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Neutral Atmospheres of the Giant Planets: An Overview of Composition Measurements


Measurements of the chemical composition of the giant planets provide clues of their formation and evolution processes. According to the currently accepted nucleation model, giant planets formed from the initial accretion of an icy core and the capture of the protosolar gas, mosly composed of hydrogen and helium. In the case of Jupiter and Saturn (the gaseous giants), this gaseous component dominates the composition of the planet, while for Uranus and Neptune (the icy giants) it is only a small fraction of the total mass. The measurement of elemental and isotopic ratios in the giant planets provides key diagnostics of this model, as it implies an enrichment in heavy elements (as well as deuterium) with respect to the cosmic composition.

Neutral atmospheric constituents in the giant planets have three possible sources: (1) internal (fromthe bulk composition of the planet), (2) photochemical (fromthe photolysis ofmethane) and(3) external (from meteoritic impacts, of local or interplanetary origin). This paper reviews our present knowledge about the atmospheric composition in the giant planets, and their elemental and istopic composition. Measurements concerning key parameters, like C/H, D/H or rare gases in Jupiter, are analysed in detail. The conclusion addresses open questions and observations to be performed in the future.

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  1. Atreya, S.K. and Romani, P.N.: 1985, ‘Photochemistry of the clouds of Jupiter, Saturn and Uranus’, in G. Hunt (ed.), Recent Advances in Planetary Meteorology, Cambridge Univ. Press, pp. 17–68.

  2. Atreya, S.K., Wong, M.H., Owen, T.C., Niemman, H.B., and Mahaffy P.R.: 1997, ‘Chemistry and clouds of Jupiter’s atmosphere: a Galileo perspective’, in C. Barbieri, J. Rahe, T.V. Johnson, and A.M. Sohus (eds.), The Three Galileos, The Man, the Spacecraft, the Telescope, Kluwer Academic Publishers.

  3. Atreya, S.K. and Wong, A.S.: 2004, ‘Couples clouds and chemistry of the giant planets – A case for multiprobes’, this volume.

  4. Baines, K.H., Mickelson, M.E., Larson, Lee, E., and Ferguson, D.W.: 1995, ‘The abundances of methane and ortho/para hydrogen on Uranus and Neptune: implications of new laboratory 4-0 H2 quadrupole line parameters’, Icarus 114, 328–340.

  5. Bézard, B., Feuchtgruber, H., Moses, J.I., and Encrenaz, T.: 1998, ‘Detection of methyl radicals (CH3) on Saturn’, Astron. Astrophys. 334, L41–L44.

  6. Bézard, B., Romani, P.N., Feuchtgruber, H., Encrenaz, T.: 1999, ‘Detection of the methyl radical on Neptune’, Astrophys. J. 515, 868–872.

  7. Bézard, B., Moses, J.I., Lacy, J., Greathouse, T., Richter, M., Griffith, C.: 2001a, ‘Detection of Ethylene (C2H4) on Jupiter and Saturn in Non–Auroral Regions’, Bull. Am. Astr. Soc. 33 p. 1079.

  8. Bézard, B., Drossart, P., Encrenaz, T., and Feuchtgruber, H.: 2001b, ‘Benzene in the giant planets’, Icarus 154, 492–500.

  9. Bézard, B., Lellouch, E., Strobel, D., Maillard, J.-P., and Drossart, P.: 2002, ‘Carbon monoxide on Jupiter: evidence for both internal and external sources’, Icarus 159, 95–111.

  10. Bjoraker, G.L., Larson, H.P., and Kunde, V.G.: 1986, ‘The abundance and distribution of water vapor in Jupiter’s atmosphere’, Astrophys. J. 311, 1058–1072.

  11. Bockelée-Morvan, D., Gautier, D., Lis, D.C., Young, K., Keene, J., Phillips, T., Owen, T., Crovisier, J., Goldsmith, P.F., and Bergin, E.A.: 1998, ‘DeuteratedWater in Comet C/1996 B2 (Hyakutake) and Its Implications for the Origin of Comets’, Icarus 133, 147–162.

  12. Combes, M., Maillard, J.-P., and de Bergh, C.: 1977, ‘Evidence for a telluric value of the 12C/13C ratio in the atmospheres of Jupiter and Saturn’, Astron. Astrophys. 61, 531–537.

