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III. Ecosmos: A Revolutionary Fertile, Habitable, Solar-Bioplanet, Incubator Lifescape

G. An Astrochemistry to Astrobiological Spontaneity

ABSCICON Astrobiology Science Conference 2015: Habitability, Habitable Worlds, and Life. www.hou.usra.edu/meetings/abscicon2015. This June event in Chicago with many premier presenters conveys how these Earthwise frontiers of a fertile genesis cosmos that fills itself with an evolutionary emergence of ovular bioplanets presages such a 21st century revolution. The list of papers and posters runs into the hundreds. The week opened with a plenary talk by James Kasting on Sustained Habitability on a Dynamic Early Earth. Concurrent sessions each day such as The Diversity of Worlds: Comparative Planetology and Habitability, Major Transitions in Evolution: Catalysts and Constraints, and Laws of Life: Exploring Universal Biology proceeded to imply an inherently life-friendly universe. Extended abstracts are available on a Program page, everyone in the field seemed to speak such as Sara Walker, Paul Davies, Lisa Kaltenegger, Leroy Cronin, Nigel Goldenfeld, Charles Lineweaver, Robert Hazen, and Abel Mendez. A few titles are Chance and Necessity in the Mineral Evolution of Terrestrial Planets, On Detecting Biospheres from Thermodynamic Disequilibrium in Planetary Atmospheres, and The Emergence of Life as a First Order Phase Transition. See also AbSciCon 2017 in Organic Cosmos for a further focus on Diverse Life and its Detection on Different Worlds, by a similar stellar cast.

Recent years have witnessed dramatic advances in our understanding of the early steps in the transition from a prebiotic world to a world transformed by a biotic component. These early steps are presumed to include the evolution of collectively autocatalytic networks of molecules, as well as the evolution of protocells that define the boundary between living and non-living matter. Since the earliest cellular life, innovations caused by gene duplication and divergence, novel gene fusions/fission, and transfer of genes between phylogenetically distinct groups have led to an explosive diversification of the metabolic and regulatory networks within cells, enabling colonization of new environmental niches as well as new mechanisms for cooperative interactions between cells. The hierarchy of life — genes within genomes, organelles within cells, cells within organisms, and organisms within societies — is not a starting condition of the evolutionary process, but an outcome of a series of major transitions in which units of low complexity combine to form units of high complexity. Ongoing revolutions in genomics and informatics are giving new insights into the process by which such transitions occur. (The Origin and Subsequent Evolution of Life Plenary Session)

Biological evolution is typically depicted as a passive process, whereby life is shaped by its environment. However, in reality life is strongly coupled to its planetary environment: evolution is a complex, dynamical process with feedback between environment and organisms. Thus, environments reflect and record not just geochemical processes, but the interaction of biology and geochemistry. This interplay between life and planetary processes is important on our own planet, where it has shaped the co-evolution of life and Earth, and should be equally important for extraterrestrial ecosystems. This requires deriving insights into universal principles that might underlie biological organization within a planetary context. (The Evolution of Metabolic Conditions)

European Space Administration. www.lifeinuniverse.org/noflash/liu. An informative, graphic exposition from Cosmology to the Origin of Life and onto Social Implications.

List of Interstellar and Circumstellar Molecules. en.wikipedia.org/wiki/List_of_interstellar_and_circumstellar_molecules.. A comprehensive, up-to-date Wikipedia posting that in March 2014 cited over 200 complex, mostly organic, compounds in the cosmic spacescape. They are neatly arranged in classes of diatomic, triatomic, then four to ten or more atoms, denatured, and others.

National Aeronautics and Space Administration NASA. www.astrobiology.arc.nasa.gov. One of the premier science and cosmic panorama sites on the Internet.

Anbar, Ariel and Edna DeVore. The Astrobiology Science Conference 2008. Astrobiology. 8/2, 2008. An introduction to the Abstracts from 39 Sessions with hundreds of papers across the widest range that a sentient bioplanet beginning to survey its natural, solar, galactic, and cosmic environs could obtain. For an example of topics: Human Exploration of Mars, Astrovirology, Habitable Extrasolar Planets, Universal Intelligence, and Microbial Consortiums. Plenary speakers included Sir Martin Rees, Paul Davies, and Sara Seager. The above authors note that this annual Santa Clara, CA meeting began modestly in 2000 and is now a major international event. But a common philosophical vista and quest is not joined in the contributions which could realize a greater phenomenal, self-witnessing genesis. Yet our sample quotes can convey an imminent, salutary cosmic Copernican revolution if we might be so mindful.

