Results 141 to 150 of about 8,069 (192)
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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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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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Science, 1982
Photography of the nucleus of comet Halley is the goal of several planned space missions. The nucleus of a comet is surrounded by a cloud of dust particles. If this cloud is optically thick, it will prevent observation of the nuclear surface. Broadband photometry of nine comets has been analyzed to determine the visibility of their nuclei.
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Photography of the nucleus of comet Halley is the goal of several planned space missions. The nucleus of a comet is surrounded by a cloud of dust particles. If this cloud is optically thick, it will prevent observation of the nuclear surface. Broadband photometry of nine comets has been analyzed to determine the visibility of their nuclei.
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Radioactive Heating of Porous Comet Nuclei
Icarus, 1995Abstract Radioactive heating is the main energy source of comets residing in the distant parts of the Solar System. It should determine whether liquid water could have existed in comets and whether comets, presumably formed of amorphous ice, could have retained the ice, at least partly, in this pristine form.
D. Prialnik, M. Podolak
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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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Sublimation Mechanisms of Comet Nuclei
Earth, Moon, and Planets, 2000In this paper the sublimation mechanisms of parent molecules from nuclei will be reviewed from the point of view of theoretical models, and the results of models will be compared with the results of the extensive observation campaign of C/1995 O1 Hale–Bopp. The simple model of a mixture of ices in which each gas sublimates independently from the others
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Solar System Research, 2009
Results of space missions to in-situ study comets and the derived current challenges to better understand the properties of comet nuclei are discussed and summarized shortly, particularly in view of the origin of comets in the protoplanetary disk. The main conclusion is that we are far away from a complete understanding of comets.
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Results of space missions to in-situ study comets and the derived current challenges to better understand the properties of comet nuclei are discussed and summarized shortly, particularly in view of the origin of comets in the protoplanetary disk. The main conclusion is that we are far away from a complete understanding of comets.
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Thermal evolution of comet nuclei
Advances in Space Research, 1999Abstract The properties of cometary surfaces which influence the thermal behavior of the nucleus such as the albedo, the emissivity and the surface temperature are critically reviewed. It is shown that these properties are less firmly established than generally believed. A brief presentation is given of the state of the art in comet modelling.
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Rotational Behaviour of Comet Nuclei
1991Numerical experiments of the rotational behaviour of comet nuclei have been performed, including the Sun and Jupiter’s disturbing torques in the models. In a stable configuration, the solar torque induces great librations that remain unchanged along the orbit.
P. Oberti, E. Bois, C. Froeschlé
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