Independent confirmation of a methane spike on Mars and a source region east of Gale Crater


Reports of methane detection in the Martian atmosphere have been intensely debated. The presence of methane could enhance habitability and may even be a signature of life. However, no detection has been confirmed with independent measurements. Here, we report a firm detection of 15.5 ± 2.5 ppb by volume of methane in the Martian atmosphere above Gale Crater on 16 June 2013, by the Planetary Fourier Spectrometer onboard Mars Express, one day after the in situ observation of a methane spike by the Curiosity rover. Methane was not detected in other orbital passages. The detection uses improved observational geometry, as well as more sophisticated data treatment and analysis, and constitutes a contemporaneous, independent detection of methane. We perform ensemble simulations of the Martian atmosphere, using stochastic gas release scenarios to identify a potential source region east of Gale Crater. Our independent geological analysis also points to a source in this region, where faults of Aeolis Mensae may extend into proposed shallow ice of the Medusae Fossae Formation and episodically release gas trapped below or within the ice. Our identification of a probable release location will provide focus for future investigations into the origin of methane on Mars.

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Fig. 1: PFS retrieval of CH4 abundance from orbit 12025.
Fig. 2: Location map and regional setting.
Fig. 3: Probabilities estimated for the 30 emission sites.
Fig. 4: Geological context of grid blocks.

Data availability

The PFS data used in this study are publicly available via the ESA Planetary Science Archive. References of terrestrial gas seepage data are reported in the Supplementary Information. Data used to map water-equivalent hydrogen are available from J. T. Wilson (Johns Hopkins University Applied Physics Laboratory, All other geological data of Mars used in this study are in the public domain and include published papers, data provided in the US Geological Survey Mars Global GIS version 2.1 (which can be accessed on the Mars GIS FTP site:; file name: (note that v21 is used in the file name for v2.1)), and Context Camera and Visible data image mosaics provided by Google Earth (Mars).

Code availability

The core GEM model used for this work is publicly available through The routines that were modified for the application to Mars are explained in ref. 39 and available upon request from F.D. ( and L.N. ( The model output used in this paper is available upon request from F.D., L.N. and S.V. ( The equations for the statistical analysis are included in the Methods. The computer code to reproduce the results is available from S.V.


  1. 1.

    Krasnopolsky, V. A., Maillard, J. P. & Owen, T. C. Detection of methane in the Martian atmosphere: evidence for life? Icarus 172, 537–547 (2004).

    Article  Google Scholar 

  2. 2.

    Formisano, V., Atreya, S., Encrenaz, T., Ignatiev, N. & Giuranna, M. Detection of methane in the atmosphere of Mars. Science 306, 1758–1761 (2004).

    Article  Google Scholar 

  3. 3.

    Mumma, M. J. et al. Strong release of methane on Mars in northern summer 2003. Science 323, 1041–1045 (2009).

    Article  Google Scholar 

  4. 4.

    Webster, C. R. et al. Mars methane detection and variability at Gale Crater. Science 347, 415–417 (2015).

    Article  Google Scholar 

  5. 5.

    Yung, Y. et al. Methane on Mars and habitability: challenges and responses. Astrobiology 18, 1221–1242 (2018).

    Article  Google Scholar 

  6. 6.

    Atreya, S. K., Mahaffy, P. R. & Wong, A. S. Methane and related trace species on Mars: origin, loss, implications for life, and habitability. Planet. Space Sci. 55, 358–369 (2007).

    Article  Google Scholar 

  7. 7.

    Oze, C. & Sharma, M. Have olivine, will gas: serpentinization and the abiogenetic production of methane on Mars. Geophys. Res. Lett. 32, L10203 (2005).

    Article  Google Scholar 

  8. 8.

    Krasnopolsky, V. A. Some problems related to the origin of methane on Mars. Icarus 180, 359–367 (2006).

    Article  Google Scholar 

  9. 9.

    Chassefière, E. Metastable methane clathrate particles as a source of methane to the Martian atmosphere. Icarus 204, 137–144 (2009).

    Article  Google Scholar 

  10. 10.

    Gough, R. V., Tolbert, M. A., McKay, C. P. & Toon, O. B. Methane adsorption on a Martian soil analog: an abiogenic explanation for methane variability in the Martian atmosphere. Icarus 207, 165–174 (2010).

