Martian Meteorite/Dr. Romanek

From: Jan Wee <>
Subject: Martian Meteorite/Dr. Romanek
Date: Sat, 07 Dec 1996 07:32:37 -0600

Discuss-lfm members,  

This Press Release from early August may be of interest to
you -- it was sent to me by Erich Landstrom, planetarium director.

Thanks Erich!

Jan Wee




ATHENS, Ga. -- A geochemist at the University of Georgia who
worked on the meteorite which researchers say may contain signs
of microscopic life on Mars says he has no doubts that a crucial
link in the chain of evidence is scientifically sound.

Dr. Christopher Romanek, now of UGA's Savannah River Ecology
Laboratory in Aiken, S.C., said that he is convinced carbonates
found inside the meteorite were formed at low enough
temperatures for life to have flourished around it on Mars.
Romanek, a co-author on the paper to be published in the Aug. 16
issue of the journal Science, performed much of the early
isotope analysis of the meteorite.

"I feel very confident about it because we have several lines of
evidence for the origin of the material," said Romanek.
"Comparing the isotopic composition of the carbonate 'globs' to
the surrounding matrix material clearly points to a
low-temperature origin."

The evidence for low-temperature formation of the meteorite is
vital to the theory, proposed by NASA scientists at a press
conference in Washington on Aug. 7, that primitive microscopic
life may have existed on Mars. The meteorite, known as Alan
Hills 84001, was found in Antarctica some 13 years ago. It was
formed on Mars 4.6 billion years ago and, according to the paper
in Science, became covered with microorganisms between 3.6
billion and 4 billion years ago.

The researchers believe that about 16 million years ago, a comet
or asteroid struck the Martian surface and blasted pieces of
rock into space, where they drifted for millions of years. The
meteorite, found in Antarctica, in 1984 fell to Earth about
13,000 years ago.

Romanek's involvement in the process occurred because of a
chance encounter with the meteorite  at the Johnson Space Center
in Houston, where he was working on a two-year postdoctoral
fellowship. His lab was near that of Lockheed-Martin researcher
Dr. David Mittlefehldt, an expert on meteorites. Mittlefehldt
had been working on the Alan Hills meteorite when he began to
notice that it possessed some unusual characteristics.

"He had been working on meteorites called diogenites, but he
realized that this particular meteorite had more in common with
other known Martian meteorites," said Romanek. "So he sent some
of the material to Dr. Bob Clayton, a preeminent isotope
geochemist at the University of Chicago for oxygen isotpe

Clayton examined the rock and confirmed that it is consistent
with a Martian origin. At that point, Mittlefehldt began to
study the meteorite more in depth, using such techniques as
electron-beam microprobe analysis. Realizing that the samples
were truly unusual in nature, Mittlefehldt walked across the
hall and asked Romanek if he would come take a look at what he
was seeing.

Romanek became involved with the project almost immediately,
looking at unusual carbonate spheroids or "globs," as they came
to be called. He was able to separate some of them from the
meteorite and began to analyze them using conventional
techniques to look for stable isotope ratios. The spheroids, as
it turned out, are composed of magnesium, iron and calcium, but
they all contain carbon and oxygen as well, and Romanek
specifically wanted to look at their isotopic signatures.

"What I found was that the samples were extremely enriched in
carbon 13 compared to materials on Earth," said Romanek. "So it
was clear it wasn't terrestrial; however the signature was
nearly identical for the 'fingerprint' that has been proposed
for the carbon dioxide of Mars. Using other models of the
isotope record, I concluded that these spheroids must have
formed between zero and 80 degrees Celsius."

Armed with this information, Romanek went to NASA scientist
Everett Gibson and said that an in-depth investigation of the
meteorite was urgent because of what he and Mittlefehldt had
found. Gibson, in turn, took the evidence to NASA microscopy
expert  David McKay, who found the samples fascinating.

As the project accelerated in intensity, it changed its focus
from being about geochemical processes to the search for
evidence of life. In the meantime, Romanek wrote a paper about
his findings which was published in a 1994 edition of  issue of
Nature, the prestigious British science journal. (Editors:
Volume 372, p. 655.)

"At this point, it was no longer an isotope problem but a
microscope problem," said Romanek, who left NASA about two years
ago to join the University of Georgia's Savannah River Ecology
Laboratory. Still, he has stayed involved with the project,
spending several weeks at a time at the Johnson Space Center in
Houston. He has also talked nearly weekly on the phone with
Gibson or Kathie Thomas-Keprta of Lockheed-Martin in Houston,
also part of the team studying the meteorite.

Did Romanek ever have a "eureka" moment when he realized the
possible magnitude of  the discovery?

"Absolutely -- every time the team had a scanning electron
microscope session," he said. "We were looking at this material
at a resolution that not a lot of people have used before in
this way. And we had to be so careful about what we were seeing.
Were they artifacts that didn't originate on the rock? Were they
dust grains? All of this had to be addressed in highly
constrained experiments. This kind of checking is invaluable,
but it takes a long time to do."

Romanek praised the review process for the upcoming Science
article, saying that it was intensely rigorous and done by
influential scientists who sent many questions and suggestions
for revision. The paper, in fact, was revised numerous times
before it was finally accepted by Science for publication.

Romanek was part of a news conference in Washington on Aug. 7 at
which panel members strongly defended their conclusions in the
Science paper. While the research was met with praise in many
quarters, it was also met with caution, including that of UCLA's
Dr. William Schopf, who had been invited to the session and
called the findings "preliminary."

Romanek will be included on future work with the meteorite.
McKay said the team hopes to find evidence of membranes or cell
walls in the sample, as well as the possible presence of amino
acids, which are the building blocks of proteins.

So far, 12 meteorites found on Earth have been determined to
have originated on Mars.


WRITER:  Phil Williams,  706/542-8501,