NASA Astrobiology Institute Director’s Corner
In the first of these columns I wrote about addressing the challenges to astrobiology. One way of addressing those challenges is to have a compelling “story.” The story of astrobiology answers the question “What is astrobiology?” The astrobiology community came together in the late 1990’s to answer this question in the first Astrobiology Roadmap. Here’s what they said:
Astrobiology is the study of the origin, evolution, distribution and destiny of life in the universe. It uses space technologies to address some of the most profound questions of human kind: How did life begin? Are there other planets like Earth? and What is our future as terrestrial life expands beyond the home planet? These questions are age-old. But now, for the first time in human history, advances in the biological sciences, space exploration and space technology make it possible for us to answer them.
They went on to summarize the disciplines of astrobiology and the missions and facilities that would make contributions, and finished this way:
By harnessing the power of knowledge and technology, astrobiologists seek to discover the intricate chain of cause-and-effect that determines how life originates and evolves, and the resultant implications for the destiny of worlds.
Later in the Roadmap the three profound questions addressed by astrobiology were rephrased as
- How does life begin and evolve?
- Does life exist elsewhere in the universe?
- What is life’s future on Earth and beyond?
This articulation of what astrobiology is all about has largely survived the test of time. The second Astrobiology Roadmap, developed by the community in 2002-2003, preserves the three rephrased questions and only slightly modifies the one-sentence definition to read
Astrobiology is the study of the origins, evolution, distribution, and future of life in the universe.
Still, I wonder if this captures the full significance of astrobiology. I believe that astrobiology is at the cutting edge of a change in world view as potentially profound as was the Copernican Revolution nearly 500 years ago. That revolution did not just replace a geocentric with a heliocentric cosmology, it ultimately overturned previous concepts of knowledge, authority, and governance. It established that humans could seek and discover truth by means of their own faculties and inventions without recourse to ecclesiastical interpretation of scripture. Once this was resolved, it was only one more step to argue that people could govern themselves without recourse to the divine right of kings. When John Locke made that connection between scientific and political thought almost 150 years after Copernicus, he laid the foundation for another Revolution, that of the American colonies against the English monarchy.
How could astrobiology have implications as momentous as those of the Copernican Revolution and the Enlightenment, I hear you ask. I don’t know and neither does anyone else. But I think about it this way. For roughly the last century we have sought to understand the nature of the universe using the principles of physics, chemistry, and geology as applied through subdisciplines such as astrophysics, space physics, geophysics, geochemistry, and cosmochemistry. We have in turn used the technologies that support these disciplines: the telescopes and detectors of astronomy; the elemental and mineralogical probes of meteoritics and geochemistry; the accelerators of particle physics, to name just a few.
We are now beginning to integrate biology into our understanding of the universe by posing questions that can only be addressed by applying biology alongside the more traditional disciplines. We now know that we cannot understand the chemistry of Earth’s atmosphere or oceans without understanding the impact of biological processes. We now have ample reason to believe that there are billions of other planets in our galaxy and that a broadened and more general concept of biology may be necessary to understand future observations of some of them. We now question why the physical constants of the universe seem to have values within narrow ranges that permit the existence of life. And we are beginning to use the tools of modern biology to understand how we might detect life on other worlds and how life might have begun on this one.
Integrating biology into our quest for knowledge about the universe implicitly reflects an extension of our concept of the scope of universal processes. It has been common to hear the origin and evolution of the universe described as starting with the Big Bang and continuing through the formation of galaxies, stars, and planets. Now we speak of it continuing through the development of life and even intelligence. We speculate that the development of life in some form may indeed be a universal process and search for evidence that it may have evolved into intelligence somewhere beyond Earth.
An excellent statement of this perspective was written for a 1996 workshop: “The study of Origins follows the 15 billion year long chain of events from the birth of the Universe at the big Bang, through the formation of the chemical elements, of galaxies, stars, and planets, through the mixing of chemicals and energy that cradled life on earth, to the earliest self-replicating organisms and the profusion of life.” The results of this workshop on “The Search for Origins” were presented to then Vice-President Al Gore, leading to a Presidential initiative called the Origins Program that included funding to add the Astrobiology Institute to the Exobiology Program, beginning today’s Astrobiology Program.
I am not entirely alone in thinking that we are at an epochal change in the development of human thought. Joel Primack, a cosmologist at the University of California at Santa Cruz, and Nancy Ellen Abrams, a lawyer, writer, and former Fulbright scholar with a long-term interest in the history, philosophy, and politics of science, have written a book entitled “The View from the Center of the Universe.” They begin with the ongoing scientific revolution in cosmology, but arrive at the same conclusion I have reached starting with astrobiology. Their view is that “Today’s scientific revolution is as powerful as the revolution wrought by Copernicus, Galileo, and Newton, but few people yet realize this. Historical shifts of such magnitude are rarely visible until later. The average person who was Copernicus’s or even Newton’s contemporary would not have fully appreciated the implications of overturning the medieval cosmology.”
If we are indeed at such a pivotal time in the development of human thought and culture, and if astrobiology indeed embodies some of the most salient concepts of this revolution, then it behooves us to tell the story of astrobiology in these striking terms. This may be the most important answer not only to the question “What is astrobiology?” but also to the question “Why does astrobiology matter?”
