Video: Explaining Earth's magnetic fieldNovember 25, 2013 in Astronomy & Space / Space Exploration
An introduction to Earth's magnetic field: what it is, where it comes from and what it's used for.
A documentary video from the European Space Agency:
Provided by European Space Agency
"Video: Explaining Earth's magnetic field" November 25, 2013 http://phys.org/news/2013-11-video-earth-magnetic-field.html