Minneapolis Star Tribune
January 14, 1998
Page: 1A
It came from outer space and filled up his pocket. A meteorite that a
Champlin man dug up in his back yard appears to be part of an asteroid core,
and that has made it a valuable piece of rock both.
By Jim Dawson
In a classic example of "manna from heaven," Al Stegora of Champlin has sold
a meteorite that dropped into his back yard thousands or millions of years
ago to a consortium of six universities and museums for $38,000.
He would have made a few thousand more if he hadn't been such a cosmic
idealist. "I knew this was something out of the ordinary," Stegora said of
the 123-pound rock, which he found in 1983 while digging a sewer excavation
in his back yard. "I had a suspicion that this was something rare."
Indeed. His "rock" was actually a chunk of metal, mostly iron and nickel,
that was probably part of a distant asteroid formed billions of years ago
when the solar system was born. A collision in deep space threw this piece
toward Earth - and into what would become Stegora's back yard.
What he didn't realize was that his rock was valuable. Scientists and
private meteorite dealers would be willing to pay tens of thousands of
dollars for it.
The tale of Stegora's rock began when he unearthed it with a backhoe while
digging for a sewer connection.
The rock, about a foot long, a foot tall and 8 inches wide, came up with a
scoop of sandy soil, but Stegora didn't notice it.
The following year, as he was finishing the project in his yard, he came
across the lumpy black rock, which weighed as much as a small adult.
He lugged it over to his doorstep and left it there for five years, he said,
hoping "somebody would see it and tell me what it was."
It was clear from its weight and the ringing sound it made when rapped with
a screwdriver that it was metal. The outside was rough, scorched and melted.
Butt of jokes
Stegora eventually moved it into his garage to get it out of the way. It sat
there for seven years and served as a curiosity and butt of jokes for
friends and relatives.
About a year ago a friend at work, Leo Winkleman, began urging Stegora to
find out what the rock really was.
"All of a sudden it was time to start looking into it," Stegora said. "I
needed somebody who knew about iron and metal rocks."
On the advice of a friend of a friend, he called Robert Pepin,
University of Minnesota geophysicist and planetary scientist.
Pepin, a researcher who keeps pieces of Mars and the moon in his
office, was just the right scientist. He told Stegora to saw off
a
corner and send it to him. Two hacksaw blades later (iron
meteorites are extremely hard) Stegora delivered a piece to Pepin.
A quick look through a mass spectrometer revealed "it was clearly
a
meteor," Pepin said. He sent it to the lab of John Wasson at the
University of California, Los Angeles. Wasson, a professor of
geochemistry, is regarded as the world's leading expert on
meteorites.
He told Pepin, in so many words, to grab it for museums and research. Metal
asteroids such as Stegora's are vital to researchers who want to study the
origins of the solar system about 5 billion years ago.
The ultimate core sample
"Metallic meteorites are usually asteroidal cores," or the metal cores from
large asteroids created in the earliest days of the solar system. And they
are the only core material available, "because we can't get the cores of
planets or large bodies," Wasson said.
His detailed tests revealed something else that scientists hadn't expected -
in chemistry and composition, Stegora's rock was an exact match with a
3-pound metal meteorite dug up by a farmer 4 miles north of Anoka in 1961.
It was clear, Pepin said, that Stegora's rock is a larger piece of the same
meteoroid that must have broken into pieces after entered the Earth's
atmosphere. The earlier, smaller find is listed as the Anoka Meteorite in
meteorite catalogues.
"Finding two pieces like this means this is probably close to where it
fell," Pepin said. "There are probably tons of it scattered around out
there."
Meanwhile, Stegora's friend, Winkleman, had put out word of the meteorite on
the Internet along with Stegora's phone number. A dealer from New York
called, and sight unseen said it was worth between $25,000 and $50,000.
Stegora was amazed at the amounts of money being discussed, but when he
found out that the dealer would chop the rock into little pieces and sell
them, he backed away from the deal.
"I really wanted to keep this in Minnesota," he said. "One of my main
concerns was that people be able to see it. I didn't want it chopped up at
all."
Making the deal
Wasson immediately began putting together a consortium of universities and
museums to buy the rock before a dealer could persuade Stegora to sell.
"We as scientists should do as much as we can to get material like this into
museums," he said. "A new iron meteorite is found about once every two
years, and once you've asphalted over the countryside (with development),
they will be harder to find."
