Astrobiology in Culture: The Search for Extraterrestrial Life as “Science”

Introduction

I n this issue, Steven Dick (2012) identifies critical issues in the history and philosophy of astrobiology, encompassing social studies of astrobiology as well. Sociological issues such as the diverse attitudes and assumptions of different scientific communities relating to the problem of life beyond Earth, the public “will to believe,” and the formation of the “discipline” of astrobiology are topics that researchers can explore productively from a social-studies-of-science perspective.1

Given the salience of science in contemporary life, it is important to study science in culture, to understand the cultural roles, functions, and authority of science. And what is “culture”? According to cultural anthropologist Clifford Geertz (1973), it is a system of inherited conceptions expressed in symbolic forms, by means of which we communicate, perpetuate, and develop knowledge and attitudes. It is a context within which social action can be “thickly”—that is, intelligibly—described. In this analysis, science is culture.

“Science” is conventionally defined as “the systematic enterprise of gathering knowledge about the universe and organizing and condensing that knowledge into testable laws and theories.”2 No single, simple definition exists; science means different things to different people in different situations. As sociologist of science Brian Wynne (1991) has noted, “There is no clear consensus even among scientists themselves as to what is ‘science’…in any specific contexts” (p 112; cf. Woolgar, 1988).

Western thinkers over four centuries have maintained a largely positivistic image of science as “a unique form of knowledge whose power transcends the particularities of time and place” (Fuller, 1996, p 31). The study of science in culture reveals how science is, rather, situated, contingent, continually evolving in response to changes in its environment.3

Basic assumptions underlying the concept of “science” employed in this analysis are that

• Science—including scientists, the process and practice of science, scientific knowledge, scientific institutions, and scientific authority—is a social construction created by scientists and others through the symbolic action of communication (cf. Latour, 1987);

Social thinkers provide insight into how language (communication, rhetoric) functions as a means of creating social reality4 and how authority arises and operates in that reality. Michel Foucault (1972, 1977, 1980) explored how power is constructed in everyday discourse and how power and authority arise out of this discourse. For Foucault (1977), discursive practices define “a legitimate perspective for the agent of knowledge, and the fixing of norms for the elaboration of concepts and theories” (p 199). Such practices are tools of what some social scientists call “boundary-work.” Thomas Gieryn (1983, 1995, 1999) describes boundary-work as a rhetorical or ideological style that entails the “attribution of selected characteristics to the institution of science…for purposes of constructing a social boundary that distinguishes some intellectual activities as ‘non-science’” (p 782). These boundaries or borders are fluid, Dwight Conquergood (1991) observes, always in the making, and they “bleed as much as they contain.”5 Gieryn's case studies (1999) reveal how the scientific elite maintain the boundaries of science by labeling what they deem “non-scientific” knowledge subjective, irrational, a matter of believing rather than knowing. Legitimate scientific knowledge, on the other hand, is described as objective, rational, impersonal, and detached.

This analysis employs the sensitizing concept of boundary-work as a theoretical framework. Gieryn (1983) observes that boundary-work “is routinely accomplished in practical, everyday settings” (p 781). For science, these settings include academic curricula, government research priorities, peer-reviewed publications, scientific conferences, mass media content, and political and popular discourse. Factors that play an especially important role in the construction of authority, credibility, and legitimacy for a field of research include rationales, goals, and objectives; acceptance by scientists and other advocates with appropriate credentials6; validation by authoritative institutions (government agencies, science academies, top-tier universities); and peer-reviewed publications. Other factors that come into play include accredited degree programs and especially Ph.D.s in the field, textbooks, and dedicated research institutes and scientific societies. Every journal paper, every letter, every scientific meeting, memo, media report, e-mail message, phone conversation, every formal and informal conversation, every element of the ongoing public and not-so-public dialogue about science contributes to the construction7 of its legitimacy, and all these settings and factors “act” within an evolving cultural context—what Bruno Latour (2005) would call an actor-network. With his actor-network theory, Latour shows how social phenomena are not fixed and stable but fluid and unstable.8

