Earth's magnetic field. Cutaway artwork showing the interior of the Earth and Earth's magnetic field lines (white). Magnetic field lines show the direction of the field. Where the lines converge (north and south poles), the field is strongest. The Earth's magnetic field is a dipole, and is thought to be generated by the movement of molten iron in the Earth's liquid outer core (yellow) as the Earth rotates. The Earth's inner core (white) and the mantle (red) are also shown. The Earth's magnetic field extends outwards into space for tens of thousands of kilometres, protecting the Earth by channelling the charged particles in the solar wind around the Earth and also towards the poles, where they produce the aurorae.