Richard. Stucke, Age 15, Of St. Louis, Mo., for his question:

How high are the Van Allen belts?

These fantastic belts of radiation were unsuspected until the IGY scientists began their probing of the realms beyond the earth's atmosphere. The two belts span the globe like monster doughnuts, and experts can give us only a rough estimate of their size and scope.

We naturally know more of the inner belt, which is closer to the surface of our planet. It begins at about 500 miles above the earth and reaches to a height of some 2500 miles. The outer belt begins at some point higher above the globe and extends outward to 10,000 miles, perhaps even farther.