Astrobiology and SETI: different evolutionary pathways




Following up on my last two posts, about astrobiology and the search for extraterrestrial intelligence (SETI), today I’m writing about the separate, non-parallel paths on which astrobiology and SETI evolved.*

Some might perceive that exobiology/astrobiology and SETI are closely linked. Actually, at least at NASA, this is, and has not been, not the case. NASA’s exobiology program and NASA’s SETI program had different origins and developed on different tracks.

In addition, since the 1980s research results in both exo/astrobiology and astronomy and astrophysics have weakened any perceived link with SETI (see yesterday’s post), with both fields focusing more and more intently on understanding the origin and evolution of stars, planets, and life; assessing planetary habitability; and detecting single-celled life as we know it and as we don’t know it. And since the late 1950s, exo/astrobiology has expanded its purview to embrace the comprehensive study of the origin, evolution, distribution, and future of life in the universe, while SETI remains primarily focused on its original, narrow goal: detect radio signals of extraterrestrial technological (that is, intelligent) origin.

Here’s an abbreviated history of the field of exo/astrobiology and NASA’s exo/astrobiology program and of the concept of SETI and NASA’s SETI program.

I’ll start with exo/astrobiology.

Exo/astrobiology arose as a field of study in the late 1950s once scientists realized they would soon have access to space – that is, the ability to look for evidence of life in the solar system.

At that time, Joshua Lederberg (who won the Nobel Prize in Physiology or Medicine in 1958) began communicating with colleagues about the possibility of searching for evidence of extraterrestrial life (not intelligent life) in the solar system.  Through the National Academy of Sciences and other means, Lederberg played a key role in NASA’s establishment of an exobiology program.

In 1959, NASA sent a “work request” to the National Academy of Sciences’ Space Science Board (SSB) for input on “basic philosophical objectives that should underlie” NASA space science activities. In this request NASA stated 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.”

In 1959, NASA funded its first exobiology grant, to Wolf Vishniac, for his Wolf Trap experiment that was intended to fly on the Viking mission to Mars (it ultimately was dropped from the mission due to weight limits).

In 1960, NASA established an exobiology research program. Also in 1960, Lederberg gave a paper on exobiology at a meeting of the Committee on Space Research, then published the paper in Science. He wrote: “Exobiology is no more fantastic than the realization of space travel itself, and we have a grave responsibility to explore its implications for science and for human welfare with our best scientific insights and knowledge.’’

In 1964, the SSB recommended to NASA associate administrator of space science and applications Homer Newell that NASA should 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.”

In the 1980s, responding to input from the scientific community, NASA expanded the purview of the program: it became the exobiology and evolutionary biology program.

Fast forward to the late 1990s, when NASA created 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 2007, the SSB’s Committee on the Origin and Evolution of Life delivered three astrobiology reports to NASA: Exploring Organic Environments in the Solar System, An Astrobiology Strategy for the Exploration of Mars, The Limits of Organic Life in Planetary Systems, and Assessment of the NASA Astrobiology Institute(established 1998).

In 2015, the astrobiology community, in collaboration with NASA’s astrobiology program, produced an astrobiology science strategy that reflects the growth in breadth, depth, and complexity in the field. Currently the astrobiology program is commencing some reorganization to better focus on key questions in astrobiology (subject of a future post).

Now to SETI.

As Steve Dick has documented in his books Plurality of Worlds: The Extraterrestrial Life Debate from Democritus to Kant(1982) and Life on Other Worlds:The 20thCentury Extraterrestrial Life Debate(2001), the idea of extraterrestrial intelligent life is thousands of years old and has been discussed among philosophers, scientists, and others throughout human history.

As to “modern” SETI, I suppose one could say that it began in 1959, when Giuseppe Cocconi and Philip Morrison published “Searching for interstellar communications” in Nature. In their paper they proposed that ground-based telescopes could be used to listen for radio signals of extraterrestrial intelligent origin.

In 1960, astronomer Frank Drake conducted the first U.S. SETI search, Project Ozma, at the Green Bank Observatory in West Virginia.

