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The Cassini Ion and Neutral Mass Spectrometer (INMS) Investigation

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Abstract

The Cassini Ion and Neutral Mass Spectrometer (INMS) investigation will determine the mass composition and number densities of neutral species and low-energy ions in key regions of the Saturn system. The primary focus of the INMS investigation is on the composition and structure of Titan’s upper atmosphere and its interaction with Saturn’s magnetospheric plasma. Of particular interest is the high-altitude region, between 900 and 1000 km, where the methane and nitrogen photochemistry is initiated that leads to the creation of complex hydrocarbons and nitriles that may eventually precipitate onto the moon’s surface to form hydrocarbon–nitrile lakes or oceans. The investigation is also focused on the neutral and plasma environments of Saturn’s ring system and icy moons and on the identification of positive ions and neutral species in Saturn’s inner magnetosphere. Measurement of material sputtered from the satellites and the rings by magnetospheric charged particle and micrometeorite bombardment is expected to provide information about the formation of the giant neutral cloud of water molecules and water products that surrounds Saturn out to a distance of ∼12 planetary radii and about the genesis and evolution of the rings.

The INMS instrument consists of a closed ion source and an open ion source, various focusing lenses, an electrostatic quadrupole switching lens, a radio frequency quadrupole mass analyzer, two secondary electron multiplier detectors, and the associated supporting electronics and power supply systems. The INMS will be operated in three different modes: a closed source neutral mode, for the measurement of non-reactive neutrals such as N2 and CH4; an open source neutral mode, for reactive neutrals such as atomic nitrogen; and an open source ion mode, for positive ions with energies less than 100 eV. Instrument sensitivity is greatest in the first mode, because the ram pressure of the inflowing gas can be used to enhance the density of the sampled non-reactive neutrals in the closed source antechamber. In this mode, neutral species with concentrations on the order of ≥104 cm−3 will be detected (compared with ≥105 cm−3 in the open source neutral mode). For ions the detection threshold is on the order of 10−2 cm−3 at Titan relative velocity (6 km sec−1). The INMS instrument has a mass range of 1–99 Daltons and a mass resolutionMM of 100 at 10% of the mass peak height, which will allow detection of heavier hydrocarbon species and of possible cyclic hydrocarbons such as C6H6.

The INMS instrument was built by a team of engineers and scientists working at NASA’s Goddard Space Flight Center (Planetary Atmospheres Laboratory) and the University of Michigan (Space Physics Research Laboratory). INMS development and fabrication were directed by Dr. Hasso B. Niemann (Goddard Space Flight Center). The instrument is operated by a Science Team, which is also responsible for data analysis and distribution. The INMS Science Team is led by Dr. J. Hunter Waite, Jr. (University of Michigan).

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References

  • Anicich, V. G., and McEwan, M. J.: 1997, ‘Ion–molecule chemistry in Titan’s ionosphere’,Planet. Space. Sci. 45, 897.

    Google Scholar 

  • Banaszkiewicz, M., Lara, L. M., Rodrigo, R., López-Moreno, J. J., and Molina-Cuberos, G. J.: 2000, ‘A coupled model of Titan’s atmosphere and ionosphere’,Icarus 147, 386.

    Google Scholar 

  • Barbosa, D. D.: 1987, ‘Titan’s atomic nitrogen torus: Inferred properties and consequences for the Saturnian aurora’,Icarus 72, 53.

    Article  Google Scholar 

  • Barbosa, D. D.: 1990, ‘Radial diffusion in Saturn’s magnetosphere’,J. Geophys. Res. 95, 17167.

    Google Scholar 

  • Bird, M. K.,et al.: 1997, ‘Detection of Titan’s ionosphere from Voyager 1 radio occultation observations,’Icarus 130, 426.

    Google Scholar 

  • Brecht, S. H., Luhmann, J. G., and Larson, D. J.: 2000, ‘Simulation of the Saturnian magnetospheric interaction with Titan’,J. Geophys. Res. 105, 13119.

