Abstract
The diverse populations of icy bodies of the outer Solar System (OSS) give critical information on the composition and structure of the solar nebula and the early phases of planet formation. The two principal repositories of icy bodies are the Kuiper belt or disk, and the Oort Cloud, both of which are the source regions of the comets. Nearly 1000 individual Kuiper belt objects have been discovered; their dynamical distribution is a clue to the early outward migration and gravitational scattering power of Neptune. Pluto is perhaps the largest Kuiper belt object. Pluto is distinguished by its large satellite, a variable atmosphere, and a surface composed of several ices and probable organic solid materials that give it color. Triton is probably a former member of the Kuiper belt population, suggested by its retrograde orbit as a satellite of Neptune. Like Pluto, Triton has a variable atmosphere, compositionally diverse icy surface, and an organic atmospheric haze. Centaur objects appear to come from the Kuiper belt and occupy temporary orbits in the planetary zone; the compositional similarity of one well studied Centaur (5145 Pholus) to comets is notable. New discoveries continue apace, as observational surveys reveal new objects and refined observing techniques yield more physical information about specific bodies.
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Andronico, G., Baratta, G.A., Spinella, F., and Strazzulla, G.: 1987, ‘Optical evolution of laboratoryproduced organics – applications to Phoebe, Iapetus, outer belt asteroids and cometary nuclei’, Astron. Astrophys. 184, 333–336.
Barucci, M.A., Fulchignoni, M., Birlan, M., Doressoundiram, A., Romon, J., and Boehnhardt, H.: 2001, ‘Analysis of Trans-Neptunian and Centaur colours: continuous trend or grouping?’, Astron. Astrophys. 371, 1150–1154.
Barucci, M.A., Doressoundiram, A., and Cruikshank, D.P.: 2004, in M.C. Festou, H.U. Keller, and H.A. Weaver (eds.), Comets II, The University of Arizona Press, in press.
Binzel, R.P. and Hubbard, W.B.: 1997, ‘Mutual events and stellar occultations’, in S.A. Stern and D.J. Tholen (eds.), in Pluto and Charon, The University of Arizona Press, Tucson, pp. 85-102.
Bockelée-Morvan, D., Lellouch, E., Biver, N., Paubert, G., Bauer, J., Colom, P., and Lis, D.C.: 2001, ‘Search for CO gas in Pluto, Centaurs and Kuiper belt objects at radio wavelengths’, Astron. Astrophys. 377, 343–353.
Broadfoot, A.L., et al.: 1989, ‘Ultraviolet spectrometer observations of Neptune and Triton’, Science 246, 1459–1466.
Brown, M.E.: 2003, Bull. Am. Astron. Soc. 35, 969 (abstract).
Brown, M.E. and Calvin, W.M.: 2000, ‘Evidence for crystalline water and ammonia ices on Pluto’s satellite Charon’, Science 287, 107–109.
Brown, M.E., Trujillo, C., and Rabinowitz, D.: 2004, Astrophys. J. Lett., in press.
Brown, R.H. and Cruikshank, D.P.: 1993, ‘Remote sensing of ices and ice-mineral mixtures in the outer solar system’, in C.M. Pieters, and P.A.J. Englert (eds.), Remote Geochemical Analysis: Elemental and Mineralogical Composition, The Cambridge University Press, pp. 455–468.
Brown, R.H., Cruikshank, D.P., Veverka, J., Helfenstein, P., and Eluszkiewicz, J.: 1995, ‘Surface composition and photometric properties of Triton’, in D.P. Cruikshank (ed.), Neptune and Triton, The University of Arizona Press, Tucson, pp. 991–1030.
Brown, R.H., Cruikshank, D.P., Pendleton, Y.J., and Veeder G.J.: 1998, ‘Identification of water ice on the Centaur 1997 CU26’, Science 280, 1430–1432.
Brown, R.H., Cruikshank, D.P., and Pendleton, Y.J.: 1999, ‘Water ice on Kuiper belt object 1996 TO66’, Astrophys. J. 519, L101–L104.
