Magentic Field     The earth is like a giant bar magnet, having a north and south end. It has a magnetic force which is called a magnetosphere that travels all around the planet and more than 40,000 miles into space in some places. The magnetic field are the lines in the picture that are going through the earth and expand from the planet. Charge particles like electrons and protons are constantly in motion following the magnetic field lines. Earth's magnetic field does not line up directly on the south and north pole, but is tilted about 11 degrees. courtesy of http://sprg.ssl.berkeley.edu/PolarCusp/mission/ On the side of the planet facing the sun, the solar wind pushes on the magnetic field, causing it to squash, while the other side can still stretch out. So our magnetic field is slightly altered. courtesy of the European Space Agency (ESA)