[meteorite-list] Compelling Evidence Found For Ancient Life On Mars

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Apr 22 09:37:34 2004
Message-ID: <200012131628.IAA08699_at_zagami.jpl.nasa.gov>

Iowa State University

Contacts:
Dennis Bazylinski, Microbiology, (515) 294-2561
Teddi Barron, News Service, (515) 294-4778

December 12, 2000

ISU SCIENTIST ON TEAM THAT FINDS COMPELLING EVIDENCE OF ANCIENT LIFE ON MARS

AMES, Iowa -- An Iowa State University professor is part of a research team
that has found compelling evidence that Mars once supported primitive life.

The researchers discovered evidence of bacteria in a Martian meteorite. Tiny
magnetite crystals -- so called magnetofossils -- embedded in the meteorite
were confirmed to be the type produced only by a biological process unique
to magnetotactic bacteria.

Dennis Bazylinski, associate professor of microbiology, was one of nine
researchers conducting the four-year investigation, which was funded by
NASA's Astrobiology Institute. A report of their research is in the December
issue of the scientific journal, "Geochimica et Cosmochimica Acta."
[http://www.elsevier.nl/cgi-bin/cas/tree/store/gca/cas_sub/browse/browse.cgi?year=2000&volume=64&issue=23&aid=2555]

"Finding these type of magnetic crystals in any material from another planet
is an amazing and important finding," said Bazylinski. He leads one of the
few labs capable of culturing these magnet-producing bacteria, which are
common in many freshwater and marine environments on Earth.

The researchers studied the magnetite crystals that were located in
carbonates in the Martian meteorite. The 4.5 billion year-old meteorite
was found in Antarctica in 1984. Earlier research has confirmed that the
carbonates formed on Mars, signaling that the magnetite crystals also
were formed on Mars.

Magnetite crystals produced by magnetotactic bacteria are chemically
pure and generally defect free and have a distinctive size and shape.
Their properties are so unusual that they have only been seen in magnetite
crystals produced through biological processes by organisms.

The researchers discovered that about one-fourth of the magnetites in
the meteorite are identical to the magnetites produced by a strain of
magnetotactic bacteria called MV-1, which have been isolated and studied
extensively by Bazylinski.

"There is currently no known chemical means of producing these magnetite
crystals with their unique morphologies," Bazylinski said. "The significance
to astrobiology and geobiology is that many scientists have been searching
for 'biomarkers' for life, that is, chemical, isotopic, and/or mineral
indications that life was present, either in extreme habitats or in ancient
materials on Earth and, of course, now in extraterrestrial materials. The
need for biomarkers is obvious and these magnetite crystals might prove
to be an excellent biomarker."

Since the team began the research in 1996, observations from the Mars
Global Surveyor have indicated that Mars had a strong magnetic field at
about time that the carbonate containing the unique magnetites was formed.

"Now we are trying to answer the question of whether magnetotactic
bacteria could have actually lived on Mars," Bazylinski said. "And we have
found certain aspects of their metabolism which suggest that they might
have been able to do so."

The journal "Science" recently published research showing evidence of
widespread sediment layers on Mars, which the researchers interpret to
be the product of many lakes. Because these lakes may have provided a
habitat for magnetotactic bacteria, this finding supports the possibility
that the bacteria may have existed on Mars, Bazylinski said.

In addition to Bazylinski, the scientists are Kathie Thomas-Keprta, Simon
Clemett, and Susan Wentworth, Lockheed Martin at Johnson Space Center;
David McKay and Everett Gibson, NASA/JSC; Joseph Kirschvink, California
Institute of Technology; H. Vali, McGill University, Montreal; and Christopher
Romanek, Savannah River Ecology Laboratory.

-30-

Note to Editors: A jpeg photo of Bazylinksi is available by e-mailing
tbarron_at_iastate.edu .
Received on Wed 13 Dec 2000 11:28:27 AM PST