It will be especially interesting to see
whether it is astronomy that absorbs biology,
or the other way around. — Fred Hoyle

"True story: During the First Astrobiology Science Conference at NASA's Ames Research Center in April 2000, President Clinton was, by coincidence, landing at the adjacent Moffett Field Air Base, where Air Force One parks when the president comes to the San Francisco area. In a scene right out of The X-Files, one of his Secret Service men, who had stopped a suspicious-looking scientist, was heard to shout anxiously into his walkie-talkie, 'What the HELL is astrobiology!?'...

Increasingly..., astrobiology has become the public face of NASA, in press releases, schools, TV documentaries, and museum exhibits — astrobiology is the new hook. Across a wide spectrum of activities, aliens are in at NASA, like never before...

What happened was that Dan Goldin, NASA's administrator at the time, took heed of the lavish press coverage [of ALH84001] and the enthusiastic public reaction to these discoveries. Halfway through his nine-year tenure at NASA (1992 to 2001), Goldin seemed convinced that exobiology, rechristened as astrobiology*, should largely define NASA's mission and public image. We were given a green light to write press releases and funding proposals highlighting the question of alien life....

It helped that, by the nineties, the second generation of planetologists was becoming well established in the field....**

Astrobiology may at times have been falsely hyped as a scientific revolution or a brand-new discipline, but it is a refreshing and encouraging development. A revolution really is going on — not a scientific revolution, but a revolution in the culture of science, one that is healthy for science in a number of ways.

First, the biocentric tilt of NASA allows us to come clean about our true reasons for wanting to explore and understand the cosmos. Questions about life in the universe have always been behind our exploration of space. We just haven't always been free or willing to admit it...

Of equal significance, astrobiology is bringing our space research more into line with the public's desires for NASA. You could look at this as merely improved marketing, but NASA administrators are encouraging us to pay more attention to what people respond to. As well we should. It is your tax dollars that pay for our science and exploration. We need to avoid [pandering] or [issuing] near reruns of press releases to boost our ratings, but by focusing on the question of life we are giving people what they want...

...Astrobiology's certain radical potential is in the way it bucks two deep trends in modern science. One is the tendency, in recent decades, for science (like everything else) to become much more market-driven. Profit is hot. Pure knowledge is not. An increasing portion of research is corporate-funded, which often blurs the scientific ethics. Particularly in the biosciences, corporate support has led to troubling conflicts of interest between scientists' pursuit of knowledge for the sake of humanity and the pursuit of private gain...

Swimming against this stream is astrobiology. It is not for profit and can't pretend otherwise. We explore space for reasons that are romantic and idealistic. The universe beckons. We want to go because we want to know. With astrobiology there is no fronting the rationale is practical or the benefits material — we do it out of curiosity and longing, to satisfy the human need to know the cosmos that spawned us. Fancy that: a scientific movement that is justified on fundamentally spiritual grounds....

...There may be no turning back. NASA has thrown itself into astrobiology, and our administrators have let the planetary science community know that we are to be astrobiologists. We need the biologists now. By making ourselves dependent on astrobiology we placing a lot of trust in that relationship. This is no longer a flirtation — we're committed to an ongoing dance with biology. A divorce at this time would be messy, embarassing and costly....

One cool thing about planetology has always been the chance to learn a lot of different kinds of science. Now this includes biology, too. For this reason I love going to astrobiology conferences. You never know what you're going to hear. The official support for astrobiology is making scientists braver in attempting to bridge disciplines. I say 'attempting' because we're out of practice at being interdisciplinary, and so there is an aggravating side to it, too. The enticingly eclectic mixture of disciplines can also be a recipe for frustration because we don't all speak the same language. All scientific conferences provide a mixture of fun and exasperation. Astrobiology conferences have more of both."

David Grinspoon
Lonely Planets: the natural philosophy of alien life
Chapter 15, HarperCollins, New York, NY, 2003

* Wes Huntress, the NASA associate administrator for Space Sciences, apparently suggested this title for NASA's renewed commitment to what had formerly been called exobiology.

** It cracks me up to see my grad school contemporaries leading planetary missions, chairing important committees, and pontificating at meetings. They act like real scientists, but I am not fooled.

