Hostname: page-component-cd9895bd7-gvvz8 Total loading time: 0 Render date: 2024-12-25T15:53:07.409Z Has data issue: false hasContentIssue false

Observational constraints on the composition and nature of comet D/Shoemaker-Levy 9

Published online by Cambridge University Press:  02 August 2016

Jacques Crovisier*
Affiliation:
Observatoire de Paris-Meudon, CNRS URA 1757, F-92195 Meudon, France

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

What did the break-up of comet Shoemaker-Levy 9 (SL9) and its subsequent impact on Jupiter teach us about the nature and constitution of this comet? The break-up of the comet apparently triggered activity of the fragments. Although a dust coma was continuously present around the fragments that orbited Jupiter, spectroscopic observations did not reveal any sign of gas. The impact itself was so energetic that most molecules of the impactor were dissociated and that any chemical memory was lost. Ultraviolet and visible spectroscopy of the impact sites revealed emission lines from several atoms, giving potential information on elemental abundances. However, the fact that both neutral and ionized atoms are emitting, and that both fundamental and inter-system lines are present, suggest that the medium is out-of-equilibrium and that emitting mechanisms other than simple resonance fluorescence are at work. Ultraviolet, infrared, and radio spectroscopy revealed lines of several molecular species, in emission and/or absorption, that are not normally present in Jupiter's upper atmosphere. In the visible, dark spots due to aerosols developed at the impact sites. It is not clear at the present time which part of this material is coming from preserved impactor material, from the recombination of the dissociated impactor material, from reactions between the impactor's and Jupiter's material, or from material coming from the lower layers of Jupiter's atmosphere. Realistic modelling of the impacts and of the following chemical reactions will be necessary to address all these issues. In this chapter, we will review the observational clues to the composition and structure of SL9 in the context of our knowledge of the composition and structure of comets and asteroids.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1996

References

A'Hearn, M. F., Millis, R. L., Schleicher, D. G., Osip, D. J. & Birch, P. V. 1995 The ensemble properties of comets: results from narrowband photometry of 85 comets, 1976-1992. Icarus, 118, 223270.Google Scholar
A'Hearn, M. F., Schleicher, D. G., Feldman, P. D., Millis, R. L. & Thompson, D. T. 1984 Comet Bowell 1980b. Astron. J. 89, 579591.Google Scholar
Anders, R. & Grevesse, E. 1989 Abundances of the elements: meteoritic and solar. Geochim. Cosmochim. Ada 53, 197214.CrossRefGoogle Scholar
Arpigny, C. 1979 Relative abundances of the heavy elements in comet Ikeya-Seki (1965 VIII). Mem. Soc. Roy. Liège 22, 189197.Google Scholar
Arpigny, C. 1994 Physical chemistry of comets: models, uncertainties, data needs. In Molecules and Grains in Space, (ed. Nenner, I.), AIP Conference Proceedings 312, pp. 205238.Google Scholar
Arpigny, C., Dossin, F., Woszczyk, A. et al. 1995 Atlas of cometary spectra. Kluwer (in press).Google Scholar
Atreya, S. K., Edgington, S. G., Trafton, L. M. et al. 1995 Abundance of ammonia and carbon disulfide in the Jovian stratosphere following the impact of comet Shoemaker-Levy 9. Geophys Res. Let. 22, 16251628.CrossRefGoogle Scholar
