The geologically youthful terrains came as a great surprise to the scientific community, because no theory was then able to predict that such a small (and cold, compared to Jupiter's highly active moon Io) celestial body could bear signs of such activity.
Os terreos xeoloxicamente recentes foron unha gran sorpresa para a comunidade científica, xa que non existía daquela teoría algunha que puidese predicir que un corpo tan pequeno (e frío, comparado coa activa lúa de Xúpiter, Ío) amosase signos de actividade.