III. A Revolutionary Organic Habitable UniVerse
H. An Astrochemistry to Astrobiological Fertility
Sephton, Mark. Organic Matter in Ancient Meteorites. Astronomy & Geophysics. 45/2, 2004. These nutrient fragments serve as cosmic time capsules which reveal early chemical steps toward life. They contain biological molecules of extraterrestrial origin that help fill in the course of complexifying animate matter.
Smith, Ian. Reactions at Very Low Temperatures. Angewandte Chimie. 45/18, 2006. A survey of the latest research in astrochemistry – the search for complex molecules in the interstellar reaches – which has now found over 135 biochemical precursors.
Smith, Ian, et al, eds. Astrochemistry and Astrobiology. Berlin: Springer, 2013. With coeditors Charles Cockell and Sydney Leach, an initial volume in a “Physical Chemistry in Action” series. A stellar cast of active scientists proceed to root and connect living beings ever more deeply in and continuous with an increasingly conducive, animate matter. Chapters run from “The Molecular Universe” by Maryvonne Gerin, “Planetary Atmospheres and Chemical Markers for Extraterrestrial Life,” Lisa Kaltenegger, onto “Life, Metabolism and Energy,” Robert Pascal and “The Physical Underpinnings of Replication” by Rebecca Turk-MacLeod, Ulrich Gerland, and Irene Chen. For effect, we join this volume with a concurrent December 2012 issue of Accounts of Chemical Research on “Origins of Chemical Evolution.” In our midst, so far unbeknownst, an innately fertile genesis universe is becoming revealed as a credible discovery, indeed a cosmic Copernican revolution.
The origin of life was a special point in our history when the principles of physics and chemistry first blossomed into the complex interactions that characterize living organisms. Biological phenomena, like replication, can be thought of as emerging from deeper microscopic structural and dynamic properties, in the same way that the physical phenomenon of friction emerges from microscopic interactions among materials. Although living organisms today are often so sophisticated that it can be difficult to see the roots of physical chemistry in their everyday operation, the very first organisms and transitional form would have been quite close to those roots. (Turk-MacLeod, 271)
Snyder, Lewis. Interferometric Observations of Large Biologically Interesting Interstellar and Cometary Molecules. Proceedings of the National Academy of Science. 103/12243, 2006. An example of our collaborative ability to explore and find an organic universe with a natural propensity to form precursors of complex, evolving life. The paper by William Klemperer, Interstellar Chemistry, in the same issue is also notable.
Interferometric observations of high-mass regions in interstellar molecular clouds have revealed hot molecular cores that have substantial column densities of large, partly hydrogen-saturated molecules. Many of these molecules are of interest to biology and thus are labeled “biomolecules.” Because the clouds containing these molecules provide the material for star formation, they may provide insight into presolar nebular chemistry, and the biomolecules may provide information about the potential for the associated interstellar chemistry for seeding newly formed planets with prebiotic organic chemistry. (12243)
Sole, Ricard and Andreea Munteanu. The Large-Scale Organization of Chemical Reaction Networks in Astrophysics. Europhysics Letters. 68/2, 2004. As a self-regulated biosphere, earth’s far-from-equilibrium atmosphere exhibits a scale-free, modular, hierarchical topology similar to cellular metabolic networks. For chemicals found in the interstellar medium, a simpler reaction graph structure holds. These two basic types of networks can then be associated with the presence or absence of extrasolar planetary life.
Ulmschneider, Peter. Intelligent Life in the Universe. Berlin: Springer, 2003. A recent review set within a Darwinian frame but whose perspective allows cosmic and earthly evolution to be distinguished by ‘a long-range direction’ of the growth of information.
Vakoch, Douglas and Matthew Dowd, eds. The Drake Equation: Estimating the Prevalence of Extraterrestrial Life through the Ages. Cambridge: Cambridge University Press, 2015. The collection is a 2010s retrospective and update of astronomer Frank Drake’s (who at 85 writes a Foreword) 1961 attempt to estimate the probability of extraterrestrial civilizations. As an equation, it involves seven aspects: the rate of galactic star formation, how many suns have planets, the number of orbital worlds, how many are then habitable, then bearing intelligent life, onto communicative civilizations, and finally their relative lifetime. The book proceeds with chapters which consider both pre-1960 versions, and what has been learned since for each component. Of course the 21st century breakthrough discoveries of prolific orbital planets factors largely. Historian Steven Dick introduces, while e.g., Chris Impey views solar systems, David Des Marais on the likelihood of life, and Seth Shostak aptly looks at the detection of signals. The chapter Fraction of Life-Bearing Planets on Which Intelligent Life Emerges, fi, 1961 to the Present by ethnologist Lori Marino is reviewed separately.
Vakoch, Douglas, ed. Communication with Extraterrestrial Intelligence. Albany: State University of New York Press, 2011. Wherein leading advocates such as Jull Tarter, Seth Shostak, Samantha Blair, Frank Drake, Kathryn Denning, and many others entertain celestial visions from exoplanets to an intergalactic Rosetta language. A typical paper might be “Pragmatism, Cosmocentrism, and Proportional consultation for CETI” by Marc Lupisella.
