John Phelps, age 6, of Wichita, Kansas, for his question:

What makes the halo around the moon?

Once in a great while, the pale moon is centered in a ghostly glow. Sometimes a misty veil seems to flow out from the edges of the moon. At other times the ghostly light is a wide circle. Once in a while two great circles appear with the moon a mere dot on the center. Usually these halos are pale light, but at times they are tinted with rainbow colors.

These halo effects do not spring from the moon itself. They are caused by particles, usually fragments of ice in our atmosphere. Moonlight, on its way down through the atmosphere, is bent, or refracted by these icy fragments. The halos, then, are a beautiful blend of moonlight and air.

Old timers say that a halo around the moon is a sign of rain. They may be right. For the lovely halos occur only when there is plenty of moisture, ice or vapor, in the air. And rain is formed from an abundance of vapor in the air.