Recorded Presentations
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Monday, March 29, 2004

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Where Do We Come From?
Paul Davies, Chair

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Cosmology and Life

Mario Livio, Space Science Telescope Institute

Recent findings in cosmology and their implications for the emergence of life in the universe are examined. Specifically: (i) the requirements for carbon-based life and their dependencies on the values of physical constants, (ii) the inflationary model and its implication for the existence of a "multiverse", (iii) the nature of dark energy and its relation to anthropic considerations, (iv) the possibility of time-varying constants in nature, and (v) the question of the potential rarity of intelligent life.

Replicating Vesicles And The Origin Of Life

Jack W. Szostak, Martin M. Hanczyc,
Irene A. Chen, Kourosh Salehi- Ashtiani,
Michael Sacerdote and Shelly Fujikawa.
Howard Hughes Medical Institute and Dept. of Molecular Biology, Massachusetts General Hospital

Cellular life requires both a genetic polymer to encode heritable information, and compartment boundaries to enable Darwinian evolution by linking genotype to phenotype. However, the earliest genetic molecules and cell membranes must have been able to replicate solely in response to chemical and physical forces, because of the absence of any biochemical machinery. Darwinian evolution and life itself may be viewed as emergent properties of systems that combine self-replicating genetic polymers and compartment boundaries.

We have recently described a laboratory demonstration of the replication of membrane vesicles. Membrane growth was based upon the addition of alkaline fatty acid micelles to buffered vesicles, as originally described by Luisi and co-workers. Extrusion through small pores resulted in vesicle division with minimal loss of contents. Repeated cycles of replication were carried out, with continuity of both membrane and contents from generation to generation. Our current work is aimed at finding more pre-biotically plausible scenarios for vesicle replication.

Constraining Scenarios for the Origin of Life:
Working Backwards, Working Forwards,
and Synthesizing Life in the Laboratory

Steven Benner, University of Florida

The origin of life is a puzzle that has long defied traditional hypothesis testing as a research program. Instead, the box containing the historical events that surrounded the emergence of the first chemical systems capable of Darwinian evolution on Earth has been constrained by research that approaches the origin event(s) in four directions: from the big bang forward in time, from the present backwards in time, from missions to the planets, and in the laboratory to understand the governing chemical constraints.

Interpreting the Tree of Life
- Beyond the Text Books

Norm Pace, University of Colorado, Boulder

Phylogenetic trees based on gene sequences of ribosomal RNAs, and other elements of the nucleic acids based information-processing system of cells, outline the evolutionary course of the genetic machinery. As deeply divergent lineages have been discovered and added to the known collection, the resolution of branching orders in the tree of life has improved. The three domains, Bacteria, Archaea and Eucarya are well established by many phylogenetic and biochemical criteria. One of the early radiating lines of descent incorporated a cyanobacterium that became the chloroplast, and a proteobacterium that became the mitochondrion. Possibly this event sparked a subsequent radiation, one line of which again diversified, into the “crown” radiation of plants, animals, stramenopiles, etc.

The Origin of Adaptability and Human Beings

Rick Potts, National Museum of Natural History

The evolution of human beings can be considered an odd and unrepeatable phenomenon, making it difficult to draw general principles of evolution, applicable broadly to life’s origin and evolution, from our own evolutionary history. One possible exception is the evolution of adaptability. Dramatic expansion in the hominin ability to interact with environments was expressed as a small population of tropical African apelike creatures eventually gave rise to a single species, Homo sapiens. The idea to be examined is that the major features of human evolution arose not from the challenges of the African savanna, ice-age Europe, and any other single array of habitat conditions, but rather from the dynamic and unstable qualities of environments.

Tuesday, March 30, 2004

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Are We Alone?
Paul Turner, Chair

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Taking the Galactic Planetary Survey

Gregory Laughlin, University of California, Santa Cruz

Within the past decade, a new branch of Astronomy — the study of alien planetary systems — has been created essentially from scratch. At last count, over 120 extrasolar planets have been detected, and more are being announced each month. The sudden wealth of information from these discoveries has opened up fascinating research areas: Can we increase the efficiency with which planetary systems are detected? Why are the planetary systems discovered thus far so different from our own? Are planetary configurations resembling our own Solar System common within the galaxy? Can terrestrial planets form and survive in orbit around a large fraction of Solar-type stars? When more than one planet can be detected orbiting a particular star, the amount of information that can be leveraged from the data is vastly increased. Multiple-planet systems are telling us a tremendous amount about the planet formation process.