    Article  Google Scholar 

  11. 11.

    Meslin, P.-Y., Gough, R., Lèfevre, L. & Forget, F. Little variability of methane on Mars induced by adsorption in the regolith. Planet. Space Sci. 59, 247–258 (2011).

    Article  Google Scholar 

  12. 12.

    Keppler, F. et al. Ultraviolet-radiation-induced methane emissions from meteorites and the Martian atmosphere. Nature 486, 93–96 (2012).

    Article  Google Scholar 

  13. 13.

    Schuerger, A., Moores, J. E., Clausen, C. A., Barlow, N. G. & Britt, D. T. Methane from UV-irradiated carbonaceous chondrites under simulated Martian conditions. J. Geophys. Res. 117, E08007 (2012).

    Article  Google Scholar 

  14. 14.

    McMahon, S., Parnell, J. & Blamey, N. J. F. Sampling methane in basalt on Earth and Mars. Int. J. Astrobiol. 12, 113–122 (2013).

    Article  Google Scholar 

  15. 15.

    Poch, O., Kaci, S., Stalport, F., Szopa, C. & Coll, P. Laboratory insights into the chemical and kinetic evolution of several organic molecules under simulated Mars surface UV radiation conditions. Icarus 242, 50–63 (2014).

    Article  Google Scholar 

  16. 16.

    Oehler, D. Z. & Etiope, G. Methane seepage on Mars: where to look and why. Astrobiology 17, 1233–1264 (2017).

  17. 17.

    Fries, M. et al. A cometary origin for Martian atmospheric methane. Geochem. Perspect. Lett. 2, 10–23 (2016).

    Article  Google Scholar 

  18. 18.

    Geminale, A., Formisano, V. & Giuranna, M. Methane in Martian atmosphere: average spatial, diurnal, and seasonal behavior. Planet. Space Sci. 56, 1194–2003 (2008).

    Article  Google Scholar 

  19. 19.

    Geminale, A., Formisano, V. & Sindoni, G. Mapping methane in Martian atmosphere with PFS-MEx data. Planet. Space Sci. 59, 137–148 (2011).

    Article  Google Scholar 

  20. 20.

    Fonti, S. & Marzo, G. A. Mapping the methane on Mars. Astron. Astrophys. 512, A51 (2010).

    Article  Google Scholar 

  21. 21.

    Krasnopolsky, V. A. A sensitive search for methane and ethane on Mars. In EPSC-DPS Joint Meeting 2011 (Copernicus, 2011).

  22. 22.

    Krasnopolsky, V. A. Search for methane and upper limits to ethane and SO2 on Mars. Icarus 217, 144–152 (2012).

    Article  Google Scholar 

  23. 23.

    Villanueva, G. L. et al. A sensitive search for organics (CH4, CH3OH, H2CO, C2H6, C2H2, C2H4), hydroperoxyl (HO2), nitrogen compounds (N2O, NH3, HCN) and chlorine species (HCl, CH3Cl) on Mars using ground-based high-resolution infrared spectroscopy. Icarus 223, 11–27 (2013).

    Article  Google Scholar 

  24. 24.

    Webster, C. R. et al. Background levels of methane in Mars’ atmosphere show strong seasonal variations. Science 360, 1093–1096 (2018).

    Article  Google Scholar 

  25. 25.

    Summers, M. E., Lieb, B. J., Chapman, E. & Yung, Y. L. Atmospheric biomarkers of subsurface life on Mars. Geophys. Res. Lett. 29, 2171 (2002).

    Google Scholar 

  26. 26.

    Lefèvre, F. & Forget, F. Observed variations of methane on Mars unexplained by known atmospheric chemistry and physics. Nature 460, 720–723 (2009).

    Article  Google Scholar 

  27. 27.

    Atreya, S. K. et al. Methane on Mars: current observations, interpretations, and future plans. Planet. Space Sci. 59, 133–136 (2011).

    Article  Google Scholar 

  28. 28.

    Viscardy, S., Daerden, F. & Neary, L. Formation of layers of methane in the atmosphere of Mars after surface release. Geophys. Rev. Lett. 43, 1868–1875 (2016).

    Article  Google Scholar 

  29. 29.

    Holmes, J. A., Patel, M. R. & Lewis, S. R. The vertical transport of methane from different potential emission types on Mars. Geophys. Res. Lett. 44, 8611–8620 (2017).

