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Prepublication Copy – Subject to Further Editorial Correction An Astrobiology Strategy for the Search for Life in the Universe ADVANCE COPY NOT FOR PUBLIC RELEASE BEFORE October 10, 2018 at 11:00 a.m. ___________________________________________________________________________________ PLEASE CITE AS A REPORT OF THE NATIONAL ACADEMIES OF SCIENCES, ENGINEERING, AND MEDICINE Committee on the Astrobiology Science Strategy for the Search for Life in the Universe Space Studies Board Division on Engineering and Physical Sciences A Consensus Study Report of PREPUBLICATION COPY – SUBJECT TO FURTHER EDITORIAL CORRECTION THE NATIONAL ACADEMIES PRESS 500 Fifth Street, NW Washington, DC 20001 This study is based on work supported by the Contract NNH17CB02B with the National Aeronautics and Space Administration. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the views of any organization or agency that provided support for the project. International Standard Book Number-13: 978-0-309-XXXXX-X International Standard Book Number-10: 0-309-XXXXX-X Digital Object Identifier: https://doi.org/10.17226/25252 Copies of this report are available free of charge from: Space Studies Board National Academies of Sciences, Engineering, and Medicine 500 Fifth Street, NW Washington, DC 20001 Additional copies of this report are available from the National Academies Press, 500 Fifth Street, NW, Keck 360, Washington, DC 20001; (800) 624-6242 or (202) 334-3313; http://www.nap.edu. Copyright 2018 by the National Academy of Sciences. All rights reserved. Printed in the United States of America Suggested Citation: National Academies of Sciences, Engineering, and Medicine. 2018. An Astrobiology Science Strategy for the Search for Life in the Universe. The National Academies Press, Washington, D.C. https://doi.org/10.17226/25252. PREPUBLICATION COPY – SUBJECT TO FURTHER EDITORIAL CORRECTION The National Academy of Sciences was established in 1863 by an Act of Congress, signed by President Lincoln, as a private, nongovernmental institution to advise the nation on issues related to science and technology. Members are elected by their peers for outstanding contributions to research. Dr. Marcia McNutt is president. The National Academy of Engineering was established in 1964 under the charter of the National Academy of Sciences to bring the practices of engineering to advising the nation. Members are elected by their peers for extraordinary contributions to engineering. Dr. C. D. Mote, Jr., is president. The National Academy of Medicine (formerly the Institute of Medicine) was established in 1970 under the charter of the National Academy of Sciences to advise the nation on medical and health issues. Members are elected by their peers for distinguished contributions to medicine and health. Dr. Victor J. Dzau is president. The three Academies work together as the National Academies of Sciences, Engineering, and Medicine to provide independent, objective analysis and advice to the nation and conduct other activities to solve complex problems and inform public policy decisions. The National Academies also encourage education and research, recognize outstanding contributions to knowledge, and increase public understanding in matters of science, engineering, and medicine. Learn more about the National Academies of Sciences, Engineering, and Medicine at www.national-academies.org. PREPUBLICATION COPY – SUBJECT TO FURTHER EDITORIAL CORRECTION Consensus Study Reports published by the National Academies of Sciences, Engineering, and Medicine document the evidence-based consensus on the study’s statement of task by an authoring committee of experts. Reports typically include findings, conclusions, and recommendations based on information gathered by the committee and the committee’s deliberations. Each report has been subjected to a rigorous and independent peer-review process and it represents the position of the National Academies on the statement of task. Proceedings published by the National Academies of Sciences, Engineering, and Medicine chronicle the presentations and discussions at a workshop, symposium, or other event convened by the National Academies. The statements and opinions contained in proceedings are those of the participants and are not endorsed by other participants, the planning committee, or the National Academies. For information about other products and activities of the National Academies, please visit www.nationalacademies.org/about/whatwedo. PREPUBLICATION COPY – SUBJECT TO FURTHER EDITORIAL CORRECTION COMMITTEE ON ASTROBIOLOGY SCIENCE STRATEGY FOR THE SEARCH FOR LIFE IN THE UNIVERSE BARBARA SHERWOOD LOLLAR, C.C., FRSC,1 University of Toronto , Chair SUSHIL K. ATREYA, University of Michigan