Hostname: page-component-848d4c4894-xfwgj Total loading time: 0 Render date: 2024-06-16T23:20:31.787Z Has data issue: false hasContentIssue false

An active nitrogen cycle on Mars sufficient to support a subsurface biosphere

Published online by Cambridge University Press:  16 January 2012

C.S. Boxe*
Earth and Space Science Division, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
K.P. Hand
Earth and Space Science Division, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
K.H. Nealson
Department of Earth Sciences, University of Southern California, Los Angeles, CA 90089, USA
Y.L. Yung
Division of Geological and Planetary Sciences, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA
A. Saiz-Lopez
Earth and Space Science Division, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA Laboratory for Atmospheric and Climate Sciences, CSIC, Toledo, Spain


Mars' total atmospheric nitrogen content is 0.2 mbar. One-dimensional (1D) photochemical simulations of Mars' atmosphere show that nitric acid (HNO3(g)), the most soluble nitrogen oxide, is the principal reservoir species for nitrogen in its lower atmosphere, which amounts to a steady-state value of 6×10−2 kg or 4 moles, conditions of severe nitrogen deficiency. Mars could, however, support ∼1015 kg of biomass (∼1 kg N m−2) from its current atmospheric nitrogen inventory. The terrestrial mass ratio of nitrogen in biomass to that in the atmosphere is ∼10−5; applying this ratio to Mars yields ∼1010 kg of total biomass – also, conditions of severe nitrogen deficiency. These amounts, however, are lower limits as the maximum surface-sink of atmospheric nitrogen is 2.8 mbar (9×1015 kg of N), which indicates, in contradistinction to the Klingler et al. (1989), that biological metabolism would not be inhibited in the subsurface of Mars. Within this context, we explore HNO3 deposition on Mars' surface (i.e. soil and ice-covered regions) on pure water metastable thin liquid films. We show for the first time that the negative change in Gibbs free energy increases with decreasing HNO3(g) (NO3(aq)) in metastable thin liquid films that may exist on Mars' surface. We also show that additional reaction pathways are exergonic and may proceed spontaneously, thus providing an ample source of energy for nitrogen fixation on Mars. Lastly, we explore the dissociation of HNO3(g) to form NO3(aq) in metastable thin liquid films on the Martian surface via condensed phase simulations. These simulations show that photochemically produced fixed nitrogen species are not only released from the Martian surface to the gas-phase, but more importantly, transported to lower depths from the Martian surface in transient thin liquid films. A putative biotic layer at 10 m depth would produce HNO3 and N2 sinks of −54 and −5×1012 molecules cm−2 s−1, respectively, which is an ample supply of available nitrogen that can be efficiently transported to the subsurface. The downward transport as well as the release to the atmosphere of photochemically produced fixed nitrogen species (e.g. NO2, NO and NO2) suggests the existence of a transient but active nitrogen cycle on Mars.

Research Article
Copyright © Cambridge University Press 2012

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)