    Article  Google Scholar 

  30. 30.

    Holmes, J. A., Lewis, S. R. & Patel, M. R. Analyzing the consistency of Martian methane observations by investigation of global methane transport. Icarus 257, 23–32 (2015).

    Article  Google Scholar 

  31. 31.

    Farrell, W. M., Delory, G. T. & Atreya, S. K. Martian dust storms as a possible sink of atmospheric methane. J. Geophys. Res. 33, L21203 (2006).

    Google Scholar 

  32. 32.

    Atreya, S. K. et al. Oxidant enhancement in Martian dust devils and storms: implications for life and habitability. Astrobiology 6, 439–450 (2006).

    Article  Google Scholar 

  33. 33.

    Delory, G. T. et al. Oxidant enhancement in Martian dust devils and storms: storm electric fields and electron dissociative attachment. Astrobiology 6, 451–462 (2006).

    Article  Google Scholar 

  34. 34.

    Knak Jensen, S. J. et al. A sink for methane on Mars? The answer is blowing in the wind. Icarus 236, 24–27 (2014).

    Article  Google Scholar 

  35. 35.

    Zahnle, K. J., Freedman, R. S. & Catling, D. C. Is there methane on Mars? Icarus 212, 493–503 (2011).

    Article  Google Scholar 

  36. 36.

    Zahnle, K. J. Play it again, SAM. Science 347, 370–371 (2015).

    Article  Google Scholar 

  37. 37.

    Wilson, A. & Chicarro, A. Mars Express: The Scientific Payload SP-1240 (European Space Agency, 2004).

  38. 38.

    Formisano, V. et al. The Planetary Fourier Spectrometer (PFS) onboard the European Mars Express mission. Planet. Space Sci. 53, 963–974 (2005).

    Article  Google Scholar 

  39. 39.

    Neary, L. & Daerden, F. The GEM-Mars general circulation model for Mars: description and evaluation. Icarus 300, 458–476 (2018).

    Article  Google Scholar 

  40. 40.

    Daerden, F. et al. A solar escalator on Mars: self-lifting of dust layers by radiative heating. Geophys. Res. Lett. 42, 7319–7326 (2015).

    Article  Google Scholar 

  41. 41.

    Etiope, G. & Oehler, D. Z. Methane spikes, background seasonality and non-detections on Mars: a geological perspective. Planet. Space Sci. (in the press).

    Article  Google Scholar 

  42. 42.

    Kerber, L. & Head, J. W. The age of the Medusae Fossae Formation: evidence of Hesperian emplacement from crater morphology, stratigraphy, and ancient lava contacts. Icarus 206, 669–684 (2010).

    Article  Google Scholar 

  43. 43.

    Wilson, J. T. et al. Equatorial locations of water on Mars: improved resolution maps based on Mars Odyssey Neutron Spectrometer data. Icarus 299, 148–160 (2018).

    Article  Google Scholar 

  44. 44.

    Voosen, P. Martian methane—spotted in 2004—has mysteriously vanished. Science (2018).

  45. 45.

    Etiope, G. Understanding the origin of methane on Mars through isotopic and molecular data from the ExoMars orbiter. Planet. Space Sci. 159, 93–96 (2018).

    Article  Google Scholar 

  46. 46.

    Vandaele, A. C. et al. NOMAD, an integrated suite of three spectrometers for the ExoMars Trace Gas Mission: technical description, science objectives and expected performance. Space Sci. Rev. 214, 80 (2018).

    Article  Google Scholar 

  47. 47.

    Korablev, O. et al. The Atmospheric Chemistry Suite (ACS) of three spectrometers for the ExoMars 2016 Trace Gas Orbiter. Space Sci. Rev. 214, 7 (2018).

    Article  Google Scholar 

  48. 48.

    Knapmeyer, M. et al. Working models for spatial distribution and level of Mars’ seismicity. J. Geophys. Res. 111, E11006 (2006).

    Article  Google Scholar 

  49. 49.

    Lanz, J. K. & Saric, M. B. Cone fields in SW Elysium Planitia: hydrothermal venting on Mars. J. Geophys. Res. 114, E02008 (2009).

    Article  Google Scholar 

  50. 50.