    Google Scholar 

  • Bridge, H. A.,et al.: 1981, ‘Plasma observations near Saturn: Initial results from Voyager 1’,Science 212, 217.

    Google Scholar 

  • Bridge, H. A.,et al.: 1982, ‘Plasma observations near Saturn: Initial results from Voyager 2’,Science 215, 563.

    Google Scholar 

  • Broadfoot, A. L.,et al.: 1981, ‘Extreme ultraviolet observations from Voyager 1 encounter with Saturn’,Science 212, 206.

    Google Scholar 

  • Carlson, R. W.: 1980, ‘Photo-sputtering of ice and hydrogen around Saturn’s rings’,Nature 283, 461.

    Google Scholar 

  • Capone, L. A., Dubach, J., Prasad, S. S., and Whitten, R. C.: 1983, ‘Galactic cosmic rays and N2dissociation on Titan’, Icarus 55, 73.

    Article  Google Scholar 

  • Chappell, C. R., Moore, T. E., and Waite, J. H., Jr.: 1987, ‘The ionosphere as a fully adequate source of plasma for the Earth’s magnetosphere’,J. Geophys. Res. 92.

  • Chassefière, E., and Cabane, M.: 1995, ‘Two formation regions for Titan’s hazes: Indirect clues and possible synthesis mechanisms’,Planet. Space Sci. 43, 91.

    PubMed  Google Scholar 

  • Clarke, J. T., Trauger, J., and Waite, J. H., Jr.: 1989, ‘Doppler-shifted H Ly α-emission from Jupiter’s aurora’,Geophys. Res. Lett. 16, 587.

    Google Scholar 

  • Comas Solá, J.: 1908, ‘Observations des satellites principeaux de Jupiter et de Titan’,Astron. Nach. 179, 289.

    Google Scholar 

  • Connerney, J. E. P. and Waite, J. H., Jr.: 1984, ‘New model of Saturn’s ionosphere with an influx of water from the rings’,Nature 312, 136.

    Google Scholar 

  • Courtin, R., Gautier, D., and McKay, C. P.: 1995, ‘Titan’s thermal emission spectrum: Reanalysis of the Voyager infrared measurements’,Icarus 114, 144.

    Google Scholar 

  • Coustenis, A.,et al.: 1989, ‘Titan’s atmosphere from Voyager infrared observations’,Icarus 80, 54.

    Google Scholar 

  • Coustenis, A.,et al.: 1991, ‘Titan’s atmosphere from Voyager infrared observations. III. Vertical distributions of hydrocarbons and nitriles near Titan’s north pole’,Icarus 89, 152.

    Google Scholar 

  • Coustenis, A.,et al.: 1998, ‘Evidence for water vapor in Titan’s atmosphere from ISO/SWS data’,Astron. Astrophys. 336, L85.

    Google Scholar 

  • Coustenis, A.,et al.: 2003, ‘Titan’s atmosphere from ISO mid-infrared spectroscopy’,Icarus 161, 383.

    Article  Google Scholar 

  • Cravens, T. E., Keller, C. N., and Ray, B.: 1997, ‘Photochemical sources of non-thermal neutrals for the exosphere of Titan’,Planet. Space Sci. 45, 889.

    Article  Google Scholar 

  • Cravens, T. E., Lindgren, C. J., and Ledvina, S. A.: 1998, ‘A two-dimensional MHD model of Titan’s plasma environment’,Planet. Space Sci. 46, 1193.

    Google Scholar 

  • Cravens, T. E., Vann, J., Clark, J., Yu, J., Keller, C. N., and Brull, C.: 2004, ‘The ionosphere of Titan: An updated theoretical model,Adv. Space Res. 33, 212.

    Article  Google Scholar 

  • Edgington, S. G.,et al.: 1998, ‘On the latitude variation of ammonia, acetylene, and phosphine altitude profiles on Jupiter from HST Faint Object Spectrograph observations’,Icarus 133, 192– 209.

