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Title: ABIOTIC OXYGEN-DOMINATED ATMOSPHERES ON TERRESTRIAL HABITABLE ZONE PLANETS

Detection of life on other planets requires identification of biosignatures, i.e., observable planetary properties that robustly indicate the presence of a biosphere. One of the most widely accepted biosignatures for an Earth-like planet is an atmosphere where oxygen is a major constituent. Here we show that lifeless habitable zone terrestrial planets around any star type may develop oxygen-dominated atmospheres as a result of water photolysis, because the cold trap mechanism that protects H{sub 2}O on Earth is ineffective when the atmospheric inventory of non-condensing gases (e.g., N{sub 2}, Ar) is low. Hence the spectral features of O{sub 2} and O{sub 3} alone cannot be regarded as robust signs of extraterrestrial life.
Authors:
;  [1]
  1. Department of the Geophysical Sciences, University of Chicago, 5734 South Ellis Avenue, Chicago, IL 60622 (United States)
Publication Date:
OSTI Identifier:
22365901
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal Letters; Journal Volume: 785; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; BIOSPHERE; COLD TRAPS; DETECTION; GASES; OXYGEN; PHOTOLYSIS; PLANETS; SATELLITE ATMOSPHERES; SATELLITES; STARS; WATER; ZONES