    Martínez-Alonso, S., Mellon, M. T., McEwen, A. S. & the HiRISE Team. Geological study of a section of Aeolis Mensae, a possible site favorable for life. In 7th International Conference on Mars Abstract 1353, 3262 (2007).

  51. 51.

    Levenberg, K. A method for the solution of certain non-linear problems in least squares. Q. Appl. Math. 2, 164–168 (1944).

    Article  Google Scholar 

  52. 52.

    Marquardt, D. W. An algorithm for least-squares estimation of nonlinear parameters. J. Soc. Ind. Appl. Math. 11, 431–441 (1963).

    Article  Google Scholar 

  53. 53.

    Ignatiev, N. I., Grassi, D. & Zasova, L. V. Planetary Fourier Spectrometer data analysis: fast radiative transfer models. Planet. Space Sci. 53, 1035–1042 (2005).

    Article  Google Scholar 

  54. 54.

    Stamnes, K., Tsay, S. C., Wiscombe, W. & Jayaweera, K. Numerically stable algorithm for discrete-ordinate-method radiative transfer in multiple scattering and emitting layered media. Appl. Opt. 27, 2502–2509 (1988).

    Article  Google Scholar 

  55. 55.

    Rothman, L. S. et al. The HITRAN2012 molecular spectroscopic database. J. Quant. Spectrosc. Radiat. Transf. 130, 4–50 (2013).

    Article  Google Scholar 

  56. 56.

    Fiorenza, C. & Formisano, V. A solar spectrum for PFS data analysis. Planet. Space Sci. 53, 1009–1016 (2004).

    Article  Google Scholar 

  57. 57.

    Kurucz, R. The solar spectrum: atlases and line identifications. In Laboratory and Astronomical High Resolution Spectra (eds Sauval, A. J., Blomme, R. & Grevesse, N.) Vol. 81, 17–31 (Astronomical Society of the Pacific, 1995).

  58. 58.

    Millour, E. et al. The Mars Climate Database (MCD version 5.2). In European Planetary Science Congress 2015 10 (Copernicus 2015).

  59. 59.

    Forget, F. et al. Improved general circulation models of the Martian atmosphere from the surface to above 80 km. J. Geophys. Res. 104, 24155–24176 (1999).

    Article  Google Scholar 

  60. 60.

    Grassi, D. et al. Methods for the analysis of data from the Planetary Fourier Spectrometer on the Mars Express Mission. Planet. Space Sci. 53, 1017–1034 (2005).

    Article  Google Scholar 

  61. 61.

    Wolkenberg, P. et al. Characterization of dust activity on Mars from MY27 to MY32 by PFS-MEX observations. Icarus 310, 32–47 (2018).

    Article  Google Scholar 

  62. 62.

    Press, W. H., Teukolsky, S. A., Vetterling, W. T. & Flannery, B. T. Numerical Recipes: The Art of Scientific Computing 3rd edn (Cambridge Univ. Press, 2007).

  63. 63.

    Smith, M., Daerden, F., Neary, L. & Khayat, S. The climatology of carbon monoxide and water vapor on Mars as observed by CRISM and modeled by the GEM-Mars general circulation model. Icarus 301, 117–131 (2018).

    Article  Google Scholar 

  64. 64.

    Musiolik, G. et al. Saltation under Martian gravity and its influence on the global dust distribution. Icarus 306, 25–31 (2018).

    Article  Google Scholar 

  65. 65.

    Vandaele, A. C. et al. Science objectives and performances of NOMAD, a spectrometer suite for the ExoMars TGO mission. Planet. Space Sci. 119, 233–249 (2015).

    Article  Google Scholar 

  66. 66.

    Robert, S. et al. Expected performances of the NOMAD/ExoMars instrument. Planet. Space Sci. 124, 94–104 (2016).

    Article  Google Scholar 

  67. 67.

    Robert, S. et al. Two test-cases for synergistic detections in the Martian atmosphere: carbon monoxide and methane. J. Quant. Spectrosc. Radiat. Transf. 189, 86–104 (2017).

    Article  Google Scholar 

  68. 68.

    Montabone, L. et al. Eight-year climatology of dust optical depth on Mars. Icarus 251, 65–95 (2015).

    Article  Google Scholar 

  69. 69.

    Abrams, M. A. Significance of hydrocarbon seepage relative to petroleum generation and entrapment. Mar. Petroleum Geol. 22, 457–477 (2005).

