2004 Annual Science Report
NASA Ames Research Center Reporting | JUL 2003 – JUN 2004
Prebiotic Organics From Space
We have made progress in all three focus areas pertinent to our task: interstellar prebiotic chemistry, observational astrobiology, and prebiotic membrane studies. In the prebiotic interstellar chemistry arena we have completed studies of the infrared (IR) properties of neutral and ionized polycyclic aromatic hydrocarbons (PAHs) frozen in realistic interstellar water ice analogs and are now preparing these results for publication. Water is a common interstellar and Solar System ice. These spectra will be used to interpret data taken with NASA’s new Spitzer IR telescope. We have found a remarkable result. When frozen in water, PAHs are readily ionized and stabilized as ions as long as the ice is kept below about 50K. This realization will have far-reaching impact on our understanding of extraterrestrial ice physics and spectroscopy.
We have studied the interstellar photostability of amino acids, nitriles, and precursor molecules in these ice analogs and compared photochemistry with proton bombardment processes.
In the observational arena we believe we have detected evidence for deuterated interstellar PAHs, making an additional link between our ongoing lab studies of PAHs and their photoproducts with important biogenic species in meteorites. This also bears on biomarker reliability. Scott Sandford, a member of this team, has spearheaded the concept development and proposal submission for the first mission dedicated to Astrobiology, ABE the Astrobiology Explorer. Lastly, we have also submitted several proposals to Spitzer to track organic species in the Milky Way and other galaxies.
Lastly, concerning primitive membranes, Dr. Charles Apel has become a member of our team. In the short time he has been with us he has assembled the equipment necessary and already started investigating primitive membrane systems.
PROJECT INVESTIGATORS:Louis Allamandola
PROJECT MEMBERS:David Deamer
RELATED OBJECTIVES:Objective 1.1
Models of formation and evolution of habitable planets
Sources of prebiotic materials and catalysts
Origins of cellularity and protobiological systems
Effects of extraterrestrial events upon the biosphere
Biosignatures to be sought in Solar System materials
Biosignatures to be sought in nearby planetary systems