Schematic illustration of the invisible magnetic field lines generated by the Earth, represented as a dipole magnet field. In actuality, our magnetic shield is squeezed in closer to Earth on the Sun-facing side and extremely elongated on the night-side due to the solar wind.
Earth’s polarity is not a constant. Unlike a classic bar magnet, the matter governing Earth’s magnetic field moves around. Geophysicists are pretty sure that the reason Earth has a magnetic field is because its solid iron core is surrounded by a fluid ocean of hot, liquid metal. The flow of liquid iron in Earth’s core creates electric currents, which in turn creates the magnetic field. Credit/Copyright: Peter Reid, The University of EdinburghLink to associated news item
