Seeking Signs of Life:
Astrobiology at 50
Last week, I was a very privileged observer at NASA’s symposium, ‘Seeking Signs of Life’, to celebrate the 50th anniversary of the exobiology program. A day-long symposium covered everything from the founding politics and economics of the program, to the fantastical predictions for the next 50 years. More than anything, it reaffirmed for me how fantastic and forward looking the multidisciplinary astrobiology community is, and how very much I want to continue to be a part of it.
The event ran from 9 am to 5 pm, and was webcast live from the Lockheed Martin Centre in Arlington VA. Archived videos of the three keynote presentations, and the four panel discussions can be found here. The following is a brief review of the day to whet your appetite!
Keynote: James Lovelock and Lynn Margulis: Exobiology in the Beginning
After opening remarks from James Green, the first keynote was delivered jointly by Professors James Lovelock (University of Oxford, UK) and Lynn Margulis (University of Massachusetts Amherst). Professor Lovelock is best known for formulating the Gaia hypothesis, now approached scientifically as Earth System Science, but has also played a major role in life detection in the solar system and beyond. He spoke of his life as a researcher, describing in a personable and charming way his work on red blood cells, on the life detection equipment for Lunar and Martian missions, and on the speedy scientific revelation that entropy reducing life will modify an atmosphere away from thermodynamic equilibrium, something which may be detectable in distant exoplanets. He politely and offhandedly dismissed the idea of Earth lying within the ‘Goldilocks Zone’ as a ‘silly idea’, as the planet requires life to modify it to make it habitable.
Professor Lovelock was followed immediately by Professor Lynn Margulis who, in her own characteristically eccentric way, reinforced Prof. Lovelock’s comments on the Gaia hypothesis, declaring that we may now call it the Gaia theory, and treat it accordingly. She urged the importance of water to life on Earth, and the importance of life to water on Earth. She ended by proposing changing the name of the planet, to Planet Water.
Panel 1: The Origins and Evolution of Exobiology and Astrobiology at NASA
The first panel discussion was entitled ‘The Origins and Evolution of Exobiology and Astrobiology at NASA’, and was chaired by Roger Launius, from the Department of Space History, at the National Air and Space Musuem, Washington DC. Speaking on the panel were Steven J. Dick, former Chief Historian at NASA, Baruch S. Blumberg, from the Fox Chase Cancer Centre, and Noel Hinners formerly from Lockheed Martin and Director of the Goddard Space Flight Centre.
Steven Dick spoke about the early genesis of astrobiology, citing Percival Lovell as a major trigger in sparking interest for life on Mars. We were told how Josh Lederberg was a catalyst for the astrobiology program at NASA, and was the first to coin the term ‘exobiology’. But why was NASA the one to lead the search for life? Not only because they were the ones going to Mars, he said, but also because they had an active policy of looking for ‘diamonds in the rough’, for funding exciting but non traditional projects like Lynn Margulis’ symbiogenesis research, and James Lovelock’s Gaia project among many others.
Noel Hinners addressed the audience next, dealing principally with the topic of the Viking landings in 1976. He told us how the Viking program was NASA’s first real search for life, and how the public were led to expect a positive result from it. Thus the disappointment felt by them and scientists around the globe caused a long hiatus in Martian exploration not only for the American space program, but for the Soviets too. Dr Hinners expressed his belief that the Viking program was premature, and that we really need significant knowledge about a planetary body before we can design the best suite of life detecting equipment. He believes that a major priority should now be a Martian sample return mission, as there is no substituting a full terrestrial lab.
Finally, Baruch Blumberg spoke, giving a potted history of the NASA astrobiology program. He listed a large number of major players involved from the start, many of whom are major NASA household names. He described the importance of the Martian meteorite ALH84001 (which was purported to contain several lines of evidence pointing to fossil life) in sparking debate and generating new ideas and hypotheses in astrobiological research. Further, he talked of his time as a research director, and how he gave his researchers relatively free reign in order to increase quality as well as quantity of results coming out of NASA.
Panel 2: Understanding the Origin, Evolution and Distribution of Life in the Universe
Following this, the second panel discussion, chaired by Lynn Rothschild of the NASA Ames Research Center, was entitled ‘Understanding the Origin, Evolution and Distribution of Life in the Universe. The panel members were Pamela G. Conrad, from the Planetary Environments Lab at the NASA Goddard Space Flight Centre, Martin Brasier from the Department of Earth Sciences, University of Oxford, and John Corliss, from the Department of Environmental Sciences and Policy, Central European University.