ALAN P. BOSS, Carnegie Institution of Washington PAUL G. FALKOWSKI, NAS,2 Rutgers, The State University of New Jersey, New Brunswick JACK D. FARMER, Arizona State University OLIVIER GUYON, University of Arizona GERALD F. JOYCE, NAS/NAM,3Salk Institute for Biological Studies JAMES F. KASTING, NAS, Pennsylvania State University VICTORIA S. MEADOWS, University of Washington PHILIP M. NECHES, NAE,4 Entrepreneurs Roundtable Accelerator CARL B. PILCHER, Blue Marble Space Institute of Science NILTON O. RENNO, University of Michigan KARYN L. ROGERS, Rensselaer Polytechnic Institute BRITNEY E. SCHMIDT, Georgia Institute of Technology ROGER SUMMONS, Massachusetts Institute of Technology FRANCES WESTALL, Centre National de la Recherche Scientifique SHELLEY A. WRIGHT, University of San Diego Staff DAVID H. SMITH, Senior Program Officer, Study Director SARAH C. BROTHERS, Associate Program Officer ANESIA WILKS, Program Coordinator MIA BROWN, Research Associate LAURA CUMMINGS, Lloyd V. Berkner Space Policy Intern CARSON BULLOCK, Lloyd V. Berkner Space Policy Intern 1 FRSC, Fellow, Royal Society of Canada. 2 NAS, Member, National Academy of Sciences. 3 NAM, Member, National Academy of Medicine. 4 NAE, Member, National Academy of Engineering. PREPUBLICATION COPY – SUBJECT TO FURTHER EDITORIAL CORRECTION v SPACE STUDIES BOARD FIONA HARRISON, NAS, California Institute of Technology, Chair ROBERT D. BRAUN, NAE, University of Colorado, Boulder, Vice Chair JAMES G. ANDERSON, NAS, Harvard University JEFF M. BINGHAM, Consultant JAY C. BUCKEY, Geisel School of Medicine at Dartmouth ADAM S. BURROWS, NAS, Princeton University MARY LYNNE DITTMAR, Dittmar Associates, Inc. JOSEPH FULLER, JR., Futron Corporation THOMAS R. GAVIN, California Institute of Technology SARAH GIBSON, National Center for Atmospheric Research VICTORIA E. HAMILTON, Southwest Research Institute ANTHONY C. JANETOS, Boston University CHRYSSA KOUVELIOTOU, NAS, The George Washington University DENNIS P. LETTENMAIER, NAE, University of California, Los Angeles ROSALY M. LOPES, Jet Propulsion Laboratory DAVID J. McCOMAS, Princeton University LARRY PAXTON, Johns Hopkins University, Applied Physics Laboratory ELIOT QUATAERT, University of California, Berkeley BARBARA SHERWOOD LOLLAR, University of Toronto HARLAN E. SPENCE, University of New Hampshire MARK THIEMENS, NAS, University of California, San Diego EDWARD L. WRIGHT, NAS, University of California, Los Angeles Staff MICHAEL H. MOLONEY, Director (until March 2, 2018) RICHARD ROWBERG, Interim Director (after March 2, 2018) CARMELA J. CHAMBERLAIN, Administrative Coordinator TANJA PILZAK, Manager, Program Operations CELESTE A. NAYLOR, Information Management Associate MARGARET KNEMEYER, Financial Officer PREPUBLICATION COPY – SUBJECT TO FURTHER EDITORIAL CORRECTION vi Preface Astrobiology is the study of the origin, evolution, distribution, and future of life in the universe. It is an inherently interdisciplinary field that encompasses astronomy, biology, geology, heliophysics, and planetary science, including complementary laboratory activities and field studies conducted in a wide range of terrestrial environments. Combining inherent scientific interest and public appeal, the search for life in the solar system and beyond provides a scientific rationale for many current and future activities carried out by the National Aeronautics and Science Administration (NASA) and other national and international agencies and organizations. In 2017, Congress directed NASA to enter into an arrangement with the National Academies of Sciences, Engineering, and Medicine to develop a science strategy for astrobiology that would outline key scientific questions, identify the most promising research in the field, and indicate the extent to which the mission priorities in existing decadal surveys address the search for life’s origin, evolution, distribution, and future in the universe (see Appendix A). In response to this congressional mandate, NASA’s associate administrator for the Science Mission Directorate approached the Space Studies Board (SSB) with a request to carry out this study (Appendix B). While retaining the core language of the law, the statement of task ultimately agreed upon between SSB and NASA incorporated additional tasks relating to the specific programmatic and scientific context of the agency’s various astrobiology-related endeavors, which are most prominently detailed in the 2015 NASA Astrobiology Strategy.1 Indeed, both the SSB and NASA regarded the nature and timing of the request to be particularly fortuitous in that the results of the study would provide important input to the next decadal surveys in astronomy and astrophysics and planetary sciences, due to start in 2018 and
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