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要旨:
One of the key findings of the Rosetta mission to the Jupiter -family comet 67P/Cht r nov Gerasimenko was its peculiar hi -lobed shape and its apparent Northern/Southern hemispheric dichotomy in large-scale morphology, This has re -ignited scientific discussions on the topic of the origin, evolution and age of the nucleus. In this work, we conduct a general numerical investigation of the role of solar -driven activity on the overall change in shape. Our goal is to isolate and study the influence of key parameters for solar -driven mass loss, and hopefully to obtain a classification of the final shapes, We consider five general classes of three-dimensional objects for various initial conditions of the spin -axis and orbital parameters, propagating them on different orbits to account for solar-driven CO ice sublimation, We also make a detailed study of the coupling between the sublimation curve and orbital parameters (for CO and 1-1,0 ices). Using the idealizations in this study, we aim to remove the ad hoc assumptions on the source distribution, composition and/or chemical inhomogeneities of the activity, as applied in similar studies that focus on explaining a particular feature or observation. Our numerical experiments show that under no conditions can a homogeneous nucleus with solar driven outgassing produce concave morphology on a convex shape. However, pre-existing concavities can he smoothed/removed for the assumed activity. In summary, the combiupling betweenlar distance, eccentricity, the spin -axis and its orientation, as well as the effects on shadowing and self-heating, do induce morphology changes that might not be deducible without numerical simulations.