Calcagno, L., Foti, G., Torrisi, L., and Strazzulla, G.: 1985, ‘Fluffy layers obtained by ion bombardment of frozen methane Experiments and applications to Saturnian and Uranian satellites’, Icarus 63, 31–38.
Cruikshank, D.P.: 1987, ‘Dark matter in the solar system’, Adv. Space Res. 7, 109–120.
Cruikshank, D.P. (ed.): 1995, Neptune and Triton, The University of Arizona Press, Tucson, 1249 pp.
Cruikshank, D.P. and Dalle Ore, C.M.: 2003, ‘Spectral models of Kuiper belt objects and Centaurs’, Earth, Moon, and Planets 92, 315–330.
Cruikshank, D. P., Roush, T. L., Owen, T. C., Quirico, E., and de Bergh, C.: 1998a, ‘The surface compositions of Triton, Pluto and Charon’, in B. Schmitt, C. de Bergh, and M. Festou (eds.), Ices in the Solar System, Kluwer Academic Publishers, Dordrecht, pp. 655–684.
Cruikshank, D.P., et al.: 1998b, ‘The composition of Centaur 5145 Pholus’, Icarus 135, 389–407.
Cruikshank, D.P., et al.: 1998c, Bull. Am. Astron. Soc. 30, 1094 (abstract).
Cruikshank, D.P., Dalle Ore, C.M., Roush, T.L., Geballe, T.R., Owen, T.C., de Bergh, C., Cash, M.D., and Hartmann, W.K.: 2001, Icarus 153, 348–360.
Cruikshank, D.P., Roush, T.L., and Poulet, F.: 2003, ‘Quantitativemodeling of the spectral reflectance of Kuiper belt objects and Centaurs’, C. R. Physique 4, 783–789.
Cruikshank, D.P., Dalle Ore, C.M., and Imanaka, H.: 2005, Icarus, submitted.
Davies, J.K., Sykes, M.V., and Cruikshank, D.P.: 1993, ‘Near-infrared photometry and spectroscopy of the unusual minor planet 5145 Pholus (1992AD)’, Icarus 102, 166–169.
Doressoundiram, A., Tozzi, G.P., Barucci, M.A., Boehnhardt, H., Fornasier, S., and Romon, J.: 2003, ‘ESO Large Programme on Trans-Neptunian Objects and Centaurs: Spectroscopic Investigation of Centaur 2001 BL41 and TNOs (26181) 1996 GQ21 and (26375) 1999 DE9’, Astron. J. 125, 2721–2727.
Dotto, E., Barucci, M. A., and de Bergh, C.: 2003, C. R. Physique 4, 775–782.
Douté, S., Schmitt, B., Quirico, E., Owen, T.C., Cruikshank, D.P., de Bergh, C., Geballe, T.R., and Roush, T.L.: 1999, ‘Evidence for methane segregation at the surface of Pluto’, Icarus 142, 421–444.
Dumas, C., Terrile, R.J., Brown, R.H., Schneider, G., and Smith, B.A.: 2001, ‘Hubble Space Telescope NICMOS spectroscopy of Charon’s leading and trailing hemispheres’, Astron. J. 121, 1163–1170.
Elliot, J.L., Dunham, E.W., Bosh, A.S., Silvan, S.M., Young, L.A., Wasserman, L.H., and Millis, R.L.: 1989, Icarus 77, 148–170.
Elliot, J.L. and Young, L.A.: 1992, Astron. J. 103, 991–1015.
Elliot, J.L., et al.: 1998, ‘Global warming on Triton’, Nature 393, 765–767.
Elliot, J.L., et al.: 2003, ‘The recent expansion of Pluto’s atmosphere’, Nature 424, 164–168.
Emery, J.P. and Brown, R.H.: 2003, ‘Constraints on the surface composition of Trojan asteroids from near-infrared (0.8-4.0 μm) spectroscopy’, Icarus 164, 104–121.
Fernández, J.A. and Brunini, A.: 2000, Icarus 145, 580–590.
