Edinburgh Research Explorer

The ultraviolet environment of Mars: Biological implications past, present, and future

Research output: Contribution to journalLiterature review

  • CS Cockell
  • DC Catling
  • WL Davis
  • K Snook
  • RL Kepner
  • P Lee
  • CP McKay

Related Edinburgh Organisations

Original languageEnglish
Pages (from-to)343-359
Number of pages17
JournalIcarus
Volume146
Issue number2
Publication statusPublished - Aug 2000

Abstract

A radiative transfer model is used to quantitatively investigate aspects of the martian ultraviolet radiation environment, past and present, Biological action spectra for DNA inactivation and chloroplast (photosystem) inhibition are used to estimate biologically effective irradiances for the martian surface under cloudless skies, Over time Mars has probably experienced an increasingly inhospitable photobiological environment, with present instantaneous DNA weighted irradiances 3.5-fold higher than they may have been on early Mars, This is in contrast to the surface of Earth, which experienced an ozone amelioration of the photobiological environment during the Proterozoic and now has DNA weighted irradiances almost three orders of magnitude lower than early Earth, Although the present-day martian UV flux is similar to that of early Earth and thus may not be a critical limitation to life in the evolutionary context, it is a constraint to an unadapted biota and will rapidly kill spacecraft-borne microbes not covered by a martian dust layer, Microbial strategies for protection against UV radiation are considered in the light of martian photobiological calculations, past and present, Data are also presented for the effects of hypothetical planetary atmospheric manipulations on the martian UV radiation environment with estimates of the biological consequences of such manipulations. (C) 2000 Academic Press.

    Research areas

  • atmospheres, evolution, exobiology, Mars, photochemistry, radiative transfer, BACILLUS-SUBTILIS SPORES, EARTHS EARLY ATMOSPHERE, MARTIAN ATMOSPHERE, ACTION SPECTRA, UV-RADIATION, SPACE ENVIRONMENT, EVOLUTION, NM, OZONE, LIFE

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