[meteorite-list] Ice Diary Encore: Thawing Out

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Apr 22 10:25:37 2004
Message-ID: <200305081932.MAA13669_at_zagami.jpl.nasa.gov>

http://www.astrobio.net/news/modules.php?op=modload&name=News&file=article&sid=454&mode=thread&order=0&thold=0

Ice Diary Encore: Thawing Out
Astrobiology Magazine
May 8, 2003

Summary: The Ice Diary series explores the adventures of a dedicated
group of meteor hunters. The National Science Foundation, NASA and
the Smithsonian collect and curate extraterrestrial samples scoured
from the South Pole. The diary entries provide a personal tour of a
recent expedition, with all the immediacy of being there.

Ice Diary Encore

Thawing Out

Caldwell, a science teacher at Douglas County High School in Castle Rock,
Colorado, joined the Teachers Experience Antarctica (TEA) program and
accompanied members of the Antarctic Search for Meteorites program (ANSMET)
last winter.

"Part of my philosophy of teaching is to show students that science is an
adventure," says Caldwell. "Aside from visiting another planet, I can't
think of a much larger adventure than traveling to Antarctica."

Caldwell and his fellow explorers arrived ready to seek out meteorites amid
the snow and ice fields of Antarctica's vast wilderness. From the permanent
base in McMurdo, the team flew to the ancient Beardmore Glacier. They then
traveled by snowmobile 60 kilometers south to the Goodwin Nunataks. After a
week of meteorite discoveries, they traversed to MacAlpine Hills. There they
hit the "mother lode," recovering more than 100 meteorites in a single day.

Fresh from his season in Antarctica, Andy Caldwell answers questions about
his experiences in the field and his goals for the future.

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Q: What did you miss the most about modern life while you were living in
Antarctica?

In all honesty, we missed very little from modern life. Of course we had
conversations about missing showers, pizza, and other "beverages," but for
the most part we had a number of fairly modern conveniences. We had a
satellite telephone, that, although expensive, allowed us to call home on
occasion. We had an HF radio that allowed us to communicate with McMurdo
station. We brought DVDs that we played on computers on bad weather days,
plus games (both card games and video). I did occasionally have dreams that
I was driving my truck. I wasn't going anyplace specific, just driving.

Q: Was there anything that you thought you'd have a hard time living
without, but when the time came, you found it wasn't necessary?

This is kind of pathetic, but I'm a die-hard Denver Broncos fan. I couldn't
imagine leaving in the middle of the season. I caught a couple of games on
Armed Forces Television at McMurdo, and got highlights from one of the other
scientists who called home every Monday to see what happened around the
league. By the end of the field season, though, I completely forgot that
they played.

Q: What was the most thrilling moment of the expedition?

It's hard to single out one. It was great finding each meteorite, seeing the
steam rising from Mt. Erebus, the world's southernmost active volcano, or
walking through the hut constructed by Captain Robert F. Scott at Cape
Evans. But I think my favorite moments came when we climbed the small peaks
in the Trans-Antarctic Mountains. We were probably the first people to reach
the summit and the first to see the vistas from the peaks. In Colorado,
you're lucky if you're the first one up that day! It was like being on
another planet and being the first to experience it.

Q: Were you ever frightened?

Overall, I had complete confidence in our mountaineer and the Air National
Guard servicemen who deployed us in the field. But there was a hairy moment
on our last traverse. I was following our mountaineer, Jamie Pierce, in
single file as we made our way across the Beardmore Glacier back to the camp
where the LC-130 was scheduled to pick us up. I saw the snow collapsing in
small pits behind Jamie's ski-doo and realized we were in a crevasse field.
Although we were careful about steering around most of the crevasses, we
couldn't spot every one. It's kind of like a minefield. There were
definitely moments I was worried about plunging into one.

Q: The Antarctic Meteorite Newsletter says that the final tally for your
group was 607 meteorites - will you be kept apprised of the scientific
findings regarding these rocks?

I hope so. The meteorites just arrived recently at the Johnson Space Center.
They will take the next few months to check them out. They will start with
the ones we labeled in the field notes as "interesting." After that, the
meteorites are sent to the Smithsonian for final analysis. This usually
takes a couple of years. At that time, a newsletter is sent to all meteorite
scientists describing each one, in case they would like to request a sample
or thin section for analysis. It could be years until we find if any of them
were significant.

Q: Do you have any valued "souvenirs" from your Antarctic experience?

We were not allowed to keep any of the meteorites for ourselves. And that's
OK, because you never know if that one will hold clues to the origin of the
Solar System or the origins of life. I did bring back t-shirts, hats-- the
usual from McMurdo. But my photographs are my best souvenirs. I was relieved
when I got my film developed. This is kind of sappy, but the friendships I
made with my teammates will last a lifetime.

Q: What were the first things you did after you got back from Antarctica?

