National Academies of Sciences, Engineering, and Medicine; Division on Engineering and Physical Sciences; Space Studies Board; Committee on Astrobiology Science Strategy for the Search for Life in the Universe.

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 Space 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 (see 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 2020, respectively. Doubly fortuitous was the fact that the same congressional language also mandated that a similar strategy be developed for exoplanet exploration.

Given close scientific ties between the astrobiology and exoplanet community, as well as the parallel timelines of the dual studies, the SSB and NASA agreed that the astrobiology and exoplanet committees should collaborate to the maximum degree feasible.

The discussions between NASA and the National Academies on the details of the task to be undertaken by the SSB converged on the following charge:

In preparation for and as an input to the upcoming decadal surveys in astronomy and astrophysics and planetary science, the National Academies of Sciences, Engineering, and Medicine will appoint an ad hoc committee to carry out a study of the state of the science of astrobiology as it relates to the search for life in the solar system and extrasolar planetary systems.

The study will have the following objectives:

  • Take account of and build on NASA’s current Astrobiology Strategy 2015;
  • Outline key scientific questions and technology challenges in astrobiology, particularly as they pertain to the search for life in the solar system and extrasolar planetary systems;
  • Identify the most promising key research goals in the field of the search for signs of life in which progress is likely in the next 20 years;
  • Discuss which of the key goals could be addressed by U.S. and international space missions and ground telescopes in operation or in development;
  • Discuss how to expand partnerships (interagency, international and public/private) in furthering the study of life’s origin, evolution, distribution, and future in the universe;
  • Make recommendations for advancing the research, obtaining the measurements, and realizing NASA’s goal to search for signs of life in the universe

In the course of conducting this study, the committee will consider and regularly consult with the concurrent study “Exoplanet Science Strategy,” in the area of assessing habitability, searching for signs of life, and other relevant areas of scientific overlap. Also the committee will not revisit or redefine the scientific priorities or mission recommendations from previous decadal surveys.

To address this statement of task, the National Academies formally established the Committee on Astrobiology Science Strategy for the Search for Life in the Universe in the fall of 2017. The committee held its first meeting at the National Academies’ Beckman Center in Irvine, California, on January 16-18, 2018. Subsequent meetings were held in Washington, D.C., at the National Academy of Sciences and the Keck Center on March 6-8 and April 25-27, respectively.

In addition, the committee solicited community input in the form of white papers (see Appendix C). A total of 53 white papers originating from members of academia, employees of the federal government, and members of the general public were received and considered by the committee.

The astrobiology committee was able to have a significant degree of engagement and coordination with the exoplanet committee during the study. A co-chair of the exoplanet committee attended the first meeting of the astrobiology committee. Subsequently, a joint session of both committees was held on March 7, 2017, during the astrobiology committee’s second and the exoplanet committee’s first meeting. In addition, one member of the astrobiology committee also served as a member of the exoplanet committee, and SSB staff associated with the study attended the meetings of both committees. Furthermore, a working group composed of four members of each committee held three closed-session teleconferences to exchange ideas and review relevant parts of each report.

A complete draft of the committee’s report was sent to external reviewers for comment on June 20. A revised draft was assembled in July and August and was approved for release by the National Academies on September 20, 2018.

This Consensus Study Report was reviewed in draft form by individuals chosen for their diverse perspectives and technical expertise. The purpose of this independent review is to provide candid and critical comments that will assist the National Academies of Sciences, Engineering, and Medicine in making each published report as sound as possible and to ensure that it meets the institutional standards for quality, objectivity, evidence, and responsiveness to the study charge. The review comments and draft manuscript remain confidential to protect the integrity of the deliberative process.

We thank the following individuals for their review of this report: John Baross, University of Washington; Courtney Dressing, University of California, Berkeley; Colin Goldblatt, University of Victoria, Canada; Martha Grover, Georgia Institute of Technology; Jonathan Lunine, NAS,2 Cornell University; Paul Mahaffy, NASA Goddard Space Flight Center; John Rummel, SETI Institute; Gary Ruvkun, NAS/NAM,3 Harvard Medical School, Massachusetts General Hospital; and Norman H. Sleep, NAS, Stanford University.

Although the reviewers listed above provided many constructive comments and suggestions, they were not asked to endorse the conclusions or recommendations of this report nor did they see the final draft before its release. The review of this report was overseen by Louis J. Lanzerotti, NAE,4 New Jersey Institute of Technology. He was responsible for making certain that an independent examination of this report was carried out in accordance with the standards of the National Academies and that all review comments were carefully considered. Responsibility for the final content rests entirely with the authoring committee and the National Academies.

Footnotes

Astrobiology

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