Ballester, G. E., Harris, W. M., Gladstone, G. R. et al. 1995 Far-UV emissions from the SL9 impacts with Jupiter. Geophys. Res. Let. 22, 24252429.CrossRefGoogle Scholar
Balsiger, H., Altwegg, K. & Geiss, J. 1995 D/H and 18O/16O-ratio in the hydronium ion and in neutral water from in situ ion measurements in comet Halley. J. Geophys. R. 100, 58275834.Google Scholar
Belton, M. J. S., Chapman, C. R. et al. 1995 Bulk density of asteroid 243 Ida from the orbit of its satellite Dactyl. Nature 374, 785788.Google Scholar
Bézard, B., Griffith, C. A., Kelly, D. et al. 1995 Mid-IR high-resolution spectroscopy of the SL9 impact sites: temperature and HCN retrievals. IAU Coll. No. 156 (poster).Google Scholar
Bjoraker, G. L., Stolovy, S. R., Herter, T. L., Gull, G. E. & Pirger, B. E. 1995 Detection of water after the collision of fragments G and K of comet Shoemaker-Levy 9 with Jupiter. Icarus (submitted).CrossRefGoogle Scholar
Bockelée-Morvan, D., Colom, P., Despois, D. et al. 1995 Observations of the Shoemaker-Levy 9 impacts on Jupiter at the Swedish-ESO submillimetre telescope. The Messenger 79, 2931.Google Scholar
& Spurný, P. 1995 Radiation study of two very bright terrestrial bolides. Icarus (submitted).Google Scholar
Borunov, S., Drossart, P., Encrenaz, T. & Dorofeeva, V. 1995 High temperature chemistry in the fireballs formed by the impacts of comet P/Shoemaker-Levy 9 in Jupiter. Icarus (submitted).Google Scholar
Carlson, R. W., Weissman, P. R., Segura, M. et al. 1995 Galileo infrared observations of the Shoemaker-Levy 9 G impact fireball: a preliminary report. Geophys Res. Let. 22, 15571560.CrossRefGoogle Scholar
Carpenter, K. G., McGrath, M. A., Yelle, R. V., Noll, K. S. & Weaver, H. A. 1995 Formation of atomic emission lines in the atmosphere of Jupiter after the comet Shoemaker-Levy 9 S impact. Bull. Amer. Astron. Soc, 27, 64.Google Scholar
Catalano, S., Rodono, M., Ventura, R. & Cacciani, A. 1995 Observations of the SL-9 impacts with a sodium magneto-optical filter. European SL-9/Jupiter Workshop, (eds. West, R. M. and Boehnhardt, H.), ESO Conference and Workshop Proceedings No. 52, pp. 209214.Google Scholar
Chernova, G. P., Jockers, K. & Kiselev, N. N. 1995 Imaging photometry and color of comet Shoemaker-Levy 9. Icarus (submitted).Google Scholar
Cochran, A. L., Whipple, A. L., MacQueen, P. J. et al. 1994 Preimpact characterization of comet P/Shoemaker-Levy 9. Icarus 112 528532.Google Scholar
Colas, F., Jorda, L., Lecacheux, J. et al. 1995 Pre-impact observations of Shoemaker-Levy 9 at Pic du Midi and Observatoire de Haute Provence. European SL-9/Jupiter Workshop, (eds. West, R. M. and Boehnhardt, H.), ESO Conference and Workshop Proceedings No. 52, pp. 2328.Google Scholar
Conrath, B. J., Gierasch, P. J., Hayward, T. et al. 1995 Palomar mid-infrared observations of comet Shoemaker-Levy 9 impact sites. IAU Coll. No. 156 (poster).Google Scholar
Copeland, R. & Lohse, J. G. 1882 Spectroscopic observations of comets III and IV, 1881, comet I, 1882, and the Great Comet of 1882. Copernicus 2, 225244.Google Scholar
Costa, R. D. D., De Freitas Pacheco, J. A., Singh, P. D., De Almeda, A. A. & Codina, S. J. 1994 Detection of lithium in the plume of the L-fragment impact of comet Shoemaker-Levy 9 with Jupiter. Preprint. Google Scholar