One product of the ongoing processes of constructing scientific authority, credibility, and legitimacy is consensus, which is itself, as Gieryn (1995) explains, “a contextually contingent product of scientists' variable interpretative procedures” (p 404). For the scientific community and other “attentive publics” (Miller, 2010), the U.S. National Academy of Sciences (NAS), the international Committee on Space Research (COSPAR), and the International Astronomical Union (IAU)—all representations of scientific authority and scientific consensus—have contributed to constructing legitimacy for exo/astrobiology and the search for extraterrestrial intelligence (SETI). In the United States, and elsewhere, “the Academy” is widely accepted as an arbiter of scientific authority, credibility, and legitimacy, and its pronouncements are widely accepted as reflecting scientific consensus.9

Since its inception in the 1950s, the NAS's Space Studies Board (SSB)10 has issued a stream of reports on exo/astrobiology, widely accepted as reflections of the consensus of the U.S. space science community, that have helped establish and maintain the field as legitimate science.11 Over decades these reports have reviewed and evaluated the results of and identified science priorities for NASA-sponsored exo/astrobiology research, and they have generally endorsed continued NASA funding for this work, effectively reinforcing the boundaries of the field. For these reasons (and also for brevity's sake12), this analysis relies on reports from the Academy13 as leading indicators of authority, credibility, and legitimacy for astrobiology and SETI. While this analysis highlights some key steps and tools in this ongoing construction process, the research space is vast enough to warrant more in-depth treatment (perhaps a book, or two). The aim is not to provide an account of Why Things Are The Way They Are but to follow Latour's lead and “resume the task of tracing associations” (Latour, 2005, p 1).

Constructing Exo/Astrobiology as Science

The term “astrobiology” became officially established in the lexicon of science when NASA established its Astrobiology Program. But the science encompassed by the field of astrobiology has a long history.14 The idea of searching scientifically for evidence of extraterrestrial microbial life is as old as the Space Age (cf. Dick, 1999; Billings, 2010), and the idea of searching for evidence of extraterrestrial intelligent life was made scientific 50 years ago (Cocconi and Morrison, 1959).

As soon as it became clear that nations would start launching spacecraft to explore the solar system, scientists started talking about how they might take advantage of access to space to look for evidence of extraterrestrial microbial life and how this endeavor related to ongoing research into the origin and evolution of life on Earth. One was Joshua Lederberg. As early as 1957, he was communicating with colleagues about the possibility of searching for evidence of extraterrestrial life, and he quickly became a key player in constructing credibility and legitimacy for the field.15 In 1958, Lederberg, at age 33, won the Nobel Prize in Physiology or Medicine. In 1960, he presented a paper on exobiology at a meeting of COSPAR, then published an article based on this paper in the journal Science: “Exobiology is no more fantastic than the realization of space travel itself,” he wrote, “and we have a grave responsibility to explore its implications for science and for human welfare with our best scientific insights and knowledge” (Lederberg, 1960, p 399). The article was reprinted in a NAS report on “Science in Space.” Thus, Lederberg, Science, and the Academy did boundary-work for the field.

On October 20, 1959, NASA sent a “work request” to the Academy's Space Science Board for input on “basic philosophical objectives that should underlie” NASA space science activities. NASA offered that one

very exciting, philosophical basis for a space science program would be to learn as much as possible about the behavior of terrestrial life forms in space and under the conditions of space flight, and to seek out extraterrestrial life. The philosophical implications of a discovery that life does indeed exist elsewhere than on earth are tremendous, and surely of interest to the entire world, as well as to the scientist. (Logsdon, 2001, p 142)

The SSB's role in helping to form, guide, and legitimate NASA's exo/astrobiology programs had officially begun.16 NASA funded its first exobiology investigation in 1959—a life-detection experiment intended for launch on the Viking mission to Mars. While this investigation ultimately did not fly on the mission, it did help to kick-start exobiology at NASA. In 1960, the agency established an exobiology research program. By this time, exobiology had a well-articulated rationale that embedded this line of research in the context of the broader scientific enterprise (Billings, 2010).

