Cross-section snapshot in time of the modeled 3-D structure of Ceres’ interior temperature for one model run with radiogenic heating, convection, and a small perturbation in interior boundary conditions. By half a billion years, a convective instability has developed in the form of hot material moving from the deep interior toward the surface in just one hemisphere, a temperature asymmetry modeled to persist for approximately 2 billion years. Credit: King et al., 2022, Figure 3c
Source: AGU Advances
Editors’ Highlights are summaries of recent papers by AGU’s journal editors.

The Dawn mission discovered an unexpectedly youthful surface on Ceres, an ice-rich dwarf planet and the asteroid belt’s largest asteroid. Few ancient large impact basins, regions of thickened crust, large-scale fractures, and hemisphere-scale variations in gravity indicate a possible role for solid state convection in reshaping the crust. However, absent tidal heating, what long-lived source of energy might drive such resurfacing was unclear. King et al. [2022] show that sufficient heat can be generated simply by radioactive decay in certain geophysical regimes in which transient asymmetric upwelling sets up degree-one, i.e., hemispherical, convection. Small initial heterogeneities in temperature lead to long-term convective consequences. This process may also be active on other small solar system bodies, explaining hemisphere-scale resurfacing/tectonics on outer solar system icy moons.  

Citation: King, S., Bland, M., Marchi, S., Raymond, C., Russell, C., Scully, J. & Sizemore, H.  Ceres’ broad-scale surface geomorphology largely due to asymmetric internal convection. AGU Advances, 3, e2021AV000571.

—Bethany Ehlmann, Editor, AGU Advances

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