Funato, U., Makino, J., Hut, P., Kokubo, E., and Kinoshita, D.: 2004, ‘The formation of Kuiper-belt binaries through exchange reactions’, Nature 427, 518–520.
Gaffey, S.J., McFadden, L.A., Nash, D., and Pieters, C.M.: 1993, ‘Ultraviolet, visible, and nearinfrared reflectance spectroscopy: laboratory spectra of geologic materials’, in C.M. Pieters and P.A.J. Englert (eds.), Remote Geochemical Analysis: Elemental and Mineralogical Composition, Cambridge University Press, New York, pp. 43–77.
Goldreich, P., Lithwick, Y., and Sari, R.: 2002, ‘Formation of Kuiper-belt binaries by dynamical friction and three-body encounters’, Nature 420, 643–646.
Grundy, W.M., Buie, M.W., and Spencer, J.R.: 2002, ‘Spectroscopy of Pluto and Triton at 3–4 microns: possible evidence for wide distribution of nonvolatile solids’, Astron. J. 124, 2273–2278.
Hainaut, O.R. and Delsanti, A.C.: 2002, ‘Colors of minor bodies in the Outer solar system. A statistical analysis’, Astron. Astrophys. 389, 641–664.
Hartmann, W.K., Tholen, D.J., and Cruikshank, D.P.: 1987, ‘The relationship of active comets, ‘extinct’ comets, and dark asteroids’, Icarus 69, 33–50.
Hartmann, W.K., Tholen, D.J., Meech, K.J., and Cruikshank, D.P.: 1990, ‘2060 Chiron – colorimetry and cometary behavior’, Icarus 83, 1–15.
Jewett, D.C.: ‘From Kuiper belt object to cometary nucleus: The missing ultrared matter’, Astron. J. 123, 1039–1049.
Jewitt, D. and Luu, J.: 1993, ‘Discovery of the candidate Kuiper belt object 1992 QB1’, Nature 362, 730–732.
Khare, B.N., Sagan, C., Arakawa, E.T., Suits, R., Callcot, T.A., and Williams, M.W.: 1984, ‘Optical constants of organic tholins produced in a simulated Titanian atmosphere - From soft X-ray to microwave frequencies’, Icarus 60, 127–137.
Khare, B.N., Thompson, W. R., Cheng, L., Chyba, C., Sagan, C., Arakawa, E. T., Meisse, C., and Tuminello, P.: 1993, ‘Production and optical constraints of ice tholin from charged particle irradiation of (1:6) C2H6/H2O at 77 K’, Icarus 103, 290–300, 1993.
Krasnopolsky, V.A. and Cruikshank, D.P.: 1995, ‘Photochemistry of Triton’s atmosphere and ionosphere’, J. Geohys. Res. 100, 21,271–21,286.
Krasnopolsky, V.A. and Cruikshank, D.P.: 1999, ‘Photochemistry of Pluto’s atmosphere and ionosphere near perihelion’, J. Geophys. Res. 104, 21,979–21,996.
Kuiper, G.P.: 1951, ‘On the origin of the solar system’, in J.A. Hynek (ed.), Astrophysics, New York: McGraw-Hill, New York, pp. 357–424.
Lellouch, E., Laureijs, R., Schmitt, B., Quirico, E., de Bergh, C., Crovisier, J., and Coustenis, A.: 2000, ‘Pluto’s non-isothermal surface’, Icarus 147, 220–250.
Levison, H.F. and Morbidelli, A.: 2003, ‘The formation of the Kuiper belt by the outward transport of bodies during Neptune’s migration’, Nature 426, 419–421.
Luu, J., Jewitt, D., and Cloutis, E.: 1994, Icarus 109, 133–144.
McKinnon, W.B., Lunine, J.I., and Banfield, D.: 1995, ‘Origin and evolution of Triton’, in D.P. Cruikshank (ed.), Neptune and Triton, The University of Arizona Press, Tucson, pp. 807–877.
Miner, E.D. and Wessen, R.R.: 2002, Neptune: The Planet, Rings and Satellites, Springer Praxis, Chichester, 297 pp.