    Article  Google Scholar 

  • Eviatar, A. and Podolak, M.: 1983, ‘Titan’s gas and plasma torus’,J. Geophys. Res. 88, 833.

    Google Scholar 

  • Eviatar, A. and Richardson, J. D.: 1990, ‘Water group plasma in the magnetosphere of Saturn’,Ann. Geophys. 8, 725.

    Google Scholar 

  • Eviatar, A. and Richardson, J. D.: 1992, ‘Thermal plasma in the inner kronian magnetosphere’,Ann. Geophys. 10, 511.

    Google Scholar 

  • Fox, J. L. and Yelle, R. V.: 1997, ‘Hydrocarbon ions in the ionosphere of Titan’,Geophys. Res. Lett. 24, 2179.

    Google Scholar 

  • Frank, L. A.,et al.: 1980, ‘Plasmas in Saturn’s magnetosphere’,J. Geophys. Res. 85, 5695.

    Google Scholar 

  • Friedson, A. J. and Yung, Y. L.: 1984, ‘The thermosphere of Titan’,J. Geophys. Res. 89, 85.

    Google Scholar 

  • Galand, M.,et al.: 1999, ‘The ionosphere of Titan: Ideal diurnal and nocturnal cases’,Icarus 140, 92.

    Article  Google Scholar 

  • Gan, L., Cravens, T. E., and Keller, C. N.: 1992, ‘Electrons in the ionosphere of Titan’,J. Geophys. Res. 97, 12137.

    Google Scholar 

  • Gan-Baruch, Z.,et al.: 1994, ‘Plasma observations in the ring plane of saturn’,J. Geophys. Res. 99, 11063.

    Google Scholar 

  • Gautier, D. and Raulin, F.: 1997, ‘Chemical composition of Titan’s atmosphere’, inHuygens: Science, Payload, and Mission, ESA Publication SP-1177, European Space Agency, Noordwijk, The Netherlands.

    Google Scholar 

  • Gurnett, D. A., Kurth, W. S., and Scarf, F. L.: 1981, ‘Plasma waves near Saturn: Initial results from Voyager 1’,Science 212, 235.

    Google Scholar 

  • Gurnett, D. A., Scarf, F. L., and Kurth, W. S.: 1982, ‘The structure of Titan’s wake from plasma wave observation’,J. Geophys. Res. 87, 1395.

    Google Scholar 

  • Hall, D. T.,et al.: 1996, ‘Fluorescent hydroxyl emissions from Saturn’s ring atmosphere’,Science 272, 516.

    PubMed  Google Scholar 

  • Hamilton, D. C. and Burns, J. A.: 1993, ‘OH in Saturn’s rings’,Nature 365, 550.

    PubMed  Google Scholar 

  • Hamilton, D. C.,et al.: 1981, ‘Composition of nonthermal ions in the Jovian magnetosphere’,J. Geophys. Res. 86, 8301.

    Google Scholar 

  • Hamilton, D. C.,et al.: 1983, ‘Energetic atomic and molecular ions in Saturn’s magnetosphere’,J. Geophys. Res. 88, 8905.

    Google Scholar 

  • Hanel, R.,et al.: 1981, ‘Infrared observations of the Saturnian system from Voyager 1’,Science 212, 192.

    Google Scholar 

  • Hartle, R. E.,et al.: 1982, ‘Titan’s ion exosphere observed from Voyager 1’,J. Geophys. Res. 87, 1383.

    Google Scholar 

  • Hidayat, T.,et al.: 1997, ‘Millimeter and submillimeter heterodyne observations of Titan: Retrieval of the vertical profile of HCN and the 12C/13C ratio’,Icarus 126, 170.

    Article  Google Scholar 

  • Hidayat, T.,et al.: 1998, ‘Millimeter and submillimeter heterodyne observations of Titan: The vertical profile of carbon monoxide in its stratosphere’,Icarus 133, 109.