Sympathy for the Devil:
The Case for Life on Venus

David Grinspoon, Southwest Research Institute, Boulder

Venus has not traditionally been considered a promising target for astrobiological exploration. I propose that Venus should be central to such an exploration program for several reasons. All of our ideas about extraterrestrial biochemistry are, of necessity, extrapolations from the single example of life which we have been able to study. Our planetary exploration, with an increasing focus on Astrobiology, is designed to "follow the water". This is a reasonable strategy but it is based, at best, on an educated guess about life’s universals. If we think beyond the specifics of a particular chemical system required to build complexity and heredity, we can ask what general properties a planet must possess in order to be considered a possible candidate for life. The answers might include an atmosphere with signs of chemical disequilibrium and active, internally driven cycling of volatile elements between the surface, atmosphere and interior. At present, the two planets we know of which possess these characteristics are Earth and Venus.

Hyperthermophilic Microorganisms
- A Possibility for Extraterrestrial Life?

Harald Huber, University of Regensberg

Hyperthermophilic microorganisms exhibit optimal growth temperatures above 80°C and represent the upper temperature border of life on our planet. They thrive in continental solfataric areas and submarine hydrothermal systems, where they form complex communities. Hyperthermophiles are highly diverse in their morphology and metabolic properties. Most of these organisms are anaerobes which use inorganic redox reactions as energy sources. These properties enable them to grow in the absence of sunlight. They appear as the most primitive organisms known so far. A nano-sized symbiont/parasite, obtained from a submarine hydrothermal system, represents a novel kingdom of Archaea, the "Nanoarchaeota". and are only 400 nm in diameter (in the range of large viruses). "N. equitans" exhibits a genome size of only 490 kb, one of the smallest genomes known so far. It offers the possibility of providing extraordinary insights into the evolution of thermophily, of minimal genetic equipment of cells, and of inter-species communications.

ALH84001 in 2004

Joe Kirschvink, California Institute of Technology
Atsuko Kobayashi, AIST, Osaka

A good biomarker is difficult to make inorganically. Ideally, it reflects the fingerprints of Darwinian Evolution through Natural Selection. Because iron is an essential trace element in virtually all living organisms, a wide variety of acquisition and storage mechanisms have evolved to meet iron demand. Many of the mechanisms involve precipitation of iron in the form of well-ordered biominerals, including magnetite, greigite, goethite, and lepidocrocite; these provide a set of potential mineral biomarkers that are sometimes preserved in the fossil record. Because their biological function in magnetotaxis is clearly understood, the small magnetite crystals formed within the magnetosomes of the magnetotactic bacteria show some of the clearest fingerprints of natural selection of any bioinorganic material. Magnetofossils, the fossil remains of these bacterial magnetosomes, have been studied extensively for the past 25 years; prior to the ALH84001 debate, their biological origin has not been in question. Ultimately, the origin of the magnetite can be resolved, and if proven, would be definitive evidence for life.

JIMO: Exploration of the Icy Worlds of Jupiter and the Astrobiology Connection

Chris McKay, NASA Ames Research Center

The Jupiter Icy Moons Orbiter (JIMO) is planned as the first in a series of missions in the NASA Prometheus project. JIMO would use nuclear-electric propulsion and nuclear power systems to enable unprecedented exploration in the outer solar system. A NASA Science Definition Team for JIMO, cochaired by T. Johnson and R. Greeley, consisted of 38 scientists and was appointed to formulate the science objectives for the mission. The SDT drew on previous studies by NASA, various National Academy of Sciences reports, and results from a community-wide "Forum" held in the summer of 2003 and attended by 130 scientists. SDT recommendations include a mission statement for JIMO to: Explore the icy moons of Jupiter and determine their habitability in the context of the Jupiter system, which includes three crosscutting themes: Oceans, Astrobiology , and Jovian System Interactions.

