for the largest
fall recovery, but we still don't know how big the biggest meteorite out
there is, so we don't know how much mass we can expect to be recovered
of the approximately 1 tonne that fell," Hildebrand said.

A large-scale search will be held in the spring, prior to the start of
cultivation and seeding, to recover as many meteorites as possible,
Hildebrand said.

He said the initiative planned for spring will be "the biggest meteorite
search effort that Canada has ever seen."

Scientists are still examining the fragments in an attempt to learn more
about where the meteor came from. It has already been classified as an
H4 type.

The rock is on the low end of the H4 scale, meaning it didn't experience
high heat on its parent asteroid.

"The meteorite also appears to show that different types of material are
mixed together in a subtle way, but we will have to study more thin
sections to better understand this," said Dr. Melinda Hutson, a Canadian
scientist at Cascadia Meteorite Laboratory at Portlant State University
who helped classify the meteorite.

"The meteorite is slightly shocked, so the material was possibly stirred
by an impact on its parent asteroid."
Received on Mon 22 Dec 2008 04:54:50 PM PST