Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Heterogeneous chemistry in the atmosphere of Mars


Hydrogen radicals are produced in the martian atmosphere by the photolysis of water vapour and subsequently initiate catalytic cycles that recycle carbon dioxide from its photolysis product carbon monoxide1,2. These processes provide a qualitative explanation for the stability of the atmosphere of Mars, which contains 95 per cent carbon dioxide. Balancing carbon dioxide production and loss based on our current understanding of the gas-phase chemistry in the martian atmosphere has, however, proven to be difficult3,4,5. Interactions between gaseous chemical species and ice cloud particles have been shown to be key factors in the loss of polar ozone observed in the Earth’s stratosphere6, and may significantly perturb the chemistry of the Earth’s upper troposphere7. Water-ice clouds are also commonly observed in the atmosphere of Mars8,9,10 and it has been suggested previously that heterogeneous chemistry could have an important impact on the composition of the martian atmosphere3,4,5,11. Here we use a state-of-the-art general circulation model together with new observations of the martian ozone layer12,13,14,15 to show that model simulations that include chemical reactions occurring on ice clouds lead to much improved quantitative agreement with observed martian ozone levels in comparison with model simulations based on gas-phase chemistry alone. Ozone is readily destroyed by hydrogen radicals and is therefore a sensitive tracer of the chemistry that regulates the atmosphere of Mars. Our results suggest that heterogeneous chemistry on ice clouds plays an important role in controlling the stability and composition of the martian atmosphere.

Your institute does not have access to this article

Relevant articles

Open Access articles citing this article.

Access options

Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1: Observed and simulated seasonal evolution of water vapour and water-ice clouds.
Figure 2: Observed and simulated seasonal evolution of martian ozone.
Figure 3: Synoptic distribution of O 3 column (micrometre atmosphere) calculated in northern spring and at aphelion.
Figure 4: Observed and simulated seasonal evolution of martian hydrogen peroxide (H2O2).


  1. McElroy, M. B. & Donahue, T. M. Stability of the Martian atmosphere. Science 177, 986–988 (1972)

    ADS  CAS  Article  Google Scholar 

  2. Parkinson, T. D. & Hunten, D. M. Spectroscopy and aeronomy of O2 on Mars. J. Atmos. Sci. 29, 1380–1390 (1972)

    ADS  CAS  Article  Google Scholar 

  3. Atreya, S. K. & Blamont, J. E. Stability of the Martian atmosphere: possible role of heterogeneous chemistry. Geophys. Res. Lett. 17, 287–290 (1990)

    ADS  Article  Google Scholar 

  4. Atreya, S. K. & Gu, Z. G. Stability of the Martian atmosphere: Is heterogeneous catalysis essential? J. Geophys. Res. 99, 13133–13145 (1994)

    ADS  CAS  Article  Google Scholar 

  5. Krasnopolsky, V. A. Photochemistry of the Martian atmosphere: Seasonal, latitudinal, and diurnal variations. Icarus 185, 153–170 (2006)

    ADS  CAS  Article  Google Scholar 

  6. Solomon, S. Stratospheric ozone depletion: A review of concepts and history. Rev. Geophys. 37, 275–316 (1999)

    ADS  CAS  Article  Google Scholar 

  7. Jaeglé, L. et al. Photochemistry of HO x in the upper troposphere at northern midlatitudes. J. Geophys. Res. 105, 3877–3892 (2000)

    ADS  Article  Google Scholar 

  8. Clancy, R. T. et al. Water vapor saturation at low altitudes around Mars aphelion: A key to Mars climate? Icarus 122, 36–62 (1996)

    ADS  CAS  Article  Google Scholar 

  9. Akabane, T., Iwasaki, K., Saito, Y. & Narumi, Y. Martian late-northern-winter polar hood opacities and non-visibility of a surface cap: 1975 and 1990 observations. Astron. Astrophys. 277, 302–308 (1993)

    ADS  Google Scholar 

  10. Mateshvili, N. et al. Martian ice cloud distribution obtained from SPICAM nadir UV measurements. J. Geophys. Res. 112 10.1029/2006JE002827 (2007)

  11. Anbar, A. D., Leu, M. T., Nair, H. A. & Yung, Y. L. Adsorption of HOx on aerosol surfaces: Implications for the atmosphere of Mars. J. Geophys. Res. 98, 10933–10940 (1993)

    ADS  CAS  Article  Google Scholar 

  12. Perrier, S. et al. Global distribution of total ozone on Mars from SPICAM/MEX UV measurements. J. Geophys. Res. 111 10.1029/2006JE002681 (2006)

