| タイトル | Gas and dust emission from comets and life spans of active areas on their rotating nuclei |
| 著者（英） | Sekanina, Z. |
| 著者所属（英） | Jet Propulsion Lab., California Inst. of Tech. |
| 発行日 | 1990-10-01 |
| 言語 | eng |
| 内容記述 | Outgassing and dust emission from discrete regions on the nuclei of comets are investigated with regard to the processes of activation, dormancy, reactivation, and extinction. With regard to P/Halley, P/Encke, P/Tempel 2, P/Machholz, P/Takamizawa, Bowell and some other new comets, the evolution of one active region of the nucleus surface appears to be independent of the evolution of another active region. The traditional concept of deactivation as a slow and monolithic process needs to be replaced with a more dynamic concept of intermittent periods of dormancy and reactivation of individual vents, varying in size. Life spans of discrete sources of activity are estimated to be at a few hundred revolutions about the sun for comets with perihelia at heliocentric distances of less than 2 AU, if the bulk density is very low. |
| NASA分類 | ASTROPHYSICS |
| レポートNO | 90A53100 |
| 権利 | Copyright |
| URI | https://repository.exst.jaxa.jp/dspace/handle/a-is/353385 |
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