    Google Scholar 

  • Hilton, D. A. and Hunten, D. M.: 1988, ‘A partially collisional model of the Titan hydrogen torus’,Icarus 73, 248.

    Article  Google Scholar 

  • Hunten, D. M.: 1972, ‘The atmosphere of Titan’,Comments Astrophys. Space Phys. 4, 149.

    Google Scholar 

  • Hunten, D. M.,et al.: 1984, ‘Titan’, in T. Gehrels and M. S. Matthews (eds.),Saturn, University of Arizona Press, Tucson, AZ, pp. 671–759.

    Google Scholar 

  • Ip, W.-H.: 1984, ‘The ring atmosphere of Saturn: Monte Carlo simulation of ring source models’,J. Geophys. Res. 89, 8843.

    Google Scholar 

  • Ip, W.-H.: 1990, ‘Titan’s upper ionosphere’,Astrophys. J. 362, 354.

    Google Scholar 

  • Ip, W.-H.: 1995, ‘The exospheric systems of Saturn’s rings’,Icarus 115, 295.

    Google Scholar 

  • Ip, W.-H.: 1997, ‘On the neutral cloud distribution in the saturnian magnetosphere’,Icarus 126, 42.

    Article  Google Scholar 

  • Johnson, R. E.: 1998, ‘Sputtering and desorption from icy surfaces’, in B. Schmittet al. (eds.),Solar System Ices, Kluwer Academic Publishers, The Netherlands, pp. 303–334.

    Google Scholar 

  • Johnson, R. E. and Sittler, E. C.: 1990, ‘Sputter-produced plasma as a measure of satellite surface composition—The Cassini mission’,Geophys. Res. Lett. 17, 1729.

    Google Scholar 

  • Johnson, R. E.,et al.: 1989, ‘The neutral cloud and heavy ion inner torus at Saturn’,Icarus 77, 311.

    Article  CAS  Google Scholar 

  • Judge, D. L., Wu, F.-M., and Carlson, R. W.: 1980, ‘Ultraviolet photometer observations of the Saturnian system’,Science 207, 431.

    Google Scholar 

  • Jurac, S., Johnson, R. E., and Richardson, J. D.: 2001a, ‘Saturn’s E ring and the production of the neutral torus’,Icarus 149, 384.

    Google Scholar 

  • Jurac, S., Johnson, R. E., Richardson, J. D., and Paranicas, C.: 2001b, ‘Satellite sputtering in Saturn’s magnetosphere’,Planet. Space Sci. 49, 319.

    Article  Google Scholar 

  • Kabin, K.,et al.: 1999, ‘Interaction of the Saturnian magnetosphere with Titan: Results of a three-dimensional MHD simulation’,J. Geophys. Res. 104, 2451.

    Article  Google Scholar 

  • Kasprzak, W. T., Niemann, H. B., and Mahaffy, P.: 1987, ‘Observations of energetic ions on the nightside of Venus’,J. Geophys. Res. 92, 291.

    Google Scholar 

  • Kasprzak, W. T.,et al.: 1996, ‘Cassini orbiter ion and neutral mass spectrometer instrument’,SPIE Proc. 2803, 129.

    Google Scholar 

  • Keller, C. N. and Cravens, T. E.: 1994, ‘One-dimensional multispecies hydrodynamic models of the wakeside ionosphere of Titan’,J. Geophys. Res. 99, 6527.

    Article  Google Scholar 

  • Keller, C. N., Cravens, T. E., and Gan, L.: 1992, ‘A model of the ionosphere of Titan’,J. Geophys. Res. 97, 12117.

    Google Scholar 

  • Keller, C. N., Cravens, T. E., and Gan, L.: 1994, ‘One-dimensional multispecies magnetohydrodynamic models of the ramside ionosphere of Titan’,J. Geophys. Res. 99, 6511.

