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Mathieu Choukroun

Photo of Mathieu Choukroun


4800 Oak Grove Drive
M/S 183-601

Pasadena, CA 91109





Curriculum Vitae:

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Member of:

Small Bodies

Group Supervisor


Dr. Choukroun is a planetary scientist whose primary research aims at better understanding the exchange processes that take place between the interior and the surface (or atmosphere/coma) of icy worlds and comets. This research involves experimental investigation of the physical and chemical properties of icy materials, and thermodynamic and geophysical modeling of icy worlds and cometary environments to apply the experimental results.

Dr. Choukroun uses a range of experimental techniques for this research, including low- to high-pressure cryogenic equipment, optical microscopy, Raman spectroscopy, differential scanning calorimetry, and since recently X-Ray diffraction. He has led or participated in the development of custom instruments dedicated to the measurement of the thermal and mechanical properties of icy materials. Particularly, he focuses on the physical properties of clathrate hydrates (ice-like materials that trap gas in molecular cages), and their implications for outgassing and atmosphere-surface-subsurface exchanges on Titan.

Dr. Choukroun is the Investigation Scientist for the MAss Spectrometer for Planetary EXploration (MASPEX) on the Europa Clipper mission currently in development. The analysis of neutral volatiles from the exosphere of Europa, is of primary importance to assess the habitability of this moon.

Dr. Choukroun participates in ESA’s Rosetta mission as Deputy Project Scientist for NASA’s contribution to Rosetta and Co-Investigator for the Microwave Instrument on the Rosetta Orbiter (MIRO). He uses thermal and radiative transfer modeling to contribute to the analysis of MIRO data and better understand the properties of the nucleus of 67P/Churyumov-Gerasimenko. He currently leads the development of a new simulation system to measure the thermal and mechanical properties of icy comet analogs and how they evolve under varying insolation conditions.

Dr. Choukroun is also involved in instrument development projects, in particular next-generation submillimeter instruments, and the development of new instrument and mission concepts to comets, Titan, and other icy worlds.


  • 2007 Ph.D. in Earth and Planetary Science, Universite de Nantes, France
  • 2004 M.Sc. in Earth Science, Universite Blaise Pascal, Clermont-Ferrand, France
  • 2002 B.Sc. Earth Science, Universite Pierre et Marie Curie, Paris, France

Professional Experience

  • 2007 Ph.D. in Earth and Planetary Science, Universite de Nantes, France
  • 2004 M.Sc. in Earth Science, Universite Blaise Pascal, Clermont-Ferrand, France
  • 2002 B.Sc. Earth Science, Universite Pierre et Marie Curie, Paris, France

Community Service

  • Regular Co-convener and Chair of Rosetta sessions at international conferences
  • Regular Co-convener and Chair of Icy Satellites sessions at international conferences
  • Peer-Reviews for international planetary science, astrophysics, scientific instrumentation journals
  • Peer-Reviews (panelist or external) for JPL internal, NASA, and French Agence Nationale de la Recherche proposals

Research Interests

  • Chemical and Physical Properties of Icy Materials
  • Composition, Structure and Dynamics of Icy Satellites
  • Composition, Activity, and Evolution of Comets

Selected Awards

  • NASA Exceptional Public Achievement Medal, 2017 “for exceptional contributions to our understanding of planetary ices and comets through experimental studies of clathrates and as Deputy Project Scientist for U.S. Rosetta.”
  • JPL Lew Allen Award, 2017 “for pioneering studies of the physical properties of cryogenic materials and contributions to MIRO and the U.S. Rosetta mission.”
  • JPL Voyager Award, 2015
  • NASA Group Achievement Award, 2015 to the U.S. Rosetta Pre-Lander Support Team
  • JPL Discovery Award, 2014
  • NASA postdoctoral Fellowship, 2017-2010

Selected Publications

Clathrate hydrates: physical chemistry and implications for TitanPetuya, C., Choukroun, M., Vu, T.H., Desmedt, A., Davies, A. and Sotin, C., 2020. Cage occupancy of methane clathrate hydrates in the ternary H2O-NH3-CH4 system. Chemical Communications, in press.Vu, T.H., Choukroun, M., Sotin, C., Muñoz‐Iglesias, V. and Maynard‐Casely, H.E., 2020. Rapid Formation of Clathrate Hydrate from Liquid Ethane and Water Ice on Titan. Geophysical Research Letters, p.e2019GL086265.

Petuya, C., Choukroun, M., Vu, T.H., Sotin, C. and Davies, A.G., 2020. Phase Behavior of Clathrate Hydrates in the Ternary H2O-NH3-Cyclopentane System. ACS Earth and Space Chemistry, 4(4), pp.526-534.

