Linda McKanna, age 14, of Mt. Horeb, Wisconsin, for her question:

How big are the earth’s magnetic poles?

Each of the earth's magnetic poles is many miles from the geographic North and South Poles. No one can draw a definite line around either of these magnetic poles and say that it extends so far and no further. The magnetic force seems to come from a large, indefinite oval area, perhaps a thousand miles in length.

What's more, the earth's magnetic poles cannot be depended upon to stay put. Experts are constantly checking the shifting of the North Magnetic Pole because it is so vital to navigation.

The latest studies suggest that the earth has more than her two magnetic poles. Several vast magnetic areas seem to occur in both the northern and southern hemispheres. The compass needle, we are now told, is attracted towards large magnetic polar areas wherever these areas occur in the northern and southern hemispheres.