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Martian Meteorite Contains No Biological Life, Research Team Says

Office of University Communication
Case Western Reserve University
Cleveland, OH

Contact: Susan Griffith, 216-368-1004, sbg4@po.cwru.edu

12/4/97

MARTIAN METEORITE CONTAINS NO BIOLOGICAL LIFE, RESEARCH TEAM SAYS

December 4 Nature article offers point-counterpoint approach to controversy

The famous Martian meteorite, ALH84001, contains no biological life forms,
according to a Case Western Reserve University researcher and
colleagues.

The team issues this report in the December 4 issue of Nature, duplicating
the methods of a team of scientists from the Johnson Space Center and
Stanford University. In rare counterpoint writings in the "Scientific
Correspondence" section, Nature allowed the Johnson Space Center
team to respond to the group's findings. This paper also appears in the
December 4 issue.

CWRU's Ralph Harvey, senior research associate in the Department of
Geological Sciences, was on the research team. The lead researcher on
the paper was John Bradley from MVA Inc. and the School of Material
Science and Engineering at Georgia Institute of Technology. The third
researcher is Hap McSween from the University of Tennessee.

The trio reports that most of the purported nanofossils or "worm-like
images" are nothing more than lamellae, or fractured surfaces of pyroxene
and carbonate crystals.

Last year, the Johnson-Stanford team announced it found evidence of
nanofossils in the meteorite. Reports of life on Mars spurred the July 4
mission to Mars to look for further evidence of life.

Allan Hills 84001 -- a meteorite the size of a potato -- remains in the
center of a spirited controversy about the possibility of life on Mars. The
meteorite was found in the 1980s in Antarctica by the National Science
Foundation's Antarctic Search for Meteorite Program (ANSMET), headed
by Harvey with headquarters at CWRU.

A Web page offers details on ANSMET, including a link to more information
on the meteorite. To view these resources, visit
http://www.cwru.edu/artsci/geol/ansmet/index.html.

Harvey, who is currently on his annual expedition to Antarctica to collect
meteorites, commented before leaving November 21 that the Johnson-
Stanford team has always argued that they had used different techniques
to study the meteorite.

Bradley, Harvey, and McSween published a paper last year in Geochimica
et Cosmochimica Acta (GCA), announcing that what the other researchers
observed was formed geologically, not biologically. The Johnson-Stanford
group also announced that these nanofossils were lying on the surface of
the meteorite.

In the first GCA study, which used transmission electron microscope
imagining (TEM), the researchers found non-biological magnetite whiskers
on or near the surfaces of the carbonates. Superficially the whiskers look
like worms, but in fact they have nothing to do with biological processes,
according to Harvey and colleagues.

The latest study took place over the past six months as the researchers
re-examined the meteorite using the new techniques. This time they found
yet another population of worm-like forms that are actually mineral
lamellae formed by non-biological, geological processes. The lamellae
look like worms or nanofossils, but when the specimen is tilted and viewed
from another angle, it clearly shows that the lamellae are attached and
part of the mineral surfaces.

"The surface topography is highly irregular on a nanometre scale, with
emergent lamellae following the major cleavage direction of the substrate,"
Bradley writes in the paper. The researchers have published pictures of
the TEM images to support their findings.

"Peculiar surface structures or segmentation on the worm-like forms are
artifacts from conductive metal coatings applied to the samples for imaging
in the electron microscope. This is not the first time metal coating
artifacts have lead to misidentification of nanofossils in rocks," Bradley
said.

"We have now found two different types of mineral forms in ALH84001
that look just like nanofossils, but they are strictly non-biological origins.
Sometimes even nature has a perverse sense of humor," he added.

Harvey stressed that during this latest study, the team was careful to use
exactly the same methods as the Johnson-Stanford group to lay to rest
any arguments that the research methods had affected the findings.

The worm-like mineral lamellae are commonly found at the fractured
surfaces of planar crystals. Harvey noted that lunar rocks -- in which there
has been no evidence of life found -- contain these same formations.

Does this put an end to the life on Mars debate? "We haven't driven the
final nail in the coffin yet about organisms in this Martian rock, but our
latest article offers a lot of insight that shows these fractures zones in
the rock are incredibly complex," Harvey said, "and that it is very
dangerous to try to draw any hypothesis from a few pictures from here
or there."
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