  13. Conrath, B.J. and Gautier, D.: 2000, ‘Saturn Helium Abundance: A Reanalysis of Voyager Measurements’, Icarus 144, 124–134.

  14. Conrath, B.J., Gautier, D., Hanel, R.A., Lindal, G., and Marten, A.: 1987, ‘The helium abundance in Uranus from Voyager infrared measurements’, J. Geophys. Res. 92, 15,003–15,010.

  15. Conrath, B.J., Gautier, D., Lindal, G., Samuelson, R.E., and Shaffer, W.E.: 1991, ‘The helium abundance of Neptune from Voyager measurements’, J. Geophys. Res. 96, 18,907–18,919.

  16. Courtin, R., Gautier, D., Marten, A., Kunde, V.: 1984, ‘The 12C/13C Ratio in Jupiter from the Voyager infrared investigation’, Icarus 53, 121–132.

  17. de Graauw, T., et al.: 1997, ‘First results of ISO-SWS observations of Saturn : detection of CO2, CH3CH2, C4H2 and tropospheric H2O’, Astron. Astrophys. 321, L13–L16.

  18. de Pater, I.: 1999, ‘The solar system at radio wavelengths’, in P.R. Weissman, L.-A. McFadden, T.V. Johnson, Encyclopedia of the solar system, San Diego, Academic Press, pp. 735–772.

  19. de Pater, I. and Massie, S.T.: 1985, ‘Models of the millimeter-centimeter spectra of the giant planets’, Icarus 62, 143–171.

  20. de Pater, I., Romani, P.N., and Atreya, S.K.: 1991, ‘Possiblemicrowave absorption by H2S in Uranus’ and Neptune’s atmospheres’, Icarus 91, 220–233.

  21. Drossart, P., and Encrenaz, Th.: 1982, ‘The abundance of water vapor on Jupiter from the Voyager IRIS data at 5 microns’, Icarus 52, 483–491.

  22. Drossart, P., Lacy, J., Serabyn, E., Tokunaga, A., Bézard, B., and Encrenaz, T.: 1985, ‘Detection of 12C13CH2 on Jupiter at 13 microns’, Astron. Astrophys. 149, L10–L12.

  23. Eberhardt, P., Reber, M., Krankowsky, D., Hodges, R.R.: 1995, ‘The D/H and 18O/16O ratios in water from comet P/Halley’, Astron. Astrophys. 302, 301–304.

  24. Encrenaz, T.: 1999, ‘The planet Jupiter’, Astron. Astrophys. Rev. 9, 171–219.

  25. Encrenaz, T.: 2000, ‘ISO observations of solar-system objects’, in F. Casoli, J. Lequeux, F. David (eds.), Infrared Astronomy, today and tomorrow, Springer-Verlag, Berlin, Paris, pp. 89–150.

  26. Encrenaz, T. and Moreno, R.: 2002, ‘The microwave spectra of planets’, in M. de Petris and M. Gervasi (eds.), Experimental Cosmology at Millimetre Wavelengths, 2K1BC Workshop, Am. Inst. of Physics Conf. Proc. 616, pp. 330–337.

  27. Encrenaz, T., Serabyn E., and Weisstein, E.W.: 1996, ‘Millimeter spectroscopy of Uranus and Neptune: Constraints on CO and PH3 tropospheric abundances’, Icarus 124, 616–624.

  28. Encrenaz, T., et al.: 1998, ‘ISO observations of Uranus: the stratospheric distribution of C2H2 and the eddy diffusion coefficient’, Astron. Astrophys. 333, L43–L46.

  29. Encrenaz, T., Schulz, B., Drossart, P., Lellouch, E., Feuchtgruber, H., and Atreya, S.K.: 2000, ‘The ISO spectra of Uranus and Neptune between 2.5 and 4.2 μm: constraints on albedos and H+ 3’, Astron. Astrophys. 358, L83–L87.

  30. Encrenaz, T., Bibring, J.-P., Blanc, M., Barucci, M.-A., Roques, F., and Zarka, P.: 2004a, The solar system, Third Edition, Springer-Verlag.

  31. Encrenaz, T., Lellouch, E., Drossart, P., Feuchtgruber, H., Orton, G.S., and Atreya, S.K.: 2004b, ‘First detection of CO in Uranus’, Astron. Astrophys. 413, L5–L9.

