There Is a Lot More to Snow Than Just Six Sides

Snow can make life difficult for humans. But it helps protect plants during winter. And it provides much of the water we use. Transcript of radio broadcast:

04 January 2010

VOICE ONE:

This is SCIENCE IN THE NEWS in VOA Special English. I'm Shirley Griffith.

VOICE TWO:

And I'm Steve Ember. Today, we tell you everything you ever wanted to know about snow.

(MUSIC)

VOICE ONE:

Justin Snow of the Indianapolis Colts stands in a snowstorm during a National Football League game on SundayWinter weather has returned to northern areas of the world. In much of the United States, winter means the return of snow. Snow is a subject of great interest to weather experts. Experts sometimes have difficulty estimating where, when or how much snow will fall. One reason is that heavy amounts of snow fall in surprisingly small areas. Another reason is that a small change in temperature can mean the difference between snow and rain.

VOICE TWO:

Snow is a form of frozen water. It contains many groups of tiny ice particles called snow crystals. These crystals grow from water particles in cold clouds. They usually grow around a piece of dust.

All snow crystals have six sides, but they grow in different shapes. The shape depends mainly on the temperature and water levels in the air. Snow crystals grow in one of two designs -- platelike and columnar. Platelike crystals are flat. They form when the air temperature is about fifteen degrees below zero Celsius. Columnar snow crystals look like sticks of ice. They form when the temperature is about five degrees below zero.