Crisp, D. & Meadows, V. 1995 Near-infrared imaging spectroscopy of the impacts of SL9 fragments C, D, G, K, N, R, V, and W with Jupiter. IAU Coll. No. 156 (poster).Google Scholar
Crovisier, J. 1994. Molecular abundances in comets. In Asteroids, Comets, Meteors 1993, (eds. Milani, A. et al.). pp. 313326. Kluwer.CrossRefGoogle Scholar
Crovisier, J., Biver, N., Bockelée-Morvan, D. et al. 1995 Carbon monoxide outgassing from comet P/Schwassmann-Wachmann 1. Icarus 115 213216.Google Scholar
Eberhardt, P., Regber, M., Krankowsky, D. & Hodges, R. R. 1995 The D/H and 18O/16O ratios in water from comet P/Halley. Astron. Astrophys. Google Scholar
Feldman, P. D., Weaver, H. A., Boice, D. C. & Stern, S. A. 1995 HST observations of Mg+ in outburst from comet D/Shoemaker-Levy 9. Icarus (in press).Google Scholar
Festou, M. C., Rickman, H. & West, R. M. 1993 Comets. Astron. Astrophys. Reviews 3, 363447 and 5, 37-163.Google Scholar
Field, G. B., Tozzi, G. P. & Stanga, R. M. 1994. Dust as the cause of spots on Jupiter. Astron. Astrophys. 294 L53L55.Google Scholar
Fitzsimmons, A., Little, J. E., Andrews, P. J. et al. 1995a Optical imaging and spectroscopy of the impact plumes on Jupiter. European SL-9/Jupiter Workshop, (eds. West, R. M. and Boehnhardt, H.), ESO Conference and Workshop Proceedings No. 52, pp. 197201.Google Scholar
Friedson, A. J. 1995 Refractory grain formation in Shoemaker-Levy fireballs. Icarus (submitted).Google Scholar
Gladstone, G. R., Hall, D. T. & Waite, J. H. Jr. 1995 EUVE observations of Jupiter during the impact of comet Shoemaker-Levy 9. Science 268 15951597.Google Scholar
Griffith, C. A., Bézard, B., Kelly, D. et al. 1995. Mid-IR spectroscopy and NH3 and HCN images of K impact site. IAU Coll. No. 156 (poster).Google Scholar
Hammel, H. B., Beebe, R. F., Ingersoll, A. P. et al. 1995 HST imaging of atmospheric phenomena created by the impact of comet Shoemaker-Levy 9. Science 267 12881296.Google Scholar
Hasegawa, H., Takeuchi, S., Yamashita, T. & Watanabe, J. 1995 Reflectivities of the cometary impact sites. IAU Coll. No. 156 (poster).Google Scholar
Hoffmann, M. 1989. Asteroid mass determination: present situation and perspectives. In Asteroids II, (eds. Binzel, R. P. et al.), pp. 228239. University of Arizona Press.Google Scholar
Huebner, W. F., Keller, H. U., Jewitt, D., Klinger, J. & West, R. (eds.) 1993 Workshop on the Activity of Distant Comets. SWRI.Google Scholar
Jessberger, E. K. & Kissel, J. 1991 Chemical properties of cometary dust and a note on carbon isotope. In Comets in the Post-Halley Era, (eds. Newburn, R. L. et al.), pp. 10751092. Kluwer.Google Scholar
Jewitt, D. 1995a Pre-impact observations of SL-9. European SL-9/Jupiter Workshop, (eds. West, R. M. and Boehnhardt, H.), ESO Conference and Workshop Proceedings No. 52, pp. 14.Google Scholar
Jewitt, D. 1995b From comets to asteroids: when hairy stars go bald. In Small Bodies in the Solar System and their Interactions with the Planets, (eds. Rickman, H. and Dahlgren, M.). Kluwer (in press).Google Scholar
Knacke, R. F. & A'Hearn, M. F. 1994 An estimate of the comet Shoemaker-Levy 9 fragment sizes from the debris fields. Earth Moon Planets 66 1112.Google Scholar
Lécluse, C., Robert, F., Gautier, D. & Guiraud, M. 1995 Laboratory determinations of deuterium exchange kinetics: application to the determination of the D/H ratio in giant planets, Icarus (in press).Google Scholar
