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The Gateway from Centaurs to Jupiter-family Comets: Thermal and Dynamical Evolution
The Astrophysical Journal, 2023 It was recently proposed that there exists a “gateway” in the orbital parameter space through which Centaurs transition to Jupiter-family comets (JFCs).
Aurélie Guilbert-Lepoutre +3 more
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Pits on Jupiter-family Comets and the Age of Cometary Surfaces
The Planetary Science Journal, 2023 Large and deep depressions, also known as pits, are observed at the surface of all Jupiter-family comets (JFCs) imaged by spacecraft missions. They offer the opportunity to glimpse the subsurface characteristics of comet nuclei and study the complex ...
Aurélie Guilbert-Lepoutre +6 more
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Comets and the Origin of Life: Structure of Comets Nuclei and Dust [PDF]
Symposium - International Astronomical Union, 2004 From observations of fragmentation events, clues to a gravitational aggregates structure of some comets nuclei are given. From in-situ and remote light scattering observations, a very high porosity is estimated for dust in comae. These results suggest a possible survival of cometary organics during atmospheric entry at the epoch of intense bombardment.
A. Chantal Levasseur-Regourd +1 more
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The Astrophysical Journal, 1990 The evolution of a comet nucleus is investigated, taking into account the crystallization process by which the gas trapped in the ice is released to flow through the porous ice matrix. The equations of conservation of the energy and of the masses of ice and gas are solved throughout the nucleus, to obtain the evolution of the temperature, gas pressure
D, Prialnik, A, Bar-Nun
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Development of an automated scoring system for plant comet assay
Frontiers in Genetics, 2015 In plants, an increasing interest for the Comet Assay was shown in the last decade and this versatile technique appears to be promising to detect the genotoxic effect of pollutants and to monitor the environment.
Bertrand Pourrut, Charles Homsy
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Comet P/2021 HS (PANSTARRS) and the Challenge of Detecting Low-activity Comets
The Planetary Science Journal, 2023 Jupiter-family comet (JFC) P/2021 HS (PANSTARRS) only exhibits a coma within a few weeks of its perihelion passage at 0.8 au, which is atypical for a comet.
Quanzhi Ye +10 more
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THERMAL SHADOWS AND COMPOSITIONAL STRUCTURE IN COMET NUCLEI [PDF]
The Astrophysical Journal, 2011 We use a fully 3-dimensional thermal evolution model to examine the effects of a non-uniform surface albedo on the subsurface thermal structure of comets. Surface albedo markings cast "thermal shadows", with strong lateral thermal gradients. Corresponding compositional gradients can be strong, especially if the crystallization of amorphous water ice is
Guilbert-Lepoutre, A., Jewitt, D.
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Ice, Ice, Maybe? Investigating 46P/Wirtanen’s Inner Coma for Icy Grains
The Planetary Science Journal, 2023 The release of volatiles from comets is usually from direct sublimation of ices on the nucleus, but for very or hyperactive comets other sources have to be considered to account for the total production rates.
Theodore Kareta +3 more
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Caryologia, 2023 Many reports highlight biological responses of crop plants after non-ionizing electromagnetic radiation (EMR) exposure based on the phenotypic and physiological levels.
Ekram Abdelhaliem +3 more
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Toxoplasma gondii infection can induce retinal DNA damage:an experimental study
International Journal of Ophthalmology, 2014 AIM: To detect whether Toxoplasma gondii (T. gondii) infection of mice can induce retinal DNA damage.METHODS: A total of 20 laboratory-bred male Swiss albino mice were used and divided into four groups:control group (non-infected animals); T ...
Nagwa Mostafa El-Sayed, Eman Mohamed Aly
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