Enceladus
Proto-Enceladus hypothesis

Enceladus is losing mass at a rate of 200 kg/second. If mass loss at this rate continued for 4.5 Gyr, the satellite would have lost approximately 30% of its initial mass. A similar value is obtained by assuming that the initial densities of Enceladus and Mimas were equal. It suggests that tectonics in the south polar region is probably mainly related to subsidence and associated subduction caused by the process of mass loss.
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