Source: AGU Advances
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.  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. https://doi.org/10.1029/2021AV000571
—Bethany Ehlmann, Editor, AGU Advances