Topic
Comet nucleus
About: Comet nucleus is a research topic. Over the lifetime, 818 publications have been published within this topic receiving 17015 citations.
Papers published on a yearly basis
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Papers
TL;DR: Measurements of the interior of Comet 67P/Churyumov-Gerasimenko by Radiowave Transmission (CONSERT) suggest the upper part of the “head” of 67P is fairly homogeneous on a spatial scale of tens of meters, and the dust component may be comparable to that of carbonaceous chondrites.
Abstract: The Philae lander provides a unique opportunity to investigate the internal structure of a comet nucleus, providing information about its formation and evolution in the early solar system. We present Comet Nucleus Sounding Experiment by Radiowave Transmission (CONSERT) measurements of the interior of Comet 67P/Churyumov-Gerasimenko. From the propagation time and form of the signals, the upper part of the “head” of 67P is fairly homogeneous on a spatial scale of tens of meters. CONSERT also reduced the size of the uncertainty of Philae’s final landing site down to approximately 21 by 34 square meters. The average permittivity is about 1.27, suggesting that this region has a volumetric dust/ice ratio of 0.4 to 2.6 and a porosity of 75 to 85%. The dust component may be comparable to that of carbonaceous chondrites.
249 citations
1 Jan 2004
TL;DR: In this paper, the evolution and activity of comets depend on different classes of parameters: defining parameters, such as size and orbit; structural parameters such as porosity and composition; and initial parameters, including temperature and live radioisotope content.
Abstract: Numerical simulation of the structure and evolution of a comet nucleus is reviewed from both the mathematical and the physical point of view. Various mathematical procedures and approximations are discussed, and different attempts to model the physical characteristics of cometary material, such as thermal conductivity, permeability to gas flow, drag of dust grains, and dust mantling, are described. The evolution and activity of comets is shown to depend on different classes of parameters: defining parameters, such as size and orbit; structural parameters, such as porosity and composition; and initial parameters, such as temperature and live radioisotope content. Despite the large number of parameters, general conclusions or common features appear to emerge from the numerous model calculations — for different comets — performed to date. Thus, the stratified structure of comet nuclei, volatile depletion, and the role of crystallization of ice in cometary outbursts are discussed.
206 citations
1 Jan 1985
TL;DR: In this article, the authors present a detailed discussion of the physics of Ices and their role in the formation and evolution of interplanetary Ices from interstellar space to the Solar System.
Abstract: Introduction: Scientific Background.- I: Physics and Remote Sensing of Ices.- The physics of Ice: Some fundamentals of planetary glaciology..- Partial phase diagram for the system NH3 - H2O: The water-rich region..- Phase transitions in solid methane at high pressure..- Clathrate hydrates in the Solar System.- Polymorphism in vapor deposited amorphous solid water..- Rheologies of H2O Ices Ih, II, and III at high pressures: A progress report..- Creep of high-pressure Ice VI..- Hugoniot of water Ice..- Measurement of the extinction of water Ice particles..- Spectral properties of water Ice and contaminants..- Outer solar system materials: Ices and color systematics..- II: Cosmochemistry of Ices and Interplanetary Particles.- Evolution of Ices from interstellar space to the Solar System.- Formation history and environment of cometary nuclei.- Stable isotopic compositions of hydrogen, nitrogen, oxygen and sulfur in meteoritic low temperature condensates.- Dust of variable porosities (densities) in the Solar System..- Molecule formation in cometary environments.- Interaction between solar energetic particles and interplanetary grains .- Sputtering of Water Ice at 30-140 K by 0.5 - 6.0 keV H+ and Ne+ ions..- Charged particle modification of Ices in the saturnian and jovian systems..- Laboratory studies of ion irradiations of water, sulfur dioxide and methane Ices..- Comment on the evolution of interplanetary grains..- III: The Icy Nuclei of Comets.- Present status of the icy conglomerate model..- The sublimation temperature of the cometary nucleus: Observational evidence for H2O snows..- Condensation and agglomeration of cometary Ice: the HDO/H2O ratio as tracer..- Amorphous and porous Ices in cometary nuclei..- Composition and structure of the comet nucleus and its evolution on a periodic orbit..- Amorphous-crystalline phase transition and the light curve of comet P/Halley..- Model for an icy halo in comets..- Ice in cometary grains..- Ultraviolet albedo of cometary grains..- S2: A clue to the origin of cometary Ice?.- Formaldehyde in comet IRAS-Araki-Alcock (1983 d) Cosmogonical implications..- The effect of dust halos and dust mantles on nuclear outgassing..- What we do not know about cometary Ices: A review of the incomplete evidence..- IV: Ices on Mars.- The martian polar caps: A Review..- Mars: Long term changes in the state and distribution of H2O..- Subsurface Ice and permfrost on Mars..- Geomorphologic evidence for ground Ice on Mars..- Comment: Compared distribution of H2O on Mars and the Earth..- Hydrolithosphere and problems of subsurface Ice in the equatorial zone of Mars..- V: Rings, Icy Satellites and Pluto.- Icy satellites, rings and Pluto..- Shock vaporization and the accretion of the icy satellites of Jupiter and Saturn..- The composition and structure of planetary rings..- Ices in planetary rings.- The small, icy satellites of Saturn..- The shapes and strengths of small icy satellites..- Icy satellites of Uranus..- The atmospheres of icy bodies..- Evolution of Titan's coupled ocean-atmosphere system and interaction of ocean with bedrock.- Importance of the tectonic motions on Ganymede..- Some remarks on the geology of Ganymede..- Tectonics of Valhalla Basin on Callisto.- Chronology of surface units on the icy satellites of Saturn..- Sulfur dioxide Ice on Io.- Methane Ice on Triton and Pluto.- Geology of Icy satellites.- VI: Summary of the Highlights of the Conference.- Summary of the highlights of the conference.- Indexes.- Author Index.- Object Index.
191 citations
University of Kent1, Baylor University2, Rutherford Appleton Laboratory3, European Space Research and Technology Centre4, Max Planck Society5, Jet Propulsion Laboratory6, University of Sheffield7, Technische Universität München8, Lund University9, Community emergency response team10, Cardiff University11
TL;DR: Data at large masses recently analysed from the DIDSY data set show clear evidence of a decrease in the mass distribution index at these masses within the coma, and it is shown that such a value of the mass index can provide sufficient mass for consistency with the observed deceleration.
Abstract: Analysis of the data from Giotto’s Dust Impact Detection System experiment (DIDSY) is presented These data represent measurement of the size of dust grains incident on the Giotto dust shield along its trajectory through the coma of comet P/Halley on 1986 March 13/14 First detection occurred at some 287000 km distance from the nucleus on the inbound leg; the majority of the DIDSY subsystems remained operational after closest approach (604 km) yielding the last detection at about 202000 km from the nucleus
155 citations
TL;DR: In this article, data from the Extarsolar Planet Observation and Deep Impact Extended Investigation (EPOXI) mission showed that the shape of the comet 103P/Hartley 2 is the evolutionary product of insolation, sublimation, and temporary deposition of materials controlled by the object's complex rotation.
147 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
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| 2025 | 1 |
| 2024 | 3 |
| 2023 | 9 |
| 2022 | 14 |
| 2021 | 7 |
| 2020 | 10 |