Munoz-Iglesias, V., Choukroun, M., Vu, T. H., Hodyss, R., Mahjoub, A., Smythe, W. D., Sotin, C. (2018). Phase Diagram of the Ternary Water-Tetrahydrofuran-Ammonia System at Low Temperatures. Implications for Clathrate Hydrates and Outgassing on Titan. ACS Earth and Space Chemistry, 2 (2), 135-146.

Choukroun M., Kieffer S., Lu X., Tobie G. (2013). Clathrate Hydrates: implication for exchange processes in the outer Solar System. In: « Science of Solar System Ices, 3rd Ed. » (S.M. Gudipati and J.C. Castillo-Rogez, Eds), Astrophysics and Space Science Library, 356, pp. 409-454, Springer, New York, NJ.

Choukroun M., Sotin C. (2012). Is Titan's shape caused by its meteorology and carbon cycle? Geophys. Res. Lett., 39, L04201.

Choukroun M., Grasset O., Tobie G., Sotin C. (2010). Stability of methane clathrate hydrates under pressure: Influence on outgassing processes of methane on Titan. Icarus, 205, 581-593, doi: 10.1016/j.icarus.2009.08.011.

Lunine J.I., Choukroun M., Stevenson D.J., Tobie G. (2009). The Origin and Evolution of Titan. In: Brown, R.H., Lebreton, J.-P., Waite, H. (Eds.), Titan from Cassini-Huygens, Ch. 3, pp. 35-59.

Rosetta, Rosetta/MIRO, 67P/Churyumov-Gerasimenko

Choukroun, M., Altwegg, K., Kührt, E., Biver, N., Bockelée-Morvan, D., Drążkowska, J., Hérique, A., Hilchenbach, M., Marschall,

R., Pätzold, M. and Taylor, M.G., 2020. Dust-to-Gas and Refractory-to-Ice Mass Ratios of Comet 67P/Churyumov-Gerasimenko from Rosetta Observations. Space Science Reviews, 216, pp.1-38.

Biver, N., Bockelée-Morvan, D., Hofstadter, M., Lellouch, E., Choukroun, M., Gulkis, S., Crovisier, J., Schloerb, F.P., Rezac, L., Von Allmen, P. and Lee, S., 2019. Long-term monitoring of the outgassing and composition of comet 67P/Churyumov-Gerasimenko with the Rosetta/MIRO instrument. Astronomy & Astrophysics, 630, p.A19.

Taylor, M.G.G.T., Altobelli, N., Buratti, B.J. and Choukroun, M., 2017. The Rosetta mission orbiter science overview: the comet phase. Phil. Trans. R. Soc. A, 375(2097), p.20160262.Fulle, M., Altobelli, N., Buratti, B., Choukroun, M., Fulchignoni, M., Grün, E., Taylor, M.G.G.T. and Weissman, P., 2016. Unexpected and significant findings in comet 67P/Churyumov-Gerasimenko: an interdisciplinary view. Monthly Notices of the Royal Astronomical Society, 462(Suppl_1), pp.S2-S8.

Choukroun M., Keihm S., Schloerb F.P., Gulkis S., Lellouch E., Leyrat C., von Allmen P., Biver N., Bockelee-Morvan D., Crovisier J., Encrenaz P., Ip W. H., Jarchow C., Janssen M., Hartogh P., Hofstadter M., Lee S., Rezac L., Beaudin G., Gaskell R., Jorda L., Keller H. U., Sierks H. (2015) Dark side of 67P/Churyumov-Gerasimenko in Aug.-Oct. 2014 : MIRO/Rosetta continuum observations of polar night in the Southern regions. Astron. Astrophys, 583, A28.

Biver N., Hofstadter M., Gulkis S., Bockelee-Morvan D., Choukroun M., Lellouch E., Schloerb F.P., Rezac L., Ip W.H., Jarchow C., Hartogh P., Lee S., von Allmen P., Crovisier J., Leyrat C., Encrenaz P. (2015). Distribution of water around the nucleus of comet 67P/Churyumov-Gerasimenko at 3.4 AU from the Sun as seen by the MIRO instrument on Rosetta. Astron. Astrophys., 583, A3.

Schloerb F.P., Keihm S., von Allmen P., Choukroun M., Lellouch E., Leyrat C., Beaudin G., Biver N., Bockelee-Morvan D., Crovisier J., Encrenaz P., Gaskell R., Gulkis S., Hartogh P., Hofstadter M., Ip W.-H., Janssen M., Jarchow C., Jorda L., Keller H.U., Lee S., Rezac L., Sierks H. (2015). MIRO Observations of subsurface temperatures of the nucleus of 67P/Churyumov-Gerasimenko. Astron. Astrophys., 583, A29.