In an August 11, 1964, memorandum to NASA associate administrator for space science and applications Homer Newell on “future goals of the space science program,” the SSB recommended that NASA adopt as its most important space science goal for 1971–1986 “the exploration of planets with particular emphasis on Mars leading toward eventual manned exploration. This objective includes the search for extraterrestrial life …” (Logsdon, 2001, pp 170–173).17 Again, the SSB reinforced the boundaries of the scientific search for extraterrestrial life—without reference to intelligence—as worthy of government funding and a legitimate scientific endeavor. Over the next 40 years the SSB produced a steady stream of boundary-building-and-maintenance reports on exobiology and astrobiology,18 maintaining the construction of the field as legitimate science. SETI was not addressed in these reports as an endeavor of high scientific priority or worthy of government funding.19

In 1997, NASA instituted an astrobiology program encompassing and expanding on its established exobiology program to include studies of chemical evolution in interstellar space, the formation and evolution of planets, and the natural history of Earth. In 2003, the SSB's Committee on the Origins and Evolution of Life (COEL) published an assessment of U.S. and international programs in astrobiology, reinforcing the boundaries demarcating exo/astrobiology as legitimate science as it observed that NASA's exobiology program had been “scientifically successful” in contributing to understanding “the origin, evolution, and distribution of life in the universe,” providing “the rationale and research basis for the establishment of the broader program of Astrobiology” (Committee on the Origins and Evolution of Life, 2003, p 26). Highlighting some important tools of boundary-work, the COEL said it was

impressed by the speed with which a community is being built in astrobiological research and education. Many of the standard indicators of the emergence of a bona fide new interdisciplinary field—journals, university programs, annual meetings, and so on—seem to suggest that Astrobiology is developing quickly and carving a special role for itself among NASA programs, and that an intellectually distinct discipline may be taking shape. (p 2)

The SSB's decadal survey of priorities in solar system exploration commissioned by NASA in 2001 (Solar System Exploration Survey, 2003) identified four “cross-cutting themes that integrate the various goals identified by the panels” (p 177), including key themes in astrobiology: the first billion years of solar system history; volatiles and organics; the stuff of life; and the origin and evolution of habitable worlds. The survey team received 24 white papers from the science community during its deliberations, most focusing on specific planetary bodies or types of bodies or particular research methodologies. The next decadal survey of solar system exploration options and priorities commissioned by NASA (Committee on the Planetary Science Decadal Survey, 2011) highlighted the growing role of astrobiology in planetary exploration. Survey chair Steve Squyres advised the astrobiology community: “Astrobiology is a major crosscutting theme of NASA's planetary science activities and a central facet of the survey's scientific scope.”20 The 199 white papers received for this survey addressed numerous topics in astrobiology, from “seeking signs of life on Mars” to “planetary science and astrobiology,” “astrobiology sample acquisition and return,” “astrobiology research priorities for Mercury, Venus, and the Moon,” “life investigation for Enceladus,” “astrobiology in Europa Jupiter system mission,” “astrobiology priorities for planetary science flight missions,” and “Mars astrobiology explorer-cacher.”

Constructing SETI as Science

The construction of SETI as a legitimate scientific endeavor began in earnest with Nature's publication of a paper by Cocconi and Morrison (1959), proposing that current science and technology could enable a search for interstellar radio signals of extraterrestrial intelligent origin. In 1960, radio astronomer Frank Drake conducted a SETI search called Project Ozma at the National Radio Astronomy Observatory in Green Bank, West Virginia. In 1961, for a Green Bank gathering of scientists with an interest in SETI, Drake concocted the so-called “Drake equation” as a tool for thinking and talking about SETI scientifically (cf. Billings, 1991). A small community of SETI scientists had begun to organize.

The legitimacy-lending SSB appointed Drake to work on its first decadal survey of astronomy and astrophysics (Committee on Space Astronomy and Astrophysics, 1979). The survey committee's report addressed SETI briefly: “This report does not address certain areas that are intimately related to space astronomy and that may…use the facilities of space astronomy. These include…the search for extraterrestrial intelligence.…Their omission is not meant to signify our lack of interest…and we recommend that they be fully discussed by appropriate bodies” (p viii). The International Academy of Astronautics' 1972 congress featured the IAA's first SETI review session. The SSB's next survey of astronomy and astrophysics (Task Group on Astronomy and Astrophysics, 1988) touched on SETI briefly as well. In considering the scientific potential of searching for evidence of life in our solar system and searching for planets around other stars, the SSB's Task Group on Astronomy and Astrophysics noted in its report:

