Richard Shamrell, age 11, of Portland. Ore... For his question:

Why are the polar regions so cold?

The earth, remember, is a round ball, and the poles are the two ends of the . Axis around which it rotates. Meantime, it orbits the sun, and the axis is tilted at an angle to the path of its orbit. The sun strikes the surface through the atmosphere. At the equator, the rays come straight down, but the sunshine that strikes the polar areas slants through a greater distance of atmosphere, And the

Shorter., more direct rays at the equator are much hotter than the long.. Sloping rays which strike the poles.

A snowy surface radiates far more heat back into space than a region of water or forest. A plowed field takes three times more heat from the energy of the sun than does a snowfield. The polar regions, then, get less heat from the sun, and they must also send more of the heat they get back into space.