Noll, K.S.: 2004, Earth, Moon, and Planets 92, 395–407.
Noll, K., Stephens, D., Grundy, W., Millis, R., Buie, M., Spencer, J., Tegler, S., Romanishin, W., and Cruikshank, D.: 2002, Bull. Am. Astron. Soc. 34, 849 (abstract).
Oort, J.: 1950, ‘The structure of the cloud of comets surrounding the solar system and a hypothesis concerning its origin’, Bull. Astron. Inst. Neth. 11, 91–110.
Owen, T.C., Cruikshank, D.P., Roush, T., de Bergh, C., Brown, R. H., Bartholomew, M. J., Elliot, J., and Young, L. 1993, ‘Surface ices and the atmospheric composition of Pluto’, Science 261, 745–748.
Poulet, F., Cuzzi, J.N., Cruikshank, D.P., Roush, T., and Dalle Ore, C.M.: 2002, ‘Comparison between the Shkuratov and Hapke scattering theories for solid planetary surfaces: Application to the surface composition of two Centaurs’, Icarus 160, 313–324.
Quirico, E., Douté, S., Schmitt, B., de Bergh, C., Cruikshank, D.P., Owen, T.C., Geballe, T.R., and Roush, T.L.: 1999, ‘Composition, physical state, and distribution of ices at the surface of Triton’, Icarus 139, 159–178.
Sicardy, B., et al.: 2003, ‘Large changes in Pluto’s atmosphere as revealed by recent stellar occultations’, Nature 424, 168–170.
Stansberry, J.A., Lunine, J.I., Hubbard, W.B., Yelle, R.V., and Hunten, D.M.: 1994, ‘Mirages and the nature of Pluto’s atmosphere’, Icarus 111, 503–513.
Stern, S.A., Buie, M.W., and Trafton, L.: 1997, ‘HST high-resolution images and maps of Pluto’, Astron. J. 113, 827–843.
Stern, S.A. and Kenyon, S.J.: 2003, ‘Collisions, accretion, and erosion in the Kuiper belt’, C. R. Physique 4, 803–808.
Stone, E.C. and Miner, E.D: 1989, ‘The Voyager 2 encounter with the Neptunian system’, Science 146, 1417–1421.
Strobel, D.F., Zhu, X., Summers, M.E., and Stevens, M.H.: 1996, ‘On the vertical thermal structure of Pluto’s atmosphere’, Icarus 120, 266–289.
Tholen, D.J. and Buie, M.W.: 1997, ‘The Orbit of Charon’, in S.A. Stern and D.J. Tholen (eds.), Pluto and Charon, The University of Arizona Press, Tucson, pp. 193–219.
Tyler, G.L., Sweetnam, D.N., Anderson, J.D., Borutzki, S.E., Campbell, J.K., Kursinski, E.R., Levy, G.S., Lindal, G.F., Lyons, J.R., and Wood, G.E.: 1989, ‘Voyager radio science observations of Neptune and Triton’, Science 246, 1466–1473.
Weidenschilling, S.J.: 2002, ‘On the origin of binary transneptunian objects’, Icarus 160, 212–215.
Weissman, P.R.: 1998, ‘The Oort cloud’, Scientific American 279, 84–89.
Yelle, R.V., Lunine, J.L., and Hunten, D.M.: 1991, ‘Energy balance and plume dynamics in Triton’s lower atmosphere’, Icarus 89, 347–358.
Young, L.A., Elliot, J.L., Tokunaga, A., de Bergh, C., and Owen, T.: 1997, ‘Detection of gaseous methane on Pluto’, Icarus 127, 258–262.
Young, E.F., Binzel, R.P., and Crane, K.: 2001, ‘A two-color map of Pluto’s sub-Charon hemisphere’, Astron. J. 121, 552–561.
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Cruikshank, D.P. Triton, Pluto, Centaurs, and Trans-Neptunian Bodies. Space Sci Rev 116, 421–439 (2005). https://doi.org/10.1007/s11214-005-1964-0
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DOI: https://doi.org/10.1007/s11214-005-1964-0