Comet 9P/Tempel 1: Evolution of the surface

Kossacki K.J.


245, 2015, 348-354, 10.1016/j.icarus.2014.09.044

Comet 9P/Tempel 1 was imaged during two consecutive perihelion passages. According to Thomas et al. (Thomas, et al. [2013]. Icarus 222, 453–466) one scarp located at 40°S receded up to 50 m. I attempted to use this observation to constrain local material properties of the nucleus. For this purpose I simulated recession of a model scarp due to sub-dust sublimation of ice. I have found, that the observed recession of the scarp can be reproduced when the dust mantle has high porosity about 0.8 and low thermal conductivity about 10 mW m−1 K−1, as found for artificial dust layers (Krause, M., Blum, J., Skorov, Yu.V., Trieloff, M. [2011]. Icarus 214, 286–296). Taking into account the temperature dependence of the sublimation coefficient of ice reduces the calculated recession rate of the scarp by about 40%.