HR: 0800h
AN: P11C-0698    [Abstracts]
TI: Oxidants: Chemical Energy for Life on Mars and in the Outer Solar System
AU: Schulze-Makuch, D
EM: dirksm@wsu.edu
AF: Washington State University, Webster Hall, Pullman, WA 99164, United States
AU: Houtkooper, J
EM: joophoutkooper@gmail.com
AF: Justus-Liebig-University, Center of Psychobiology an Behavioral Medicine, Giessen, 35394, Germany
AU: * Cooper, J
EM: John.F.Cooper@nasa.gov
AF: Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, MD 20771, United States
AB: Redox gradients are essential for life as we know it. Strong oxidants to retain these gradients are produced in a variety of planetary environments by UV and ionizing radiation. Houtkooper and Schulze-Makuch (2007) previously suggested hydrogen peroxide as an essential biological ingredient for putative Martian life to adapt to the challenging near-surface conditions on the Red Planet. On Earth, adaptation and use of oxidants is widespread. Examples are microorganisms that use or produce oxidants, and the microbe Acetobacter peroxidans, which uses the decomposition of H2O2 as its major metabolic pathway. However, oxidants may also be critical biogenic components on outer Solar System objects of high astrobiological potential such as Europa and Enceladus. Exothermic reactivity of oxidants additionally contributes heat for habitable environments and acceleration of chemical processes potentially supporting life. Oxidation chemistry produces volatile gases and other detectable species that may be diagnostic of recent and ongoing biochemistry. More reduced chemical environments like the Titan atmosphere, and more isolated liquid water habitats like the deep-lying subsurface oceans of Ganymede and Callisto, may be astrobiologically impacted by externally driven inputs of oxidants over billions of years. Houtkooper, J.M. and Schulze-Makuch, D. (2007) A possible biogenic origin for hydrogen peroxide on Mars: the Viking results reinterpreted. Int. J. of Astrobiology 6: 147-152. Cooper, J. F., P. D. Cooper, E. C. Sittler, S. J. Sturner, A. M. Rymer, and M. E. Hill. Radiolytic gas-driven cryovolcanism in the outer solar system, J. Geophys. Res., in review.
DE: 0406 Astrobiology and extraterrestrial materials
DE: 0456 Life in extreme environments
DE: 5200 PLANETARY SCIENCES: ASTROBIOLOGY
DE: 6221 Europa
DE: 6225 Mars
SC: Planetary Sciences [P]
MN: 2007 Fall Meeting