Media Contributed by Rick
Michael Faraday cropped
Earth's magnetic field This stereoscopic visualization shows a simple model of the Earth's magnetic field. The magnetic field partially shields the Earth from harmful charged particles emanating from the sun. The field is stretched back away from Sun by solar particle and radiation pressures. The geomagnetic field is generated (and regenerated) as the conducting fluid of the Earth's mantle and core, driven by convection of heat from deeper in the interior, induces an electromotive force (EMF) with the existing magnetic field. This process is very similar to the way an electric generator generates a voltage. That voltage then drives an induced current in the conducting fluid, which also produces a magnetic field. This feedback mechanism helps maintain the field, continuously converting the thermal energy in the Earth into magnetic field energy. The magnetic field line data used in this visualization is from a simplified static model. More complex models deform the magnetic field over time as the Earth rotates and experiences solar pressures. Many of the field lines (particulary near the back, away from the Sun) should eventually connect (north and south poles), but the 3d model used in this visualization does not extend far enough to see this. The day/night terminator is aligned with the Sun and is therefore aligned with the magnetic field too.
