[meteorite-list] Park Forest Meteorite Goes On Display At Chicago Field Museum

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Apr 22 10:16:32 2004
Message-ID: <200308110519.WAA29032_at_zagami.jpl.nasa.gov>

http://www.starnewspapers.com/star/spnews/news/10-sp3.htm

Meterorite goes on display at Field Museum
By Erika Enigk
The Star (Illinois)
August 10, 2003

Pieces of a meteorite that landed in Park Forest in March are now on display at
Chicago's Field Museum.

Village officials and staff viewed the space rocks, which fell to the Earth on
March 27, during a reception at the museum on Aug. 2.

Trustee Harold Brown said Olivier Rieppel, chairman and curator of the
museum's geology department, welcomed the group. The group viewed the
meteorite after a slide presentation by Meenakshi Wadhwa, associate curator
of meteorics.

"At the top of the glass case, it says, 'It came from outer space: the Park
Forest meteorite,'" Brown said. "I thought it was great."

Wadhwa said the meteorite most likely came from the asteroid belt and is
about 4.5 billion years old. Scientists can estimate the age in the same way
they estimate the age of Earth rocks, she said.

"You use the decay of radioactive isotopes as a clock," she said. "It's a
standard procedure for Earth rocks as well."

The rock was likely on the outside of a larger rock in the asteroid belt, where
asteroids are constantly colliding, Wadhwa said. Pieces broke off and began
their own elliptical orbits, until the rock's orbit met the Earth's.

When the "stony" meteorite that eventually fell into pieces upon Park Forest
entered the Earth's atmosphere, it was about two or three meters long, the
size of a car, Wadhwa said. Gravity, velocity and friction from the atmosphere
caused it to break into pieces at the rock's weak zones, she said.

"It's more common to see that happening in stony types of meteorites," she
said. "Iron meteorites tend not to break into as many smaller pieces.

"The largest known meteorite is an iron meteorite about the size of a car," she
said.

Meteorite pieces fell all over the South Suburbs, she said.

"It fell all the way from Crete to Olympia Fields," village manager Janet
Muchnik said.

The Park Forest event was the first time a meteorite has fallen in such a
populated area, Wadhwa said. However, there are reports of meteorite events
every year, she said.

"There's something like 100 tons of stuff that falls on the Earth every day from
outer space," she said, much of which are dust-like particles.

Wadhwa said the meteorite event has been important for the scientific
community.

"Just about everything we know about the beginning of our planet comes from
studying meteorites like this one," she said. "What's been wonderful is how
this event has increased public interest in meteorites."

The Field Museum is preserving the meteorite pieces in a climate-controlled
environment, but Muchnik said several Park Forest residents still have other
pieces in their homes.

Wadhwa offered words of wisdom to those people for the care and handling of
the items.

The metal in meteorites tends to rust quickly, she said, so the rocks should be
in a cool, dry place. People can keep moisture from getting to them by putting
the rocks in a plastic bag, then putting that bag inside another plastic bag
containing silica gel.

"We store a lot of our meteorites that way," she said.

People also should resist the temptation to touch the meteorites, she said.

"Sweat from your fingers will corrode the metal," she said.

Erika Enigk may be reached at (708) 802-8847 or via e-mail at
eenigk_at_starnewspapers.com
Received on Mon 11 Aug 2003 01:19:15 AM PDT