Wasson convinced the Field Museum of Chicago, the Smithsonian Institution in
Washington, D.C., Harvard University, the British Museum in England, and his
own institution, UCLA, to chip in funds totaling $38,000.
But there were two problems with his deal. The $38,000 was probably less
than Stegora could get on the open market, and each of the contributors
wanted a piece of the rock, but Stegora wasn't inclined to cut it up.
Pepin negotiated an agreement in which the meteorite would be cut into large
slices, one going to each of the consortium members that agreed to put it on
public display - something Stegora wanted. Another slice would remain at the
University of Minnesota for no cost, sort of a handling fee for Pepin's
work. Another piece would go to scientists for immediate study, and a final
piece would be polished and given to Stegora and his family.
Wasson couldn't meet the probable market value, believed to be about $42,000
or $43,000, but he came close enough.
Stegora agreed to the deal. On Monday morning he turned the meteorite over
to Pepin and was handed the $38,000 check.
"It wasn't the money I was after," Stegora said. "It was making sure it got
displayed for my family. This way more people will see it, and some kid in
the future may see it and be inspired by it." Stegora, who is divorced, has
three children, ranging in age from 16 to 21.
He wanted the meteorite to be named Isis after the Egyptian goddess of
fertility ("It sounded nice," he said). But there are rules about that.
Meteorites have to be named after a permanent geological feature or location
near where they fall, so this rock will be named Anoka II or something
equally uninspired, Pepin said.
The last problem Stegora faces with his manna from heaven is figuring out
how to pay taxes on it. Repeated questions to the Internal Revenue Service
(IRS) have generated much laughter by normally staid revenue agents and
discussions about everything from "windfall profits" to "income from mineral
rights."
The IRS informed Stegora that the official ruling will arrive in his mail
today.
Rock show
Stegora's meteorite will be on display beginning at noon today at the
Weisman Art Museum, 333 E. River Rd., on the main campus of the University
of Minnesota. The meteorite will be at the museum for about a month.
Admission is free. For more information, call 625-9494.
>From meteoroid to meteorite
Terminology
Technically speaking, a meteorite is a meteroid that has landed. A meteor is
a luminous streak produced when a meteoroid enters Earth's atmosphere.
Classes
Meteorites are nickel-irons, silcate minerals or mixture of both. They are
classified according to their composition:
- Aerolites, or stones, are mostly silicate minerals with some nickel-iron.
They are subgrouped into chrondites or achrondrites, depending on whether
they contain chrondri, an aggregate of olivine and/or pyroxene.
- Siderolites (stony-irons) are composed, on average, of 50 percent
nickel-iron and 50 percent silicates.
- Siderites (irons) are primariloy made of nickel-iron.
Breaking up
Extreme pressure and heat on the front surface cause many meteoroids to
break up into smaller pieces, resulting in a meteor shower. The larger,
heavier pieces travel farther than smaller pieces, causing a dispersion
ellipse on the ground.
Speed
The speed of a meteor depends upon its cosmic velocity (the speed of its
orbit around the sun) and whether it's travling with or against Earth's
orbit. Its speed as it hits Earth's atmosphere can range from 7.4 miles per
second to 43.5 miles per second.
Earth's atmosphere rapidly slows small and medium-sized meteoroids to the
point that they lose their cosmic velocity and literally fall to Earth by
the force of gravity. Those that aren't burned up in the process strike
Earth at speeds ranging from 330 to 660 feet per second.
Size
Meteors result from objects that range in size from dust particles to many
tons. The white, hairline streak that shoots across the night sky is
produced by a meteroid no larger than a grain of sand. Those that produce
fireballs may be no larger than a baseball.
Meteoroids that are five or six feet across and weigh several tons can
survive a fiery fall through the atmosphere, but rarely do much damage when
they hit. Very large meteorites and asteroids, rangeing from a few hundred
feet to a few miles across, cause cataclysmic destruction when they hit.
The asteroid believed to have hit in the Yucatan Peninsula 65 million years
ago is estimated to have been six miles wide. The impact first heated much
of the Earth's surface to about 600 degrees Fahrenheit, then shrouded the
planet in ash, dust and smoke, creating months of darkness and cold. Its
impact is believed to have wiped out 65 percent of all species on Earth,
including the dinosaurs.
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