Results 91 to 100 of about 10,002 (189)
A review of exoplanetary biosignatures [PDF]
Physics Reports, 2017 We review the field of exoplanetary biosignatures with a main focus upon atmospheric gas-phase species. Due to the paucity of data in Earth-like planetary atmospheres a common approach is to extrapolate knowledge from the Solar System and Early Earth to Earth-like exoplanets. We therefore review the main processes (e.g.
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Frontiers in Astronomy and Space SciencesEarly diagenetic nodules with low permeable and weather-resistant structures are considered to be favorable for biosignature preservation. Numerous nodular structures forming in neutral-to-alkaline and saline diagenetic fluids were previously identified ...
Yan Chen, Zongjun Yin, Wei Lin
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Evaluating Biogenicity on the Geological Record With Synchrotron-Based Techniques
Frontiers in Microbiology, 2019 The biogenicity problem of geological materials is one of the most challenging ones in the field of paleo and astrobiology. As one goes deeper in time, the traces of life become feeble and ambiguous, blending with the surrounding geology.
Flavia Callefo +8 more
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The discovery of inhabited exoplanets hinges on identifying biosignature gases. JWST is revealing potential biosignatures in exoplanet atmospheres, though their presence is yet to provide strong evidence for life. The central challenge is attribution: how to confidently identify biogenic sources while ruling out, or deeming unlikely, abiotic ...
Constantinou, Tereza +3 more
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Frontiers in Microbiology, 2017 The “Rare Earth” hypothesis—put forward by Ward and Brownlee in their 2000 book of the same title—states that prokaryote-type organisms may be common in the universe but animals and higher plants are exceedingly rare.
Stefan Fox, Henry Strasdeit
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Habitability and biosignatures
Preprint of a chapter for the 'Encyclopedia of Astrophysics' (Editor-in-Chief Ilya Mandel, Section Editor Dimitri Veras) to be published by Elsevier as a Reference ...
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Biosignature False Positives [PDF]
, 2018 In our search for life - whether within the earliest part of Earth's geologic record, on planets within our solar system such Mars, or especially for extrasolar planets - we must infer the presence of life from its impact on the local or global environment. These "biosignatures," often identified from the known influence of terrestrial organisms on the
Chester E. Harman, Shawn Domagal-Goldman
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Extreme Forward Scattering Observed in Disk-averaged Near-infrared Phase Curves of Titan
The Planetary Science JournalTitan, with its thick and hazy atmosphere, is a key world in our solar system for understanding light scattering processes. NASA’s Cassini mission monitored Titan between 2004 and 2017, where the derived data set includes a large number of whole disk ...
Chase Cooper +4 more
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An exploration of origin of life for exoplanetary science
Frontiers in Astronomy and Space SciencesThe factors that enable life to begin define the difference between an inhabited planet and one that is simply habitable. While used extensively in Origins, Worlds, and Life: A Decadal Strategy for Planetary Science and Astrobiology 2023–2032 ...
Finnegan Keller +5 more
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Metabolic Processes Preserved as Biosignatures in Iron-Oxidizing Microorganisms: Implications for Biosignature Detection on Mars [PDF]
Iron-oxidizing bacteria occupy a distinct environmental niche. These chemolithoautotrophic organisms require very little oxygen (when neutrophilic) or outcompete oxygen for access to Fe(II) (when acidophilic).
Emerson, David +3 more
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