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.

Stability against freezing of aqueous solutions on early Mars


Many features of the Martian landscape are thought to have been formed by liquid water flow1,2 and water-related mineralogies on the surface of Mars are widespread and abundant3. Several lines of evidence, however, suggest that Mars has been cold with mean global temperatures well below the freezing point of pure water4. Martian climate modellers5,6 considering a combination of greenhouse gases at a range of partial pressures find it challenging to simulate global mean Martian surface temperatures above 273 K, and local thermal sources7,8 cannot account for the widespread distribution of hydrated and evaporitic minerals throughout the Martian landscape3. Solutes could depress the melting point of water9,10 in a frozen Martian environment, providing a plausible solution to the early Mars climate paradox. Here we model the freezing and evaporation processes of Martian fluids with a composition resulting from the weathering of basalts, as reflected in the chemical compositions at Mars landing sites. Our results show that a significant fraction of weathering fluids loaded with Si, Fe, S, Mg, Ca, Cl, Na, K and Al remain in the liquid state at temperatures well below 273 K. We tested our model by analysing the mineralogies yielded by the evolution of the solutions: the resulting mineral assemblages are analogous to those actually identified on the Martian surface. This stability against freezing of Martian fluids can explain saline liquid water activity on the surface of Mars at mean global temperatures well below 273 K.

This is a preview of subscription content, access via your institution

Relevant articles

Open Access articles citing this article.

Access options

Rent or buy this article

Get just this article for as long as you need it


Prices may be subject to local taxes which are calculated during checkout

Figure 1: Liquid water on Mars at subzero temperatures.
Figure 2: Analysis of ice formation during the evaporation/freezing sequence.


  1. Sagan, C. & Mullen, G. Earth and Mars: evolution of atmospheres and surface temperatures. Science 177, 52–56 (1972)

    Article  ADS  CAS  Google Scholar 

  2. Baker, V. R. Water and the martian landscape. Nature 412, 228–236 (2001)

    Article  ADS  CAS  Google Scholar 

  3. Bibring, J. P. et al. Global mineralogical and aqueous Mars history derived from OMEGA/Mars Express data. Science 312, 400–404 (2006)

    Article  ADS  CAS  Google Scholar 

  4. Gaidos, E. & Marion, G. Geological and geochemical legacy of a cold early Mars. J. Geophys. Res. 108 10.1029/2002JE002000 (2003)

  5. Kasting, J. F. CO2 condensation and the climate of early Mars. Icarus 94, 1–13 (1991)

    Article  ADS  CAS  Google Scholar 

  6. Colaprete, A. & Toon, O. B. Carbon dioxide clouds in an early dense Martian atmosphere. J. Geophys. Res. 108 5025 10.1029/2002JE001967 (2003)

    Article  CAS  Google Scholar 

  7. Griffith, L. L. & Shock, E. L. Hydrothermal hydration of Martian crust: illustration via geochemical model calculations. J. Geophys. Res. 102, 9135–9143 (1997)

    Article  ADS  CAS  Google Scholar 

  8. Segura, T., Toon, O. B., Colaprete, A. & Zahnle, K. Environmental effects of large impacts on Mars. Science 298, 1977–1980 (2002)

    Article  ADS  CAS  Google Scholar 

  9. Brass, G. W. Stability of brines on Mars. Icarus 42, 20–28 (1980)

    Article  ADS  CAS  Google Scholar 

  10. Kuzmin, R. O. & Zabalueva, E. V. On salt solutions in the Martian criolithosphere. Solar Syst. Res. 32, 187–197 (1998)

    ADS  Google Scholar 

  11. Forget, F. & Pierrehumbert, R. T. Warming early Mars with carbon dioxide clouds that scatter infrared radiation. Science 278, 1273–1276 (1997)

    Article  ADS  CAS  Google Scholar 

  12. Squyres, S. W. & Kasting, J. F. Early Mars: how warm and how wet? Science 265, 744–749 (1994)

    Article  ADS  CAS  Google Scholar 

  13. Halevy, I., Zuber, M. T. & Schrag, D. P. A sulfur dioxide climate feedback on early Mars. Science 318, 1903–1907 (2007)

    Article  ADS  CAS  Google Scholar 

  14. Chevrier, V., Poulet, F. & Bibring, J.-P. Early geochemical environment of Mars as determined from thermodynamics of phyllosilicates. Nature 448, 60–63 (2007)

