Materials required: paper, markers or colored pencils or crayons, maybe watercolor paints, pictures of northern lights (can be obtained off the internet very nicely!), and a magnet and something it will attract.
Preparation time is about 10 minutes.
This activity is appropriate for all ages, although the younger kids may not get the magnetic field conneciton.
At least a half hour is needed for this activity, and it can take an entire afternoon visit.

    To begin, discuss the earth's magnetic field, in simple terms, and show the magnet and how it attracts say a paper clip. Then discuss how the air is made of gas, and that gas makes colors near the poles because of the magnetic attraction. (You can find really great info. on auroras including the specific colors that different gases make by doing a quick search in yahoo!.) Then, show some pictures.
    Next, tell the kids they are going to make their own northern lights! Pass out paper and coloring things and help them be creative!