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

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

Scharf, Caleb. Extrasolar Planets and Astrobiology. Sausalito, CA: University Science Books, 2009. When a realm of celestial objects, first definitively viewed only in 1995, can merit an excellent, thorough textbook then a certain maturity has been reached. As Director of the Columbia University Astrobiology Center, Scharf dutifully covers all aspects of planetary composition, various atmospheres, habitable zones, prebiotic cosmochemistry, and so on. And it would seem that the implications of such a novel filling in of the cosmic neighborhood, similar to the finding of myriad galaxies in the 1920s and 1930s, has not yet registered. For it reveals a cosmos which by its innate nature spawns a prolific expanse of earth-like abodes for life to generate complex and conscious forms. In the final pages, Scharf indeed broaches a view quite at odds with the current mechanical model, in so many words that an organic genesis universe is being found with its own essence and destiny.

At the start of the book, we posited that life is a phenomenon that emerges in this Universe as naturally as physical “laws,” such as Newtonian gravity. It certainly seems that many of the pieces that go together to enable life as we know it are indeed inevitable. Star and planet formation, and complex carbon chemistry, are generic features of the cosmos, and these appear to be critical for life. (450)

Schneider, Jean, et al. The Far Future of Exoplanet Direct Characterization. Astrobiology. 10/1, 2010. Some 21 space scientists from across Europe and the U. S. look ahead to at last being able, conceivably, meet cousin creatures on other companion worlds.

We describe future steps in the direct characterization of habitable exoplanets subsequent to medium and large mission projects currently underway and investigate the benefits of spectroscopic and direct imaging approaches. We show that, after third- and fourth-generation missions have been conducted over the course of the next 100 years, a significant amount of time will lapse before we will have the capability to observe directly the morphology of extrasolar organisms. (Abstract, 121)

Seager, Sara. Exoplanet Atmospheres: Physical Processes. Princeton: Princeton University Press, 2010. The MIT astronomer provides the first book length treatment of a subject hardly imaginable until just now, via the epochal discovery of an organic cosmos filled with habitable worlds. A chapter with this title by the author and Drake Deming can be found in the Annual Review of Astronomy and Astrophysics (48/631, 2010).

Over the past twenty years, astronomers have identified hundreds of extrasolar planets--planets orbiting stars other than the sun. Recent research in this burgeoning field has made it possible to observe and measure the atmospheres of these exoplanets. This is the first textbook to describe the basic physical processes--including radiative transfer, molecular absorption, and chemical processes--common to all planetary atmospheres, as well as the transit, eclipse, and thermal phase variation observations that are unique to exoplanets. (Publisher website)

At a few special times in history, astronomy changed the way we see the universe. Hundreds of years ago, humanity believed that Earth was the center of everything – that the known planets and stars all revolved around Earth. In the late sixteenth century, the Polish astronomer Nicolaus Copernicus presented his revolutionary new view of the universe, where the sun was the center, and Earth and the other planets all revolved around it. Gradually, science adopted this “Copernican” theory, but this was only the beginning. In the early twentieth century, astronomers concluded that there are galaxies other than our own Milky Way. Astronomers eventually recognized that our Sun is but one of hundreds of billions of stars in our Galaxy, and that our Galaxy is but one of upward of hundreds of billions of galaxies. Wen and if we find that other Earths are common and we see that some of them have signs of life, we will as last complete the Copernican Revolution – a final conceptual move of the Earth, and humanity, away from the center of the universe.” (Chapter, 668-669)

Seager, Sara. Exoplanet Habitability. Science. 340/577, 2013. The MIT astro-atmospheric researcher and spokeswoman for a prolific universe filled with exoworlds contends that “habitable zones” around a star wherein life can form, along with the wide range that planetary objects can take from small rocky to gas giants need be held in abeyance as we explore and learn about a stochastic, contingent cosmos.

If there is one important lesson from exoplanets, it is that anything is possible within the laws of physics and chemistry. Planets of almost all masses, sizes, and orbits have been detected (Fig. 1), illustrating not only the stochastic nature of planet formation but also a subsequent migration through the planetary disk from the planet’s place of origin. The huge diversity of exoplanets and the related anticipated variation in their atmospheres, in terms of mass and composition, have motivated a strong desire to revise the view of planetary habitability. In parallel, there is a growing acceptance that even in the future, the number of suitable planets accessible to detailed follow-up observations may be very small. (577)

Seager, Sara. Exoplanets Everywhere. Sky & Telescope. August, 2013. With the Kepler planet finder satellite now offline, yet fulfilling its promise beyond expectations, the MIT planetologist surveys this revolutionary universe dawning in our midst. “Putting all the results together, we’ve learned that, on average, every star should have at least one planet.” (19) A galactic cosmos is suddenly filled with suns orbited by objects of every possible variety, size, shape, and trajectory. Earthkind’s collaborative telescopic, instrumentation, and computer capabilities are lately able to image moons, atmospheres, and spectroscopic signs of organisms.

Seager, Sara. The Search for Habitable Planets with Biosignature Gases Framed by a ‘Biosignature Drake Equation.’. International Journal of Astrobiology. Online May, 2017. The MIT astrobiologist continues her frontier project to finesse ways to better evaluate the life-bearing state of myriad exoplanets which are constantly being found. Some 50 years on, the Drake equation (search Vakoch) is thus modified to express the degrees of atmospheric conductivity for living, evolutionary organisms.

