  During recent decades, data from space missions have provided strong evidence
of deep liquid oceans underneath a thin outer icy crust on several moons of
Jupiter, particularly Europa. But these observations have also raised many
unanswered questions regarding the oceanic motions generated under the ice, or
the mechanisms leading to the geological features observed on Europa. By means
of direct numerical simulations of Europa's interior, we show here that
Jupiter's magnetic field generates a retrograde oceanic jet at the equator,
which may influence the global dynamics of Europa's ocean and contribute to the
formation of some of its surface features by applying a unidirectional torque
on Europa's ice shell.