Life and Death on Icy Worlds

Jere Lipps, University of California, Berkeley

Life and Death are important on icy worlds. Life on icy worlds occurs in the Solar System and probably throughout the Universe. Among them are Earth (Antarctica, Snowball Earth) and probably one or more of the Icy Moons of Jupiter (JIMs). These worlds provide the three things life requires — the chemicals of life, energy to drive it, and habitats to support it. Death also occurs on icy worlds resulting in potential preservation of life forms and products as fossils that may have a story of the origin and evolution of life on the icy world. On Earth’s current and past icy worlds, life abounded. It lives in close association with ice-shelves and sea ice in Antarctica and the Arctic icy worlds. There life lives easily in a wide variety of sub-ice, inter-ice, and surficial ice habitats. Earth’s fossil record shows that life endured the Neoproterozoic Snowball Earth, covered entirely or substantially by ice; life was not eliminated and opportunities continued over tens of millions of years for its existence. Life has no problem with ice.

Uncovering Extraterrestrial Intelligence:
When Will It Happen, and What Will We Find?

Seth Shostak, SETI Institute

It’s been four decades since the first modern SETI experiment, and researchers have still not recorded a confirmed peep from the cosmos. But new telescopes, improved backend hardware, and novel ways of looking for signals are all accelerating our scrutiny of the sky. While Project Phoenix has carefully examined ~500 nearby, Sun-like star systems over the course of 8 years, the Allen Telescope Array, now under construction, will be able to exceed this number of "targets" in its first year of full operation. Thereafter, its reconnaissance of star systems can be expected to speed up in accordance with Moore’s Law, an empirically observed, exponential growth in the capabilities of digital electronics. Within two dozen years, the number of targets examined by the Allen Telescope Array will tally in the millions. The brute force march of technology is the most probable path in accelerating that first discovery. Indeed, the numbers suggest that such a discovery — if it occurs — will come within our lifetimes.

The Meaning of Life. Astrobiology and Society

Steven Dick, NASA Chief Historian

The National Aeronautics and Space Act of 1958 charges NASA with eight objectives, including "the establishment of long-range studies of the potential benefits to be gained from, the opportunities for, and the problems involved in the utilization of aeronautical and space activities for peaceful and scientific purposes." The new space exploration vision distributed after President Bush’s January 14, 2004 announcement also noted that "exploration of the solar system will be guided by compelling questions of scientific and societal importance." In line with these pronouncements, the NASA History Office has recently placed the societal implications of space exploration under its purview. Space exploration has societal implications at many levels, ranging from commercial spinoffs to applications satellites, humanity’s self-image, and an evaluation of our place in the universe. But perhaps no area of space exploration has more potential for societal implications than astrobiology.

Wednesday, March 31, 2004

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Where Are We Going? The Earth
Stuart Pimm, Chair

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Our Place in the Solar System

Ghassem Asrar, NASA Office of Earth Science

No abstract yet

What are the Future Implications of Population, Affluence and Technology Growth Projections? How can the Future be Scientifically Analyzed?

Steven Schneider, Stanford University

Inordinate contention attends complex socio-technical problems such as global warming. The polarized extremes (end of the world versus good for us) are, I believe, the two lowest probability cases, yet they dominate media and political debates and editorial pages. No responsible scientist would claim to have precise expectations about our climatic future, its implications for nature and our lives or the costs of doing something about it. Nevertheless, a great deal of consensus exists about many aspects of the topic, despite the large uncertainties which accompany other components.

Climate debates often are polarized. Positions are painted in black and white, and people are loath to acknowledge weaknesses in their views, and thus becomes a "courtroom epistemology: It is not my job to make my opponent's case."

Although this attitude permeates politics, it is unacceptable in science. In fact, it is the reason many scientists refuse to participate in the public process. What such 'purist' scientists forget, is that if we don't try to explain what is going on in our fields in the necessary brevity to be heard, someone else — often less qualified — will just do it for us.