    Article  Google Scholar 

  • Keller, C. M., Anicich, V. G., and Cravens, T. E.: 1998, ‘Model of Titan’s ionosphere with detailed hydrocarbon chemistry’,Planet. Space Sci. 46. 1157.

    Article  Google Scholar 

  • Khurana, K. K., Kivelson, M. G., and Russell, C. T.: 1997, ‘Interaction of Io with its torus: Does Io have an internal magnetic field?’,Geophys. Res. Lett. 34, 2391.

    Article  Google Scholar 

  • Kiser, R. W.: 1965,Introduction to Mass Spectrometry and Its Applications, Prentice-Hall, Inc., Englewood Cliffs, NJ.

  • Kivelson, M. G. and Russell, C. T.: 1983, ‘The interaction of flowing plasmas with planetary ionospheres: A Titan–Venus comparison’,J. Geophys. Res. 88, 49.

    Google Scholar 

  • Kivelson, M. G.,et al.: 1996, ‘Discovery of Ganymede’s magnetic field by the Galileo spacecraft’,Nature 384, 537.

    Article  Google Scholar 

  • Kostiuk, T.,et al.: 1997, ‘Ethane abundance on Titan’,Planet. Space Sci. 45, 931.

    Article  Google Scholar 

  • Kuiper, G. P.: 1944, ‘Titan: A satellite with an atmosphere’,Astrophys. J. 100, 378.

    Article  Google Scholar 

  • Kunde, V. G.,et al.: 1981, ‘C4H2, HC3N, and C2N2in Titan’s atmosphere’,Nature 292, 686.

    Article  Google Scholar 

  • Lammer, H. and Bauer, S. J.: 1991, ‘Nonthermal atmospheric escape from Mars and Titan’,J. Geophys. Res. 96, 1819.

    Google Scholar 

  • Lammer, H. and Bauer, S. J.: 1993, ‘Atmospheric mass loss from Titan by sputtering’,Planet. Space Sci. 41, 657.

    Article  Google Scholar 

  • Lanzerotti, L. J.,et al.: 1983, ‘Implications of Voyager data for energetic ion erosion of the icy satellites of Saturn’,J. Geophys. Res. 88, 8765.

    Google Scholar 

  • Lara, L. M.,et al.: 1996, ‘Vertical distribution of Titan’s atmospheric neutral constituents’,J. Geophys. Res. 101, 23261.

    Article  Google Scholar 

  • Lazarus, A. J. and McNutt, R. L., Jr.: 1983, ‘Low energy plasma ion observations in saturn’s magnetosphere’,J. Geophys. Res. 88, 8831.

    Google Scholar 

  • Ledvina, S. A. and Cravens, T. E.: 1998, ‘A three-dimensional MHD model of plasma flow around Titan’,Planetary and Space Sci. 46, 1175.

    Article  Google Scholar 

  • Lellouch, E.,et al.: 1989, ‘Titan’s atmosphere and hypothesized ocean: A reanalysis of the Voyager 1 radio-occultation and IRIS 7.7-μm data’,Icarus 79, 328.

    Article  Google Scholar 

  • Lellouch, E.,et al.: 1990, ‘Titan’s thermosphere profile’,Icarus 83, 308.

    Article  Google Scholar 

  • Lewis, J. S.: 1971, ‘Satellites of the outer planets: Their physical and chemical nature’,Icarus 15, 174.

    Article  Google Scholar 

  • Lindal, G. F.,et al.: 1983, ‘The atmosphere of Titan: An analysis of the Voyager 1 radio occultation measurements’,Icarus 53, 348.

    Article  Google Scholar 

  • Luhmann, J. G.: 1996, ‘Titan’s ion exosphere wake: A natural ion mass spectrometer?’,J. Geophys. Res. 101, 29387.

    Article  Google Scholar 

  • Luhmann, J. G. and Walker, R. J.: 1981, ‘Model exospheres of the ringed planets’,Geophys. Res. Lett. 8, 107.