Dr Rothschild presented a concise and informative introduction to the session, defining astrobiology as the three questions: Where did we come from?; Are we alone?; and Where are we going?, the first of which falling within the remit of the panellists.
Pamela Conrad spoke first. She described her work on modelling habitable zones around stars, stating that above all else, a habitable environment depends not only on location, but also on raw materials and on timing. Thus, the nature of the habitable environment and the nature of the inhabitants are inexorably entwined. She mentioned the likelihood of a habitable environment on Earth during the Hadean (4.6 – 3.8 billion years ago), and listed among other things the necessity of a magnetic field and physically stable rocks to make an environment conducive to life.
Following this, Jack Corliss spoke on the research topic that has become his life’s work: the synthesis of life around hydrothermal vent systems. He described how the submarine hot springs were detected remotely, and an expedition planned to investigate, using the submersible ‘Alvin’. After finding these hydrothermal systems teeming with life, Dr Corliss said that the hypothesis of life originating here ‘seemed obvious’. In a series of well presented illustrations, he described how synthesis of organic molecules, organisation into cellular structures, and the adaptation of metabolic processes may all occur at different points within the vent system.
Professor Brasier concluded the session concisely with the presentation of a new concept in the study of Mass Extinctions. He described how, although many extinction events have been accounted for by meteorite strikes, lava flows, and ice ages, these events occur frequently elsewhere within the rock record, without having the same effect on the biosphere. The explanation for this is that the extinctions are driven chaotically, by the collapse of highly interconnected systems. In short, the state of the ecological system determines that small triggers can have large, non-linear consequences.
Following a brief lunch, an award ceremony took place, where various senior contributing members of the program were honoured for their service to the scientific community. Among those recognised were Professors Lynn Margulis and James Lovelock, Michael Meyers, and Baruch Blumberg.
Keynote: Daniel S Goldin
Next on the agenda was the second keynote address, delivered by NASA Administrator Daniel S. Goldin. He spoke of his time at NASA, seeing it through 3 presidential administrations, and the accompanying political and economic changes. The tone of his address seemed somewhat melancholy, bemoaning slow moving NASA for missing out on the biological revolution of the 50’s and 60’s, the lingering bad image of the Association following the Apollo and Challenger catastrophes, and the continuing budgetary constraints on the space program. The content wasn’t all negative though. He described the continuing excitement of the public in response to the astrobiology program and the search for life, despite the lack of concrete results. Further, he expressed the encouraging conclusions from meetings with worldwide religious leaders, that the search for life was not in conflict with those religions. He concluded on the positive note that Exobiology and Astrobiology represented an unprecedented merging of all disciplines, and that by competitively engaging organisations rather than individuals, the field can remain sustainable and productive.
Panel 3: Who Are We? Where Are We Going? Are We Alone? Astrobiology in Culture
Following this, the third panel discussion of the day, chaired by Linda Billings of the School of Media and Public Affairs at the George Washington University, was entitled ‘Who are we? Where are we going? Are we alone? Astrobiology in Culture.’ Sitting on this panel were Marc Kaufman, Science Writer at the Washington Post, Connie Berkta from the Geophysical Lab at the Carnegie Institution, and David Grinspoon, Curator of Astrobiology at the Denver Museum of Nature and Science.
Linda Billings began by introducing the panellists with respect to their journalistic and academic publications, and went on define culture as a process by which reality is maintained and transformed, explaining how astrobiology, being of international interest, plays a fundamental role in cultural development.
MarkKaufman began by professing to not being a follower of Star Trek or of NASA but maintained that this gives him the opportunity to give a public view of the astrobiology program. He went on to say that the public is in fact fascinated by the search for extraterrestrial life, with as many as 80% of polled Americans believing there is life elsewhere in the universe. Further, he applauded the efforts of scientists involved in astrobiology, in their efforts to help him as a non-scientist understand concepts central to their individual research.
Connie Bertka followed, and with her background in science and religion, was able to give a more theistic view of the search for life, already previously touched on my Daniel Goldin. She made the point that when children inevitably ask the questions central to the astrobiology program: ‘Why are we here? Where did we come from?’ and ‘Where are we going?’ then most parents will turn not only to science, but also to religion, for answers. She presented the figure that 42% of Americans still don’t accept the concept of evolution, and that this figure hasn’t changed in 50 years. Such a fact is discouraging, and it contributes to making the question of the origin and evolution of life especially challenging, as most people turn to religion. However, she said, the numbers of people describing themselves as ‘Spiritualist’, both from a theistic and an atheistic point of view, has risen, and this reflects an encouraging increase in independent thought, rather than institutionalised religion.