  32. Fegley, B., Jr. and Prinn, R.G.: 1989, ‘Solar nebula chemistry – Implications for volatiles in the solar system’, in H.A. Weaver, L. Danly, and M. Fall (eds.): 1989, The Formation and Evolution of Planetary Systems, Cambridge Univ. Press, Cambridge and New York, USA, pp. 171–205.

  33. Feuchtgruber, H., Lellouch, E., de Graauw, T., Bézard, B., and Encrenaz, T.: 1997, ‘External supply of oxygen to the atmospheres of the giant planets’, Nature 389, 159–162.

  34. Feuchtgruber, H., Lellouch, E., Bézard, B., Encrenaz, T., de Graauw, T., and Davis G.R.: 1999, ‘Detection of HD in the atmospheres of Uranus and Neptune: a new determination of the D/H ratio’, Astron. Astrophys. 341, L17–L21, 1999.

  35. Feuchtgruber, H., Lellouch, E., Encrenaz, T., Bézard, B., Coustenis, A., Drossart, P., Salama, A., de Graauw, T. and Davis, G.R.: 1999, ‘Oxygen in the stratospheres of the giant planets and Titan’, ESA SP-427, pp. 133–136.

  36. Fouchet, T., Lellouch, E., Bézard, B., Encrenaz, T., Drossart, P., Feuchtgruber, H., de Graauw, T.: 2000, ‘ISO-SWS observations of Jupiter: measurements of the ammonia tropospheric profile and of the 14N/15N ratio’, Icarus 143, 223–243.

  37. Fox, K., Owen, T., Mantz, A.W., Rao, N.K.: 1972, ‘A tentative identification of 13CH4 and an Estimate of 12C/13C in the atmosphere of Jupiter’, Astrophys. J. 176, L81–L84.

  38. Gautier, D. and Owen, T.: 1989, ‘The composition of outer planet atmospheres’, in S.K. Atreya, J.B. Pollack, and M.S. Shapley (eds.), Origin and evolution of planetary and satellite atmospheres, S.K. Atreya, J.B. Pollack, and M.S. Shapley (eds.), Univ. Arizona Press, Tucson, pp. 487–512.

  39. Geiss, J. and Gloeckler, G.: 1998, ‘Abundances of deuterium and helium-3 in the protosolar cloud’, Space Sci. Rev. 84, 239–250.

  40. Guilloteau, S., Dutrey, A., Marten, A., and Gautier, D. : 1994, ‘CO in the atmosphere of Neptune: detection of the J=1−0 line in absorption’, Astron. Astrophys. 279, 661–667.

  41. Irvine, W. and Knacke, R.F.: 1989, ‘The chemistry of interstellar gas and grains’, in S.K. Atreya, J.B. Pollack, and M.S. Shapley (eds.), Origin and evolution of planetary and satellite atmospheres, Univ. Arizona Press, Tucson, pp. 3–34.

  42. Kunde, V.G., Hanel, R.A., Maguire, W.C., Gautier, D., Baluteau, J.P., Marten, A., Chedin, A., Husson, N., and Scott, N.: 1982, ‘The tropospheric gas composition of Jupiter’s north equatorial belt (NH3, PH3, CH3D, GeH4, H2O) and the jovian D/H isotopic ratio’, Astrophys. J. 263, 443–467.

  43. Larson, H.P.: 1980, ‘Infrared spectroscopic observations of the outer planets, their satellites, and the asteroids’, Ann. Rev. Astron. Astrophys. 18, 43–75.

  44. Larson, H.P., Fink, U., Treffers, R., and Gautier, T.N.: 1975, ‘Detection of water vapor on Jupiter’, Astrophys. J. 197, L137–L140.

  45. Lellouch, E., Bézard, B., Fouchet, T., Feuchtgruber, H., Encrenaz, T., and de Graauw, T.: 2001, ‘The deuterium abundance in Jupiter and Saturn from ISO-SWS observations’, Astron. Astrophys. 370, 610–622.

  46. Lellouch, E., Bézard, B., Moses, J.I., Davis, G.R., Drossart, P., Feuchtgruber, H., Bergin, E.A., Moreno, R., and Encrenaz, T.: 2002, ‘The origin of water vapor and carbon dioxide in Jupiter’s stratosphere’, Icarus 159, 112–131.

