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An Astronomical Search for the Essential Ingredients for Life: Placing Our Habitable System in Context

We plan to carryout three investigations concerning the astronomical constraints on the possible origins of life in the Universe.

Our first module will focus on astrochemical investigations concerning the building blocks of life. Under the leadership of L. Ziurys, we plan to: (i) undertake laboratory studies to determine signatures for pre-biotic compounds that might exist in the interstellar medium, with special emphasis on ribose; (ii) initiate an observational search for these gas-phase molecules that are important for life using millimeter and sub-millimeter radio telescopes to which we have access; and (iii) conduct theoretical studies into the stability of complex organic molecules in the gas phase ISM and the evolution of their abundances in circumstellar disks in order to interpret the broader implications of our findings for the possibility of life elsewhere in the Universe. This module will address Goal #3 in the NAI revised roadmap.

Our second module will focus on the formation and evolution of habitable worlds under the leadership of S. Strom and J. Najita (NOAO). We plan to: (i) undertake an observational program to learn when, when, where, and how frequently planets form around young stars to provide the possibility for constraints on habitable planet formation; (ii) conduct an observational characterization of circumstellar environments that give rise to life and initiate a theoretical modeling program to determine the frequency of giant impacts as traced through circumstellar dust disk evolution, connecting the evolution of dusty disks around sunlike stars to the history of our solar system; and (iii) investigate the time evolution of the UV/x-ray flux of young solar-type stars from the protstellar phase through the epoch of terrestrial planet formation to mature planetary systems. The investigation will also include studies of stars that have evolved further than the Sun, so as to predict the future variability of the Sun. This module addresses Goal #1 of the NAI Revised Roadmap, as well as aspects of #4 and #6.

Our third module, under the leadership of R. Angel and P. Hinz and is aimed at the characterization of planetary systems. We plan to: (i) initiate an observational program aimed at the direct detection and characterization of astrobiologically relevant extra-solar giant planets (EGPs) to determine their frequency around solar-type stars and characterize their composition through spectroscopy; (ii) initiate a theoretical study of giant planet atmospheres extending current modeling efforts down to 0.1 MJupiter as a first step in understanding the detectability of biosignatures in planet atmospheres with liquid water present; and (iii) extend observational work on the observed earthshine spectrum to near-infrared wavelengths to close a gap in our understanding as well as initiate a monitoring program. This module addresses goals #1 and #7 in the NAI Revised Roadmap.

Our special emphasis on the revised roadmap Goal #1 arises because of current lack of understanding of how the Solar System arose, and how it fits with the many other planetary systems which are being discovered, and which have substantial differences from the Solar System. Our goal is to set a better, more appropriate starting point for consideration of the origin of life, and to start to explore the question of whether Earth is or is not rare.

Our plans to strengthen the astrobiology community revolve around the creation of the Laplace Center for interdisciplinary astrobiology studies and the Astrobiology Winter School to be held annually here at the University of Arizona. The Laplace Center will be an interdisciplinary program (IDP), a standard system for interdisciplinary research and teaching at UA. It will serve as a focus for our interdisciplinary research efforts and strengthen the growing ties between the Departments of Astronomy, Planetary Sciences, NOAO, Geosciences, Chemistry and Biochemistry. Future plans call for including also Microbiology and Ecology and Evolutionary Biology as well as the Tree Ring Laboratory, Optical Sciences, and parts of the Medical College.

The Center will host 2-3 extended visitors per year and organize meetings to increase scientific interactions across the boundaries that exist within the College of Science. The Winter School will train up to twenty students per year over the period of performance of this proposal. We plan to host visiting faculty for up to two months per year from partner NAI node institutions as well as 10 graduate students for a four-month curriculum in the origins of life. In collaboration with colleagues throughout the College of Science we will offer two interdisciplinary courses for graduate credit that focus on the boundaries between the disciplines and take advantage of the unique observational and laboratory facilities on the University of Arizona campus.

Our efforts to “Strengthen the Astrobiology Community” will include production of first rate scholars in areas important to the future success of the field. In addition to extant interdisciplinary graduate programs at the University of Arizona such as those in Planetary Science (Astrobiology Minor), Chemistry (Astrochemistry emphasis), and Optical Sciences (various joint degree programs) we will introduce an Astrobiology minor as part of the IDP for the departments within the College of Science.

A particularly innovative part of this proposed project is for a significant and integrated education and public outreach component led by Tim Slater. Because a comprehensive program to improve the public’s understanding of the this interdisciplinary science requires targeting schools, we will work directly with secondary school teachers on improving their understanding of the myriad of underlying concepts surrounding the search for other worlds. Initially, we plan to conduct systematic studies of the understanding and beliefs about the scientific search for other worlds held by K-14 students, teachers, and the general public. In addition to contributing to the scholarly literature base of science education, a detailed understanding of the existing notions and attitudes people have about this interdisciplinary science are crucial to designing the most effective education and public outreach programs. This will be accomplished through a systematic series of surveys, interviews, and carefully monitored instructional interventions. The results will be disseminated through journal articles and presentations at professional education conferences.

Finally, we also plan to help other graduate students and university faculty supported by this program to become informed about the reasoning difficulties K-12 students, teachers, and the general public have with understanding the search for other worlds. If research scientists have an appreciation for the specific parts of this science that people find difficult, they will be better able to communicate the exciting results and enhance the public’s attitudes toward supporting this endeavor. This will be accomplished by conducting frequent workshops and contributing scholarly papers at professional science conferences as well as regularly contributing to the program’s seminar series. In support of these efforts, the team will undertake the creation and dissemination of an astrobiology public speakers toolkit and a dynamic FAQ (frequently asked questions).