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

H. Stellar Planetary Systems: A Diverse Profusion of Galaxies, Solar Orrerys and Habitable Zones

Fischer, Debra. Early Start for Rocky Planets. Nature. 486/331, 2012. The Yale University astronomer reviews a Letter in this issue “An Abundance of Small Exoplanets around Stars with a Wide Range of Metallicities” by Lars Buchhave, et al, a large team from Copenhagen, NASA and California. They find the chemical composition of stars which host smaller planets to be more varied than those with larger planets. This result is seen to favor an earlier start and prevalence for more earth-like worlds.

Fisher, Theresa, et al.. A Complex Systems Approach to Exoplanet Atmospheric Chemistry: New Prospects for Ruling Out the Possibility of Alien Life-As-We-Know-It. arXiv:2310.05359. Arizona State University astrobiologists TF, Estelle Janin and Sara Walker post a latest comprehensive review as Earthumanity prepares to seek and rightly identify near and further occasions of inhabited exoworlds. A segment wonders over how to evaluate what evolutionary stage they may have reached, with attention to global civilizations. The especial contribution herein is a novel notice of life’s multiplex anatomy and physiology as vital indicators. See also PyATMOS: A Scalable Grid of Hypothetical Planetary Atmospheres by Aditya Chopra, et al at 2308.10624; and Fully fluorinated non-carbon compounds NF3 and SF6 as technosignature gases by Sara Seager, et al at 2308.13667 for other studies.

The near-term capability to characterize terrestrial exoplanet atmospheres may bring us closer to discovering alien life. However, detectable candidate biosignature gases are subject to false positives that can be produced abiotically. To distinguish, we take a complex systems approach using a chemical reaction network analysis of planetary atmospheres. Network properties like mean degree and shortest path length can effectively display when CH4 is produced from methanogenesis and serpentinization. Our results confirm how a network theoretic approach can clearly specify biological, abiotic and anomalous atmospheres. (Excerpt)

Beyond the implications for biosignature detection, the influence of biology on atmospheric reaction networks may provide a window into the physics of life itself. If there is a ‘universal biology’ dictated by the physical constraints of the universe, one manifestation may be in its network topology. For instance, one might model planetary evolution as a multilayer network, where each layer represents the chemistry in the geosphere, biosphere, or atmosphere and technosphere. In any case, further investigation into atmospheric reaction networks is warranted in a variety of fields of exoplanet science and astrobiology. (16)

Fisher, Theresa, et al.. Network and Kinetics-based Biosignatures: Implications for the Putative Habitable World Observatory Design. arXiv:2501.04737. Seven University of Arizona, NASA Ames, ASU, UC Riverside and Carnegie Institution for Science astroscholars contend that factoring in the presence of nonlinear spatial and dynamic phenomena as an indication of animate vitalities could augment looking for physical gases and microbial rudiments.

Seven University of Arizona, NASA Ames, ASU, UC Riverside and Carnegie Institution for Science astroscholars contend that factoring in the presence of nonlinear spatial and dynamic phenomena as an indication of animate vitalities could augment looking for physical gases and microbial rudiments.

Folger, Tim. The Planet Boom. Discovery. May, 2011. One of many post-Kepler satellite reports trying to convey this awesome discovery of an innately world-seeding, gravid cosmos. Per the quote, our earth can be known as far from rare. By any measure galaxies will be filled with solar systems, which seem to proliferate in every imaginable variety. And as Bill Borucki, for many years NASA’s champion of the Kepler mission, comments, this fantastic vista brings a profound significance to earth’s stirring ability via humankind to learn and decide to succeed.

For the first time, we have a handle on the odds, and the numbers beaming in from Kepler are not only encouraging but staggering. “Our galaxy contains 200 billion stars,” (Geoffrey) Marcy says, “I would guess that at least 30 percent of them have an earth-size planet. So 30 percent of 200 billion, that’s at least 60 billion Earth-size planets just in our galaxy alone.” (33)

Franck, Siegfried, et al. Extraterrestrial Gaias. Schneider, Stephen, et al, eds. Scientists Debate Gaia. Cambridge: MIT Press, 2004. The detection of extrasolar, earth-like planets takes on a new dimension when viewed through the lens of the Gaia perspective. Whether they are life-bearing can be ascertained by the composition of their atmosphere.

The general question is whether an Earth-sized planet discovered outside the solar system can accommodate a self-regulating geosphere-biosphere system with homeorrhesis (i.e., sister of Gaia). (315)

Frank, Adam. How Nature Builds a Planet. Discover. July, 2005. The latest info on varieties of planetary formation as an intelligent earth learns about its own origin and those of its neighbors.