Lellouch, E., Paubert, G., Moreno, R. et al. 1995 Chemical and thermal response of Jupiter's atmosphere following the impact of comet Shoemaker-Levy 9. Nature 373 592595.Google Scholar
Lyons, J. R. 1995. Thermochemical and kinetic modeling of the SL9 impact debris. IAU Coll. No. 156 (poster).Google Scholar
Marten, A., Gautier, D., Owen, T. et al. 1995 The collision of the comet Shoemaker-Levy 9 with Jupiter: detection and evolution of HCN in the stratosphere of the planet. Geophys. Res. Lett. 22 15891592.Google Scholar
Matthews, H. E., Jewitt, D. & Senay, M. C. 1995 IAU Circ. No. 6234. Google Scholar
Meech, K. J. & Weaver, H. A. 1995 Unusual comets(?) as observed from the Hubble Space Telescope. In Small Bodies in the Solar System and their Interactions with the Planets, (eds. Rickman, H. and Dahlgren, M.). Kluwer (in press).Google Scholar
Montebugnoli, S., Bortolotti, C., Cattani, A. et al. 1995 Detection of the 22-GHz line of water during and after the SL-9/Jupiter impact. European SL-9/Jupiter Workshop, (eds. West, R. M. and Boehnhardt, H.), ESO Conference and Workshop Proceedings No. 52, pp. 261266.Google Scholar
Nicholson, P. D., Gierasch, P. J., Hayward, T. L. et al. 1995 Palomar observations of the R impact of comet Shoemaker-Levy 9: II. Spectra. Geophys. Res. Lett. 22 16171620.Google Scholar
Noll, K. S., McGrath, M. A., Trafton, L. M. et al. 1995. HST spectroscopic observations of Jupiter after the collision of comet P/Shoemaker-Levy 9. Science 267 13071313.Google Scholar
Orton, G., A'Hearn, M., Baines, D. et al. 1995 Collision of comet Shoemaker-Levy 9 with Jupiter observed by the NASA Infrared Telescope Facility. Science 267 12771282.Google Scholar
Prangé, R., Emerich, C., Talavera, A. et al. 1994 IAU Circ. No. 6041.Google Scholar
Preston, G. W. 1967 The spectrum of comet Ikeya-Seki (1965f). Astron. J. 147 718742.Google Scholar
Rauer, H. & Osterloh, M. 1995. A search for differences in colour of the fragments of comet Shoemaker-Levy 9. Astron. Astrophys. 295 L31L34.Google Scholar
Rauer, H., Despois, D., Moreno, R. et al. 1995 IAU Circ. No. 6236. Google Scholar
Rickman, H. 1994 Cometary nuclei. In Asteroids, Comets, Meteors 1993, (eds. Milani, A. et al.), pp. 297312. Kluwer.Google Scholar
Roos-Serote, M., Barucci, A., Crovisier, J. et al. 1995a Metallic emission lines during the impacts L and Q1 of SL-9 on Jupiter. Geophys. Res. Let. 22 16211624.Google Scholar
Roos-Serote, M., Barucci, A., Crovisier, J. et al. 1995b Pic-du-Midi observations of atomic lines following impacts L and Q1 of comet SL-9 with Jupiter. European SL-9'/Jupiter Workshop, (eds. West, R. M. and Boehnhardt, H.), ESO Conference and Workshop Proceedings No. 52, pp. 203208.Google Scholar
Scotti, J. V., Gehrels, T. & Metcalfe, T. S. 1994 Spacewatch observations of the surface brightness of comet P/Shoemaker-Levy 9. Preprint. Google Scholar
Sekanina, Z. 1995a The splitting of the nucleus of comet Shoemaker-Levy 9. European SL-9/Jupiter Workshop, (eds. West, R. M. and Boehnhardt, H.), ESO Conference and Workshop Proceedings No. 52, pp. 4355.Google Scholar
Sekanina, Z. 1995b Nuclei of SL-9 on images taken with the Hubble Space Telescope. European SL-9/'Jupiter Workshop, (eds. West, R. M. and Boehnhardt, H.), ESO Conference and Workshop Proceedings No. 52, pp. 2935.Google Scholar
Sekanina, Z., Chodas, P. W. & Yeomans, D. K. 1994 Tidal disruption and the appearance of periodic comet Shoemaker-Levy 9. Astron. Astrophys. 289 607636.Google Scholar
