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تسجيل مستخدم جديدA Review of Exoplanetary Biosignatures
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John Lee Grenfell
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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. atmospheric photochemistry and transport) affecting the most commonly-considered species (e.g. O2, O3, N2O, CH4 etc.) in the context of the modern Earth, Early Earth, the Solar System and Earth-like exoplanets. We consider thereby known abiotic sources for these species in the Solar System and beyond. We also discuss detectability issues related to atmospheric biosignature spectra such as band strength and uniqueness. Finally, we summarize current space agency roadmaps related to biosignature science in an exoplanet context.
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In the coming years and decades, advanced space- and ground-based observatories will allow an unprecedented opportunity to probe the atmospheres and surfaces of potentially habitable exoplanets for signatures of life. Life on Earth, through its gaseo
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