Results 191 to 200 of about 282,415 (218)

Carbonaceous matter in cometary dust and coma

Advances in Space Research, 1995
The analysis of carbonaceous matter in p/Halley's dust and coma via mass spectrometry of positive ions is reviewed. Dust impact generated ions were analyzed by the PUMA instrument aboard VEGA I, and coma plasma ions by the PICCA instrument aboard GIOTTO. For the organic molecules results an overall C:H:O:N ratio of 1.:1.4:0.6:0.1.
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Confirmation of dust clusters in the coma of Comet Halley

Advances in Space Research, 1989
Measurements from the Ducma dust counter and mass analyzer on the Vega spacecraft are compared with those from the SP-1 sensor on the same spacecraft. It is shown that the sequence of pulses recorded by the SP-1 instruments show deviations from a random distribution. Some of the nonrandom sequences observed by SP-1 are in the same time intervals as the
J.A. Simpson, A.J. Tuzzolino, L.V. Ksanfomality, R.Z. Sagdeev, O.L. Vaisberg   +4 more
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The Large-Grained Dust Coma of 174P/Echeclus

Publications of the Astronomical Society of the Pacific, 2008
On 2005 December 30, Y.-J. Choi and P. R. Weissman discovered that the formerly dormant Centaur 2000 EC98 was in strong outburst. Previous observations by P. Rousselot et al. spanning a 3-year period indicated a lack of coma down to the 27 mag arcsec 2 level.We present Spitzer Space Telescope MIPS observations of this newly active Centaur--now known as
Bauer, James M., Choi, Young-Jun, Weissman, Paul R., Stansberry, John A., Fernández, Yanga R., Roe, Henry G., Buratti, Bonnie J., Sung, Hyun-Il   +7 more
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Dust Measurements in the Coma of Comet 81P/Wild 2 by the Dust Flux Monitor Instrument

Science, 2004
We present measurements of the dust particle flux and mass distribution from the Stardust Dust Flux Monitor Instrument (DFMI) throughout the flyby of comet 81P/Wild 2. In the particle mass regime from 10 –14 to 10 –7 kilograms, the spacecraft encountered regions of intense swarms of particles,
Anthony J, Tuzzolino, Thanasis E, Economou, Ben C, Clark, Peter, Tsou, Donald E, Brownlee, Simon F, Green, J A M, McDonnell, Neil, McBride, Melusine T S H, Colwell   +8 more
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Cometary dust coma models. II. Computer experiments

Astronomische Nachrichten, 1986
AbstractComputer simulations of a cometary dust coma are presented which take into account different distribution functions of the ejected material as well as anisotropic ejection due to the rotation of the nucleus and single active regions on its surface.
Gottlöber, S., Liebscher, D.-E., Mücket, J. P., Müller, V.   +3 more
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The nature of dust grains in the comae of Comets černis and Bowell

Earth, Moon, and Planets, 1985
The currently available infrared data on scattered light from the dust comae of Cernis and Bowell set stringent upper limits to the contribution of icy grains. For Comet Cernis the data is consistent with only a 10% mass fraction of water-ice included within silicate-organic-carbon grains of scale radius 15 microns, while for Comet Bowell there is no ...
F. Hoyle, N. C. Wickramasinghe, M. K. Wallis   +2 more
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Cometary dust coma models. I. Analytic calculations

Astronomische Nachrichten, 1986
AbstractThe dust coma of comets is calculated within the fountain model of isotropically ejected particles. A method to estimate the particle size distribution is proposed.
Gottlöber, S., Liebscher, D.-E., Mücket, J. P., Müller, V.   +3 more
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Properties of dust in the coma of Churyumov-Gerasimenko

2010
The last apparition of comet 67P/Churyumov-Gerasimenko before the Rosetta spacecraft ren-dezvous in 2014 has taken place in 2008-2009. Observations have therefore been carried out to optimize the mission. In this context, observations of solar light scattered by dust, with em-phasis on polarimetric data, provide comparisons between the dust properties ...
Levasseur-Regourd, Anny Chantal, Hadamcik, Edith, Sen, Asole Kumar, Lasue, Jérémie, Fulle, Marco, Gupta, Rajiv   +5 more
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Coma morphology and dust emission pattern of comet Halley

Advances in Space Research, 1985
Abstract This contribution starts with a short overview on cometary dust modelling and then focuses on the application of coma modelling with respect to in-situ measurements of cometary dust and ground based observations. The fountain model, valid for the dynamics of small cometary dust particles, is discussed.
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Dust and Gas in Comae of Four Short-Period Comets

Small Solar System bodies are widely regarded as the primary repositories of primordial matter, preserved since the early stages of planetary system formation. Among these, long-period comets (LPCs) represent a unique class of objects; their dynamical trajectories keep them at vast distances from the Sun for most of their existence, ensuring that their
Olena Shubina, Oleksandra Ivanova, Leonid Shakun   +2 more
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