A further, more specialized search involves intelligent life. Such a search has a different character than the broader-based search for life and is not addressed in this study. Obviously, if the NASA Search for Extra-terrestrial Intelligence (SETI) program were to find radio signals from another planetary system, it would be a tremendously exciting and significant event. In the case of the more restricted study described here, even the hint of life in another planetary system would trigger a new era in planetary research. (Task Group on Astronomy and Astrophysics, 1988, p 17)

Although the SSB had not endorsed SETI as a scientific priority or an endeavor worthy of government funding, NASA initiated a 10-year SETI research and development program in the 1980s,21 to culminate in a ground-based search. NASA started its SETI listening project in 1992. The U.S. Congress cancelled it in 1993.22 As NASA historian Stephen Garber (1999) has observed, NASA's SETI program “was a relative anomaly in terms of a small, scientifically valid program that was canceled for political expediency” (p 3). The SETI community at the time lacked sufficient organization, financing, and political clout to sustain NASA funding for its work. The 1989 passage of a federal budget deficit reduction law had prompted Congress to take a “last in, first out” approach to budget cutting. While SETI did not lose its scientific legitimacy entirely, its advocates did not succeed in engineering an SSB endorsement of SETI as a scientific priority. SETI lost political legitimacy, falling off Congress's list of things to pay attention to and NASA's list of things to do. To date the NAS has not published any reports specifically on SETI, nor any reports identifying SETI as a scientific priority or an endeavor worthy of government funding.

SETI was mentioned only in passing in the SSB's survey of astronomy and astrophysics for the new millennium (Astronomy and Astrophysics Survey Committee, 2001): “This committee, like previous survey committees, believes that the speculative nature of SETI research demands continued development of innovative technology and approaches, which need not be restricted to radio wavelengths” (p 172). Shortly thereafter the SETI Institute published an optimistic 20-year “roadmap” for SETI (SETI Science & Technology Working Group, 2002). In this document SETI scientists reinforced the case for passive radio listening as “the most-cost-effective strategy” (p 235), while calling for expanding SETI into the optical and infrared ranges. “A modestly funded SETI effort should be a component of [NASA's new Astrobiology] program,” they suggested, and “the SETI Institute should engage in discussions with NASA and the NSF to encourage them to join a public/private partnership for direct participation in SETI projects.” In addition, “a concerted attempt should be made to encourage the US Congress to support the visionary nature of the SETI endeavor” (p 236).

SETI was addressed briefly in a 2003 SSB assessment of the science of astrobiology. In this report, the SSB's COEL23 commented,

The search for intelligent life on worlds beyond Earth represents the most romantic and publicly accessible aspect of the search for life, yet is perhaps the most problematic. No as yet known remote-sensing technique can detect the presence of intelligent versus complex life forms, other than by listening for electromagnetic forms of communication leaking from or deliberately sent from another world. (Committee on the Origins and Evolution of Life, 2003, p 44)24

SETI is not addressed in the SSB's latest decadal surveys of astronomy and astrophysics (Committee for a Decadal Survey of Astronomy and Astrophysics, 2010) and planetary science (Committee on the Planetary Science Decadal Survey, 2011).

It may be argued that SETI scientists have helped to propel the now-established field of extrasolar planet searching into being. Early exoplanet searcher Bruce Campbell (1991) wrote more than 20 years ago, in a book about SETI: “For life to originate, thrive, and evolve to intelligent forms at many locations throughout our galaxy, there must almost certainly be an abundance of extrasolar planets…similar to Earth orbiting other stars.” While “exotic life” might thrive in extraterrestrial environments that are hostile to life as we know it, he argued, “Earth-like planets have all the essential ingredients [for life as we know it] without stretching the probabilities” (p 97). By 1990 the credibility-constructing SSB issued its first report on extrasolar planet searching (Committee on Planetary and Lunar Exploration, 1990), noting that “barring interception of signals from intelligent life elsewhere by radio listening searches” (p 6), only a thorough survey of exoplanets could enable scientists to determine whether “Earths”—that is, planets hosting intelligent life—are rare or common. As of this writing, leading exoplanet searcher Geoff Marcy, who in December 2011 was named the University of California-Berkeley's Watson and Marilyn Alberts Chair in SETI, also leads an optical SETI project funded by the SETI Institute and The Planetary Society.25 While scientific interest in exoplanet habitability is tightly linked with scientific interest in the possibility of extraterrestrial life, this author would argue that the link between exoplanet searching and SETI is somewhat more tenuous.

