[meteorite-list] Article - CU-Boulder Researchers to Analyze Meteorite That Fell Outside Berthoud, Colo.

From: ken newton <magellon_at_meteoritecentral.com>
Date: Mon Oct 11 16:03:23 2004
Message-ID: <416AE705.3090008_at_earthlink.net>


AScribe The Public Interest Newswire
Mon Oct 11 10:55:00 2004 Pacific Time

      CU-Boulder Researchers to Analyze Meteorite That Fell Outside
    Berthoud, Colo.

       BOULDER, Colo., Oct. 11 (AScribe Newswire) -- University of
Colorado at Boulder researchers will scientifically analyze a meteorite
that fell outside Berthoud, Colo., last week, only the fifth to ever
have been seen falling and subsequently recovered in Colorado, experts say.

       The meteorite weighs more than 2 pounds and is about as large as
a baseball, although it is irregular in shape. It appears to be made of
igneous rock and is melted on its surface from the heat of entering the
atmosphere. The meteorite probably broke off an asteroid or planetary body.

       "Its igneous composition reveals that it was chipped off an
asteroid large enough to undergo some form of volcanic activity," said
Nick Schneider, associate professor of astrophysical and planetary

       Megan and John Whiteis of Berthoud, and Megan's son, Casper,
provided the meteorite to aerospace engineering sciences assistant
professor Scott Palo for scientific analysis after they saw it land in
their backyard. The couple had just walked out their back door into the
yard at 1:30 p.m. on Oct. 5, when the meteorite flew over their heads
and landed about 100 feet ahead of them.

       Megan's mother, Marilyn Meador, contacted the National Center for
Atmospheric Research and spoke with Dr. Maura Hagan who emailed Palo.
Palo is an expert in radio meteors -- the study of ionized meteor trails
in the upper atmosphere using radio waves. Palo spent the next few days
putting together a team of scientists interested in helping to analyze
the specimen. The team includes:

       - Jack Murphy, curator emeritus of the Denver Museum of Nature
and Science, who is writing a book on Colorado meteorites

       - Chris Peterson, of Cloudbait Observatory, a Colorado fireball
observation network in Guffey, Colo., who is working to reconstruct the
trajectory and orbit of the meteorite using infrasound and observations

       - Assistant Professor Stephen Mojzsis of the CU-Boulder
department of geological sciences

       - Associate Professor Nick Schneider of the CU-Boulder department
of astrophysical and planetary sciences and the Laboratory for
Atmospheric and Space Physics (LASP)

       - Doug Duncan, director of Fiske Planetarium

       The first scientific test will measure gamma rays being emitted
by the meteorite. It is likely the test will be performed at NASA's
Johnson Space Center later this week. Because this is a fresh fall, the
volatile chemical species can be measured. Analysis of the rare gasses
and gamma ray emissions will provide information about the size and
history of the meteorite before it entered the Earth's atmosphere.

       Analysis of the meteorite trajectory and orbit also will be
conducted in an effort to learn where this meteorite originated. Over
the past 7 years to 10 years, a surprising number of fireballs have been
observed during the first week of October. Scientists have little
understanding about the source of the fireballs but the Berthoud
meteorite could provide a wealth of information about these recent
events. The possibility of tracking a meteorite back to its place of
origin in the asteroid belt is a rare opportunity. Researchers are
asking the public to report any fireball sightings in the sky during
October in order to help determine the meteorite's trajectory and point
of origin. Fireball sightings can be reported by going to

       Residents of Berthoud also are asked to keep their eyes open for
any rocks that appear unusual with a smooth, black, shiny crust. People
who find objects they think may be a meteorite should contact Jack
Murphy at (000)-000-0000.

       Discoverers Megan and John Whiteis have expressed their keen
interest in making the Berthoud meteorite available for educational
purposes. Until needed for scientific analysis, the meteorite will be
displayed and discussed in CU classrooms and at Fiske Planetarium. CU
faculty will work with local K-12 educators and the discoverers to bring
the excitement and importance of the Berthoud meteorite to schools and
museums around the state.

       Viewing times at Fiske will be posted at www.colorado.edu/fiske
and requests for class visits should be made to Suzanne Traub-Metlay at


       CONTACTS: Scott Palo, 303-492-4289

       CU-Boulder News Services -- Jim Scott, 303-492-3114, or Carol
Rowe, 303-492-7426


       CU-Boulder, Oct. 11, 2004

       A meteoroid is a small object - generally smaller than the size
of a pebble - and usually comes from asteroids, the moon, comets or Mars.

       Thousands of meteorites fall to Earth each year. Meteorites
generally become visible at about 60 miles from the ground due to the
intense heating from striking the atmosphere at speeds of at least
20,000 mph. Only the largest meteors are bright enough to see in the
daytime sky.

       The average weight of a shooting star, or meteor, in the sky is
less than one ounce -- about the size of a pea or smaller. Larger
meteors that hit the ground become meteorites by definition. Most
meteors decay into dust in the atmosphere and never make contact with
Earth's surface.

       The largest known meteorite is a 70-ton specimen still embedded
in the ground in Grootfontein in southwest Africa. The largest meteorite
ever found in the United States is the Willamette meteorite, which was
found in Oregon and weighs about 15 tons.

       Fireballs are defined as any meteor that is brighter than Venus
in the night sky. The appearance of a fireball is often followed by a
sonic boom.

       A meteorite generally is named for the locale, region or town
where it was found.

       Meteorites generally are classified into three categories: Stony,
iron and stony-iron. Only about 10 per cent of the meteorites that reach
Earth are "iron meteorites." Iron meteorites are rare because they
typically become buried upon impact. Of the 75 meteorites that have been
recovered in Colorado, 14 are iron.

       Stone meteorites can be divided into chondrite and achondrite
types. Chondrites contain chondrules, tiny, spherical blobs of silicates
from the earliest solar system formation which pre-date planetary

       Achondrite meteorites, like the one recently discovered near
Berthoud, Colo., make up about 7 percent of all known meteorites.
Achondrite meteorites are made from chondritic material that was melted
and re-crystalized while still on or within its parent solar system body.

       Achondrite meteorites may be pieces of planets and moons ejected
during impacts or collisions eons ago and may have traveled through the
solar system for millions of years. The now-famous Allan Hills meteorite
from Mars was discovered in 1998 in Antarctica and continues to be
controversial since some scientists believe it contains microscopic
evidence for life.

Received on Mon 11 Oct 2004 04:03:17 PM PDT

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