The Solar Cycle

You probably already know that the Sun is really a big ball of gases.  It also has a very strong magnetic field.  You can think of the Sun as having a large bar magnet going straight through its center.  Imaginary lines called magnetic field lines are created by this magnet, and they loop around the Sun, starting from the north end of the magnet and ending at the south end.  They make up the Sun's magnetic field.  You can see this in the picture below.

Imagine that the bar magnet turns inside the Sun to create the solar cycle.  The magnet flips, but it takes it 11 years to do so.  The number of sunspots changes during this time, so that during solar maximum, there are lots of sunspots and during solar minimum, there are few sunspots.  A full solar cycle takes 22 years.  (Remember that there isn't a real magnet in the Sun, but its the best way to understand its magnetic field.)