Gieryn (1983) tells us, “Descriptions of science as distinctively truthful, useful, objective or rational may best be analyzed as ideologies: incomplete and ambiguous images of science nevertheless useful for scientists' pursuit of authority and material resources” (p 793). He asks, “What images of science do scientists present to promote their authority?” (p 783). The Drake equation (see above) can be interpreted as an embodiment of the ideology of positivistic—truthful, useful, objective, and rational (that is, authoritative, credible, and legitimate)—science. The Drake equation has been widely popularized as a rationale for SETI, and Drake himself has said the equation “encapsulates our understanding of the evolution of our galaxy and of our solar system.”26 But what does this equation actually do, and mean, especially for nonscientists?

While the equation may encapsulate Drake's understanding, it may not do the same for others, depending on the assumptions underlying others' thinking. In mathematics, an equation is “an expression or a proposition, often algebraic, asserting the equality of two quantities.”27 Drake concocted his equation to look like a mathematical expression: N=R* f _p n _e f _l f _i f _c L. This author would argue, however, that the Drake equation is not an equation. It is, rather, a tool for speculating, for “guesstimating” how many planets in the Milky Way galaxy might host intelligent life. This guesstimating process rests on a number of assumptions, so its product, the number of communicating civilizations in our galaxy, is by no means a precise quantity, with possible answers ranging from zero to millions or billions.28 None of these factors has a fixed value. Each factor represents a range—in some cases, a very wide range—of estimates based on current scientific knowledge, which is not fixed. Some agreement arguably may exist on the value of R*. But, while astronomers have already identified hundreds of extrasolar planets, given the vastness of the galaxy they have barely begun the task of determining the value of f _p. After f _p, determining values is barely more than a matter of guessing.

Drake himself (1991) has argued that his equation “is carefully not speculative. Those who use it to contemplate life in the Universe, or to plan searches, are going to great lengths to be nonspeculative fuddy-duddies” (p 116). Revealing some of his assumptions about the universe, Drake said, “The equation tells us that…it is worth searching. There is a real chance that with realistic resources, and in acceptable time, we will find one of those other civilizations” (p 117).29 In the end, the equation raises many questions, highlights the vastness of the range of possible answers, and ultimately does not tell us anything that might conflict with our assumptions about the universe.

Astrobiology and SETI face one important challenge in common. Extraterrestrial life, whether single-celled, complex, or intelligent, may not be recognizable to human life. Recognizable or not, it may only exist so far away from Earth that scientists may never be able to detect any signs of it. Astrobiology focuses on searching for evidence of habitability and microbial life in our own solar system, and the scientific consensus is that Earth is the only planet in our solar system where intelligent life has evolved. Thus SETI necessarily must search beyond our solar system, and the greatest challenge to SETI is the size of the space to be searched.

SETI technology—radio and optical telescopes, signal detection equipment, and signal processing systems—has advanced greatly since searchers got their start. Nonetheless, current technology can only search a small fraction of our own Milky Way galaxy. The universe is populated with an estimated 125 billion to 500 billion galaxies. While scientists have greatly expanded knowledge and understanding of the universe over 50 years of study, the universe is largely unexplored. The author can accept the scientific perspective that the universe has a potential for widespread life and, thus, that a scientific search for evidence of extraterrestrial prebiotic chemistry and life seems reasonable. However, the author is not convinced that humankind has the technological, let alone the financial, wherewithal to conduct a widespread search for extraterrestrial intelligent life in our own galaxy, let alone the universe.

