Building blocks of life formed on Mars

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