    Google Scholar 

  • Luhmann, J. G.,et al.: 1991, ‘A comparison of induced magnetotails of planetary bodies: Venus, Mars, and Titan’,J. Geophys. Res. 96, 11199.

    Google Scholar 

  • Lunine, J. I.: 1993, ‘Does Titan have an ocean? A review of current understanding of Titan’s surface’,Rev. Geophys. 31, 133.

    Article  Google Scholar 

  • Lunine, J. I.: 1994, ‘Does Titan have oceans?’,Am. Scientist 82, 136.

    Google Scholar 

  • Lunine, J. I., Stevenson, D. J., and Yung, Y. L.: 1983, ‘Ethane ocean on Titan’,Science 222, 1229.

    Google Scholar 

  • Lutz, B. L., deBergh, C., and Owen, T.: 1983, ‘Titan: The discovery of carbon monoxide in its atmosphere’,Science 220, 1374.

    Google Scholar 

  • Maguireet al.: 1981, ‘C3H8and C3H4in Titan’s atmosphere’,Nature 292, 683.

    Article  Google Scholar 

  • Mahaffy, P. M. and Lai, K.: 1990, ‘An electrostatic quadrupole deflector for mass spectrometer applications’,J. Vac. Sci. A8, 3244.

    Google Scholar 

  • Matheson, P. L. and Shemansky, D. E.: 1996, ‘Magnetospheric neutral clouds from Saturn’s icy satellites’ (abstract),Bull. Am. Astron. Soc., Division of Planetary Sciences meeting.

  • McNutt, R. L., Jr. and Richardson, J. D.: 1988, ‘Constraints on Titan’s ionsphere’,Geophys. Res. Lett. 15, 709.

    Google Scholar 

  • Morfill, G. E.,et al.: 1983, ‘Some consequences of meteoroid impacts on Saturn’s rings’,Icarus 55, 439.

    Google Scholar 

  • Müller-Wodarg, I. C. F., and Yelle, R. V.: 2002, ‘The effect of dynamics on the composition of Titan’s upper atmosphere’,Geophys. Res. Lett. 29, 54-1, doi 10.1029/2002GL016100.

    Google Scholar 

  • Müller-Wodarg, I. C. F., Yelle, R. V., Mendillo, M., Young, L. A., and Aylward, A. D.: 2000, ‘The thermosphere of Titan simulated by a global three-dimensional time-dependent model’,J. Geophys. Res. 105, 20833.

    Article  Google Scholar 

  • Nagy, A. F. and Cravens, T. E.: 1998, ‘Titan’s ionosphere: A review’,Planet. Space Sci. 46, 1149.

    Article  Google Scholar 

  • Nagy, A. F., Barakat, A. R., and Schunk, R. W.: 1986, ‘Is Jupiter’s ionosphere a significant plasma source for its magnetosphere?’,J. Geophys. Res. 91, 351.

    Google Scholar 

  • Ness, N. F., Acuna, M. H., Behannon, K. W., and Neubauer, F. M.: 1982, ‘The induced magnetosphere of Titan’,J. Geophys. Res. 87, 1369.

    Google Scholar 

  • Neubauer, F. M.,et al.: 1984, ‘Titan’s magnetospheric interaction’, in T. Gehrels and M. S. Matthews (eds.),Saturn, University of Arizona Press, Tucson, AZ, pp. 760–787.

    Google Scholar 

  • Niemann, H. B.,et al.: 1997, ‘The gas chromatograph mass spectrometer aboard Huygens’, inHuygens: Science, Payload and Mission ESA SP 1177, p. 85.

  • Owen, T.: 1982, ‘The composition and origin of Titan’s atmosphere’,Planet. Space Sci. 30, 833.

    Google Scholar 

  • Pospieszalska, M. K. and Johnson, R. E.: 1989, ‘Magnetospheric ion bombardment profiles of satellites—Europa and Dione’,Icarus 78, 1.