In this talk, we discuss the prospects for a new cosmological modeling paradigm which treats the evolution of the universe in full generality, as the complex, nonlinear dynamical system that it is. We will explore the possibility that the emergence of complex structures will in turn provide insight into the likelihood of the emergence of life in the universe. (419, Steven Weinstein)

Using a hypothetical molecular system called an autocell as an exemplar, I argue that a quite general logic involving the co-dependence of two reciprocal self-organizing molecular processes—autocatalysis and self-assembly of molecular enclosures— may be the simplest molecular system able to self-replicate and maintain self-similar chemical dynamical identity… (453) Because of its simplicity, and the plausibility of instantiating it in a wide variety of molecular substrates, supporting it in non-aqueous solutions, and in extreme conditions, the spontaneous emergence of autocellularity might be a widespread phenomenon in the universe. (453, Terrence Deacon)

Arney, Gilda, et al. Organic Haze as a Biosignature in Anoxic Earth-like Atmospheres. International Journal of Astrobiology. 18/4, 2018. GA and Shawn Domagal-Goldman, NASA Goddard Space Flight Center, and Victoria Meadows, NASA Astrobiology Institute, report how the early Earth (Archean eon 3.8–2.5 billion years ago) was covered a complex haze such as biogenic organic sulfur gases (CS2, OCS, CH3SH, and CH3SCH3) within complex clouds of precursor chemicals. As this vital envelope becomes more specified, its properties can serve as a reference for evaluating exoplanets with regard to their relative habitability.

Bains, William. What do We Think Life Is? International Journal of Astrobiology. Online September, 2013. A British astrobiologist associated with Earth and Planetary Sciences, MIT, and SENS Research Foundation Laboratory, Cambridge, UK, contends that this fledgling field needs a better definition of what “living things” are to rightly proceed. Four vital properties are then cited: complex structure, dynamic self-maintenance, natural groups of organisms, and an internal formative code. These qualities are also seen to complement the “programme-metabolism-container” triad of theorist Mark Bedau and others.

The conundrum of finding a ‘definition’ for life can be side-stepped by asking how people actually identify examples of life, and using this as the basis for life detection strategies. I illustrate how astrobiologists actually select things that are living from things that are not living with a simple exercise, and use this as the starting point to develop four characteristics that underlie their decisions: highly distinctive structure (physical or chemical), dynamic behaviour (physical or chemical), multiple instances of life forming a ‘natural group’ and that the structural and dynamic characteristics of the group are independent of the details of the substrate on which life is growing. I show that these all derive the role of a code in the dynamic maintenance and propagation of life. I argue that evolution is neither a useful nor a practical way of identifying life. I conclude with some specific ways that these general categories of the observable properties of life can be detected. (Abstract)

Barge, Laura, et al. Determining the ‘‘Biosignature Threshold’’ for Life Detection on Biotic, Abiotic, or Prebiotic Worlds. Astrobiology. April, 2022. Jet Propulsion Laboratory and NASA Goddard Space Flight Center astro-researchers sketch out necessary considerations to instrument and detect signs of life over this procession from minimal animation to complex precursors for organic evolution. We note that a basic assumption seems to be a natural fertility which proceeds on its way wherever possible, an imminent 21st century revolution.

