The gravity and shape data acquired by the Dawn spacecraft during its primary mission revealed that Ceres is partially differentiated with an interior structure consistent with a volatile-rich crust, a mantle of hydrated rock and isostatically compensated topography^1,2,3. Detailed analyses showed that the mechanically strong crust overlays a weak, fluid-bearing upper mantle⁴. Previous studies, however, assumed that Ceres’s crust is a uniform layer. Here, we report findings from the new high-resolution gravity data from Dawn’s second extended mission (XM2), which reveal a complex crustal structure of Ceres. In the low-altitude regions probed by the Dawn spacecraft during the XM2 phase, we observe that gravity–topography admittance progressively shifts to a lower density solution at higher degrees, implying a radial density gradient across Ceres’s crust that is consistent with decreasing porosity with depth and/or increasing content of dense phases, such as rock and salts. That gradient brings a critical new constraint on the crustal freezing history, suggesting that the salts and silicates concentrated in the liquid phase while the crust was growing. Localized spectral analysis of the new data also shows evidence for a lower crustal density in the north polar region than in the south or near the equator, supporting impact-driven porosity variations for the observed latitudinal density differences⁵. On the local scale, the new data show evidence for density or rheological variations within the crust, in association with lobate landslides and ejecta deposits that were inferred to be ice-rich^6,7 as well as an extensional fault system⁸. These inferences provide geophysical context for geological features on the surface and help us advance our understanding of the evolution of an ice-rich but heat-starved body, whose evolution was in part shaped by impacts.

黎明航天器在执行其主要任务期间获得的重力和形状数据显示，谷神星的内部结构与富含挥发物的地壳，水合岩石的地幔以及经等静压补偿的地形^1,2,3一致，具有部分差异。详细分析表明，机械坚固的地壳覆盖了较弱的，带有流体的上地幔⁴。但是，以前的研究假设Ceres的地壳是均匀的层。在这里，我们报告了来自Dawn的第二次扩展任务（XM2）的新的高分辨率重力数据的发现，这些数据揭示了谷神星的复杂地壳结构。在XM2阶段由Dawn航天器探测到的低海拔区域中，我们观察到重力-地形导纳在较高程度上逐渐移向较低密度的解，这暗示了Ceres地壳上的径向密度梯度与深度随深度的减小而一致。和/或增加密相（例如岩石和盐）的含量。该梯度对地壳冻结历史带来了关键的新约束，表明盐和硅酸盐在地壳生长时集中在液相中。⁵。在当地范围内，新数据显示出壳内的密度或流变学变化的证据，与叶状滑坡和喷出的沉积物（据推测富含冰）^6,7以及伸展断层系统^8有关。这些推论为地表上的地质特征提供了地球物理背景，并帮助我们加深了对富含冰但热度不足的物体的演化的理解，该物体的演化部分受撞击的影响。