    Article  Google Scholar 

  • Pospieszalska, M. K. and Johnson, R. E.: 1991, ‘Micrometeorite erosion of the main rings as a source of plasma in the inner Saturnian plasma torus’,Icarus 93, 45.

    Article  Google Scholar 

  • Richardson, J. D.: 1986, ‘Thermal ions at Saturn: Plasma parameters and implications’,J. Geophys. Res. 91, 1381.

    Google Scholar 

  • Richardson, J. D.: 1998, ‘Thermal plasma and neutral gas in Saturn’s magnetosphere’,Rev. Geophys. 36, 501.

    Article  Google Scholar 

  • Richardson, J. D. and Sittler, E. C., Jr.: 1990, ‘A plasma density model for Saturn based on Voyager observations’,J. Geophys. Res. 95, 12019.

    Google Scholar 

  • Richardson, J. D., Eviatar, A., and Siscoe, G. L.: 1986, ‘Satellite tori at Saturn’,J. Geophys. Res. 91, 8749.

    Google Scholar 

  • Richardson, J. D.,et al.: 1998, ‘OH in Saturn’s magnetosphere: Observations and implications’,J. Geophys. Res. 103, 20245.

    Article  Google Scholar 

  • Rishbeth, H., Yelle, R. V., and Mendillo, M.: 2000, ‘Dynamics of Titan’s thermosphere’,Planet. Space Sci. 48, 51.

    Google Scholar 

  • Roboz, A. and Nagy, A. F.: 1994, ‘The energetics of Titan’s ionosphere’,J. Geophys. Res. 99, 2087.

    Article  Google Scholar 

  • Samuelson, R. E.,et al.: 1981, ‘Mean molecular weight and hydrogen abundance in Titan’s atmosphere’,Nature 292, 688.

    Article  Google Scholar 

  • Samuelson, R. E.,et al.: 1983, ‘CO2on Titan’,J. Geophys. Res. 88, 8709.

    Google Scholar 

  • Samuelson, R. E., Nath, N. R., and Borysow, A.: 1997, ‘Gaseous abundances and methane supersaturation in Titan’s atmosphere’,Planet. Space. Sci. 45, 959.

    Article  Google Scholar 

  • Sandel, B. R.,et al.: 1982, ‘Extreme ultraviolet observations from the Voyager 2 encounter with Saturn’,Science 215, 548.

    Google Scholar 

  • Schardt, A. W.,et al.: 1984, ‘The outer magnetosphere’, in T. Gehrels and M. S. Matthews (eds.),Saturn, University of Arizona Press, Tucson, AZ, pp. 416–459.

    Google Scholar 

  • Shemansky, D. E. and Hall, D. T.: 1992, ‘The distribution of atomic hydrogen in the magnetosphere of Saturn’,J. Geophys. Res. 97, 4143.

    Google Scholar 

  • Shemansky, D. E.,et al.: 1993, ‘Detection of the hydroxyl radical in the Saturn magnetosphere’,Nature 363, 329.

    Article  Google Scholar 

  • Shi, M.,et al.: 1995, ‘Sputtering of water ice surfaces and the production of extended neutral atmospheres’,J. Geophys. Res. 100, 26387.

    Article  Google Scholar 

  • Smith, G. R.,et al.: 1982, ‘Titan’s upper atmosphere: Composition and temperature from the EUV solar occultation results’,J. Geophys. Res. 87, 1351.

    Google Scholar 

  • Smyth, W. H. and Marconi, M. L.: 1993, ‘The nature of the hydrogen tori of Titan and Triton’,Icarus 101, 18.

    Article  Google Scholar 

  • Strobel, D. F. and Shemansky, D. E.: 1982, ‘EUV emission from Titan’s upper atmosphere: Voyager 1 encounter’,J. Geophys. Res. 87, 1361.

    Google Scholar 

  • Strobel, D. F., Meier, R. R., Summers, M. E., and Strickland, D. J.: 1991, ‘Nitrogen airglow sources: Comparison of Triton, Titan, and Earth’,Geophys. Res. Lett. 18, 689.

