Nathan Snyder, age 15 , of Gadsden, Ala., for his question:

WHAT ARE SUNSPOTS?

Sometimes a strong loop of magnetic lines of force extend through the sun's surface. Where the lines cross through the surface, they lower the temperature of the gas. This gas does not shine so brightly as the surrounding gas, and it appears as a dark patch on the sun. These dark patches are called "sunspots."

Because a magnetic loop both leaves and re enters the surface, two sunspots are associated with the loop. After a few days, a magnetic loop may break up into several thinner loops. Each of these loops crosses the surface at a different place. The original sunspot breaks up into several sunspots that form a sunspot group.

The number of visible sunspots varies from about five to approximately 100. It takes about 11 years for the number to increase from the minimum to the maximum. This 11 year period is called the sunspot cycle.

Astronomers do not know why sunspot cycles take place.

A typical sunspot may have a diameter of about 20,000 miles.