  47. Linsky, J.L.: 1998, ‘Deuterium abundance in the Local Interstellar Medium and possible spatial variations’, Space Sci. Rev. 84, 285.

  48. Mahaffy, P.R., Donahue, T.M., Atreya, S.K., Owen, T.C., and Niemann, H.B.: 1998, ‘Galileo Probe Measurements of D/H and 3He/4He in Jupiter’s Atmosphere’, Space Sci. Rev. 84, 251–263.

  49. Marten, A., Gautier, D., Owen, T., Sanders, D., Tilanus, R.T., Deane, J., and Matthews, H.: 1991, B.G. Marsden (ed.), Neptune, IAUC 5331.

  50. Marten, A., Gautier, D., Owen, T., Sanders, D.B., Matthews, H.E., Atreya, S.K., Tilanus, R.P.J., and Deane, J.R.: 1993, ‘First observations of CO and HCN on Neptune and Uranus at millimeter wavelengths and their implications for atmospheric chemistry’, Astrophys. J. 406, 285–297.

  51. Meier, R., Owen, T., Matthews, H.E., Jewitt, D.C., Bockelée-Morvan, D., Biver, N., Crovisier, J., Gautier, D.: 1998, ‘A Determination of the HDO/H2O Ratio in Comet C/1995 O1 (Hale-Bopp)’, Science 279, 842–844.

  52. Mizuno, H.: 1980, ‘Formation of the giant planets’, Progress of Theoretical Physics 64, 544–557.

  53. Owen, T. and Encrenaz, T.: 2003, ‘Element abundances and isotopic ratios in the giant planets and Titan’, Space Sci. Rev. 106, 121–138.

  54. Owen, T., Mahaffy, P., Niemann, H.B., Atreya, S., Donahue, T., Bar-Nun, A., and de Pater, I.: 1999, ‘A low-temperature origin of the planetesimals that formed Jupiter’, Nature 402, 269–270.

  55. Owen, T., Mahaffy, P.R., Niemann, H.B., Atreya, S.K., and Wong, M.: 2001, ‘Protosolar nitrogen’, Astrophys. J. 553, L77–L79.

  56. Pollack, J.B., Hubickyj, O., Bodenheimer, P., Lissauer, J.J., Podolak, M., Greenzweig, Y.: 1996, ‘Formation of the giant planets by concurrent accretion of solids and gas’, Icarus 124, 62–85.

  57. Prinn, R.G. and Fegley, B.: 1989, ‘Solar nebula chemistry: origin of planetary, satellite and cometary volatiles’, in S.K. Atreya, J.B. Pollack, and M.S. Shapley (eds.), Origin and evolution of planetary and satellite atmospheres, Univ. Arizona Press, Tucson, pp. 78–136.

  58. Rosenqvist, J., Lellouch, E., Romani, P., paubert, G., and Encrenaz, T.: 1992, ‘Millimeter-wave observations of Saturn, Uranus and Neptune: CO and HCN on Neptune’, Astrophys. J. 392, L99–L102.

  59. Schulz, B., Encrenaz, T., Bézard, B., Romani, P., Lellouch, E., and Atreya, S.K.: 1999, ‘Detection of C2H4 in Neptune using ISO/PHT-S observations’, Astron. Astrophys. 350, L13–L17.

  60. Simon-Miller, A.A., Flasar, F.M., Achterberg, R., Conrath, B., Gierasch, P.J., Kunde, V., Nixon, C.A., Jennings, D.E., Romani, P., Carlson, R., Cassini CIRS Team: 2003, ‘Jupiter Observations by Cassini CIRS: Atmospheric Dynamics, Temperatures and Composition’, Bull. Amer. Astron. Soc. 34, 659–659.

  61. Stevenson, D.J.: 1982, ‘Interiors of the giant planets’, Ann. Rev. Earth Plan. Sci. 30, 755–764.

  62. Von Zahn, U., Hunten, D.M., and Lehmacher, G.: 1998, ‘Helium in Jupiter’s atmosphere: Results from the Galileo probe helium interferometer experiment’, J. Geophys. Res. 103, 22,815–22,830.

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Correspondence to Thér‘se Encrenaz.

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Encrenaz, T. Neutral Atmospheres of the Giant Planets: An Overview of Composition Measurements. Space Sci Rev 116, 99–119 (2005).

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  • neutral atmospheres
  • giant planets
  • composition measurements