A permanent magnet has a magnetic field because of how the electrons are traveling, but how does a whole planet have a magnetic field? Do the electrons travel all the way to the atmosphere and come back?

gmackematix

Magnetism is a force at a distance caused by moving charges. The Earth's magnetic field is thought to be a result of the flow of electrons within its core but why there should be any alignment in a hot molten fluid is still a mystery to scientists. http://www.geocities.com/SunsetStrip/Palms/8423/earth.htm Jan 24 05, 8:51 PM

peasypod

TAW, the earth's magnetic field is generated from the core not the atmosphere (the Van Allen belts etc are caused by the earth's magnetic field not vice versa, although the magnetic field is strongly effected by the solar wind). A permanent magnet is globally magnetic due to allignment of locally magnetic domains. As gmack has said, how the domains are alligned in the earth's fluid core is a non-trivial problem. The electrons in the Van Allen belts circulate along field lines until they hit the mirror points (the earth's magnetic field produces a magnetic bottle effect) corresponding to the aurora australis and borealis. Jan 25 05, 5:13 AM