[meteorite-list] Quarter-Ton Brahin Meteorite on Display at Portland State University

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu May 12 14:23:04 2005
Message-ID: <200505121822.j4CIMTZ07631_at_zagami.jpl.nasa.gov>

http://www.dailyvanguard.com/vnews/display.v/ART/2005/05/12/4282ea0895e52

A souvenir from space

Quarter-ton meteorite lands in the Geology department's basement office

Story by Art Chenoweth
Portland State University Vanguard
May 12, 2005

Portland State students now have the opportunity to see a rare
meteorite, big enough to smash through a house to the ground.

This meteorite is a stone-like mass as big as three basketballs but very
dense - it weighs more than 500 pounds. It is on display during office
hours on a sturdy table in the Geology department, 17 Cramer Hall
basement. It has an internationally approved name, Brahin, named for the
city in Belarus, formerly in the Soviet Union.

Smaller pieces of this meteorite were found in 1810 and this large piece
in 1819.

The rock formation is of the type known as a pallasite.

"It's a rare type," said Alex Ruzicka, assistant professor in planetary
sciences and meteorites, and one of three individuals involved in PSU's
Cascadia Meteorite Laboratory. The others are Melinda Hutson, an adjunct
professor in geology, and Dick Pugh, a retired high school teacher.

Regarding the Brahin pallasite, Ruzicka said, "This is as rare as it
gets. There's not much of this type hitting earth. The only other
pallasite he knows of is a slice of one in the American Museum of
Natural History.

Brahin actually is on loan from Edwin Armstrong, a dealer in meteorites
at ET Meteorites of Lake Oswego. Armstrong would like to sell the
meteorite, perhaps to a wealthy philanthropist who would later donate it
to a museum. Meanwhile, it is getting exposure to potential buyers at
Portland State, rather than gathering dust in storage.

Meteorites are pieces broken off from asteroids, thousands of which
orbit between Mars and Jupiter. Some celestial accident takes place
which breaks off pieces of the asteroid to become meteors hurtling
through the air and frequently seen as fireballs. If they hit the
ground, they become meteorites.

The pallasite is rare because it is composed of two substances from deep
within the core of the asteroid. Part of this is alivine, a gem quality
substance which can be employed as a gemstone called peridot. The other
substance is the heavier part of the meteorite, a naturally-created
steel alloy.

Ruzicka said this natural steel is also what forms the core of the earth.

"Studying a pallasite gives us information about what it might be like
inside the earth," he said.

He speculated as to what Brahin may have looked like as it streaked
toward earth as a meteor.

"It likely would have been seen as a tremendously bright object," he
said. "Brighter than the full moon." As it heated up from the friction
of the air it would have started breaking up, making different trails in
the sky, probably as many as 10 or 12 pieces.

Had it fallen on a car, he said, "It would have taken the whole car." If
it had fallen in a populated city like Portland, "it probably would have
destroyed a good portion of someone's house. It would take out anything
it hits directly."

Meteorite dealing has become a business. It is especially favored by
desert Bedouins. Finding a meteorite in a desert is easier than finding
it in the woods or mountains.

Oregon is not a meteorite-heavy state. Only four meteorites have ever
been recovered in Oregon, and no pallasites. A very small octahedrite
was found in 1952 near Klamath Falls. Fragments of chrondite fell on a
police officer's house in Salem on May 11, 1981. The first meteorite
found was an octahedrite, discovered at Sam's Valley in Jackson County
in 1894.

But the biggest, Ruzicka revealed, was the 15-ton Willamette Stone, also
an octahedrite. It was found in 1902 on property owned by Oregon Steel
Co. near what was then the town of Willamette, now incorporated into
West Linn.

The Oregon Steel employee who found the stone attempted to assert
ownership of it. The case eventually went to the Oregon Supreme Court,
which ruled that meteorites belong to the people who own the land the
meteorite fell on. The stone was sold to a wealthy philanthropist, who
donated it to the American Museum of Natural History.

The Cascadian Laboratory does not maintain its own museum. Some of its
exhibits, along with other mineral exhibits, may be viewed at the Rice
Northwest Museum of Rocks and Minerals. It is located in the Hillsboro
area. On Highway 26, take the Helvetia/Shute Rd. exit and head north.

-------------------------------------------
 
Meteor now believed to be demise of dinosaurs

The display of a heavy meteorite at Portland State brings up an old
question. Why did all the dinosaurs suddenly disappear?

Through the years, many explanations have emerged but lately it has been
argued that a huge meteorite wiped out the beasts. Is this likely?

"Probably so," said Alex Ruzicka, assistant professor who serves as
director of the PSU Cascadia Meteorite Laboratory.

But how can just one big meteorite, no matter how big, create so
devastating an effect? Ruzicka pointed out some consequences of a huge
meteorite that might not occur to the casual inquirer.

Such a gigantic meteorite does exist. It hit the earth probably 66
million years ago in the Yucatan area of Mexico. It is now covered with
sediment but drillings have confirmed its existence.

As Ruzicka explained, a meteorite that big would be creating almost
unbelievable heat as it crashed through the earth's atmosphere.

"Any organism in the area would be vaporized," he said. The heat would
likely set forests afire throughout the globe.

The impact would create a tremendous dust cloud blocking all sunlight,
killing plants and starving any surviving herbivorous dinosaurs as well
as the carnivores who fed on them.

"The climate would be much cooler for a decade or so," he elaborated,
further impacting the dinosaur population, if any still existed. "The
rain would probably be very acidic," he surmised, meaning death to plant
life. The impact created evidence of great tsunami waves that have been
found in Texas and would have assured further devastation.

This wasn't the earliest such environmental disaster recorded, Ruzicka
revealed.

"There was an even bigger extinction 250 million years ago," he said.
That would have occurred in the Permian age, before dinosaurs became the
dominant species.

The cataclysm of 66 million years ago meant that most species that
survived lived underground or in the water, Ruzicka said.

"It changed the course of evolution on earth. It enabled the mammals to
become dominant."
Received on Thu 12 May 2005 02:22:28 PM PDT