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

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

Burrows, Adam and Geoffrey Marcy. Exoplanets. Proceedings of the National Academy of Sciences. 111/12599, 2014. An introduction to authoritative papers as a current update upon this fledgling field dubbed Comparative Exoplanetology. The endeavor has seen two phases – Marcy and colleagues detection circa 1995 of another orbital world and the post 2009 Kepler satellite findings of a galaxy and cosmos filled with as many planets as stars. Articles such as The Future of Spectroscopic Life Detection on Exoplanets by Sara Seager, Exploring Exoplanet Populations with NASA’s Kepler Mission by Natalie Batalha, Structure of Exoplanets by David Spiegel, et al, Requirements and Limits for Life in the Context of Exoplanets by Chris McKay, and Remote Life-Detection Criteria, Habitable Zone Boundaries, and the Frequency of Earth-like Planets around M and Late K Stars by James Kasting, et al open vistas upon a revolutionary habitable universe. How incredible that our precious Earth by way of a late worldwide collaboration, sophisticated instrumentation, computer analysis, is now able to realize, explore, quantify, atmospheres, signs of life, stochastic frequencies, and so on. We have just begun to imagine an actual fecund ecosmos which by its own propensities seems to sow and seed itself with ovular worlds in solar incubators.

Byrne, Xander, et al. Atmospheres as a Window to Rocky Exoplanet Surfaces. arXiv:2312.11133.. As our worldwise neighborhood census expands apace, four Cambridge University astronomers including Oliver Shorttle propose that further insights could be achieved by probing deeper into their geospheres. See also companion efforts such as Phanerozoic biological reworking of the continental carbonate rock reservoir at 2312.09011, Past and Present Dynamics of the Iron Biogeochemical Cycle at 2312.09044, and Coupled atmospheric chemistry, radiation, and dynamics of an exoplanet generate self-sustained oscillations by Yangcheng Luo, et al in PNAS (120/51, 2023) as this Earthmost work of ecosmic quantification goes forth.

As findings about exoplanet atmospheres quantify their chemistry and composition, we ask how much deeper can these studies go. For small planets with modest atmospheres, the first layer will be their rocky surface. Using an equilibrium chemistry code, we find a boundary in surface pressure-temperature space which simultaneously separates distinct mineralogical regimes and atmospheric regimes, enabling inference of surface mineralogy from spectroscopic observations of the atmosphere. Our results pave the way to the prospect of characterizing exoplanetary surfaces as new data for short period rocky planet atmospheres emerge. (Excerpt)

Our results demonstrate strongly non-linear crustal evolution after the rise of the complex Phanerozoic biosphere. This outcome suggests that complex life may generate unique biogeochemical trajectories on otherwise geologically similar worlds, posing a new challenge in the hunt for life beyond Earth. (2312.09044)

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)

Cloutier, Ryan. Exoplanet Demographics: Physical and Orbital Properties.. arXiv:2409.13062. A McMaster University astronomer provides a comprehensive survey to appear in the 2025 Encyclopedia of Astrophysics to be published by Elsevier all about the ever expanding proliferation of a world bearing universe. This preprint contains an extensive glossary along with visuals and graphs as an Earthuman sapience begins our ecosmokinder quest.

The discovery of over 5700 exoplanets has led to the field of exoplanet demographics over the past decade. Astronomers have been conducting statistical studies in search of trends in various planetary and host stellar parameters. In this chapter, we review many major features for physical and orbital conditions of known exoplanets including the Radius Valley, the Neptunian Desert, the Peas in a Pod pattern, dynamical properties that point toward likely formation/migration mechanisms, as well as trends with host stellar parameters such as the time-evolution of exoplanetary systems and the search for planets within the Habitable Zone. The overarching theme is that exoplanetary systems exhibit an incredible diversity of planet properties and system architectures that do not exist within our own solar system.

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)

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