I had a few days in New Zealand, so I got a haircut and beard trim right
away. When I got home, I couldn't wait to visit a restaurant known for its
ribs. I had to jump back into teaching almost right away, so on the way
home, I prepared a PowerPoint presentation on Antarctica for my students.
This gave me a chance to get my lesson plans together and get the students
fired up for the semester.

Q: Has your experience in Antarctica changed your outlook or perceptions in
any way?

Absolutely, but it's really hard to put into words. There's a phrase down
there, "Everybody needs a little Antarctica." I think I feel a little more
humbled than before. A local newspaper misquoted me recently saying that I
said, "(after this experience) I can do anything!" I don't feel that way at
all. In fact, for the first time in my life, I don't feel I have to top this
experience. I like to climb Colorado's mountains and go backpacking in the
wilderness. But now I want to do these activities for the experience, not to
climb higher than before or hike further than before.

Q: What are your plans for the future? Would you go back to Antarctica for
another meteorite-hunting expedition?

In the near future, I want to do a lot with my students. I have them
involved with a project sponsored by the Denver Museum of Nature and Science
called the All Sky Camera Network. This is a group of a dozen schools around
Colorado that have digital cameras trained on a curved mirror that are
trying to spot bolide events. When linked and triangulated, we hope to trace
these events and recover the meteorites if any make it to the ground. We
have caught several this year and hope to do field searches this summer.
It's great to get students involved in this type of authentic research.

As far as going back to Antarctica, I would love to, of course. However, the
competition is fierce to become an ANSMET member. I didn't realize this
until recently when I attended the Lunar and Planetary Conference and saw
how many qualified scientists wanted to go. The TEA program that sent me is
a one time only deal. TEA is sponsored by the National Science Foundation,
and they paid all my expenses so that I wasn't a burden on my research team.
If I went again, ANSMET would have to cover the costs of a substitute for my
classes, plus any other fees. ANSMET is planning on taking someone from the
Artists and Writers program in the future.

An astronaut on our team is trying to convince me to apply to NASA's
Educator Astronaut program. While I'm honored that she thinks I'm qualified,
I need some time to think about it. I'd like to spend some time with my
students and try to be a better teacher here.

What's Next

Linda Welzenbach, one of the ANSMET team members, described in an Ice Diary
entry what happens to the meteorites once they arrive at Johnson Space
Center (JSC):

[The meteorites are kept in cabinets that are] filled with Nitrogen gas,
which is used to dry out any ice or snow that adhered to the meteorites when
they were collected.

The gas also keeps out moisture, salts, metals, and organic compounds for as
long as the meteorites remain stored in that environment. After they've been
thawed and dried, they are weighed, described, photographed, and given a
name.

After NASA has cataloged the meteorite, they remove a few grams and send it
to me at the Smithsonian for identification and description. I conduct a
macroscopic investigation of the chips, separating out the unique
chondrites, achondrites, and irons for in-depth analyses, while the rest of
the ordinary chondrites are set aside to be classified using standard
optical mineralogy methods.

[The meteorite samples we select for in-depth analyses] go to our Polished
Thin Section preparer, who will take the chip, impregnate it with epoxy,
glue it to an inch-round glass slide, cut off most of the sample, and grind
the remainder down to the a thickness of 30 to 40 microns. At this thickness
you can see through the rock. When placed under a microscope, you see a
kaleidoscopic view of all of the individual minerals. Using an Electron
Microprobe, you can find out the chemical make-up of the individual mineral
crystals.

For the ordinary chondrites, we remove a small piece from the chip for
classification using a petrographic microscope. We grind the tiny sample
into a powder (tiny mineral crystals) and immerse them in special optical
oils on a glass slide. Our observation of optical effects that occur between
the crystal and the oil tell us something about the iron content of the
mineral.

When all the meteorites are classified, we send the data back to JSC, where
it will be published in the Antarctic Meteorite Newsletter. Scientists all
over the globe will read it to find out about the new meteorite samples
available for research. NASA handles the scientist's requests for samples:
there are up to 75 per year for an average of 600 samples. In the 26 years
the program has been operating, over 300 investigators from 24 nations have
received over 10,000 samples.

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Since 1976, the Antarctic Search for Meteorites program (ANSMET),
funded by the Office of Polar Programs of the National Science
Foundation, has recovered more than 10,000 specimens from meteorite
stranding surfaces along the Transantarctic Mountains. Dr. Ralph Harvey and
John Schutt are members of each field party, serving as ANSMET continues to
be one of the few Antarctic research projects that invites graduate students
and senior researchers from other institutions to participate in our field
work on a volunteer basis--including the Teacher Experiencing Antarctica
(TEA) program. As a multi-agency collaboration, the NSF supports field
operations, NASA supports storage curation, distribution and notification of
recovered samples, and the Smithsonian provides long term curation
facilities for the collection and assist in sample characterization.

In this multi-part Ice Diary series, all commentary is attributed to Andy
Caldwell unless otherwise noted, and reprinted by permission as part of his
participation in the TEA program.
Received on Thu 08 May 2003 03:32:18 PM PDT