Scientists have identified a major change in the movement of molten iron deep inside Earth’s outer core beneath the equatorial Pacific. Data indicate that around 2010 a broad flow that had been moving westward changed direction and began moving rapidly eastward. Satellite observations, including measurements from ESA missions, helped researchers reconstruct the shift through changes in Earth’s magnetic field. The cause of the reversal remains uncertain, and scientists are studying what it reveals about dynamics deep inside the planet.