Christine Scott, Age 13, Of Stasca, Ill., for her question:

What is heat lightning?

When a storm is overhead we see the lightning as it rips in ragged lines through the glowering sky. In a second, or at most after a few seconds, the flash is followed by a roar of thunder. But we see heat lightning from a distance. It glimmers through the dark clouds like a wide sheet of light, and as a rule the flash is not followed by a peal of thunder.

The heat lightning that shimmers near the horizon is the reflection of forked or zig zag flashes of lightning in a distant storm cloud. Sound, even the pealing sound of thunder, peters out in a few miles. The thunder that erupts with the distant heat lightning fades away before it reaches us.