Exo/astrobiology has produced an impressive body of research results over the past 50 years (cf. Committee on the Origins and Evolution of Life, 2003; see also Solar System Exploration Survey, 2003, p 157), enabling planetary exploration missions to zero in on potentially habitable environments beyond Earth (cf. Committee on the Planetary Science Decadal Survey, 2011). In a recent assessment of balance in NASA's science programs, the SSB (Committee on an Assessment of Balance in NASA's Science Programs, 2006) highlighted the key role that astrobiology plays in NASA's science portfolio:

The [SSB's latest] decadal surveys for astrophysics and for solar system exploration both embraced astrobiology as a key component of their programs, with the questions encompassed by astrobiology serving as overarching themes for the programs as a whole. The missions put forward in the solar system exploration survey are all key missions in astrobiology, whether they are labeled as such or not. And issues and missions related to astrobiology represent one of the key areas of interest identified in the astronomy and astrophysics communities. (p 20)

In the SSB's 2011 decadal survey of planetary exploration, astrobiology also received prominent attention. Even while NASA had a SETI program, the Academy did not have much to say about SETI. Today the goal of privately funded SETI searches remains to find evidence of extraterrestrial intelligence, and since SETI began no evidence has been found. While SETI scientists have refined their rationale for searching as astrobiological and other scientific observations and discoveries improve understanding of the formation of planetary systems, boundary conditions for life, and the nature of habitability, whether this expanded understanding strengthens the case for SETI is a matter of interpretation.

Astrobiology and SETI beyond NASA

Astrobiology and SETI reside within a common boundary at the IAU, established in 1919 “to promote and safeguard the science of astronomy in all its aspects through international cooperation.”30 The IAU has more than 10,000 individual members, 68 national members, 12 divisions, and 40 commissions. In 1982, the IAU created Commission 51, “Bioastronomy: Search for Extraterrestrial Life,”31 focusing on the search for extrasolar planets, the formation and evolution of planetary systems, astrobiology, and SETI. Commission 51 has organized “Bioastronomy” meetings approximately every three years since 1984, and these meetings address astrobiology and SETI. Astrobiology and SETI are positioned similarly with the International Society for the Study of the Origin of Life (ISSOL).32 In 2005, ISSOL changed its official name to ISSOL: The International Astrobiology Society. ISSOL holds scientific meetings every three years, with the latest—and the first held jointly with IAU Commission 51—taking place in France in 2011. The first biennial Astrobiology Science Conference took place in 2001, with the latest occurring in 2012.33 SETI scientists participate in these conferences.

Exo/astrobiology papers have been published widely for 50 years in leading science journals such as Nature, Science, and Proceedings of the National Academy of Sciences, as well as more specialized scientific publications. As noted above, Nature published the first scientific paper about SETI. The peer-reviewed journal Astrobiology, launched in 2001, cites a range of fields as its purview, from bioastronomy to exobiology to planetary geoscience. There is no explicit mention of SETI anywhere on the journal's Web site. The journal has published articles about SETI, however.34 The International Journal of Astrobiology, published since 2002, cites SETI as a topic it covers.35

In its 2003 assessment of astrobiology, the SSB's COEL asserted that it

sees no merit in debating the validity of a search whose negative results arguably tell us little about the ubiquity of life. The debate has no merit because the foundational motivation for the search is the popular aspiration to communicate with other forms of intelligence as much like or unlike us as we care to imagine. It would be dissembling, to say the least, to discourage such a search (especially one enabled by private funding) at the same time that astrobiology as a whole taps in to the same emotions and aspirations to excite the public about the general search for life's origins, evolution, and cosmic ubiquity. (pp 44–45)

Astrobiology and SETI Today

Fifty years of exo/astrobiology research have advanced understanding of the evolution of early Earth and other planetary bodies, the origins and evolution of life, the coevolution of life and environment, interstellar chemistry, extremophilic life, and the nature of habitability on Earth and elsewhere. Astrobiology is now well established worldwide, with government-funded research programs, dedicated research institutes, and professional societies in North and South America, Europe, and the Asia-Pacific region.36 It is widely accepted in official and popular discourse as an authoritative, credible, and legitimate multidisciplinary field of study—not yet a discipline, and perhaps not well suited to becoming a discipline. SETI is also established as a legitimate scientific enterprise. However, in the U.S., neither NASA nor any other government agency nor the broader scientific community has established SETI as a funded program or research priority. From this author's perspective, SETI proceeds as a sort of subsidiary or adjunct to astrobiology, within the boundaries of “legitimate” astrobiology though located near the outer limits. That said, delineation of the boundaries, and relations, between astrobiology and SETI is, and promises to remain, an ongoing process.

