Rodney Lazar, age 10, of Gary, Indiana, for his question:

Where does snow come from?

Some people think that the snow falls down like the rain from the clouds on high. Well, sometimes it does    but not always. True, it rarely if ever falls down from a clear blue sky. But it does not fall from a single dark cloud like those that shed summer showers. As a rule, it falls when a mass of filmy pale grey cloudy material fills the whole sky. Snow is formed from moisture in the air    so are rain and hail and all other forms of weathery wetness.

The air above is usually colder than the ground below. When it gets cold enough, its tiny particles of moisture become tiny crystals of ice. When weather conditions are just right, millions of these tiny crystals may team together and arrange themselves in feathery snowflakes. Often this starts several miles up in the sky and the flakes grow bigger as they flutter down. But sometimes snowflakes can form from the moisture in misty grey clouds not far above the ground. In any case, all snow forms from tiny crystals of frozen moisture in the atmosphere