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

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

Cabrol, Nathalie. The Coevolution of Life and Environment on Mars. Astrobiolog. 18/1, 2018. The French-American, SETI Institute Carl Sagan Center, planetary scientist scopes out a research program which sets up a relative contrast between Earth and Mars with regard to early life stages, gain and loss of habitability, and geo-atmospheric conditions. Although one woman is doing this, the greater project is due altogether to a thinking planet as it just now proceeds to consider a neighbor world by way of similar temporal and spatial environments.

Cabrol, Nathalie. Using Machine Learning to Optimize the Search for Biosignatures. Nature Astronomy. 7/3, 2023. We cite this article by the senior French-American astrobiologist and director of the Carl Sagan Center for the Study of Life in the Universe at the SETI Institute as such a far and wide celestial neighborhood census becomes facilitated by AI methods (see our EI section).

A probabilistic machine learning-based framework for recognizing and predicting microbial landscape patterns at nested spatial scales was developed. The approach substantially increased the probability of detecting biosignatures when tested at a Martian analogue in the high Andes. This search tool has applications for detecting biosignatures on terrestrial or icy planets.

Carroll, Michael. The Hunt for Earth’s Bigger Cousins. Astronomy. April, 2017. As worldwide humankind continues to explore, discover and quantify a widest array of planetary objects, many articles as this keep up with their findings. Here a science writer and author of Earths of Distant Suns (2016) notes that a most prevalent size seems to be 2 to 10 times our home planet, which are known as Super Earths or Sub Neptunes. We also enter because in several places it is observed that this orderly solar system is an anomaly amongst the usual chaos, continents in motion via plate tectonics are rare, wholly gaseous atmospheres are common, and so on. So the case of an extraordinary great Earth continues to build.

Cassan, Arnaud, et al. One or More Bound Planets per Milky Way Star from Microlensing Observations. Nature. 481/167, 2012. A team of some 41 scientists within the Probing Lensing Anomalies Network (PLANET) collaboration, based at Institut d’Astrophysique de Paris, Université Pierre and Marie Curie, further support the 21st century revolution to realize an innately conducive cosmos that seemingly seeds itself with as many worlds as there are stars in the sky.

We conclude that stars are orbited by planets as a rule, rather than the exception. (167) Planets around stars in our Galaxy thus seem to be the rule rather than the exception. (169)

Chang, Kenneth. 7 Earth-Size Planets Orbit Dwarf Star, NASA and European Astronomers Say. New York Times. February 23, 2017. As a graphic display to lead the front page, this is a report about the widely-noted discovery of the most solar system-like, multi-world array found to date. We also note that while a cooperative humanity can reveal such frontiers, as readers know, the rest of the daily news was about a precious planet consumed with barbaric, terminal violence.

Not just one, but seven Earth-size planets that could potentially harbor life have been identified orbiting a tiny star not too far away, offering the first realistic opportunity to search for signs of alien life outside the solar system. The planets orbit a dwarf star named Trappist-1, about 40 light-years, or 235 trillion miles, from Earth. All seven are very close to the dwarf star, circling more quickly than the planets in our solar system. The innermost completes an orbit in just 1.5 days. The farthest one completes an orbit in about 20 days. That makes the planetary system more like the moons of Jupiter than a larger planetary system like our solar system.

Chen, Jingjing and David Kipping. Probabilistic Inference of the Masses and Radii of Other Worlds. arXiv:1603.08614. Columbia University astronomers look back upon the past two decades, especially by the Kepler satellite, of novel planetary discoveries to propose four object classes – Terran (rocky earths), Neptunian worlds, larger Jovian orbs (both gaseous) and stars. By these views, the so-called Super Earths actually appear to be mini-Neptunes or gas dwarfs. It is thus concluded: This independent analysis adds further weight to the emerging consensus that rocky Super-Earths represent a narrower region of parameter space than originally thought. Effectively, then, the Earth is the Super-Earth we have been looking for.

