[meteorite-list] Researchers Harvest the Spoils of Chicago Meteor Shower (Park Forest Meteorite)

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Apr 22 10:25:39 2004
Message-ID: <200305132329.QAA23198_at_zagami.jpl.nasa.gov>

http://news.nationalgeographic.com/news/2003/05/0513_030513_tvmeteorites.html

Researchers Harvest the Spoils of Chicago Meteor Shower
Bijal P. Trivedi
National Geographic Today
May 13, 2003

Around midnight on March 26, hundreds of meteorites rained on the Chicago
suburbs of Park Forest and Olympia Fields, about 35 miles (56 kilometers)
southwest of downtown.

The larger meteorites punched holes in roofs and dented cars. One meteorite
embedded itself in the Park Forest fire station.

"We were asleep when it happened," says Phillip Jones, a retired
electrical designer who lives in Olympia Fields. "My youngest
granddaughter came into our room saying she had heard a noise but
we told her she was dreaming and to go back to sleep."

The next morning, Jones found a foot-wide hole in the ceiling-then a
second hole through the kitchen floor into the basement.

Jones' daughter reported that there seemed to be a furry animal in a
pile of laundry in the basement-it was, in fact, a six-pound,
six-inch-wide (2.7-kilogram, 15-centimeter) remnant from the
origin of the solar system, about 4.5 billion years ago, fuzzy with roof
insulation.

The morning after the shower, Meenakshi Wadhwa, a planetary
scientist and associate curator at The Field Museum of Chicago with
an international reputation for the study of meteorites, particularly
those from Mars, was driving to work when she heard a radio report
that people were bringing meteorites to the Park Forest police station
to be held as "evidence." She took a detour.

Meteorites, Big Business

Wadhwa is used to searching farther afield. She has trekked to
Antarctica for meteorites.

She has also set her sights on Mars. Wadhwa is co-investigator of
SCIM (Sample Collection for Investigation of Mars), one of the four
missions competing for a NASA expedition to the Red Planet in 2007.
SCIM is the only mission that plans to return to Earth with samples.

At the Forest Park police station, residents had brought in 15 to 20
meteorites. "It was pretty exciting," Wadhwa says. "This is the
freshest material I have ever seen-it had landed just a few hours
earlier."

"This is the first time that a meteorite shower has hit such a
populated area," says Wadhwa. "It is amazing that nobody got hurt."

Wadhwa wasn't the only interested party. A throng of meteorite
collectors and dealers was haggling with residents.

"It looked like an open air bazaar," says Steven Simon, a research
associate at the Geophysical Sciences department at the University
of Chicago and a colleague of Wadhwa's who lives in Park Forest.

Meteorites are big business. Many of the Park Forest meteorites
ended up on eBay within a few days. A meteorite dubbed the Park
Forest "Smasher"-weighing 145 grams (five ounces)-is currently at
auction for $5,000.

"We were competing directly with dealers to acquire the rocks for the
museum," Wadhwa says. The Field Museum spent about $30,000 to
acquire about six pounds (2.7 kilograms) of meteorites for the
collection. Almost none of the new material came from public
donation.

The meteor shower occurred when a meteoroid about the size of a
small car hit the Earth's atmosphere, Wadhwa believes. Its
provenance may have been the asteroid belt between Mars and
Jupiter, 167 million miles (270 million kilometers) from Earth.

Collision Course with Earth

"(The Park Forest meteoroid's) orbit may have been on a collision
course with Earth," says Wadhwa. "Many objects cross Earth's
orbit, and there are many near misses. NASA even has a program to
discover objects that may endanger the Earth."

Between 50,000 and 100,000 tons (one hundred and two hundred
million pounds) of space dust and meteorites fall on the planet every
year. Wadhwa knows the territory. In 1999 the International
Astronomical Union named an asteroid for her: "8356 Wadhwa."

Asteroids and meteoroids are believed to have formed about 4.5
billion years ago from clouds of dust and gas-the same material that
condensed to form the sun and all the planets. In fact, says Wadhwa,
analyses of the sun's composition "reveals an almost perfect match
with carbonaceous chondrite meteorites."

Wadhwa and Simon have already begun to analyze the Park Forest
meteorites. She has sliced the rocks into wafer-thin slivers and
examined them with an electron microprobe.

Some areas of the rocks seem to show areas of melting-which
suggests to her that "they were battered around with other
asteroids," Wadhwa says.

Wadhwa and Simon will co-author a study of the Park Forest
collection for the July meeting of the international Meteoritical Society
in Munster.

The Park Forest meteoroid turns out to be one of the more common
chondrite types found on Earth. But Simon points out that "every little
rock is another piece of the puzzle to the formation of the solar
system."

Wadhwa has returned to Park Forest. "It was a bit of a pilgrimage,"
she says. "There was nothing scientific I got out of it. I study these
things, and it is just exciting to see the evidence. I wanted to see the
hole in the roof with my own eyes."
Received on Tue 13 May 2003 07:29:02 PM PDT