Gulkis S., Allen M., von Allmen P., Beaudin G., Biver N., Bockelee-Morvan D., Choukroun M., Crovisier J., Davidsson B., Encrenaz P., Encrenaz T., Frerking M., Hartogh H., Hofstadter M., et al. (2015). Subsurface properties and early activity of comet 67P/Churyumov-Gerasimenko. Science, 347 (6620), aaa0709, DOI: 10.1126/science.aaa0709.

Water Ice: physical properties and thermodynamics

Choukroun, M., Molaro, J.L., Hodyss, R., Marteau, E., Backes, P., Carey, E.M., Dhaouadi, W., Moreland, S. and Schulson, E.M., 2020. Strength evolution of ice plume deposit analogs of Enceladus and

Europa. Geophysical Research Letters, 47, e2020GL088953.

Molaro, J.L., Choukroun, M., Phillips, C.B., Phelps, E.S., Hodyss, R., Mitchell, K.L., Lora, J.M. and Meirion‐Griffith, G., 2019. The microstructural evolution of water ice in the solar system through sintering. Journal of Geophysical Research: Planets. 124(2), pp.243-277.

Vance S.D., Bouffard M., Choukroun M., Sotin C. (2014). Ganymede's internal structure including thermodynamics of magnesium sulfate oceans in contat with ice. Planet. Space Sci., 94, 62-70.

Choukroun M., Grasset O. (2010). Thermodynamic data and modeling of the water and water-ammonia phase diagrams for planetary geophysics. J. Chem. Phys., 133, 144502.

Sohl F., Choukroun M., Kargel J.S., Kimura J., Pappalardo R., Vance S., Zolotov M. (2010). Subsurface water oceans within icy moons: chemical composition and exchange processes. Space Sci. Rev., 153, 485-510, doi: 10.1007/s11214-010-9646-y.

Choukroun M., Grasset O. (2007). Thermodynamic model for water and high-pressure ices up to 2.2 GPa and down to the metastable domain. J. Chem. Phys., 127, 124506.

Salts and other non-ice materials: properties and implications for Ocean Worlds

Cable, M.L., Vu, T.H., Malaska, M., Maynard-Casely, H.E., Choukroun, M. and Hodyss, R., 2020. Properties and Behavior of the Acetonitrile-Acetylene Co-Crystal under Titan Surface Conditions. ACS Earth and Space Chemistry, in press.

Vu, T.H., Choukroun, M., Hodyss, R. and Johnson, P.V., 2020. Probing Europa's subsurface ocean composition from surface salt minerals using in-situ techniques. Icarus, p.113746.

Johnson, P.V., Hodyss, R., Vu, T.H. and Choukroun, M., 2019. Insights into Europa's ocean composition derived from its surface expression. Icarus, 321, pp.857-865.

Thomas, E.C., Vu, T.H., Hodyss, R., Johnson, P.V. and Choukroun, M., 2019. Kinetic Effect on the Freezing of Ammonium-Sodium-Carbonate-Chloride Brines and Implications for the Origin of Ceres' Bright Spots. Icarus, 320, 150-158.

Cable, M.L., Vu, T.H., Maynard-Casely, H.E., Choukroun, M. and Hodyss, R., 2018. The Acetylene-Ammonia Co-crystal on Titan. ACS Earth and Space Chemistry, 2(4), pp.366-375.Vu, T.H., Hodyss, R., Johnson, P.V. and Choukroun, M., 2017. Preferential formation of sodium salts from frozen sodium-ammonium-chloride-carbonate brines-Implications for Ceres' bright spots. Planetary and Space Science, 141, pp.73-77.

Vu, T.H., Hodyss, R., Choukroun, M., & Johnson, P.V. (2016). Chemistry of frozen sodium-magnesium-sulfate-chloride brines : implications for surface expression of Europa's ocean composition. Astrophys. J. Lett., 816(2), L26.

Cable M.L., Vu T.H., Hodyss R., Choukroun M., Malaska M.J., Beauchamp P.M. (2014). Experimental determination of the kinetics of formation of the benzene-ethane co-crystal and implications for Titan. Geophys. Res. Lett., 41 (15), 5396-5401.

Vu T.H., Cable M.L., Choukroun M., Hodyss R.P., Beauchamp P.M. (2014). Formation of a New Benzene-Ethane Co-Crystalline Structure Under Cryogenic Conditions. J. Phys. Chem. A, 118 (23), 4087-4094.

Fortes A.D., Choukroun M. (2010). Phase behaviour of ices and hydrates. Space Sci. Rev., 153, 185-218, doi : 10.1007/s11214-010-9633-3.