All magnetic objects produce invisible lines of force, extending between the poles of the object. Note that I said the lines were INVISIBLE. An easy way to see these invisible field lines is to spread iron filings on a sheet of paper and place a bar magnetic under the paper. The iron filings will arrange themselves around the magnet and along the magnetic field lines.

The earth acts like a very large magnet. Just as a bar magnet produces field lines, so too does Earth. And, just as the magnetic field of a bar magnet pushes iron filings into a pattern, so too does the Earth's magnetic field. That is why a compass always points North. You can visualize the Earth's invisible magnetic field lines by thinking of the Earth as having a bar magnet running from the North to South poles.

Magnetic fields also push things that have been charged by static electricity. Charged objects are objects that act like your hair when it sticks to the brush after you brush it. If these charged objects are moving in the magnetic field, they will be pushed by that field.

In the case of outer space, the charged objects pushed by the Earth's magnetic field are ions and electrons. You may remember that ions are atoms that have had one or more electrons knocked off of them.