A thermal modelling of cometary activity with a crystallized water ice nucleus

✍ Scribed by S. Yabushita; N. Hatta

• Book ID: 104634184
• Publisher: Springer Netherlands
• Year: 1987
• Tongue: English
• Weight: 382 KB
• Volume: 37
• Category: Article
• ISSN: 1573-0794
• DOI: 10.1007/bf00130889

✦ Synopsis

Arguments are presented to suggest that surface layers of the nuclei of periodic comets consist of crystallized rather than amorphous water ice and thermal modelling of such nuclei is presented. The rate of sublimation of water from a rotating nucleus is found to be greater than that from a uniformly heated nucleus. When the model is applied to P/Halley, the sublimation rate at perihelion is found to be 8.1 x 10" mol s-' for a nucleus rotating with a period of 50 hours and 7.6 x lo*' for a uniformly heated nucleus on the premise that the effective radius of the nucleus is 2.5 km. The total sublimation of water per revolution is 5.38 x 1O36 molecules for P/Halley and 3.91 x 1O36 molecules per P/Crommelin. The result so obtained is discussed in relation to the observational data.