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

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

Lai, Yanhong, et al.. Ocean Circulation on Tide-locked Lava Worlds, Part II: Scalings.. arXiv:2408.09985.. We cite this work by Climate and Ocean-Atmosphere Studies, Peking University and Earth, Atmosphere and Planetary Science, MIT astronomers for its content and in a philoSophia view to glimpse the present spacescape vista whereof a collaborative sapiensphere has at last formed over an infinitesimal bioplanet and in a few decades learned to explore, quantify an infinity of vicarious global, solar and galactic phenomena. See also Lapi, Andrea, et al. Semi-empirical Estimates of the Cosmic Planet Formation Rate by Andrea, Lapi, et al at 2408.08611 for another example of our Earthuman multiversal acumen.

On tidally locked lava planets, a magma ocean can form on the permanent dayside. Its circulation can be driven by stellar radiation and atmospheric winds. In this study, we develop scaling laws for the magma ocean depth, oceanic current speed, and heat transport convergence driven by stellar and wind forcings in three different dynamic regimes: non-rotating viscosity-dominant Regime I, non-rotating inviscid limit Regime II, and rotation-dominant Regime III. (Excerpt)

Lammer, Helmut. Origin and Evolution of Planetary Atmospheres: Implications for Habitability. Heidelberg: Springer, 2013. At the outset, it is worth notice that studies of this vast scale go on at all, unimaginable a decade ago, as a global civilization begins to learn about a fertile cosmos filled with neighbor bioworlds. An Austrian Academy of Sciences, Space Research Institute, astrophysicist, drawing upon an international collaboration, can describe the “physics and chemistry of planetary protoatmosphere formation and composition.” Might one add as if the phenomenal way a certain genesis universe tries to describe, understand, and create itself? See also the copious article “What Makes a Planet Habitable?” by Lammer, et al below.

Figure 1: Illustration of Earth-analogue class I, Martian-type class II, Icy moon-type classes III and IV and Water world class V habitats. Class I habitats represent planetary bodies on which stellar and geophysical conditions allow Earth-analogue planets to evolve so that complex multicellular life forms may originate and inhabit the planets hydrosphere, surface and subsurface environments. (x)

A careful study of various astrophysical and geophysical aspects indicate that Earth-analogue class I habitats have to be located at the right distance of the habitable zone from their host stars, must lose their protoatmospheres during the right time period, should maintain plate tectonics over the planet’s lifetime, should have nitrogen as the main atmospheric species after the stellar activity decreased to moderate values and finally, the planet’s interior should have developed conditions that an intrinsic strong global magnetic field could evolve. The recent discoveries of numerous planetary candidates by NASA’s Kepler space observatory indicate that there may be millions of smaller terrestrial-type planets within orbit locations inside the habitable zones of their host stars in the Galaxy. (xi)

Lammer, Helmut and Maxim Khodachenko, eds. Characterizing Stellar and Exoplanetary Environments. Berlin: Springer, 2015. As the synopsis notes, this volume edited by Austrian Space Research Institute scientists expands the human horizon to a deeply welcoming cosmos spacescape. A closing chapter is Living with Stars: Future Space-Based Exoplanet Search and Characterization Missions.

In this book an international group of specialists discusses studies of exoplanets subjected to extreme stellar radiation and plasma conditions. It is shown that such studies will help us to understand how terrestrial planets and their atmospheres, including the early Venus, Earth and Mars, evolved during the host star’s active early phase. The book presents an analysis of findings from Hubble Space Telescope observations of transiting exoplanets, as well as applications of advanced numerical models for characterizing the upper atmosphere structure and stellar environments of exoplanets. The book is divided into four main parts, grouping chapters on exoplanet host star radiation and plasma environments, exoplanet upper atmosphere and environment observations, exoplanet and stellar magnetospheres, and exoplanet observation and characterization. The book closes with an outlook on the future of this research field.

Lammer, Helmut, et al. What Makes a Planet Habitable? Astronomy and Astrophysics Review. 17/2, 2009. Some 15 senior members of the European astrospace community from Austria, Germany, France, Holland, Sweden, England, and onto Russia and the US, provide an extensive review of a galaxy and cosmos seemingly rift with worlds of every kind, as the Abstract notes. As these many studies express, an innately conducive milieu of solar systems, suitable biospheres, earth-analogs, seems increasingly evident. The paper agrees that life’s origin requires the common minimum of a membrane vesicle, metabolic proteins, and an information carrier, along with a driving energy gradient.

This work reviews factors which are important for the evolution of habitable Earth-like planets such as the effects of the host star dependent radiation and particle fluxes on the evolution of atmospheres and initial water inventories. We discuss the geodynamical and geophysical environments which are necessary for planets where plate tectonics remain active over geological time scales and for planets which evolve to one-plate planets. A classification of four habitat types is proposed. Class I habitats represent bodies on which stellar and geophysical conditions allow Earth-analog planets to evolve so that complex multi-cellular life forms may originate. Class II habitats includes bodies on which life may evolve but due to stellar and geophysical conditions that are different from the class I habitats, the planets rather evolve toward Venus- or Mars-type worlds where complex life-forms may not develop. Class III habitats are planetary bodies where subsurface water oceans exist which interact directly with a silicate-rich core, while class IV habitats have liquid water layers between two ice layers, or liquids above ice. Furthermore, we discuss from the present viewpoint how life may have originated on early Earth, the possibilities that life may evolve on such Earth-like bodies and how future space missions may discover manifestations of extraterrestrial life. (Abstract)

Laughlin, Gregory and Jack Lissauer. Exoplanetary Geophysics: An Emerging Discipline. Schubert, Gerald, ed.. Treatise on Geophysics. Amsterdam: Elsevier, 2015. A chapter for this 11 volume, 2nd edition by UC Santa Cruz, and NASA Ames scientists as terrestrial studies can now be extended to a galactic and cosmic scale. Who are we Earthlings to be the universe's way of describing and comprehending itself?

