The detection of extra-terrestrial life and the consequences for science and society

Development of Sensitive Methods for the Detection of Minimum Concentrations of DNA on Martian Soil Simulants

Several methods used for the quantification of DNA are based on UV absorbance or the fluorescence of complexes with intercalator dyes. Most of these intercalators are used in gels to visualize DNA and its structural integrity. Due to many extraterrestrial samples, such as meteorites or comets, which are likely to contain very small amounts of biological material, and because the ability to detect this material is crucial for understanding the origin and evolution of life in the universe, the development of assays that can detect DNA at low limits and withstand the rigors of space exploration is a pressing need in the field of astrobiology. In this study, we present a comparison of optimized protocols used for the fast and accurate quantification of DNA using common intercalator dyes. The sensitivity of assays exceeded that generated by any commercial kit and allowed for the accurate quantification of minimum concentrations of DNA. The methods were successful when applied to the detection and measurement of DNA spiked on soil samples. Furthermore, the impact of UV radiation as a harsh condition on the surface of Mars was assessed by DNA degradation and this was also confirmed by gel electrophoresis. Overall, the methods described provide economical, simple-step, and efficient approaches for the detection of DNA and can be used in future planetary exploration missions as tests used for the extraction of nucleic acid biosignatures.

Relative Likelihood of Success in the Search for Primitive versus Intelligent Extraterrestrial Life

We estimate the relative likelihood of success in the searches for primitive versus intelligent life on other planets. Taking into account the larger search volume for detectable artificial electromagnetic signals, we conclude that both searches should be performed concurrently, albeit with significantly more funding dedicated to primitive life. Based on the current federal funding allocated to the search for biosignatures, our analysis suggests that the search for extraterrestrial intelligence (SETI) may merit a federal funding level of at least $10 million per year, assuming that the average lifetime of technological species exceeds a millennium.

Critical issues in the history, philosophy, and sociology of astrobiology

Fifty years after serious scientific research began in the field of exobiology, and forty years after serious historical research began on the subject of extraterrestrial life, this paper identifies and examines some of the most important issues in the history, philosophy, and sociology of what is today known as astrobiology. As in the philosophy of science in general, and in the philosophies of particular sciences, critical issues in the philosophy and sociology of astrobiology are both stimulated and illuminated by history. Among those issues are (1) epistemological issues such as the status of astrobiology as a science, the problematic nature of evidence and inference, and the limits of science; (2) metaphysical/scientific issues, including the question of defining the fundamental concepts of life, mind, intelligence, and culture in a universal context; the role of contingency and necessity in the origin of these fundamental phenomena; and whether or not the universe is in some sense fine-tuned for life and perhaps biocentric; (3) societal issues such as the theological, ethical, and worldview impacts of the discovery of microbial or intelligent life; and the question of whether the search for extraterrestrial life should be pursued at all, and with what precautions; and (4) issues related to the sociology of scientific knowledge, including the diverse attitudes and assumptions of different scientific communities and different cultures to the problem of life beyond Earth, the public "will to believe," and the formation of the discipline of astrobiology. All these overlapping issues are framed by the concept of cosmic evolution-the 13.7 billion year Master Narrative of the Universe-which may result in a physical, biological, or postbiological universe and determine the long-term destiny of humanity.

Astrobiology and society: building an interdisciplinary research community

This paper reports recent efforts to gather experts from the humanities and social sciences along with astrobiologists to consider the cultural, societal, and psychological implications of astrobiology research and exploration. We began by convening a workshop to draft a research roadmap on astrobiology's societal implications and later formed a Focus Group on Astrobiology and Society under the auspices of the NASA Astrobiology Institute (NAI). Just as the Astrobiology Science Roadmap and various astrobiology science focus groups have helped researchers orient and understand their work across disciplinary contexts, our intent was to apply the same approach to examine areas beyond the physical and life sciences and expand interdisciplinary interaction and scholarly understanding. These efforts continue as an experiment in progress, with an open invitation to interested researchers-astrobiologists as well as scholars in the humanities and social sciences-to become involved in research, analysis, and proactive discussions concerning the potential impacts of astrobiology on society as well as the possible impacts of society on progress in astrobiology.