Results 191 to 200 of about 9,305 (228)
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Note on the structure of comet nuclei
Planetary and Space Science, 1999Abstract The recent developments in cometary studies suggest rather low mean densities and weak structures for the nuclei. They appear to be accumulations of fairly discrete units loosely bound together, as deduced from the observations of Comet Shoemaker–Levy 9 during its encounter with Jupiter. The compressive strengths deduced from comet splitting
Fred L Whipple
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Disintegration of comet nuclei
Physics-Uspekhi, 2012The breaking up of comets into separate pieces, each with its own tail, was seen many times by astronomers of the past. The phenomenon was in sharp contrast to the idea of the eternal and unchangeable celestial firmament and was commonly believed to be an omen of impending disaster, especially for comets with tails stretching across half the sky. It is
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Comet nuclei and Trojan asteroids: A new link and a possible mechanism for comet splittings
Icarus, 1990Relatively elongated shapes, implied by recent evidence of a greater incidence of high amplitude lightcurves for comet nuclei and Trojan asteroids than for similarly scaled main belt asteroids, are suggested to have evolved among comet nuclei and Trojans due to volatile loss.
William K Hartmann, David J Tholen
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Kinematics and Physics of Celestial Bodies, 2012
An attempt is made to determine the spatial location of the main source of short-period comet nuclei. Numerical calculations for the orbital evolution of Jupiter family comets, medium-period comets, and Centaurs are used to show that the orbits of small solar system bodies tend to evolve in the direction of increasing semimajor axes.
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An attempt is made to determine the spatial location of the main source of short-period comet nuclei. Numerical calculations for the orbital evolution of Jupiter family comets, medium-period comets, and Centaurs are used to show that the orbits of small solar system bodies tend to evolve in the direction of increasing semimajor axes.
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Implications of the small spin changes measured for large Jupiter-family comet nuclei [PDF]
Monthly Notices of the Royal Astronomical Society, 2018 Rotational spin-up due to outgassing of comet nuclei has been identified as a possible mechanism for considerable mass-loss and splitting. We report a search for spin changes for three large Jupiter-family comets (JFCs): 14P/Wolf, 143P/Kowal-Mrkos, and ...
Rosita Kokotanekova +2 more
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Research Notes of the AAS, 2020
Abstract Centaurs are an interesting class of small bodies orbiting between Jupiter and Neptune. Several show some sort of activity and are classified as comets, in addition to minor planets. However, is activity a sufficient criterion for comet classification? The ancient definition of a comet as a small body orbiting the Sun that shows
Daniel C. Boice, Panida Boonmasai
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Abstract Centaurs are an interesting class of small bodies orbiting between Jupiter and Neptune. Several show some sort of activity and are classified as comets, in addition to minor planets. However, is activity a sufficient criterion for comet classification? The ancient definition of a comet as a small body orbiting the Sun that shows
Daniel C. Boice, Panida Boonmasai
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Temperatures within comet nuclei
Journal of Geophysical Research: Solid Earth, 1985We have performed a theoretical study of temperatures beneath the surface of a comet's nucleus. We solve the one‐dimensional heat conduction equation for the outer portion of the comet. The upper boundary condition of the model is given by energy balance at the surface of the nucleus, including conduction of heat inward, radiation, insolation as ...
S W, Squyres, C P, McKay, R T, Reynolds
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On the visibility of nuclei of dusty comets
Icarus, 1981Abstract The problem of visibility of a cometary nucleus discussed in general terms for single scattering by dust grains. The ratio of radiatio scattered in the dust column above the surface and that reflected from the nucleus determines the visibility of features on the nuclear surface.
R. Hellmich, H.U. Keller
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Numerical simulation of comet nuclei I. Water-ice comets
Icarus, 1985A one-dimensional numerical model of pure water-ice cometary nuclei is presented, and the influence of the nuclear interior as a heat reservoir on the behavior of the nuclear surface is examined. It is shown that a number of effects, including the thermal inertia due to heat stored in the core and the release of latent heat, which goes entirely into ...
G. Herman, M. Podolak
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