Finally, we were addressed by David Grinspoon, who as the only curator of astrobiology in a major museum, can claim in his collection such artefacts as the original Miller-Urey apparatus, and many Earth and space rocks illustrating the search for life. He discussed how astrobiology at NASA has an excellently integrated Education and Public Outreach program, that is helping improve the reputation and image of scientific debate. He mentioned how truly interdisciplinary astrobiology is, and how it is a fun and positive way of presenting scientific connections to the public.
Panel 4: Homing in on ET Life: Where and How to Look
The final discussion panel of the day was entitled ‘Homing in on ET Life: Where and How to Look’, and was moderated by Michael A. Meyer of the Mars Exploration Program at NASA HQ. Panellists were Daniel P. Glavin from NASA Goddard Space Flight Centre, Victoria Meadows from the Virtual Planetarty Laboratory at the Department of Astronomy, Univeristy of Washington, and Steven A. Benner from the Foundation of Applied Molecular Evolution.
Daniel Glavin was first to speak, and he described the excitement that the discovery of organic compounds and materials in meteorites such as the Martian rock ALH84001 and the carbonaceous chondritic Murchison meteorite. Despite the fact that life signatures in ALH84001 have been all but disproven, the stir that their initial report caused is undeniable. Results from the Murchison meteorite and others showed that there are without a doubt organic compounds in space, as well as abundant carbon bombarding all cosmic objects. The major challenge however, he said, would be finding a signature for life among that abundant carbon, and that this would be a target for the upcoming Mars Science Laboratory rover to be launched this year.
Vikki Meadows followed, with a discussion of the search for life outside the solar system. She began by questioning: ‘Where is life most likely to be?’ As energy and nurtients are fairly easy to come by around stars, the so-called rate limiting step would be the presence of a liquid solvent such as water. Thus, she said, the habitable zone around a star where it is neither too hot or too cold for liquids to exist, would be the best place to start looking. She maintained that this may not be the only place that life exists, but that in the great vastness of space, it is the best place to start. She finished by mentioning some of the exciting possibilities for detecting life on extra solar planets, such as looking for the ‘glint of light reflecting from off oceans’ or the characteristic reflectivity of forests.
The panel was concluded by Steve Benner, who began by distributing five beautiful rocks around the audience, two of which were real fossils, and three remaining questionable. His point in doing this was to demonstrate the difficulty in identifying historical life here on earth, let alone elsewhere in the universe. He discussed how, in trying to define life, our ‘Laundry List’ only describes terrestrial life, and that it may be different elsewhere. Even scientists from different disciplines take different views, he said, quoting that modelling physicists and biologists believe life is easy to start, whereas chemists see the chemistry of life as extremely difficult to get going.
Keynote: Steve Squyres: The Next 50 Years
The concluding keynote address was delivered by Steve Squyres of the Department of Astronomy, Cornell University, and looked forward to the next 50 years of the Exobiology Program. Being primarily concerned with Martian exploration Professor Squyres focussed on the fascinating topic of explorative missions to be considered in the Decadal Plan and beyond. The day could not have ended on a more exciting and engaging topic. Stressing that none of the missions he was about to describe would necessarily be pursued within the next ten years, he went on to outline marvellously fantastical proposals for investigating Venus, Titan, Mars, the Moon, Asteroids and Comets. Comet surface sample return to non-cryogenically collect and return cometary material to Earth; a Mars trace gas orbiter to monitor the composition and distribution of methane on the red planet; and the Mars Polar Lander to observe changes in the polar ice caps and potentially look for life, were among some of the far reaching but achievable goals. Longer term mission proposals included a three-phase Martian sample return, a Titan lake lander and submersible suite, and a Europa ice drill and submersible. I personally sat, open mouthed and amazed that these missions were being seriously considered and could take place within my lifetime.
What a fantastic way to end the day! As I shuffled out among NASA’s brightest and best, I was filled with an overarching sense of awe and motivation. To be a part of this world, whether academic or professional, is a privilege that a meeting like this can really help to push home. I look forward to the next 50 years!
Don’t forget, that the archived videos can be found here, also watch this space for further comments and discussion on some of the topics discussed at the symposium.