    Article  Google Scholar 

  70. 70.

    Etiope, G. & Klusman, R. W. Microseepage in drylands: flux and implications in the global atmospheric source/sink budget of methane. Global Planet. Change 72, 265–274 (2010).

    Article  Google Scholar 

  71. 71.

    Etiope, G., Nakada, R., Tanaka, K. & Yoshida, N. Gas seepage from Tokamachi mud volcanoes, onshore Niigata Basin (Japan): origin, post-genetic alterations and CH4–CO2 fluxes. Appl. Geochem. 26, 348–359 (2011).

    Article  Google Scholar 

  72. 72.

    Klusman, R. W., Leopold, M. E. & LeRoy, M. P. Seasonal variation in methane fluxes from sedimentary basins to the atmosphere: results from chamber measurements and modeling of transport from deep sources. J. Geophys. Res. Atmos. 105, 24661–24670 (2000).

    Article  Google Scholar 

  73. 73.

    Macgregor, D. S. Relationships between seepage, tectonics and subsurface petroleum reserves. Mar. Petroleum Geol. 10, 606–619 (1993).

    Article  Google Scholar 

  74. 74.

    Malmqvist, L. & Kristiansson, K. A physical mechanism for the release of free gases in the lithosphere. Geoexploration 23, 447–453 (1985).

    Article  Google Scholar 

  75. 75.

    Mazzini, A. & Etiope, G. Mud volcanism: an updated review. Earth Sci. Rev. 168, 81–112 (2017).

    Article  Google Scholar 

  76. 76.

    Schumacher, D. & Abrams M.A. (eds) Hydrocarbon Migration and Its Near-Surface Expression. AAPG Memoir 66, 446 (American Association of Petroleum Geologists, 1996).

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We thank Environment and Climate Change Canada for providing the GEM model for research purposes, and for support. We thank J. T. Wilson for providing the data used to map the water-equivalent hydrogen from improved-resolution Mars Odyssey Neutron Spectrometer data. We thank O. Witasse, D. Titov, P. Martin and the ESA Science Ground Segment and Flight Control teams for successful operation of the MEx mission over more than a decade. The PFS experiment was built at the Institute for Space Astrophysics and Planetology (formerly the Institute for Interplanetary Space Physics) of the National Institute for Astrophysics, and is currently funded by the Italian Space Agency (agreement number 2018-2-HH.0) in the context of the science activities for the Nadir and Occultation for Mars Discovery spectrometer and the Atmospheric Chemistry Suite onboard the Trace Gas Orbiter ExoMars 2016, and for PFS-MEx. D.O. is supported by the Planetary Science Institute. S.V. and L.N. are supported by the ESA PRODEX Office (contract number Prodex_NOMADMarsScience_C4000121493_2017-2019). S.V. is also supported by the ‘Excellence of Science’ project ‘Evolution and Tracers of Habitability on Mars and the Earth’ (FNRS 30442502). P.W. is supported by the ‘UPWARDS’ project, funded from the European Union’s Horizon 2020 research and innovation programme under grant agreement number 633127. S.A. has been supported by the FNRS ‘CRAMIC’ project under grant agreement number T.0171.16. This paper is dedicated to our colleague, V. Formisano, who recently passed away.

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M.G. and S.A. developed the new approach to PFS data selection and treatment. M.G. performed the CH4 retrieval. A.A., P.W. and S.A. supervised the PFS science operations, planning, commanding and data archiving. A.C.-M. provided ancillary data and other geometrically relevant models for PFS and MEx through the SPICE software suite. A.C.-M., J.M.-Y.l.P. and D.M. contributed to planning the PFS observations and successful implementation and execution of the PFS spot-tracking observations. V.F. developed the concept and was the former principal investigator for PFS-MEx. S.V., F.D. and L.N. developed and performed the GCM simulations and analysis. G.E. and D.O. performed the geological analysis and evaluation of terrestrial seepage patterns. M.A. was responsible for the PFS-MEx project from the Italian Space Agency side. All authors contributed to interpretation of the results and preparation of the manuscript.

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Correspondence to Marco Giuranna.

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Giuranna, M., Viscardy, S., Daerden, F. et al. Independent confirmation of a methane spike on Mars and a source region east of Gale Crater. Nat. Geosci. 12, 326–332 (2019).

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