  13. Clancy, R. T. et al. Mars ozone measurements near the 1995 aphelion: Hubble space telescope ultraviolet spectroscopy with the faint object spectrograph. J. Geophys. Res. 101, 12777–12783 (1996)

    ADS  Article  Google Scholar 

  14. Clancy, R. T., Wolff, M. J. & James, P. B. Minimal aerosol loading and global increases in atmospheric ozone during the 1996–1997 Martian northern spring season. Icarus 138, 49–63 (1999)

    ADS  CAS  Article  Google Scholar 

  15. Fast, K. et al. Ozone abundances on Mars from infrared heterodyne spectra I: Acquisition, retrieval, and anticorrelation with water vapor. Icarus 181, 419–431 (2006)

    ADS  CAS  Article  Google Scholar 

  16. Lefèvre, F., Lebonnois, S., Montmessin, F. & Forget, F. Three-dimensional modeling of ozone on Mars. J. Geophys. Res. 109 10.1029/2004JE002268 (2004)

  17. Moudden, Y. & McConnell, J. C. Three-dimensional on-line chemical modeling in a Mars general circulation model. Icarus 188, 18–34 (2007)

    ADS  CAS  Article  Google Scholar 

  18. Montmessin, F., Forget, F., Rannou, P., Cabane, M. & Haberle, R. M. Origin and role of water ice clouds in the Martian water cycle as inferred from a general circulation model. J. Geophys. Res. 109 10.1029/2004JE002284 (2004)

  19. Smith, M. D. Interannual variability in TES atmospheric observations of Mars during 1999–2003. Icarus 167, 148–165 (2004)

    ADS  CAS  Article  Google Scholar 

  20. Clancy, R. T. & Nair, H. Annual (perihelion–aphelion) cycles in the photochemical behavior of the global Mars atmosphere. J. Geophys. Res. 101, 12785–12790 (1996)

    ADS  Article  Google Scholar 

  21. Lebonnois, S. et al. Vertical distribution of ozone on Mars as measured by SPICAM/Mars-Express using stellar occultations. J. Geophys. Res. 111 10.1029/2005JE002643 (2006)

  22. Montabone, L., Lewis, S. R. & Read, P. L. Interannual variability of Martian dust storms in assimilation of several years of Mars Global Surveyor observations. Adv. Space Res. 36, 2146–2155 (2005)

    ADS  Article  Google Scholar 

  23. Cooper, P. L. & Abbatt, J. P. Heterogeneous interactions of OH and HO2 radicals with surfaces characteristic of atmospheric particulate matter. J. Phys. Chem. 100, 2249–2254 (1996)

    CAS  Article  Google Scholar 

  24. Sander, S. P. et al. Chemical Kinetics and Photochemical Data for Use in Atmospheric Studies, Evaluation Number 15. JPL Publ. 06–2 (Jet Propulsion Lab., Pasadena, 2006)

    Google Scholar 

  25. Barth, C. A. et al. Mariner 9 ultraviolet spectrometer experiment: Seasonal variation of ozone on Mars. Science 179, 795–796 (1973)

    ADS  CAS  Article  Google Scholar 

  26. Encrenaz, T. et al. A stringent upper limit of the H2O2 abundance in the Martian atmosphere. Astron. Astrophys. 396, 1037–1044 (2002)

    ADS  CAS  Article  Google Scholar 

  27. Fouchet, T. et al. Martian water vapor: Mars Express PFS/LW observations. Icarus 190, 32–49 (2007)

    ADS  CAS  Article  Google Scholar 

  28. Encrenaz, T. et al. Hydrogen peroxide on Mars: Evidence for spatial and seasonal variations. Icarus 170, 424–429 (2004)

    ADS  CAS  Article  Google Scholar 

  29. Encrenaz, T. et al. Simultaneous mapping of H2O and H2O2 on Mars from infrared high-resolution imaging spectroscopy. Icarus 195, 547–556 (2008)

    ADS  CAS  Article  Google Scholar 

  30. Clancy, R. T., Sandor, B. J. & Moriarty-Schieven, G. H. A measurement of the 362 Ghz absorption line of Mars atmospheric H2O2 . Icarus 168, 116–121 (2004)

    ADS  CAS  Article  Google Scholar 

Download references


Much of this work was done while F.L. was on leave from CNRS at the Instituto de Astrofísica de Andalucía (Granada, Spain). We thank M. Smith, who provided the TES data.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Franck Lefèvre.

Supplementary information

Supplementary Information

The file contains Supplementary Notes and related Supplementary Figures 1-3 with Legends. (PDF 854 kb)

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Lefèvre, F., Bertaux, JL., Clancy, R. et al. Heterogeneous chemistry in the atmosphere of Mars. Nature 454, 971–975 (2008).

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI:

Further reading


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing