Hostname: page-component-745bb68f8f-b95js Total loading time: 0 Render date: 2025-01-11T01:20:34.054Z Has data issue: false hasContentIssue false
  • English
  • Français

Swansong Biospheres: The biosignatures of inhabited earth-like planets nearing the end of their habitable lifetimes

Published online by Cambridge University Press:  06 January 2014

Jack T. O'Malley-James ,
Jane S. Greaves ,
John A. Raven  and
Charles S. Cockell
Jack T. O'Malley-James
Affiliation:
School of Physics & Astronomy, University of St Andrews, St Andrews, UK email: [email protected]
Jane S. Greaves
Affiliation:
School of Physics & Astronomy, University of St Andrews, St Andrews, UK email: [email protected]
John A. Raven
Affiliation:
Division of Plant Sciences, University of Dundee at TJHI, The James Hutton Institute, Invergowrie, Dundee, UK email: [email protected]
Charles S. Cockell
Affiliation:
UK Centre for Astrobiology, School of Physics & Astronomy, University of Edinburgh, Edinburgh, UK email: [email protected]
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

The biosignatures of life on Earth are not fixed, but change with time as environmental conditions change and life living within those environments adapts to the new conditions. A latitude-based climate model, incorporating orbital parameter variations, was used to simulate conditions on the far-future Earth as the Sun enters the late main sequence. Over time, conditions increasingly favour a unicellular microbial biosphere, which can persist for a maximum of 2.8 Gyr from present. The biosignature changes associated with the likely biosphere changes are evaluated using a biosphere-atmosphere gas exchange model and their detectability is discussed. As future Earth-like exoplanet discoveries could be habitable planets nearing the end of their habitable lifetimes, this helps inform the search for the signatures of life beyond Earth

Keywords

AstrobiologySun: evolutionEarth
Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 8 , Symposium S299: Exploring the Formation and Evolution of Planetary Systems , June 2013 , pp. 378 - 379
Copyright
Copyright © International Astronomical Union 2013 

References

Caldeira, C. & Kasting, J. F.: The lifespan of the biosphere revisited, Nature, Vol. 360, pp. 721–723, 1992.CrossRefGoogle Scholar
Gough, D. O.: Solar interior structure and luminosity variations, Solar Phys., Vol. 74, pp. 21–34, 1981.CrossRefGoogle Scholar
O'Malley-James, J. T., Cockell, C. S., Greaves, J. S., & Raven, J. A.: Swansong Biospheres II: The final signs of life on terrestrial planets near the end of their habitable lifetimes, 2013b, arXiv: 1310.4841Google Scholar
O'Malley-James, J. T., Greaves, J. A., Raven, J. A., & Cockell, C. S.: Swansong Biospheres: refuges for life and novel microbial biospheres on terrestrial planets near the end of their habitable lifetimes, Int. J. Astrobiology, Vol. 12, pp. 99–112, 2013a.CrossRefGoogle Scholar