One of the most beautiful objects formed by nature is a snowflake. It would take most of us a long time to design shape as beautiful as a single snowflake. Yet in an ordinary snowstorm, billions upon billions of snowflakes fall to the earth and no two are exactly alike!
Snow, as you may know, is just frozen water. In fact, you may ask why snow is white if it’s just frozen water. Shouldn’t it be colorless? The white appearance is caused by the fact that the many surfaces in all the ice crystals that make up a snowflake reflect light, and we, therefore, see it as white.
When water freezes, it forms crystals. This simply means that the molecules come together in a special arrangement or geometrical form, and we call this a crystal. It so happens that a water molecule consists of three units-two atoms of hydrogen and one of oxygen. So when it crystallizes, it has to form either three-sided or six-sided figures.
The water that freezes to form snow is in the form of water vapor in the atmosphere. As it freezes, the crystals that form are so small that they are invisible. But when snow is being formed, these crystals are carried up and down in the atmosphere by air currents.
As they move up and down, a group of crystals begins to collect around something. It might be around a speck of dust, or around a tiny drop of water. The group of crystals gets larger and larger so that soon there might be hundreds of crystals gathered around one nucleus.
When such a group becomes large enough, it begins to float down toward the ground and we call it a snowflake. Some snowflakes are more than an inch in diameter! The size of a snowflake depends on the temperature. The colder the temperature, the smaller the snowflakes that will form.
Did you know that in many parts of the world snow has fallen that has been blue, green, red, and even black? This is due to the presence of certain fungi or dust in the air around which the snowflakes formed.
Read: What Is Dew?