Auditing the Earth: Present Changes,
Future Changes, and Irreversibility

Stuart Pimm, Duke University

We use 50 percent of the world's freshwater supply. We consume 42 percent of the world's plant growth. We are liquidating animals and plants 100 times faster than the natural rate of extinction. Such numbers should make it clear that the human impact on our planet has been, and continues to be, extreme and detrimental. Yet even after decades of awareness of our environmental peril, there remains passionate disagreement over what the problems are and how they should be remedied. Much of the impasse stems from the fact that the problems are difficult to quantify. How do we assess the impact of habitat loss on various species, when we haven't even counted them all? And just what factors go into that 42 percent of biomass that we are hungrily consuming? It is only through an understanding of the numbers that we will be able to break that impasse and come to agreement.

The Dynamics of Global Biodiversity:
Insights from the Fossil Record

David Jablonski, University of Chicago

The most striking biodiversity pattern on planet Earth is the latitudinal diversity gradient, with maximum richness of species, higher taxa, and body plans near the equator and a stepwise decline in all three metrics towards the poles. Correlations across latitude between diversity and mean annual temperature (or other covariates with solar energy input) occur in a wide variety of marine and land-based taxa, suggesting that energy or a closely related variable shapes these pervasive trends on a global scale. However, this static picture tells us little of the dynamics underlying the origin and maintenance of this gradient. In a preliminary analysis that begins to integrate the fossil record of marine bivalves – chosen for their high diversity, excellent fossil record and increasingly standardized taxonomy -- with the group’s present-day biogeography, we show that the cradle vs museum debate hinges on a false dichotomy: the tropics are both the primary diversity source and accumulator. Taxa first appear in the tropics and then expand outwards without losing tropical occupancy, while the high latitudes are primarily a diversity sink. The tropics are so rich today not only because they are the source of young taxa, but because the geographic ranges of old, mostly widespread taxa overlap there with young and spatially restricted taxa.

Eyes Wide Shut: Exploring Solutions Past.
Lessons Learned from the Archaeological Record

Anabel Ford, University of California, Santa Barbara

Detecting the nature of our ancient cultural landscape has long been the prevue of archaeology, gathering information from all arenas to piece together the prehistory of an extinct culture. Archaeological interpretations must embrace differences yet there is the struggle with the unknown and unknowable. As a Maya archaeologist, I share examples of how our subtle prejudices can influence our interpretations and what it can take to create a level of objectivity. Once seeing the ancient Maya forest landscape with new eyes, what are the lessons learned?

Thursday, April 1, 2004

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Where Are We Going? Space Exploration
Scott Hubbard, Chair

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New Vision of Exploration: Science at NASA

John Grunsfeld, NASA Chief Scientist

Summary: John Grunsfeld, the last astronaut to touch the Hubble Telescope and new NASA Chief Scientist, outlines the new "National Vision for Space Exploration." The primary goal of this vision is to advance US scientific, security and economic interests through a robust space exploration program. At the core of this vision is the exploration of life. NASA's mission remains "to understand and protect our home planet, to explore the universe and search for life, and to inspire the next generation of explorers."

Astrobiology: Crossing the Threshold
in Space Exploration

Michael Meyer, NASA Ames Research Center

Summary: Michael Meyer lays out NASA's "Astrobiology Roadmap" and calls on the scientific community to join in on this extraordinary multidecadal exploration. "Today, humanity has the potential to seek answers to the most fundamental questions posed about the existence of life beyond Earth." A portion of Meyer's talk is devoted to inviting a larger array of scientists into astrobiology, particularly those that may be unfamiliar with the field and may not know how to begin.

Ecological Forecasting: A New Approach
to Earth Science at NASA

Woody Turner, NASA Office of Earth Science

Summary: NASA possesses the technology to perform ecological forecasting in a manner that no other organization can. Just as the early weather satellites fundamentally changed meteorological forecasting, current- and next-generation earth-orbiting satellites may well act as a similar catalyst, transforming our view of macroecological processes.

Humans in Space

Charlie Barnes, NASA Office of Biological and Physical Research

Summary The Office of Biological and Physical Research is working towards processes that will allow almost indefinite stays in space. Although completely closed recycling systems may never be fully realized, there are projects underway that hold the promise of greatly extending those periods of human spacecraft inhabitation. The systems being investigated now will determine the feasibility of human travel to the other planets in the next several decades.