The field of prebiotic chemistry has shown that complex organic systems that exhibit life-like properties can be produced abiotically in the laboratory. Understanding these chemical reactions is important for astrobiology since we do not know the extent to which they might exist on other worlds. To interpret organic signatures detected during a planetary mission, we advocate for (1) gaining a more complete understanding of prebiotic/abiotic chemical possibilities in diverse planetary environments and (2) involving experimental prebiotic samples as analogues when generating comparison libraries for ‘‘life-detection’’ mission instruments. (Excerpt)

As a community, astrobiologists should develop a sample collection of complex abiotic organic standards, drawing from OOL experiments and from synthetic chemistries, as well as experiments that simulating this early stage on diverse exoplanets. Designing mission instruments relative to detection limits of molecules, minerals, or other measurement can be advantageous. However, it is important to keep in mind that the ‘‘life detection’’ threshold may be specific to a planetary environment and geologic history. (9)

Bergner, Jennifer, et al. Astrochemistry with the Orbiting Astronomical Satellite for Investigating Stellar Systems (OASIS). arXiv:2111.07456. A 17 member team from the USA, Denmark, Sweden, France, Germany, and the Netherlands, including Brett McGuire and Daewook Kim review how this latest instrument will much expand our Earthuman knowledge all about the fertile spacescape from which life and people arose.

Astrochemistry along the star- and planet-formation sequence studies how prebiotic carriers of the elements CHNOPS are incorporated into nascent planetesimals and planets. Here, we highlight advances that will be possible with the Orbiting Astronomical Satellite for Investigating Stellar Systems (OASIS), a NASA mission concept for a space-based observatory that will utilize an inflatable 14-m reflector along with a heterodyne receiver system. Line surveys of star-forming regions, including high-mass hot cores, protostellar outflow shocks, and prestellar cores, will also be surveyed for high-excitation organics and small hydrides. (Abstract excerpt)

Berne, Olivier and A. G. G. M. Tielens. Formation of Buckminsterfullerene (C60) in Interstellar Space. Proceedings of the National Academy of Sciences. 109/401, 2012. As the Abstract details, Leiden University astrochemists are able to add the discovery of this megamolecule to a conducive nebulae nursery filled with complex biological precursors.

Buckminsterfullerene (C60) was recently confirmed as the largest molecule identified in space. However, it remains unclear how and where this molecule is formed. It is generally believed that C60 is formed from the buildup of small carbonaceous compounds in the hot and dense envelopes of evolved stars. Analyzing infrared observations, obtained by Spitzer and Herschel, we found that C60 is efficiently formed in the tenuous and cold environment of an interstellar cloud illuminated by strong ultraviolet (UV) radiation fields. This implies that another formation pathway, efficient at low densities, must exist. Based on recent laboratory and theoretical studies, we argue that polycyclic aromatic hydrocarbons are converted into graphene, and subsequently C60, under UV irradiation from massive stars. This shows that alternative—top-down—routes are key to understanding the organic inventory in space. (Abstract, 401)

Bishop, Shawn and Ramon Egli. Discovery Prospects for a Supernova Signature of Biogenic Origin. Icarus. 212/2, 2011. As the Abstract details, European astrophysicists report a remarkable indication of a biologically active and intrinsically fecund interstellar milieu. The Abstract contains the fascinating technical details. Who are we Homo Sapiens to be able to do and find such revelations?

Approximately 2.8 Myr before the present our planet was subjected to the debris of a supernova explosion. The terrestrial proxy for this event was the discovery of live atoms of 60Fe in a deep-sea ferromanganese crust. The signature for this supernova event should also reside in magnetite (Fe3O4) microfossils produced by magnetotactic bacteria extant at the time of the Earth-supernova interaction, provided the bacteria preferentially uptake iron from fine-grained iron oxides and ferric hydroxides. Using estimates for the terrestrial supernova 60Fe flux, combined with our empirically derived microfossil concentrations in a deep-sea drill core, we deduce a conservative estimate of the 60Fe fraction as 60Fe/Fe ≈ 3.6 × 10−15. This value sits comfortably within the sensitivity limit of present accelerator mass spectrometry capabilities. The implication is that a biogenic signature of this cosmic event is detectable in the Earth’s fossil record. (Abstract, 960)

Blake, Geoffrey and Edwin Bergin. Prebiotic Chemistry on the Rocks. Science. 520/161, 2015. Praise for a paper The Comet-Like Composition of a Protoplanetary Disk as Revealed by Complex Cyanides (Karin Oberg) in the same issue about the detection of organic nitrile compounds in embryonic solar systems. The implication is “a vast reservoir of ice and volatile species that seed the surfaces of young rocky planets or moons.”

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