In the current cultural environment, non-experts might be led to conclude that the ultimate goal of astrobiology is to make contact with extraterrestrial intelligent life. For self-described astrobiologists working on SETI, it may be; but for the astrobiology community writ large, it is not. Outside the scientific community, astrobiology is a household word, and even people who might say they do not know what astrobiology is may be engaged with the work that astrobiologists do. This broad, deep, cross-cultural public engagement with the study of the origin and evolution of life and the possibility of extraterrestrial life adds strength to the scientific rationale for astrobiology research and provides a great opportunity to inform people of all ages about science. It also generates opportunities for the rapid global dissemination of misconceptions and misunderstandings.

ET and ETI

One aspect of the study of the origin and evolution of life in the universe that scientists do not yet appear to have found a way to adequately explain to non-experts is the vast knowledge void that remains to be filled between scientific understanding of the emergence of life and the emergence of intelligence in life. Non-experts have far less trouble than scientists do in condensing and simplifying the immense “spaces” of time and complexity that lead to prebiotic chemistry and then to life, to molecules and then to cells, and to microbial life and then to intelligent life. They do this not because they are ignorant but mainly because they are not scientists. They are not trained to think like scientists. And it can be argued that they do not need to be.

The terms “astrobiology” and “SETI” are both widely recognized inside and outside the scientific community. They have scientific (official) and popular meanings. What these terms mean to people who are not scientists is something that members of the scientific community might do well to understand better. Today the idea of extraterrestrial life seems more popular than ever, inside and outside scientific and other scholarly circles. What do members of the astrobiology community mean when they say, write, hear, or read the terms “extraterrestrial” or its abbreviated form “ET”? The word is an adjective, used to modify a noun, which is a representation of a thing, indicating that the thing is beyond Earth. It is also used as a noun, by experts and others, meaning something quite different: an extraterrestrial intelligent being.37

Astrobiologists may believe they are clear about what they mean by “extraterrestrial” or “ET.” How can they be sure that their meanings are clearly conveyed to others? Adding to the complexity of the communication challenge facing the astrobiology community is that astrobiologists continue to debate over exactly what “life” is,38 while neuroscientists and psychologists continue to rethink what “intelligence” is (cf. Neisser et al., 1996; McGrew, 2009). Many pop-culture takes on extraterrestrial life appear to rest on the assumptions that it is common and like Earth life and that intelligence is a typical result of evolution. How might the scientific community improve public understanding of these subjects? How might clarity be provided?

Conclusion

In exploring the roles and functions of astrobiology in culture, it may be useful to think about the story of astrobiology as a cultural narrative (cf. Geertz, 1973). Such narratives are a primary means of creating and sustaining culture, conveying knowledge, values, rules, and norms. They are “a basic human strategy for coming to terms with fundamental elements of [human] experience, such as time, process, and change.”39 These narratives function as texts and as strategies for navigating through life. They are human attempts to make sense of the world. Scientific theories and observations, hypotheses and findings, ideas and facts are also attempts to make sense of the world, from a particular perspective, which we call the scientific worldview.

While narrative theorists continue to explore whether and how broader cultural narratives are similar to or different from scientific methods of explanation, this author would argue that the story of astrobiology is both a scientific, “official” narrative and a broader cultural narrative. The story of astrobiology is a story about science, but it is also more than a science story. The scientific story of the search for life elsewhere is intricately intertwined with the story of how life began on Earth. This story is unfolding in the broader context of a story about who we are and where we are going, and why. Both the scientific and broader cultural narratives of astrobiology are part of the ongoing human endeavor to understand who, what, where, and why we are.

As Iris Fry (2000) notes in her history of the study of origins of life, the possibility of extraterrestrial life and the conduct of missions to search for it are subjects that were long the territory of speculative essays, science fiction, and tabloid newspapers, not science. But over the last half century, science has laid claim to the narrative of life in the universe. Yet astrobiology continues to mean different things to different people, in popular and scientific culture. Social scientific research into the origin and evolution of astrobiology as a specialized program of research in the space sciences, addressing how traditional scientific disciplines aid, abet, or resist the creation of new, multidisciplinary “disciplines” or fields, might shine some light on whether and how this construction process is consistent or variable across cultural boundaries.40 ^, 41

