[meteorite-list] Relic of Life in that Martian Meteorite? A Fresh Look (ALH84001)

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Wed Mar 22 21:17:40 2006
Message-ID: <200603221819.k2MIJcp23337_at_zagami.jpl.nasa.gov>

http://www.eurekalert.org/pub_releases/2006-03/ci-rol032206.php

Public release date: 22-Mar-2006

Contact: Marc Fries
m.fries_at_gl.ciw.edu
202-478-8993
Carnegie Institution

Relic of life in that Martian meteorite? A fresh look

Since the mid-1990s a great debate has raged over whether organic
compounds and tiny globules of carbonate minerals imbedded in the
Martian meteorite Allan Hills 84001 were processed by living creatures
from the Red Planet. The materials have been under intense scrutiny ever
since. Scientists at the Carnegie Institution's Geophysical Laboratory,
with colleagues,1 have taken a fresh look at how material associated
with carbonate globules was created using sophisticated instrumentation
and they compared the results to analogous globules from a volcanic
complex on Svalbard, an island north of Norway. It does not appear that
living organisms were at work. The research is presented at NASA's
Astrobiology Science Conference (AbSciCon) 2006 at the Ronald Reagan
Building in Washington, D.C. March 26-30. See
http://abscicon2006.arc.nasa.gov/ for details.

To some, the tiny carbonate globules from the meteorite seem to resemble
minerals that arise from microbial activity on Earth. The team focused
on whether macromolecular carbon (MMC) in and around the globules was
processed organically or not--an unresolved issue. The team had a
complete depth profile of the meteorite. Lead author Andrew Steele
explained, "By using micro-Raman spectroscopy and a scanning electron
microscope we could detect both the structure of the minerals and the
forms of carbon present. We did a similar analysis on carbonate globules
from Earth in terrain analogous to Mars--the Bockjord Volcanic Complex
on Svalbard--for comparison."

The researchers found that the macromolecular carbon is always
associated with the mineral magnetite. This association is important
because magnetite is known to act as a catalyst in the formation of MMC.
Macromolecular carbon present within the carbonate globules in ALH84001
may represent the first evidence of non-biological synthesis of organic
molecules on Mars.

"Although we haven't settled the debate on whether evidence of life is
contained in Allan Hills, we have shown that these carbon complexes
likely formed by non-biological processing on Mars," concluded Steele.

###

Talk and poster schedule subject to change. See
http://abscicon2006.arc.nasa.gov/agenda.php for the latest information.

[1] Andrew Steele, et al., "A comprehensive imaging and Raman spectroscopy
study of ALH84001 and a terrestrial analogue from Svalbard"
Monday, March 27th, 10:15 am
Ronald Reagan Building, Horizon A & B, Session 3: Cold Mars Analogue
Environments

*The research was part of the Arctic Mars Analog Svalbard Expedition
(AMASE). Researchers come from the following institutions: lead
institution, Physics of Geological Processes, University of Oslo; The
Carnegie Institution of Washington, Geophysical Laboratory and
Department of Terrestrial Magnetism; NASA Jet Propulsion Laboratory;
University of Leeds; University of Oxford; Universidad de Burgos, Spain;
The Smithsonian Institution; Penn State University; Geological
Institute, University of Oslo and Idaho National Laboratory.

The Carnegie Institution of Washington (www.CarnegieInstitution.org)
has been a pioneering force in basic scientific research since 1902.
It is a private, nonprofit organization with six research departments
throughout the U.S. Carnegie scientists are leaders in plant biology,
developmental biology, astronomy, materials science, global ecology,
and Earth and planetary science.

This work is supported by the NASA Astrobiology Institute (NAI). The
NAI, founded in 1998, is a partnership between NASA, 16 major U.S. teams
and six international consortia. NAI's goal is to promote, conduct, and
lead integrated multidisciplinary astrobiology research and to train a
new generation of astrobiology researchers. For more information about
the NAI on the Internet, visit: http://nai.nasa.gov/

 
Received on Wed 22 Mar 2006 01:19:38 PM PST