In April 2010, fifty years to the month after the first experiment in the Search for Extraterrestrial Intelligence (SETI), scholars from a range of disciplines--including astronomy, mathematics, anthropology, history, and cognitive science--gathered at NASA's biennial Astrobiology Science Conference (AbSciCon) for a series of sessions on the search for intelligent life. This book highlights the most recent developments in SETI discussed at that conference, emphasizing the ways that SETI has grown since its inception. The volume covers three broad themes: First, leading researchers examine the latest developments in observational SETI programs, as well as innovative proposals for new search strategies and novel approaches to signal processing. Second, both proponents and opponents of "Active SETI" debate whether humankind should be transmitting intentional signals to other possible civilizations, rather than only listening. Third, constructive proposals for interstellar messages are juxtaposed with critiques that ask whether any meaningful exchange is possible with an independently evolved civilization, given the constraints of contact at interstellar distances, where a round-trip exchange could take centuries or millennia. (Publisher)
Van Dischoeck, Ewine. Astrochemistry of Dust, Ice and Gas. Faraday Discussions.. 168/9, 2014. Online at arXiv:1411.5280, the Leiden University and MPI Extraterrestrial Physics researcher describes a celestial expanse which by its innate nature appears as a fertile milieu for organic life and evolution. See also Water: From Clouds to Planets by Ewine van Dishoeck, et al at arXiv:1401.8103.
A brief introduction and overview of the astrochemistry of dust, ice and gas and their interplay is presented, aimed at non-specialists. The importance of basic chemical physics studies of critical reactions is illustrated through a number of recent examples. Such studies have also triggered new insight into chemistry, illustrating how astronomy and chemistry can enhance each other. Much of the chemistry in star- and planet-forming regions is now thought to be driven by gas-grain chemistry rather than pure gas-phase chemistry, and a critical discussion of the state of such models is given. Recent developments in studies of diffuse clouds and PDRs, cold dense clouds, hot cores, protoplanetary disks and exoplanetary atmospheres are summarized, both for simple and more complex molecules, with links to papers presented in this volume. In spite of many lingering uncertainties, the future of astrochemistry is bright: new observational facilities promise major advances in our understanding of the journey of gas, ice and dust from clouds to planets. (Abstract)
Van Dishoeck, Ewine. Astrochemistry: Overview and Challenges. arXiv:1710.05940. The Leiden Observatory professor of molecular astrophysics is also president-elect of the International Astronomical Union. This posting surveys the robust confirmation of an interstellar and extragalactic medium that seems to innately form and seed itself with increasingly complex chemicals and bioprecursors. Might one muse that they are just the materials that planets need to form and life to evolve so we peoples might achieve their intelligent description? It is to appear as a chapter in IAU Symposium 332: Astrochemistry VII: Through the Cosmos from Galaxies to Planets (2018).
This paper provides a brief overview of the journey of molecules through the Cosmos, from local diffuse interstellar clouds and PDRs to distant galaxies, and from cold dark clouds to hot star-forming cores, protoplanetary disks, planetesimals and exoplanets. Recent developments in each area are sketched and the importance of connecting astronomy with chemistry and other disciplines is emphasized. Fourteen challenges for the field of Astrochemistry in the coming decades are formulated. (Abstract)
Vukotic, Branislav and Milan Cirkovic. Astrobiological Complexity with Probabilistic Cellular Automata. Origins of Life and Evolution of Biospheres. Online July, 2012. In an extensive paper, also arXiv:1206.3467, Astronomical Observatory Belgrade astrophysicists consider how a nonlinear “digital perspective” analysis might help quantify the appearance and proliferation of life, intelligence and civilizations across the Milky Way. See also their 2010 “Cellular Automation of Galactic Habitable Zone” at arXiv:1001.4624, and from Russia, “Where is Everybody: New Approach to the Fermi Paradox” arXiv:1007.2774 by I. V. Bezsudnov and A. A. Snarskii. And noted above, Cambridge University Press has published a major 2012 work by Cirkovic The Astrobiological landscape.
The search for extraterrestrial life and intelligence constitutes one of the major endeavors in science, but has yet been quantitatively modeled only rarely and in a cursory and superficial fashion. We argue that probabilistic cellular automata (PCA) represent the best quantitative framework for modeling the astrobiological history of the Milky Way and its Galactic Habitable Zone. The relevant astrobiological parameters are to be modeled as the elements of the input probability matrix for the PCA kernel. With the underlying simplicity of the cellular automata constructs, this approach enables a quick analysis of large and ambiguous space of the input parameters. We perform a simple clustering analysis of typical astrobiological histories with “Copernican” choice of input parameters and discuss the relevant boundary conditions of practical importance for planning and guiding empirical astrobiological and SETI projects. In addition to showing how the present framework is adaptable to more complex situations and updated observational databases from current and near-future space missions, we demonstrate how numerical results could offer a cautious rationale for continuation of practical SETI searches. (Abstract, Vukotic & Cirkovic)
Webb, Stephen. If the Universe is Teeming with Aliens-- Where is Everybody? New York: Copernicus Books, 2002. A wide ranging survey, appropriate to the subject, which considers 50 possible answers to Enrico Fermi’s famous question about extraterrestrial life. Webb’s own persuasion is that they are not there at all, earth life is unique. In a second 2015 edition next, the intense phase of global scientific discovery since 2002 appears to confirm this.