2014 Annual Science Report
NASA Jet Propulsion Laboratory - Titan Reporting | SEP 2013 – DEC 2014
Titan as a Prebiotic System Activity Report
We are calculating how much material, over time, is ejected from geysers on the moon Enceladus and ends up on the moon Titan, and how this material may be important for pre-biological chemistry on Titan.
We have analyzed infall to the Titan system of both interplanetary and circum-Saturnian dust and ice particles, to establish limiting exogenic fluxes of several elements, such as Germanium and Oxygen that may be important in allowing facilitating potential Titanian metabolisms. We have collaborated with Co-I Steven Benner who has identified some interesting possible chemical bases for life in liquid methane, but finds that they may depend on the supply of some relatively rare (in terms of cosmic abundance) elemental species, such as Germanium. We have adopted the formalism developed by Spahn et al. (2006) to interpret the Cassini dust measurements to make predictions of the limiting external fluxes of some of these potentially biologically important species. There are two primary sources: Interplanetary dust particles (IDPs) and E-ring particles (ERPs) ERP’s are generated by the plumes of Enceladus and extend past Titan. We have modified model calculations constrained by the Cassini CDA/HRD and ground based observations, as well as observations from previous spacecraft. Our results suggest that IDPs are a larger source by an order of magnitude, but the ERP flux may dominate for oxygen and other interesting elements. Assuming chondritic abundances, we find a very small flux of Germanium and other trace elements of interest (Arsenic, Molybdenum).
PROJECT MEMBERS:Steven Benner
RELATED OBJECTIVES:Objective 2.2
Outer Solar System exploration
Sources of prebiotic materials and catalysts
Origins and evolution of functional biomolecules
Origins of energy transduction