[meteorite-list] Building Blocks of Life Formed on Mars (ALH84001)

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Wed, 12 Dec 2007 11:26:32 -0800 (PST)
Message-ID: <200712121926.LAA25610_at_zagami.jpl.nasa.gov>

  
http://www.ciw.edu/news/building_blocks_life_formed_mars

Building blocks of life formed on Mars
Carnegie Institution for Science
December 11, 2007

Washington, DC - Organic compounds contain carbon and hydrogen and form
the building blocks of all life on Earth. By analyzing organic material
and minerals in the Martian meteorite Allan Hills 84001, scientists at
the Carnegie Institution's Geophysical Laboratory have shown for the
first time that building blocks of life formed on Mars early in its
history. Previously, scientists have thought that organic material in
ALH 84001 was brought to Mars by meteorite impacts or more speculatively
originated from ancient Martian microbes.

The Carnegie-led team made a comprehensive study of the ALH 84001
meteorite and compared the results with data from related rocks found on
Svalbard, Norway. The Svalbard samples occur in volcanoes that erupted
in a freezing Arctic climate about 1 million years ago - possibly
mimicking conditions on early Mars.

"Organic material occurs within tiny spheres of carbonate minerals in
both the Martian and Earth rocks," explained Andrew Steele, lead author
of the study. "We found that the organic material is closely associated
with the iron oxide mineral magnetite, which is the key to understanding
how these compounds formed."

The organic material in the rocks from Svalbard formed when volcanoes
erupted under freezing conditions. During cooling, magnetite acted as a
catalyst to form organic compounds from fluids rich in carbon dioxide
(CO2) and water (H2O). This event occurred under conditions where no
forms of life are likely to exist. The similar association of carbonate,
magnetite and organic material in the Martian meteorite ALH 84001 is
very compelling and shows that the organic material did not originate
from Martian life forms but formed directly from chemical reactions
within the rock. This is the first study to show that Mars is capable of
forming organic compounds at all.

The organic material in the Allan Hills meteorite may have formed during
two different events. The first, similar to the Svalbard samples, was
during rapid cooling of fluids on Mars. A second event produced organic
material from carbonate minerals during impact ejection of ALH 84001
from Mars.

"The results of this study show that volcanic activity in a freezing
climate can produce organic compounds," remarked co-author Hans E.F.
Amundsen from Earth and Planetary Exploration Services. "This implies
that building blocks of life can form on cold rocky planets throughout
the Universe."

"Our finding sets the stage for the Mars Science Laboratory (MSL)
mission in 2009," remarked Steele, who is a member of the Sample
Analysis on Mars (SAM) instrument team onboard MSL. "We now know that
Mars can produce organic compounds. Part of the mission's goal is to
identify organic compounds, their sources, and to detect molecules
relevant to life. We know that they are there. We just have to find them."

The research is published in Meteoritics & Planetary Science
http://meteoritics.org/index.htm

For more information on the MSL mission and the SAM instrument see
http://mars.jpl.nasa.gov/msl/ and http://ael.gsfc.nasa.gov/marsSAM.shtml

_________________

This research was funded by NASA SRLIDA, ASTEP, NAI and ASTID programs;
the Marshall Scholarship program; and the University of Oxford, Earth
Sciences Department and was carried out in collaboration with the Arctic
Mars Analog Svalbard Expedition (AMASE) project.
Received on Wed 12 Dec 2007 02:26:32 PM PST