    Google Scholar 

  • Strobel, D. F., Summers, M., and Zhu, X.: 1992, ‘Titan’s upper atmosphere: Structure and ultraviolet emissions’,Icarus 100, 512.

    Article  Google Scholar 

  • Strobel, D. F.,et al.: 1993, ‘Upper limit on Titan’s atmospheric argon abundance’,Icarus 103, 333.

    Article  Google Scholar 

  • Swaminathan, V., Alig, R., Murray, W., and Sarnoff, D.: 1996, ‘Design of an improved miniature ion neutral mass spectrometer for NASA applications’, NASA Contract NAS5-32823.

  • Taylor, F. W. and Coustenis, A.: 1998, ‘Titan in the solar system’,Planet. Space Sci. 46, 1085.

    Article  Google Scholar 

  • Thompson, W. R., McDonald, G. D., and Sagan, C.: 1994, ‘The Titan haze revisited: Magnetospheric energy sources and quantitative tholin yields’,Icarus 112, 376.

    PubMed  Google Scholar 

  • Toublanc, D.: 1995, ‘Photochemical modeling of Titan’s atmosphere’,Icarus 113, 2.

    PubMed  Google Scholar 

  • Trafton, L. M.: 1972, ‘On the possible detection of H2in Titan’s atmosphere’,Astrophys. J. 175, 285.

    Article  Google Scholar 

  • Vervack, R. J., Jr.: 1997, ‘Titan’s upper atmospheric structure derived from Voyager ultraviolet spectrometer observations’, Ph.D. dissertation, The University of Arizona, Tucson, AZ.

  • Vervack, R. J., Jr., Sandel, B. R., and Strobel, D. F.: 2004, ‘New perspectives on Titan’s upper atmosphere from a reanalysis of the Voyager 1 uvs solar occultations by Titan’,Icarus 170, 91.

    Google Scholar 

  • Waite, J. H., Jr.: 1981, ‘The ionosphere of Saturn’, Ph.D. dissertation, University of Michigan, Ann Arbor, MI.

  • Weiser, H., Vitz, C., and Moos, H. W.: 1977, ‘Detection of Lyman alpha emission from the Saturnian disk and from the ring system’,Science 197, 755.

    Google Scholar 

  • Wilson, E. H.: 2002, ‘Investigations into the photochemistry of the current and primordial atmosphere of Titan’, Ph.D. Thesis, University of Michigan, Ann Arbor, MI.

  • Wilson, G. R. and Waite, J. H., Jr.: 1989, ‘Kinetic modeling of the Saturn ring-ionosphere plasma environment’,J. Geophys. Res. 94, 17287.

    Google Scholar 

  • Wolf, D. A. and Neubauer, F. M.: 1982, ‘Titan’s highly variable plasma environment’,J. Geophys. Res. 87, 881.

    Google Scholar 

  • Yelle, R. V.: 1991, ‘Non-LTE models of Titan’s upper atmosphere’,Astrophys. J 383, 380.

    Article  Google Scholar 

  • Yelle, R. V.,et al.: 1997, ‘Engineering models for Titan’s atmosphere’, inHuygens: Science, Payload, and Mission, ESA Publication SP-1177, European Space Agency, Noordwijk, The Netherlands.

  • Yung, Y. L.: 1987, ‘An update of nitrile photochemistry on Titan’,Icarus 72, 468.

    PubMed  Google Scholar 

  • Yung, Y. L., Allen, M., and Pinto, J. P.: 1984, ‘Photochemistry of the atmosphere of Titan: Comparison between model and observations’,Astrophys. J. Suppl. 55, 465.

    PubMed  Google Scholar 

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Waite, J.H., Lewis, W.S., Kasprzak, W.T. et al. The Cassini Ion and Neutral Mass Spectrometer (INMS) Investigation. Space Sci Rev 114, 113–231 (2004). https://doi.org/10.1007/s11214-004-1408-2

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