The attitudes and assumptions cited in Dick's (2012) discussion of critical issues—ranging from the labeling of astrobiology as a field or a discipline42 to the public “will to believe” in the existence of extraterrestrial life and extraterrestrial intelligence—are a product of different experiences, worldviews, perspectives, interests, and priorities. A considerable variety of attitudes and assumptions can be found within the scientific community alone. Across the myriad of communities of knowledge and belief, both expert and non-expert, the variety appears to approach the infinite. In communicating with experts and others, how can astrobiologists be sure that the meanings and messages they intend to deliver are received, interpreted, and applied as intended? How can astrobiologists be sure that they are comprehending, let alone answering, questions others ask about the origin, evolution, distribution, and future of life in the universe? While these questions are worth considering, in the context of the preceding discussion they may not be easily answered, if at all.

Scientific views on life and the universe are growing ever more complex. Findings, claims, and theories relating to the physical universe now encompass concepts of phenomena that—at best—may only be observed indirectly—for example, dark matter and dark energy, parallel universes and multiverses, and “weird life” that may be nothing like terrestrial life. The same sort of trend characterizes the field of mass communication. Mass media today are evolving at a pace it is barely possible to keep up with, and social media are democratizing communication. Now anybody can be a journalist, and a single casual blogger can make, if briefly, an impact nearly equal to a story in the New York Times. At the same time, scientists and their funders and employers are trying harder to get the word out about the research they are doing. The rapidly expanding volume and complexity of scientific knowledge and a widely differing array of worldviews make it difficult for non-experts to comprehend the physical world in the same ways that scientists do. Even scientists may have a hard time keeping up with advances in fields other than their own.43

Astrobiology offers new insights into the past, present, and future place of human and other life in space. For example, at the same time that research into the origin, evolution, and distribution of life is revealing that life is highly resilient, these same lines of research are helping to reveal how life and its environment are deeply interdependent, improving understanding of life on Earth and prospects for life elsewhere, and contributing to understanding of global climate history and evolution. The American rhetorical critic Janice Hocker Rushing (1986) has postulated that the post-Apollo-era focus of space exploration on the search for evidence of extraterrestrial life was a product of a widespread understanding that humankind exists in a universe, not just on a planet. From this perspective, the narrative of astrobiology is part of a larger narrative that tells a story of, in Rushing's words, “a spiritual humbling of self.”44

Today the field of astrobiology is growing rapidly worldwide, the pace of scientific discovery in the field is brisk, and the possibility of extraterrestrial life is widely considered to be a serious scientific question, inside and outside the scientific community. As astrobiology continues to evolve, rhetorical boundary-work (Gieryn, 1995) is continually in progress in the field. Delineation of the boundaries of SETI as science and the boundaries, and relations, between astrobiology and SETI is an ongoing process. In the current cultural environment, non-experts might be led to conclude that the ultimate goal of astrobiology is to make contact with extraterrestrial intelligent life. For self-described astrobiologists working on SETI, it may be, but for the astrobiology community writ large, it is not.

This paper provides an overview of the complex social processes involved in constructing the boundaries and relations between exo/astrobiology and SETI. The topic is worthy of more in-depth study. The author offers this analysis as a “phase A” study of the topic. A relativist rather than classical sociological approach to the topic is recommended. As Latour (1996) explains, classical sociology “explains what has happened, blames, denounces, rectifies” (p 199). Relativist sociology, on the other hand, has no fixed reference frame, and relativist sociologists aim to learn what society is composed of from those who are composing it—the boundary-workers, as it were. From a relativist perspective, there is no objective “truth” to find, and all a researcher can do is record the stories people tell her and interpret them according to a theoretical framework of her choice.

Linda Billings is a research professor with the School of Media and Public Affairs at George Washington University in Washington, DC, and a principal investigator with NASA's astrobiology program, doing science communication research. This work was supported by NASA grant NNX09AI58A. The author wishes to thank participants at the Ven symposium for their comments on this paper. The views expressed herein are solely the author's.

Abbreviations

COEL, Committee on the Origins and Evolution of Life; COSPAR, Committee on Space Research; IAU, International Astronomical Union; ISSOL, International Society for the Study of the Origin of Life; NAS, National Academy of Sciences; SETI, the search for extraterrestrial intelligence; SSB, Space Studies Board.