Chiang, Eugene and Gregory Laughlin. The Minimum-Mass Extrasolar Nebula: In Situ Formation of Close-in Super-Earths. Monthly Notices of the Royal Astronomical Society. 431/3444, 2013. In a typical paper now infusing such august journals, University of California, Berkeley, and Santa Cruz, astrophysicists continue to show how profligate cosmic nature is when it comes to seeding herself with all manner of solar-planetary systems and ovular bioworlds.

Close-in super-Earths, with radii R ≈ 2–5R⊕ and orbital periods P < 100 d, orbit more than half, and perhaps nearly all, Sun-like stars in the Universe. We use this omnipresent population to construct the minimum-mass extrasolar nebula (MMEN), the circumstellar disc of solar-composition solids and gas from which such planets formed, if they formed near their current locations and did not migrate. In a series of back-of-the-envelope calculations, we demonstrate how in situ formation in the MMEN is fast, efficient, and can reproduce many of the observed properties of close-in super-Earths, including their gas-to-rock fractions. Testable predictions are discussed. (Abstract)

cockell, Charles, et al. Sustained and comparative habitability beyond Earth. Nature Astronomy. 8/1, 2024. In a special on Astrobiology, eleven exolife scientists including Lisa Kaltenegger address these open near and farther frontiers to search for analog neighbors from microbial to technological across geological timescales. A prime concern is how to seek, detect, and evaluate by what kind of relative atmospheric signatures. See also Is the apparent absence of extraterrestrial technological civilizations down to the zoo hypothesis or nothing? by Ian Crawford and Inferring chemical disequilibrium biosignatures for Proterozoic Earth-like exoplanets by Amber Young.

Habitability is usually defined for a specific time during a planet’s evolution. But how is that habitability sustained over billions of years? Comparing habitable conditions across different Solar System bodies is key to our understanding of the underlying processes driving long-term habitability. (Editor)

Although we understand of the physical and chemical conditions required to support the evolution, growth and reproduction of organisms, we have a rudimentary grasp of the planetary conditions required to sustain those conditions over long geological timescales. We propose a stronger interface between geophysics and biology is required to quantify extended, comparative habitability. This program will be enabled by missions in our Solar System to icy bodies such as Europa, Enceladus and Titan, along with telescopes. An ultimate objective to determine whether Earth is a rare outpost by way of a multi-billion-year biosphere, or whether such conditions for sustained habitability here exist elsewhere in the Universe. (Abstract)

Cockell, Charles, et al.. Habitability. Astrobiology. 16/1, 2016. As an exceptional, sapient biosphere begins to survey and quantify a prolific galactic and cosmic neighborhood, an 18 member team from across Europe, including Helmet Lammer, posts this consideration about conducive spacescape zones for incubator solar systems. We quote the long Abstract, and wonder whom over the great Earth is doing this? See also for example The Inner Edge of the Habitable Zone for Synchronously Rotating Planets around Low-Mass Stars at arXiv:1602.05176.

Habitability is a widely used word in the geoscience, planetary science, and astrobiology literature, but what does it mean? In this review on habitability, we define it as the ability of an environment to support the activity of at least one known organism. We adopt a binary definition of “habitability” and a “habitable environment.” An environment either can or cannot sustain a given organism. However, environments such as entire planets might be capable of supporting more or less species diversity or biomass compared with that of Earth. A clarity in understanding habitability can be obtained by defining instantaneous habitability as the conditions at any given time in a given environment required to sustain the activity of at least one known organism, and continuous planetary habitability as the capacity of a planetary body to sustain habitable conditions on some areas of its surface or within its interior over geological timescales. We also distinguish between surface liquid water worlds (such as Earth) that can sustain liquid water on their surfaces and interior liquid water worlds, such as icy moons and terrestrial-type rocky planets with liquid water only in their interiors. This distinction is important since, while the former can potentially sustain habitable conditions for oxygenic photosynthesis that leads to the rise of atmospheric oxygen and potentially complex multicellularity and intelligence over geological timescales, the latter are unlikely to. Habitable environments do not need to contain life. Although the decoupling of habitability and the presence of life may be rare on Earth, it may be important for understanding the habitability of other planetary bodies (Abstract)

Coelho, Liqia, et al. Purple is the new green: biopigments and spectra of Earth-like purple worlds.. arXiv:2404.10105. Cornell University and University of Minnesota astroscientists including Lisa Kaltenegger (See also her new book Alien Earths: The New Science of Planet Hunting in the Cosmos) expand and extol the frontiers of exoplanet searches as they go forward with new telescopes and instruments. They scope and inspire a grand quest for other neighbors, which requires a widest allowance for what forms and features may be possible.