The discovery of thousands of exoplanets in the last two decades has uncovered a wide diversity of planets that are very different from those in our own Solar System. Ideas for how to detect signs of life in the variety of planetary possibilities, by way of biosignature gases, are expanding, although they largely remain grounded in study of familiar gases produced by life on Earth and how they appear in Earth's spectrum as viewed as an exoplanet. What are the chances we will be able to observe and identify biosignature gases on exoplanets in the coming two decades? I review the status of the search for habitable planets and biosignature gases framed by a ‘Biosignature Drake Equation’. (Abstract)

Seager, Sara, ed. Exoplanets. Tucson: University of Arizona Press, 2010. Synoptic chapter by leading contributors cover the many subjects of this grand revision as to what kind of celestial spacescape we persons might awaken to. But within a multiverse scheme that prohibits anything at all going on, with life and mind a merest patina, we have not begun to appreciate this discovery of a placental cosmos that innately seeds itself with myriad ovular worlds. An Introduction by Seager and Jack Lissauer gives a good entry to our Earth’s early amazement with a galaxy and cosmos seemingly filled with siblings and neighbors.

The discovery of exoplanets is arguably the greatest scientific revolution since the time of Copernicus. Simply stated, humanity now knows for the first time as a scientific fact: there actually are planets around other stars. (Richard Binzel, Space Sciences Series Editor)

Seager, Sara, organizer, moderator. The Next 40 Years of Exoplanets. http://seagerexoplanets.mit.edu/next40years.htm. Full video talks can be found here from this May 27, 2011 event at MIT where advocates and researchers waxed on this grand vista just opening for our intelligent, technological world. But all is not well in this endeavor. Pioneer finder Geoff Marcy denounced NASA cuts of future search projects, due much to a myopic, pinched bureaucracy. Anyway, speakers such as David Charbonneau, Vikki Meadows “A Futuristic Virtual Planetary Laboratory,” Shawn Murphy, Natalie Batalha, Dimitar Saselov “Life, the Universe, and Everything,” William Bains “New Life and New Civilizations,” and others extoled many promising pathways. The meeting was covered in Science for August 19, 2011 as “A Distant Glimpse of Alien Life?”

Setiawan, Johny, et al. A Giant Planet Around a Metal-Poor Star of Extragalactic Origin. Science. December 17, 2010. A European Space Agency team reports the first sighting of an extrasolar globe that appears to have initially come from beyond our local galaxy. Another significant indicator is registered of our Earth’s epochal discovery of a different kind of cosmos that innately seeds itself with such myriad potentially ovular worlds.

Because HIP 13044 belongs to a group of stars that have been accreted from a disrupted satellite galaxy of the Milky Way, the planet most likely has an extragalactic origin. (1642)

Seyler, Lauren, et al. Metabolomics as an Emerging Tool in the Search for Astrobiologically Relevant Biomarkers. Astrobiology. June, 2020. A seven member team from the Woods Hole Oceanographic Institution, Centro de Astrobiología, Madrid, Blue Marble Space Institute, Seattle, and Cal Tech including James Cleaves scope out how such an expansive –omics approach, properly integrated and applied, can well facilitate this grand new exoplanetary phase as Earthlings begin to search for near and far celestial neighbors.

It is now easy to sequence and recover microbial genomes from environmental samples. If transcriptional and translational functions can be assigned to these genomes, it should be possible to understand the molecular inputs and outputs of a microbial community. However, gene-based tools alone are presently insufficient to describe the full suite of chemical reactions and small molecules that compose a living cell. Metabolomic tools have developed quickly and now enable rapid detection and identification of small molecules within biological and environmental samples. These technologies will soon facilitate the detection of novel enzymatic activities, novel organisms, and potentially extraterrestrial life-forms. (Abstract)

Shahar, Anat, et al, Anat, et al. What Makes a Planet Habitable. Science. 364/434, 2019. Carnegie Institute of Washington geochemists add another requirement for life’s long-term viability. Suitable internal core conditions are a vital factor within the overall conduciveness for living systems to appear and evolve.

The Milky Way Galaxy teems with planetary systems, most of which are unlike our own. It is tempting to assume that life can only originate on a planet that is similar to Earth, but different planets able to sustain Earth-like features could be important for habitability studies. To aud the search for extraterrestrial life, scientists must assess which features of Earth are essential to the development and sustenance of life for billions of years and whether the formation of such planets is common. External effects such as stellar variability and orbital stability affect habitability, but internal processes that sustain a clement surface are also vital. A combination of observations, experiments, and modeling of planetary interiors can guide the search for extraterrestrial life. (Summary)

Shibata, Sho and Andre Izidoro. Formation of super-Earths and mini-Neptunes from rings of planetesimals.. arXiv:2501.03345. Earth, Environmental and Planetary Sciences, Rice University astroscientists describe the presence of what is now seen as common interactivity between these disparate candidates.

The solar system planetary architecture has been proposed to be consistent with the terrestrial and giant planets forming from material rings. Here, we show that super-Earths and mini-Neptunes may share a similar formation pathway. In our simulations, super-Earths accrete from rocky material rings in the inner disk. Mini-Neptunes originate from rings beyond the water snowline via pebble accretion. Our results predict that planets at ~1 au in systems with close-in super-Earths and mini-Neptunes are water-rich. (Excerpt)

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