%0 Journal Article %1 ZAHNLE1994 %A ZAHNLE, K. %A MACLOW, M. M. %D 1994 %J Icarus %K ATMOSPHERE; SOLAR %N 1 %P 1--17 %T THE COLLISION OF JUPITER AND COMET SHOEMAKER-LEVY-9 %V 108 %X A simple description of the disruption and deceleration of 100-m- to 5-km-diameter comets striking Jupiter is combined with numerical simulations of the subsequent explosions to predict the fate of Comet Shoemaker-Levy 9. Kilometer-size objects of density 1 g/cm3 explode at about the 10-bar level; a fragment of the same diameter but of density 0.3 g/cm3 explodes at about the 2-bar level. Detailed numerical simulations of the first 3 min of the explosion were performed using the astrophysical hydrodynamics program ZEUS-3D. Our numerical simulations begin either with hot cylinders with dimensions suggested by the disruption and deceleration model or with an initial wake constructed from a moving line charge. In all cases, extensive plumes of hot gas are expelled from the atmosphere. The models with wakes evolve about twice as fast as the initially confined models. Models of both types generate similar pressure waves into the planet. Temperatures and negative hydrogen ion opacities were computed by solving a battery of Saha equations. For atmospheric entry, light curves were computed assuming thermal radiation by clean jovian air with a surface area consistent with the (changing) cross-sectional area of the impactor. On entry the largest bolides could be very bright, possibly as bright as Jupiter for observers placed to see them, although for kilometer-size impactors the luminosity peak is obscured by clouds. The timescale is about 10 sec. For the fireball, light curves were computed from the numerical simulations assuming a grey atmosphere. Metals from the vaporized comet provide electrons that dramatically increase the opacity of Jovian air at low temperature; the resulting effective radiating temperature of the fireball is of order 3000 K. The fireball rises through and above the atmosphere, brightening at first as its surface area increases, but later fading to invisibility as its temperature drops and its opacity plummets. The timescale is about 100 sec. (C) 1994 Academic Press, Inc.

@article{ZAHNLE1994, abstract = {A simple description of the disruption and deceleration of 100-m- to 5-km-diameter comets striking Jupiter is combined with numerical simulations of the subsequent explosions to predict the fate of Comet Shoemaker-Levy 9. Kilometer-size objects of density 1 g/cm3 explode at about the 10-bar level; a fragment of the same diameter but of density 0.3 g/cm3 explodes at about the 2-bar level. Detailed numerical simulations of the first 3 min of the explosion were performed using the astrophysical hydrodynamics program ZEUS-3D. Our numerical simulations begin either with hot cylinders with dimensions suggested by the disruption and deceleration model or with an initial wake constructed from a moving line charge. In all cases, extensive plumes of hot gas are expelled from the atmosphere. The models with wakes evolve about twice as fast as the initially confined models. Models of both types generate similar pressure waves into the planet. Temperatures and negative hydrogen ion opacities were computed by solving a battery of Saha equations. For atmospheric entry, light curves were computed assuming thermal radiation by clean jovian air with a surface area consistent with the (changing) cross-sectional area of the impactor. On entry the largest bolides could be very bright, possibly as bright as Jupiter for observers placed to see them, although for kilometer-size impactors the luminosity peak is obscured by clouds. The timescale is about 10 sec. For the fireball, light curves were computed from the numerical simulations assuming a grey atmosphere. Metals from the vaporized comet provide electrons that dramatically increase the opacity of Jovian air at low temperature; the resulting effective radiating temperature of the fireball is of order 3000 K. The fireball rises through and above the atmosphere, brightening at first as its surface area increases, but later fading to invisibility as its temperature drops and its opacity plummets. The timescale is about 100 sec. (C) 1994 Academic Press, Inc.}, added-at = {2009-11-03T20:21:25.000+0100}, author = {ZAHNLE, K. and MACLOW, M. M.}, biburl = {https://www.bibsonomy.org/bibtex/254ed9186f3edd8148295bb4fc64d3a91/svance}, citedreferences = {AHRENS TJ, 1993, B AM ASTRON SOC, V25, P1043 ; ANDERS E, 1989, GEOCHIM COSMOCHIM AC, V53, P197 ; ATREYA SK, 1986, ATMOSPHERES IONOSPHE ; BIBERMAN LM, 1980, ACTA ASTRONAUT, V7, P53 ; BRONSHTEN VA, 1983, PHYSICS METEORIC PHE ; CARLSON BE, 1992, ASTROPHYS J, V388, P648 ; CHAMBERLAIN JW, 1987, THEORY PLANETARY ATM ; CHAPMAN CR, 1993, Nature, V363, P492 ; CHEVALIER R, 1994, IN PRESS ASTROPHYS J ; CHYBA CF, 1993, Nature, V361, P40 ; DOBROVOLSKIS AR, 1990, Icarus, V88, P24 ; GLASSTONE S, 1977, EFFECTS NUCLEAR WEAP ; HILLS JG, 1993, ASTRON J, V105, P1114 ; JONES EM, 1982, GEOL SOC AM SPEC PAP, V190, P175 ; KLEIN RI, 1990, EVOLUTION INTERSTELL, P117 ; KLEIN RI, 1994, ASTROPHYS J, V420, P213 ; KOMPANEETS AS, 1960, SOV PHYS DOKL, V5, P46 ; LEWIS JS, 1980, Icarus, V43, P85 ; MACLOW MM, 1988, ASTROPHYS J, V324, P776 ; MACLOW MM, 1989, ASTROPHYS J, V337, P141 ; MACLOW MM, 1994, SPLIT COMETS CRATER ; NOVOTNY E, 1973, INTRO STELLAR ATMOSP ; Peale SJ, 1989, Icarus, V82, P36 ; SCOTTI JV, 1993, Nature, V365, P733 ; SEKANINA Z, 1993, Science, V262, P382 ; STONE JM, 1992, APJS, V80, P753 ; SVETSOV VV, 1994, UNPUB DISINTEGRATION ; TAUBER ME, 1976, Icarus, V28, P351 ; VANLEER B, 1977, J COMPUT PHYS, V23, P276 ; WALKER JCG, 1986, Icarus, V68, P87 ; WEAVER HA, 1993, HST OBSERVATIONS COM ; WEST RA, 1986, Icarus, V65, P161 ; ZAHNLE KJ, 1992, J GEOPHYS RES, V97, P10243 ; ZAHNLE KJ, 1993, SOME CONSEQUENCES CO ; ZELDOVICH YB, 1966, PHYSICS SHOCK WAVES}, interhash = {57425ba60ba0bcc0278b79be20613542}, intrahash = {54ed9186f3edd8148295bb4fc64d3a91}, journal = {Icarus}, keywords = {ATMOSPHERE; SOLAR}, number = 1, owner = {svance}, pages = {1--17}, timestamp = {2009-11-03T20:22:21.000+0100}, title = {THE COLLISION OF JUPITER AND COMET SHOEMAKER-LEVY-9}, volume = 108, year = 1994 }