We have all heard that no two snowflakes are alike, but few of us could have guessed that there are about 35 separate distinct classifications of snowflakes, each having their own limitless variations.
Even more impressive then this knowledge is the fact that there are people out there in the world of snow science that discovered this fact, and have actually put these beautiful crystals into categories. However, through the years, the snowflake has remained a source of mystery and wonder, and, is still being studied.
In 1611, Johannes Kepler published a paper on the snowflake, asking why it was six sided.
In 1931, an American, William Bentley actually photographed more than 5000 snow crystals.
In 1932, a nuclear physicist, Ukichiro Nakaya, not having access to nuclear facilities on the North Island of Japan, began to study and photograph snowflakes, and, by 1954, he published a book on snow crystals. He was actually the first person to complete a scientific study of snow crystals, both natural and artificial.
In 1966, two meteorologists, C. Magono and C.W. Less created a classification of snow crystal t ypes. There are 80 types in their table.
According to the international standards of snow crystals, there are seven basic kinds of snow crystals.
1. What we usually think of as the normal, beautifully. intricate snowflake is usually formed when the temperature is above 28 degrees. This is called a star, or a stellar crystal and forms when the moisture in the air is high.
2. When the moisture decreases in the atmosphere, the stars become less and less ornate, flatten down, and become plates.
3. When the temperature goes below 28 degrees, and the moisture is high, needles are formed. These are those sharp, stinging, snow falls that we are familiar with in some some blizzard conditions.
4. If the temperature is below 28 degrees, and the moisture drops, the needles turn into cylinders, or columns.
5. Capped columns occur when a cylinder or column enters an area of the atmosphere where plates are formed. Plates form over each end causing the crystal to look like a spool.
6. Dendrites are considered to be the most beautiful snowflakes, and the most elaborate. They form at about 5 degrees in areas with high moisture content.
7. Irregular forms.
Some other forms include, bullet rosettes, triangular shaped crystals, and twelve sided flakes. The variations and patterns in all these types of snow crystals are limitless.
http://www.its.caltech.edu/~atomic/snowcrystals/class/class.htm
http://www.its.caltech.edu/~atomic/snowcrystals/earlyobs/earlyobs.htm