Gaidos, Eric, et al. New Worlds on the Horizon: Earth-Sized Planets Close to Other Stars. Science. 318/210, 2007. We are presently witness to a unique historical achievement, not imaginable any time sooner, when our sentient planet via telescope, satellite, and computer instrumentation, along with a global research network, can detect a plethora of kindred orbs around other stars throughout the galaxy. What then is an ovular bioplanet of which we should be mindful? Might human beings at once ‘therefore choose Earth’, and seek to begin a celestial conversation?

Gargaud, Muriel, et al. Habitability in the Universe from the Early Earth to Exoplanets. Origins of Life and Evolution of Biospheres. 46/4, 2016. An introduction to a special issue as a profligate cosmic vista opens to us Earthlings. Typical papers are Host Star Evolution for Planet Habitability, Review on the Role of Planetary Factors on Habitability, and The Logic of Life by Robert Pascal and Addy Pross, abstract below.

In this paper we propose a logical connection between the physical and biological worlds, one resting on a broader understanding of the stability concept. We propose that stability manifests two facets - time and energy, and that stability’s time facet, expressed as persistence, is more general than its energy facet. That insight leads to the logical formulation of the Persistence Principle, which describes the general direction of material change in the universe, and which can be stated most simply as: nature seeks persistent forms. Significantly, the principle is found to express itself in two mathematically distinct ways: in the replicative world through Malthusian exponential growth, and in the ‘regular’ physical/chemical world through Boltzmann’s probabilistic considerations. By encompassing both ‘regular’ and replicative worlds, the principle appears to be able to help reconcile two of the major scientific theories of the 19th century – the Second Law of Thermodynamics and Darwin’s theory of evolution – within a single conceptual framework. (Pascal, Pross)

Gaudi, B. Scott, et al. The Demographics of Exoplanets. arXiv:2011.04703. SG, Ohio State University, Jessie Christiansen, Caltech, and Michael Meyer, University of Michigan post a chapter to appear in ExoFrontiers: Big Questions in Exoplanetary Science (Bristol: IOP Publishing Ltd) AAS-IOP ebooks, 2021). It is a sign of a new maturity if this fast-moving, expansive field of exoplanetary science can begin to lay out a program for a near and farther census. Amongst many aspects are the shape of the explanet, host star interactions, multiple formation paths for gas giants, and so on. But as the second quote notes, these studies come up with more evidence of how special our own Sun – Earth system really is.

In the broadest sense, the primary goal of exoplanet demographic surveys is to determine the frequency and distribution of planets as a function of as many of the physical parameters that may influence planet formation and evolution as possible, over as broad of a range of these parameters as possible. By comparing these planet distributions to the predictions of planet formation theories, we can begin to both test and refine these theories. In this chapter, we review the major results on exoplanet demographics to date. (Abstract)

How common are solar system analogs? One of the most surprising results from Kepler is that the majority of stars appear to host relatively close-in, compact systems of super-Earths and/or sub-Neptunes. As our solar system does not host any analogues of such planets; this suggests that planetary architectures like our own (with small rocky planets in the temperate zone and gas giants beyond the ice line) may not be common. (5)

Gaudi, B. Scott, et al. The Habitable Exoplanet Observatory Mission Concept Report. arXiv:2001:06683. We note this 500 page mission statement by some 200 astroscientists with a main base at Jet Propulsion Laboratory as a premier example into the 2030s of our collaborative Earthkind personsphere beginning to explore, quantify and spread forth in a revolutionary genesis universe.

Gelino, Dawn and Jason Wright. NASA and the Search for Technosignatures. arXiv:1812.08681. The 70 page main report from a September 2018 Workshop on how we Earthlings might look for and validly detect the presence of exo-civilizations with technical capacities. Some sections are Pulsed Radio, Continuous Wave Radio, Laser, Searches, also Limits of Megastructures, Waste Heat for Stars and Galaxies, and much more as our human to Anthropo sapience is just beginning to explore cosmic neighborhoods.

Gerrit, Horstmann, et al. Tidally Forced Planetary Waves in the Tachocline of Solar-like Stars. arXiv:2208.00644. We cite this entry by German (Dresden), Georgian (Tbilisi) and Austrian (Graz) astrophysicists as a current worldwide finding about solar system phenomena to an extent that the composite sun and its orbital orrery appear to act as an integral whole unit.

The tachocline is the transition region of stars of more than 0.3 solar masses, between the radiative interior and the differentially rotating outer convective zone.

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