Moonstruck

Jeffrey Taylor, University of Hawaii

Summary: The accretion of the planets from planetary embryoes was a violent epoch lasting only a a few hundred million years immediately following the formation of the sun. Was there a second cataclysmic bombardment 700 million years later that struck the inner solar system, a bombardment so violent that it may have boiled away the Earth's first oceans and atmosphere? The moon preserves those answers. Taylor outlines the important questions that may drive possible research programs for the coming decade.

The Wonderful World of Back Contamination:
Strep, Lines and 16mm Film

John Rummel, NASA Headquarters

In late 1969, Apollo 12 astronauts landed on the Moon near the site of the Surveyor III spacecraft, which had landed there, near the eastern shore of Oceanus Procellarum, in April 1967. When they returned to Earth, the mission also returned the entire Surveyor TV camera, as well as other selected parts. Subsequently, the camera was partially disassembled, and portions were subjected to microbial sampling and analysis. The results of this sampling was reported to the Second Lunar Science Conference, and one of the groups claimed that a live microbe — Streptococcus mitis — was found, and that it most likely had made the round trip to the lunar surface and back, and survived. Beyond the conference proceedings, this result was first reported widely by print and broadcast reporters as proof that Earth microbes can survive the harsh lunar environment. But did S. mitis really make the trip? And if so, did it make the trip on Surveyor or on Apollo? This talk will examine the strange case of "Streptococcus mitis on the Moon," and discuss what it may mean in terms of a return-to-the-Moon and on-to-Mars program that is being envisioned by NASA. The implications of microbial survival in hostile environments is discussed, and potential methods to ameliorate the in. uence of human-associated microbes on the astrobiological exploration of Mars are put forward.

Mars Program Science Trajectory

Scott Hubbard, NASA Ames Research Center
Jim Garvin, NASA Headquarters

Summary: Although a general outline of rovers, scouts and orbiting spacecraft has been defined for the next decade of Mars exploration, the path that this exploration will assume has been made dependent on the results returned at each stage of the exploration. The verification that water once flowed on the surface of Mars by the Spirit and Opportunity rovers has already partially dictated which approaches in this discovery-driven research should be taken and which should be abandoned.

Biology and the Future of Mars

Chris McKay, NASA Ames Research Center

It is possible that at some time in the future we might recreate a habitable climate on Mars, returning it to the life-bearing state it may have enjoyed early in its history. Our studies of Mars are still in a preliminary state but everything we have learned suggests that it may be possible to restore Mars to a habitable climate. Long part of the intersection of science and fiction, serious studies of planetary ecosynthesis on Mars began after the results of the Viking mission indicated that all the compounds needed for life were present on the surface of Mars is some accessible form. Recent work has focused on the use of climate models to compute the timescales to warm Mars. Planetary ecosynthesis on Mars has implications for the objectives and conduct of robotic and human exploration. In particular the question of forward contamination must be considered in a new way if we wish to control the introduction of life to Mars in advance of planetary ecosynthesis.

Planetary Exploration and Exobiology
in Europe's Aurora Programme

Olivier Angerer, Jorge Vago,
Didier Schmitt, Franco Ongaro
ESA-ESTEC and ESA-HQ

In November 2001, the European Space Agency’s Aurora programme for planetary exploration was approved. This programme aims at formulating and implementing a European long-term strategy for the robotic and human exploration of the solar system bodies that hold promise for finding traces of life. For the foreseeable future, Mars naturally becomes the main object of attention, and as a frame for the long-term planning the time around 2030 has been assumed as start for a crewed mission towards Mars. To gather knowledge and experience on important topics and to develop required technologies robotic missions are foreseen. The first major mission, ExoMars, will focus on the search for past and present life on the Martian surface/subsurface, using a dedicated instrument package called "Pasteur". The second "flagship" mission will be a Mars Sample Return mission. Beyond the robotic missions, longer-term planning and system studies for the crewed mission are ongoing. In the ambitious timeline, technology rehearsal missions are foreseen as well as a crewed mission to the moon.

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These lectures were recorded with financial assistance
from the US National Science Foundation.