    Article  ADS  CAS  Google Scholar 

  15. Kasting, J. F. Warming early Earth and Mars. Science 276, 1213–1215 (1997)

    Article  CAS  Google Scholar 

  16. Kuhn, W. R. & Atreya, S. W. Ammonia photolysis and the greenhouse effect in the primordial atmosphere of the Earth. Icarus 37, 207–213 (1979)

    Article  ADS  CAS  Google Scholar 

  17. Johnson, S. S., Mischna, M. A., Grove, T. L. & Zuber, M. T. Sulfur-induced greenhouse warming on early Mars. J. Geophys. Res. 113 E08005 10.1029/2007JE002962 (2008)

    Article  ADS  CAS  Google Scholar 

  18. Gendrin, A. et al. Sulfates in martian layered terrains: the OMEGA/Mars Express view. Science 307, 1587–1591 (2005)

    Article  ADS  CAS  Google Scholar 

  19. Osterloo, M. M. et al. Chloride-bearing materials in the southern highlands of Mars. Science 319, 1651–1654 (2008)

    Article  ADS  CAS  Google Scholar 

  20. Tosca, N. J., Knoll, A. H. & McLennan, S. M. Water activity and the challenge for life on early Mars. Science 320, 1204–1207 (2008)

    Article  ADS  CAS  Google Scholar 

  21. Karunatillake, S. et al. Chemical compositions at Mars landing sites subject to Mars Odyssey Gamma Ray Spectrometer constraints. J. Geophys. Res. 112 E08S90 10.1029/2006JE002859 (2007)

    Article  CAS  Google Scholar 

  22. Marion, G. M. & Kargel, J. S. Cold Aqueous Planetary Geochemistry with FREZCHEM 102–109 (Springer, 2008)

    Book  Google Scholar 

  23. Phillips, R. J. et al. Ancient geodynamics and global-scale hydrology on Mars. Science 291, 2587–2591 (2001)

    Article  ADS  CAS  Google Scholar 

  24. Sagan, C., Toon, O. B. & Gierasch, P. J. Climatic change on Mars. Science 181, 1045–1049 (1973)

    Article  ADS  CAS  Google Scholar 

  25. Brain, D. A. & Jakosky, B. M. Atmospheric loss since the onset of the Martian geologic record: combined role of impact erosion and sputtering. J. Geophys. Res. 103, 22689–22694 (1998)

    Article  ADS  CAS  Google Scholar 

  26. Fairén, A. G. et al. Evidence for Amazonian acidic liquid water on Mars—A reinterpretation of MER mission results. Planet. Space Sci. 57, 276–287 (2009)

    Article  ADS  Google Scholar 

  27. Parkhurst, D. L. & Appelo, C. A. J. User's Guide to PHREEQC (Version 2)—A Computer Program for Speciation, Batch-Reaction, One-Dimensional Transport, and Inverse Geochemical Calculations US Geol. Surv. Wat. Resour. Invest. Rep. 99–4259 (1999)

    Google Scholar 

  28. Debye, P. & Hückel, E. Zur theorie der electrolyte: I. Gefrierpunkterniedindung und Verwandte Ersheinungen. Phys. Z. 24, 185–206 (1923)

    CAS  MATH  Google Scholar 

  29. Pitzer, K. S. Thermodynamics 3rd edn (McGraw-Hill, 1995)

    Google Scholar 

  30. Marion, G. M., Kargel, J. S. & Catling, D. C. Modeling ferrous-ferric iron chemistry with application to Martian surface geochemistry. Geochim. Cosmochim. Acta 72, 242–266 (2008)

    Article  ADS  CAS  Google Scholar 

Download references


Work by A.G.F. and A.F.D. was supported by ORAU-NPP. We thank J. Kasting and J. Kargel for reviews that significantly improved the paper.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Alberto G. Fairén.

Supplementary information

Supplementary Information.

This file contains a Supplementary Discussion with Figures, Supplementary Tables 1-2 and Supplementary References. (PDF 1062 kb)

PowerPoint slides

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Fairén, A., Davila, A., Gago-Duport, L. et al. Stability against freezing of aqueous solutions on early Mars. Nature 459, 401–404 (2009).

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI:

This article is cited by


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