Lemonick, Michael. Can We Find Another Earth? Discover. March, 2002. The rapid progress in detecting stars with orbiting planets by perturbations in their movement due to the orbiting bodies, now over 100, leads to plans for telescopes able to focus in from Jupiter to Earth size globes.

Lemonick, Michael. Mirror Earth: the Search for Our Planet’s Twin. New York: Walker, 2012. Once science editor at Time magazine, the prolific author engagingly presents the incredible project and promise of finding another earth-like habitable world, which are now expected to abound across galaxy and cosmos. This is accomplished through vignette interviews with proponents such as William Borucki, Geoff Marcy, Dimitar Sasselov, David Charbonneau, and especially “female exoplaneteers” Natalie Batalha, Deborah Fisher, and Sara Seager. The abiding scenario and incentive is a fertile universe whereof bioworlds and evolutionary life flourishes. As an aside, I found this on the new book shelf at the Integrated Science and Engineering Library, University of Massachusetts at Amherst next to Destiny or Chance Revisited: Planets and their Place in the Cosmos by Stuart Taylor (Cambridge UP, 2012) which opts for the negative “rare Earth” view, now mostly discredited, of a forbidding spacescape where inhabited worlds are extreme accidents (which as usual says more about the writers).

Lin, Wen-Xu et al. Decoding the Future of Exoplanets: Asteroseismic Confirmation of Subgiant and Red Giant Hosts.. arXiv:2411.14703. Eight Yunnan University, Kunming, and University of Chinese Academy of Sciences, Beijing propose that exoworld characterizations would benefit if this significant property of relative seismic activity could be studied and factored in

Asteroseismology has become a powerful tool to unravel the actual relationships between evolved stars and their planetary systems. In this study, we investigate the evolutionary stages of five exoplanet host stars which exhibit solar-like oscillations. By measuring asteroseismic parameters such as the period spacing of dipole gravity modes (ΔΠ1), we confirm these stars' evolutionary states as subgiants or RGB stars. This research highlights the profound role of asteroseismology in advancing our knowledge of planetary system evolution and opens new pathways for exploring how stellar evolution impacts planetary survival. (Excerpt)

Lineweaver, Charles and Aditya Chopra. The Habitability of Our Earth and Other Earths: Astrophysical, Geochemical, Geophysical, and Biological Limits on Planet Habitability. Annual Review of Earth and Planetary Sciences. Volume 40, 2012. An Australian National University astrophysicist and a geologist offer an extensive chapter that summarizes these epochal advances of the past decade. The result is the discovery of an expansive array of habitable zones from earth’s crust to galactic neighborhoods. By any measure, our collaborative humankind is presently coming upon a profoundly life, sentience, and people bearing genesis universe.

For life forms like us, the most important feature of the Earth is its habitability. Understanding habitability and using that knowledge to locate the nearest habitable planet may be crucial for our survival as a species. Over the past decade, expectations that the universe could be filled with habitable planets have been bolstered by the increasingly large overlap between terrestrial environments known to harbor life and the variety of environments on newly detected rocky exoplanets. The inhabited and uninhabited regions on Earth tell us that temperature and the presence of water are the main constraints can be used in a habitability classification scheme for rocky planets. Our compilation and review of recent exoplanet detections suggests that the fraction of stars with planets is 100%, and that the fraction with rocky planets may be comparably large. We review extensions to the circumstellar habitable zone including an energy habitable zone to start and maintain life, and the galactic habitable zone. (Abstract)

The increasingly large overlap between terrestrial environments known to harbor life and the surface environments of newly detected rocky exoplanets bolsters expectations that the universe may be filled with habitable planets. The fraction of stars with planets is approximately 100%. The fraction of stars with a rocky planet in the HZ could be comparably large. The water content of rocky planets is highly variable. This variability can be used to classify their habitability, e.g., ocean planets, Earth-like planets, and desert planets. (Summary Points)

Lissauer, Jack. Extrasolar Planets. Nature. 419/355, 2002. A news report about a galaxy and cosmos becoming filled with detectable planetary objects.

Natural philosophers have speculated on the existence of world around other suns for millennia. Now that real data are available, we find a diversity far beyond that expected by scientists, or science-fiction writers. (355)

Lissauer, Jack and Imke de Pater. Fundamental Planetary Science: Physics, Chemistry and Habitability. Cambridge: Cambridge University Press, 2014. It is a good sign that a novel scientific endeavor and subject area has come of age when a comprehensive text can be written about it. Lissauer, NASA Kepler project senior scientist, and de Pater, UC Berkeley and Delft University, situate a wealth of worlds in a conducive cosmos from Astrophysics and Atmospheres to Solar and ExoPlanetary Formation, Dynamics, Surfaces, Interiors, Moons, Comets, Meteors, Rings, and the Life that originated and arose to altogether be able to do this. But an implied Copernican revolution to an innately planet making universe, as so many ovular earths, has not yet occurred.

Lisse, Carey, et al. Abundant Circumstellar Silica Dust and SiO Gas Created by a Giant Hypervelocity Collision in the ~12 Myr HD172555 System. Astrophysical Journal. 701/2019, 2009. A team of astronomers using NASA’s Spitzer Space Telescope has found this evidence of a collision between a larger, Mercury size, and a smaller, Moon like object, which is then seen to imply how our earth formed by a similar impact. We cite as one example in this weekly, telephone-book size, periodical by thousands of researchers of humankind’s sentient surveillance and reconstruction of its galactic and cosmic environs, as if a planetary person.

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