The intimate mixture of ice and silicate within the uppermost few kilometres of Ceres influences its geology and the evolution of its subsurface. Both ground ice and cryovolcanic processes have been hypothesized to form geologic terrains on Ceres, including within Occator crater, where they have been suggested to influence the post-impact surface evolution. Both types of processes involve the presence and expression of volatiles and brines, such that distinguishing between them could be difficult. Here, we use images and topography data from the NASA Dawn mission to investigate the morphology, age and distribution of mounds and hills within Occator crater, and infer their origin. The shapes and relative ages of many of these features suggest that they formed as impact-induced water-rich flows that covered the crater floor refroze in a manner similar to the formation of periglacial ice-cored mounds on Earth called pingos. We suggest that impacts on Ceres produced hydrologic conditions for surface changes in the absence of cryovolcanic processes. Our findings imply that cryo-hydrologic processes extend beyond Earth and Mars, and have been active on Ceres in the geologically recent past.

谷神星最上方几公里内冰和硅酸盐的紧密混合物会影响其地质和地下演化。地面冰和低温火山作用的过程都被认为可以在谷神星上形成地质地形，包括在Occator陨石坑内，并建议它们会影响撞击后的地表演化。两种类型的过程都涉及挥发性物质和盐水的存在和表达，因此很难区分它们。在这里，我们使用来自NASA Dawn任务的图像和地形数据来调查Occator陨石坑内丘陵和丘陵的形态，年龄和分布，并推断其起源。这些特征中许多特征的形状和相对年龄表明，它们是由撞击引起的富水流形成的，这些流覆盖了火山口的底面，以与在地球上形成冰河丘陵丘（称为pingos）类似的方式形成。我们建议，在没有低温冰晶过程的情况下，对谷神星的影响产生了表面变化的水文条件。我们的发现表明，低温水文过程扩展到地球和火星之外，并且在最近的地质历史中一直活跃在谷神星上。