Senay, M. C. & Jewitt, D. 1994 Coma formation driven by carbon monoxide release from comet Schwassmann-Wachmann 1. Nature 371 229231.Google Scholar
Sprague, A. L., Bjoraker, G. L., Hunten, D. M. et al. 1995 Observations of H2O following the R and W impacts of comet SL-9 into Jupiter's atmosphere. Science (submitted).Google Scholar
Stüwe, J. A., Schulz, R. & A'Hearn, M. F. 1995 NTT observations of SL-9: imaging and spectroscopy. European SL-9/'Jupiter Workshop, (eds. West, R. M. and Boehnhardt, H.), ESO Conference and Workshop Proceedings No. 52, pp. 1720.Google Scholar
Tancredi, G. & Lindgren, M. 1994 Searching for comets encountering Jupiter: first campaign. Icarus 107 311321.Google Scholar
Tejfel, V. G., Kharitonova, G. A., Sinyaeva, N. V. et al. 1995 The reflectivity of the aerosol material in the G, L and E impact-regions. IAU Coll. No. 156 (poster).Google Scholar
Trilling, D. E., Keller, H. U., Rauer, H., Schulz, R. & Thomas, N. 1995 Observations of P/Shoemaker-Levy 9 in Johnson B, V and R filters from Calar Alto Observatory on 2/3 June, 1994. European SL-9/Jupiter Workshop, (eds. West, R. M. and Boehnhardt, H.), ESO Conference and Workshop Proceedings No. 52, pp. 3741.Google Scholar
Vanysek, V. 1995 A note on the fragments size of SL-9 and debris field. European SL-9/Jupiter Workshop, (eds. West, R. M. and Boehnhardt, H.), ESO Conference and Workshop Proceedings No. 52, pp. 297298.Google Scholar
Weaver, H. A., A'Hearn, M. F., Arpigny, C. et al. 1995 The Hubble Space Telescope (HST) observing campaign on comet P/Shoemaker-Levy 9. Science 267 12821288.Google Scholar
Weaver, H. A., Feldman, P. D., A'Hearn, M. F. et al. 1994 Hubble Space Telescope observations of comet P/Shoemaker-Levy 9 (1993e), Science 263 787791.Google Scholar
West, R. A., Karkoshka, E., Friedson, A. J. et al. 1995 Impact debris particles in Jupiter's atmosphere. Science 267 12961301.Google Scholar
West, R. M. 1995 Nature and Structure of the impacting objects. European SL-9/Jupiter Workshop, (eds. West, R. M. and Boehnhardt, H.), ESO Conference and Workshop Proceedings No. 52, pp. 407410.Google Scholar
West, R. M., Hook, R. & Hainaut, O. 1995. A morphological study of SL-9 CCD images obtained at La Silla (July 1-15, 1994). European SL-9/Jupiter Workshop, (eds. West, R. M. and Boehnhardt, H.), ESO Conference and Workshop Proceedings No. 52, pp. 510.Google Scholar
Wilson, P. D. & Sagan, C. 1995 Chemistry of the Shoemaker-Levy 9 jovian impact blemishes: indigenous cometary vs. shock-synthesized organic matter. IAU Coll. No. 156 (poster).Google Scholar
Wink, J., Lucas, R., Guilloteau, S. & Dutrey, A. 1994 Interferometric observations of HCN J=l-0 during the SL-9 crash on Jupiter. IRAM Newsletter 18 5.Google Scholar
Wyckoff, S., Wagner, M., Wehinger, P., Schleicher, D. & Festou, M. 1984 Onset of sublimation in comet P/Halley. Nature 316 241242.Google Scholar
Xie, X., Mumma, M. J. & Olson, K. M. 1995 Physical properties of swarmed SL9 fragments at impact. IAU Coll. No. 156 (poster).Google Scholar
Yelle, R. V. & McGrath, M. A. 1995 Ultraviolet spectroscopy of the SL9 impact sites, I: the 175-230 nm region. Icarus (submitted).Google Scholar
Zahnle, K. & Mac Low, M.-M. 1995 A simple model for the light curve generated by a Shoemaker-Levy 9 impact. J. Geophys. Res. 100 1688516894.Google Scholar