ongoing question as to why scientists cannot find organic material on
the surface of Mars may be answered after all.Published in
the journal Astrobiology, the article is titled
"Photocatalytic Decomposition of Carboxylated Molecules on
Light-Exposed Martian Regolith and its Relation to Methane Production
on Mars." Written by Ilya Shkrob, Sergey Chemerisov, and Timothy
Marin, from Argonne National Laboratory and Benedictine University in
Illinois, the three conclude that there may be no 'safe haven' for
such organic molecules on Mars.On Earth, plant-like organisms
use photosynthesis to covert carbon and water into carbon dioxide.
However, the opposite is proposed to happen on mars. The iron oxides,
well known for giving the planet its red color, are
photocatalysts. They use the ultraviolet light, absorbed through the
Mars' thin atmosphere, as energy to oxidize organic compounds trapped
in soil particles, thereby converting them to gases such as carbon
dioxide and methane."This is an interesting result and
may be an important step in solving the enduring mystery of organics
on Mars," says Christopher McKay, "We see organics in many
places in the solar system but have not been able to detect them on
Mars--the planet that we think had the most Earth-like conditions.
Why? Could it be our instrument approach has been wrong? Or could it
be that there is some chemistry on Mars that is actively destroying
organics? This work points toward this latter explanation."
goes on to explain that Mars might have, in fact, a self cleaning
surface, which means to find any evidence of carbon-containing
molecules, astronauts will have to dig deep. McKay is the Senior
Editor of Astrobiology and a Research Scientist at NASA Ames Research
authors suggest that instead of looking for organic organisms to
prove life on Mars, other methods for determining life may have to be
employed. In essence, many have been looking for something (proteins,
amino acids, organic compounds) that was never there to begin with.
It is now reasonable to suggest deep drilling tactics, that will
dig up rocks and soils that have retained the preserved organics.
With this new study, many hope we are one step closer to determining
if life is, or ever was, present on the Martian planet.Astrobiology
is a peer-reviewed journal published by Mary Ann Liebert, Inc. The
article is available online for free at www.liebertpub.com/ast.
The journal is published ten times a year in print and online.