Exobiology and Evolutionary Biology

Evolution of Preplanetary Matter in Analogs of the early Solar System: From Spitzer to SOFIA and JWST

PI: Douglas Whittet

We propose to extend and develop an established and highly successful research program focused on understanding the evolution of preplanetary matter from molecular clouds to protoplanetary disks in regions where stars that may host habitable planets are being born. The presence of presolar interstellar matter in primitive Solar-System bodies is widely acknowledged, but we lack a comprehensive general model that explains the causal relationship between these reservoirs and predicts the nature of preplanetary matter in different systems. Our primary goals are (i) to understand the processes by which interstellar matter evolves, and (ii) to predict the organic inventories of early solar systems in both low- and high-mass star formation regions. Recent studies have identified numerous young solar analogs in a wide range of environments, from isolated systems and loose, low-mass associations to giant molecular clouds that spawn luminous star clusters. We propose to examine such analogs in each of these situations, to fully explore possible scenarios for the birth of our Solar System, and hence to provide discrimination between possible astrochemical models.

Our proposal has specific relevance to the objective of NASA’s Exobiology and Evolutionary Biology program “to delineate the galactic and planetary conditions conducive to the origin of life”. To this end, we will utilize the wealth of observational data available from the Archive of the Spitzer Space Telescope and from new and upcoming NASA facilities, including the Stratospheric Observatory for Infrared Astronomy (SOFIA) and the Wide-field Infrared Survey Explorer (WISE). We will also develop strategies and prioritize targets for future study with the James Webb Space Telescope (JWST), scheduled to come into operation toward the end of the proposed grant period. Key science goals already identified for the JWST include those central to this proposal, namely the birth of stars and protoplanetary systems and the origins of planets and life. Infrared spectroscopy is our primary tool for remote study of preplanetary materials. Astronomical observations will be interpreted with the aid of data for laboratory analogs and chemical models. Our team has extensive expertise in all relevant areas.