In 1961, the National Academy of Sciences convened a meeting on SETI at the Green Bank Observatory. Frank Drake and Philip Morrison were in attendance, as was Carl Sagan (see below).

In 1968, John Billingham, a physician by training who had worked with NASA Johnson Space Center on spacesuit technology, joined NASA’s Ames research center in Mountain View, California, as chief of its biotechnology division. Shortly after arriving, he happened to read Soviet astronomer Iosif Shklovskii and Carl Sagan’s book, Intelligent Life in the Universe, published in the U.S. in 1966. (Shklovskii had first published the book in Russian.) Billingham reportedly found the book fascinating, and he began to talk with colleagues at Ames about the possibility of some sort of SETI project at Ames.

In 1969, Hans Mark became director of NASA Ames. Billingham proposed to Mark that NASA do a design study of a system for detecting ETI signals. Mark approved funds for a small study. Billingham oversaw the study in 1970 and then went back to Mark with a proposal for a larger study. Mark approved it.

In 1971, Barney Oliver, then at Hewlett Packard, led the larger study, which produced a concept for a large-scale SETI search called Project Cyclops. The cost of the 10-15 year project was estimated at $6 billion-$10 billion. Obviously, it was a non-starter.

In 1973, SETI researchers at Ames developed a SETI project plan and briefed it to NASA administrator James Fletcher, who did not approve it. In 1974, NASA Ames presented a revised SETI project plan to NASA HQ, and Fletcher approved  $140,000 for SETI in fiscal year 1975.

In 1976, NASA Jet Propulsion Laboratory (JPL) director Bruce Murray proposed conducting an all-sky SETI survey. (The NASA Ames SETI team favored a targeted search.) In 1976, NASA HQ approved $775,000 for a SETI research program to be managed by NASA Ames.

By 1977, SETI funding did not materialize. Mark complained to NASA HQ: “We will be lucky to see a third of that.”

In 1978, Democratic Senator William Proxmire gave SETI a Golden Fleece award. Those awards were intended to bring attention to projects that Proxmire deemed “government waste.”

In 1979, the first joint Ames/JPL SETI program meeting took place. NASA budgeted $300,000 for SETI. In 1980, NASA budgeted $500,000 for SETI, drafted a program plan, and formed a SETI Science Working Group. In 1981, NASA HQ cut the 10-year SETI program plan in half.

In 1981, Sen. Proxmire attached an amendment to NASA’s FY82 appropriations legislation that prohibited spending on SETI. In 1982, Carl Sagan came to SETI’s rescue, obtaining a meeting with Proxmire, the result of which was that Proxmire agreed not to enforce the prohibition. Proxmire told me in a telephone interview (for my chapter in First Contact) that while Sagan’s efforts and NASA’s responses to his questions convinced him that there was just enough sense to SETI to justify the small amount of funding allotted to it, “there’s absolutely no evidence whatsoever” that life exists beyond Earth.

In fiscal year 1983, Congress appropriated $1.6 million for SETI, for the first year of a five-year R&D program.

In 1987 and 1989, Barney Oliver briefed White House officials on SETI, at the request of White House Science Advisor William Graham (who at some point served as acting administrator of NASA).

In 1989, the Ames and JPL SETI teams began advocacy campaigning on Capitol Hill. (It was at this point that I went to work with the SETI program, as a contractor, to help with advocacy planning.) Advocates for the Ames team were SETI Institute employees and not subject to restrictions placed on civil servants.

In October 1992, the two-pronged SETI search – the High-Resolution Microwave Survey – began. In the summer of 1993, Congress canceled the project.

To my mind, the history/evolution of exo/astrobiology more closely parallels the history/evolution of planetary protection. Exo/astrobiology and SETI evolved on very different, non-parallel tracks.

* Much of the information in this post comes from my chapter on NASA’s SETI program, “From the observatory to Capitol Hill,” in Ben Bova and Byron Preiss, eds., First Contact: The Search for Extraterrestrial Intelligence, New American Library, 1990; and from my paper, “Astrobiology in culture: the search for extraterrestrial life as science,” Astrobiology 12(10), 2012. I am a consultant to NASA’s astrobiology program. No one asked me to write this post.




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