TY - JOUR
T1 - Atmospheric composition of exoplanets based on the thermal escape of gases and implications for habitability
T2 - Atmospheric composition of exoplanets
AU - Konatham, Samuel
AU - Martin-Torres, Javier
AU - Zorzano, Maria Paz
N1 - Funding Information:
Data accessibility. The datasets analysed in this study are available at the Planetary Habitability Laboratory (PHL), University of Puerto Rico, Arecibo: http://phl.upr.edu/projects/habitable-exoplanets-catalog/data/ database and http://exoplanet.eu/. The datasets generated during the current study will evolve with the availability of new data and updates to the exoplanet catalogues. All up-to-date datasets will be made publicly available by the Group of Atmospheric Science, LTU, Sweden: https://atmospheres.research.ltu.se/ exoplanets_species.php. Extended results and tables are available in the electronic supplementary material. Authors’ contributions. J.M.-T. had the original idea of applying kinetic theory to classify exoplanets. S.K. developed the code to implement the concept, analysed the existing observational databases and prepared the figures and tables. S.K., J.M.-T. and M.-P.Z. analysed the data, prepared the figures, interpreted the results and wrote the manuscript. Competing interests. The authors declare that they have no competing interests. Funding. This research has been funded by the Knut and Alice Wallenberg Foundation, Kempe Foundation, The County Administrative Board of Norrbotten and Luleå University of Technology. M.-P.Z.’s research at CAB has been partially supported by the Spanish State Research Agency (AEI) project no. MDM-2017-0737 Unidad de Excelencia ‘María de Maeztu’-Centro de Astrobiología (INTA-CSIC). Acknowledgements. We thank all the referees for their valuable comments. We are grateful for their constructive remarks, which led to a significant improvement to the manuscript.
PY - 2020/9/1
Y1 - 2020/9/1
N2 - The detection of habitable exoplanets is an exciting scientific and technical challenge. Owing to the current and most likely long-lasting impossibility of performing in situ exploration of exoplanets, their study and hypotheses regarding their capability to host life will be based on the restricted low-resolution spatial and spectral information of their atmospheres. On the other hand, with the advent of the upcoming exoplanet survey missions and technological improvements, there is a need for preliminary discrimination that can prioritize potential candidates within the fast-growing list of exoplanets. Here we estimate, for the first time and using the kinetic theory of gases, a list of the possible atmospheric species that can be retained in the atmospheres of the known exoplanets. We conclude that, based on our current knowledge of the detected exoplanets, 45 of them are good candidates for habitability studies. These exoplanets could have Earth-like atmospheres and should be able to maintain stable liquid water. Our results suggest that the current definition of a habitable zone around a star should be revisited and that the capacity of the planet to host an Earth-like atmosphere to support the stability of liquid water should be added.
AB - The detection of habitable exoplanets is an exciting scientific and technical challenge. Owing to the current and most likely long-lasting impossibility of performing in situ exploration of exoplanets, their study and hypotheses regarding their capability to host life will be based on the restricted low-resolution spatial and spectral information of their atmospheres. On the other hand, with the advent of the upcoming exoplanet survey missions and technological improvements, there is a need for preliminary discrimination that can prioritize potential candidates within the fast-growing list of exoplanets. Here we estimate, for the first time and using the kinetic theory of gases, a list of the possible atmospheric species that can be retained in the atmospheres of the known exoplanets. We conclude that, based on our current knowledge of the detected exoplanets, 45 of them are good candidates for habitability studies. These exoplanets could have Earth-like atmospheres and should be able to maintain stable liquid water. Our results suggest that the current definition of a habitable zone around a star should be revisited and that the capacity of the planet to host an Earth-like atmosphere to support the stability of liquid water should be added.
KW - atmospheres
KW - exoplanets
KW - habitability
KW - kinetic theory
KW - thermal escape
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U2 - 10.1098/rspa.2020.0148
DO - 10.1098/rspa.2020.0148
M3 - Article
AN - SCOPUS:85093084656
VL - 476
JO - Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences
JF - Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences
SN - 0080-4630
IS - 2241
M1 - 20200148
ER -