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“One of the most important scientific questions today is how many potential Earth-like Habitats (EHs) exist in the Galaxy, and how many of these planets could, in principle, support aerobic life?” according to an article in the peer-reviewed journal Astrobiology by Helmut Lammer and Manuel Scherf, from the Austrian Academy of Sciences, Space Research Institute. In two additional articles in Astrobiology, the authors, together with Laurenz Spross, from the University of Graz, derived a new formula that can be used to estimate the maximum occurrence rate of EHs in the Galaxy, and applied this formulation to the galactic disk by considering only requirements that are already scientifically quantifiable. Click here to read the articles now.
In conjunction with the derivation of their new formula, the investigators discussed two crucial, though often neglected factors that are related to planetary accretion and the formation of primordial hydrogen-dominated atmospheres as well as to geophysical processes that are necessary for carbon-silicate and nitrogen-cycles to evolve and be stable over billions of years. “These factors can be fine-tuned and/or constrained soon by the characterization of exoplanetary atmospheres with present and future space observatories and large ground-based telescopes,” stated the investigators.
Application of the formula led to the conclusion that EHs are relatively rare, and that the probability of extraterrestrial intelligence is significantly rarer still.
“One of the most important goals of astrobiology is to figure out, among the billions of planets in the galaxy, how many are Earth-like,” says Astrobiology Associate Editor Charles Lineweaver, PhD, from Australian National University. “In previous studies ‘Earth-like’ was usually crudely understood to be wet rocky planets in the habitable zone of their host star. The papers in this issue of Astrobiology are more specific about what Earth-like means. They make reasonable assumptions about the range of atmospheric compositions that could be conducive to the evolution of complex life. They conclude that the evolution of complex life on other planets in our galaxy is probably quite rare.”
About the Journal
Astrobiology, led by Editor-in-Chief Sherry L. Cady, PhD, Professor Emeritus at Portland State University, and a prominent international editorial board comprised of esteemed scientists in the field, is the authoritative peer-reviewed journal for the most up-to-date information and perspectives on exciting new research findings and discoveries emanating from interplanetary exploration and terrestrial field and laboratory research programs. The Journal is published monthly online with Open Access options and in print. Complete tables of content and a sample issue may be viewed on the Astrobiology website.
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Mary Ann Liebert, Inc. is a global media company dedicated to creating, curating, and delivering impactful peer-reviewed research and authoritative content services to advance the fields of biotechnology and the life sciences, specialized clinical medicine, and public health and policy. For complete information, please visit the Mary Ann Liebert, Inc. website.
Journal
Astrobiology
Method of Research
Computational simulation/modeling
Subject of Research
Not applicable