"There may be no 'safe haven' for these organic molecules on Mars," conclude Ilya Shkrob, Sergey Chemerisov, and Timothy Marin, from Argonne National Laboratory and Benedictine University, in Illinois, in their article entitled "Photocatalytic Decomposition of Carboxylated Molecules on Light-Exposed Martian Regolith and its Relation to Methane Production on Mars."
Unlike on Earth, where plants and other organisms convert carbon dioxide and water into organic compounds via photosynthesis, the authors propose that the opposite happens on the surface of Mars. The iron oxides that make up Martian soil and give the planet its distinctive red color are photocatalysts. They use energy from ultraviolet light absorbed through the thin Martian atmosphere to oxidize carbon-containing organic molecules trapped in soil particles, converting them to carbon dioxide and gases such as methane.
The authors present study data to support this model and to explain why it might not be realistic to rely on the discovery of proteins, amino acids, and other carbon-containing compounds in the upper soil layers of Mars to determine whether life forms are or have been present on the planet.
"This is an interesting result and may be an important step in solving the enduring mystery of organics on Mars," says Christopher P. McKay, Senior Editor of Astrobiology and Research Scientist at NASA Ames Research Center. "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. Mars may have a self cleaning surface. If so, we may have to dig deeply to find any organic materials."
"The importance of drilling below the Martian surface for rocks and soils that might retain preserved organics is certainly on the minds of future mission scientists," says Sherry L. Cady, PhD, Editor of Astrobiology and Associate Professor in the Department of Geology at Portland State University. "The possible 2018 joint ESA-NASA mission is a case in point."
Astrobiology is an authoritative peer-reviewed journal published 10 times a year in print and online. The Journal provides a forum for scientists seeking to advance our understanding of life's origins, evolution, distribution, and destiny in the universe. The complete tables of content and the full text for this issue may be viewed online at www.liebertpub.com/ast
Mary Ann Liebert, Inc. (www.liebertpub.com) is a privately held, fully integrated media company known for establishing authoritative peer-reviewed journals in many promising areas of science and biomedical research. Its biotechnology trade magazine, Genetic Engineering & Biotechnology News (GEN), was the first in its field and is today the industry's most widely read publication worldwide. A complete list of the firm's 60 journals, books, and newsmagazines is available at www.liebertpub.com
Vicki Cohn | EurekAlert!
Astronomers find unexpected, dust-obscured star formation in distant galaxy
24.03.2017 | University of Massachusetts at Amherst
Gravitational wave kicks monster black hole out of galactic core
24.03.2017 | NASA/Goddard Space Flight Center
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
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