With more than 5500 detected exoplanets, the search for life is entering a new era. Using life on Earth as our guide, we look beyond green landscapes to expand our ability to detect signs of surface life on other worlds. While oxygenic photosynthesis gives rise to green landscapes, bacteriochlorophyll-based anoxygenic phototrophs can also color their habitats. Here, we characterize the reflectance spectra of purple sulfur and purple non-sulfur bacteria from a variety of anoxic and oxic environments. Our biological pigment data base for purple bacteria and the high-resolution spectra of Earth-like planets, including ocean worlds, snowball planets, and frozen worlds are available online, providing a tool for modellers and observers to train retrieval algorithms, optimize search strategies, and inform models.

Cooke, Ilsa and Ian Sims. Experimental Studies of Gas-Phase Reactivity in Relation to Complex Organic Molecules in Star-Forming Regions. ACS Earth and Space Chemistry. Online June, 2019. We note this entry by University of Rennes, CNRS, France astrophysical chemists as an example in this new journal of how sophisticated these research endeavors have become as they quantify ever increasing evidence of an intrinsic biocosmic essence which brings forth, complexifies, develops and evolves as it reaches our human ability and purpose to retrospectively learn and continue For later work see Variability due to climate and chemistry in observations of oxygenated Earth-analogue exoplanets at arXiv:2209.07566.

The field of astrochemistry concerns the formation and abundance of molecules in the interstellar medium, star-forming regions, exoplanets, and solar system bodies. These astrophysical objects contain the chemical material from which new planets and solar systems are formed. Around 200 molecules have thus far been observed in the interstellar medium; almost half containing six or more atoms and considered “complex” by astronomical standards. All of these complex molecules consist of at least one carbon atom and thus the term complex organic molecules (COMs) has been coined by the astrochemical community. In the following review, we present recent laboratory efforts to produce quantitative kinetic data for gas-phase reactions at low temperatures. (Abstract excerpt)

The scope of ACS Earth and Space Chemistry includes the application of analytical, experimental and theoretical chemistry to investigate research questions relevant to the Earth and Space. The journal notes the highly interdisciplinary nature of research in this area, with chemistry and chemical research tools as the unifying theme. It publishes broadly in the domains of high- and low-temperature geochemistry, atmospheric chemistry, marine chemistry, planetary chemistry, astrochemistry, and analytical geochemistry.

Cuntz, Manfred, et al. Habitability of Super-Earth Planets around Main-sequence Stars including Red Giant Branch Evolution. International Journal of Astrobiology. 11/1, 2012. As this Kepler planet finder satellite era increasingly reveals a creative cosmos that seems to seed itself with a stochastic infinity of orbiting orbs, University of Texas, Potsdam Institute, and University of Guanajuato, Mexico astrophysicists quantify the suitability of such big brother worlds for life’s inevitable appearance and evolution. Please consider with Gowanlock, et al, as Great Earth comes to explore with amazement a grand new neighborhood.

In a previous study published in Astrobiology, we focused on the evolution of habitability of a 10 M⊕ super-Earth planet orbiting a star akin to the Sun. This study was based on a concept of planetary habitability in accordance with the integrated system approach that describes the photosynthetic biomass production taking into account a variety of climatological, biogeochemical and geodynamical processes. In the present study, we pursue a significant augmentation of our previous work by considering stars with zero-age main-sequence masses between 0.5 and 2.0 M⊙ with special emphasis on models of 0.8, 0.9, 1.2 and 1.5 M⊙. Our models of habitability consider geodynamical processes during the main-sequence stage of these stars as well as during their red giant branch evolution. Pertaining to the different types of stars, we identify the so-called photosynthesis-sustaining habitable zone (pHZ) determined by the limits of biological productivity on the planetary surface. We obtain various sets of solutions consistent with the principal possibility of life. (15)

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