Shape, morphology and spin-axis evolution of Kuiper belt objects due to nucleus activities
Abstract
One of the key findings of the Rosetta mission to the Jupiter family comet 67P/CG was its peculiar bi-lobed shape along with the apparent north/south dichotomy in large scale morphology. This has reignited scientific discussion on the topic of origin, evolution and age of the nucleus. In this work we aim to investigate the role of activity on the overall shape, spin axis, and orbit evolution for comet candidate objects during their 'storage' phase in the Kuiper belt. We consider four classes of three-dimensional (3D) shapes for various initial condition of spin-axis and orbital parameters, propagating them for ∼109 years. Accounting for solar driven CO ice sublimation (and Knudsen diffusion), we estimate the spin states change and derive upper limits on mass loss distribution on the surface. The results provide argument for activity driven origin of large scale morphology structures, as well as significant alteration of pre-existing landforms due to sublimation. Meanwhile, we investigate, in the framework of sublimation driven activity, whether there are observable morphological defining features, which simply cannot be produced within range of our parameters, indicating positive evidence for other processes. Furthermore, we present information on which orbit and spin parameters would favor evolution into elongated or even bi-lobed shapes such as the shape of 19P/Borrelly or 103P/Hartely 2, and weather longitudinal variation of location of the 'neck' can be achieved within the constraints of the model is also discussed.
- Publication:
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43rd COSPAR Scientific Assembly. Held 28 January - 4 February
- Pub Date:
- January 2021
- Bibcode:
- 2021cosp...43E.838Z