Compasses and Magnetic North

What is a compass? Why does the needle on a compass point to the North Pole? Learn more about the magnetism of the Earth and compasses:

http://gsc.nrcan.gc.ca/geomag/nmp/northpole_e.php

http://www.howstuffworks.com/compass.htm

http://science.nasa.gov/headlines/y2003/29dec_magneticfield.htm

http://hyperphysics.phy-astr.gsu.edu/Hbase/magnetic/MagEarth.htmlÂ