Brad Parker, age 10, of Cherokee, North Carolina, for his question:

What causes sunspots on the sun?

For a long time astronomers thought that sunspots were gargantuan magnetic storms. They do not resemble our weathery storms but on a super scale they do resemble our ordinary magnets. Magnetism is a mysterious cosmic force that obeys somewhat the same behavior patterns in the stupendous sun and in a tiny toy magnet. A small magnet is surrounded by a force field of invisible lines that loop between the opposite poles. Astronomers nova see similar patterns in the eruption of sunspots.

Compared with the sun, the magnetic field of the solid earth is fairly steady. The ionized solar gases are mobile, which creates a mish mash of many magnetic pockets. Force lines erupt from far below, loop up and descend. At the points where a loop leaves and returns to the surface the temperature drops, perhaps 2,000 degrees. Sunspots occur at these two surface points. Meantime the enormous arch of magnetic force above the surface disrupts the solar atmosphere. The temperature rises, there are solar flares and streams of sunspot energies pour out into space.