Bogard, D.D., Clayton, R.N., Marti, K., Owen, T. & Turner, G. (2001). Space. Sci. Rev. 96, 425458.CrossRefGoogle Scholar
Boxe, C.S. & Saiz-Lopez, A. (2008). Atmos. Chem. Phys. 8, 48554864.CrossRefGoogle Scholar
Boxe, C.S. et al. (2003). J. Phys. Chem. A 107, 1140911413.CrossRefGoogle Scholar
Boxe, C.S. et al. (2005). J. Phys. Chem. A 109, 85208525.CrossRefGoogle Scholar
Boxe, C.S. et al. (2006). J. Phys. Chem. A 110, 76137616.CrossRefGoogle Scholar
Boxe, C.S. et al. (2011). Int. J. Astrobiol. submitted.Google Scholar
Bullock, M., Stoker, C., McKay, C. & Zent, A. (1994). Icarus 107, 142154.CrossRefGoogle Scholar
Capone, D.G., Popa, R., Flood, B. & Nealson, K. (2006). Science 312, 708709.CrossRefGoogle Scholar
Dubowski, Y., Colussi, A.J., Boxe, C.S. & Hoffmann, M.R. (2002). J. Phys. Chem. A 106, 69676971.CrossRefGoogle Scholar
Ducluzeau, A.-L., Lis, R.V., Duval, S., Schoepp-Cothenet, B., Russell, M. & Nitschke, W. (2009). Trends Biochem. Sci. 34, 915.CrossRefGoogle Scholar
Field, C.B., Behrenfeld, M.J., Randerson, J.T. & Falkowski, P. (1998). Science 281, 237240.CrossRefGoogle Scholar
Fox, J.L. & Delgarno, A. (1983). J. Geophys. Res. 88(A11), 90279032.CrossRefGoogle Scholar
Graham, R.C., Hirmas, D.R., Wood, Y.A. & Amrhein, C. (2008). Geology 36, 259262.CrossRefGoogle Scholar
Grannas, A.M., Bausch, A.R. & Mahanna, K.M. (2007). J. Phys. Chem. A 111, 1104311049.CrossRefGoogle Scholar
Grannas, A.M., Shepson, P.B. & Filley, T.R. (2004). Global Biogeochem. Cycles 18, doi: 10.1029/2003GB002133, GB1006(1-10).CrossRefGoogle Scholar
Harman, H. & McKay, C. (1995). Planet. Space Sci. 43, 123128.CrossRefGoogle Scholar
Huber, H. et al. (2002). Nature 417, 6367.CrossRefGoogle Scholar
Jakosky, B.M. & Phillips, R.L. (2001). Nature 412, 237244.CrossRefGoogle Scholar
King, M.D., France, J.L., Fisher, F.N. & Beine, H.J. (2005). J. Photochem. Photobiol. A 176, 3949.CrossRefGoogle Scholar
Klingler, J.M., Mancinelli, R.L. & White, M.R. (1989). Adv. Space Res. 9, 173176.CrossRefGoogle Scholar
Lide, David R. (eds) (2006). CRC Handbook of Chemistry and Physics, 89th edn (Internet Version 2009). CRC Press/Taylor and Francis, Boca Raton, FL.Google Scholar
Mack, J. & Bolton, J.R. (1999). J. Photochem. and Photobiol. A 128, 113.CrossRefGoogle Scholar
Mancinelli, R.L. & Banin, A. (2003). Int. J. Astrobiol. 2, 217225.CrossRefGoogle Scholar
McElroy, M.B., Kong, T.Y. & Yung, Y.L. (1977). J. Geophys. Res. 82, 43794388.CrossRefGoogle Scholar
McKay, C.P. & Stoker, C.R. (1989). Rev. Geophys. 27, 189214.CrossRefGoogle Scholar
Mellon, M. & Jakosky, B. (1993). J. Geophys. Res. 98, 33433364.Google Scholar
Price, P.B. (2007). Microbiol. Ecol. 59, 217231.CrossRefGoogle Scholar
Qiu, R., Green, S.A., Honrath, R.E., Peterson, M.C., Lu, Y. & Dziobak, M. (2002). Atmos. Environ. 36, 25632571.CrossRefGoogle Scholar
Rubio, L.M. & Ludden, P.W. (2005). J. Bacteriol. 187, 405414.CrossRefGoogle Scholar
Squyres, S.W., Clifford, S.M., Kuzmin, R.O., Zimbelman, J.R. & Costard, F.M. (1992). In Mars, ed. Kieffer, H., Jakosky, B., Snyder, C. & Matthews, M., pp. 523554. University of Arizona Press, Tuscon, AZ.Google Scholar
Summers, D.P. & Khare, B. (2007). Astrobiology 7, 333, doi: 10.1089/ast.2006.0032.CrossRefGoogle Scholar
Takenaka, N. et al. (1996). J. Phys. Chem. 100, 1387413884.CrossRefGoogle Scholar
Walvoord, M.A. et al. (2003). Science 302, 10211024.CrossRefGoogle Scholar
Weiss, B.P., Yung, Y.L. & Nealson, K.H. (2000). Proc. Natl Acad. Sci. USA 97, 13951399.CrossRefGoogle Scholar
Yung, Y.L. & Demore, W.B. (1999). Photochemistry of Planetary Atmospheres, Oxford University Press, Oxford.CrossRefGoogle Scholar
Zehr, J.P., Jenkins, B.D., Short, M.D. & Steward, G.F. (2005). Environ. Microb. 5, 539554.CrossRefGoogle Scholar
Zuo, Y. & Deng, Y. (1998). Chemosphere 36, 181188.CrossRefGoogle Scholar