Ten facts about snowflakes
1. The word snowflake is often used to refer to what’s technically a snow crystal. Snowflakes can be made up of hundreds, or even thousands, of individual snow crystals.
2. Snow crystals grow fastest in temperatures around 5 °F, but no one knows why.
3. Almost all snowflakes are six-sided, or hexagonally symmetrical.
4. It’s virtually impossible for two naturally occurring snowflakes to be exactly alike.
5. The shape of a snowflake is determined by atmospheric factors such as temperature and humidity.
6. Sticking out your tongue to catch a few falling flakes is fine, but eating snow off the ground is a bad idea, as it may contain pathogenic substances.
7. In the 19th century, an American named Wilson Bentley developed a method for photographing snowflakes in great detail with the help of a microscope. He took more than 5,000 photos during his lifetime, many of which are now on display in various museums.
8. In 1951 the International Commission on Snow and Ice devised a system for categorizing snowflakes according to their shape. The seven main shapes according to this classification are plates, stellar crystals, columns, needles, spatial dendrites, capped columns, and irregular forms.
9. Individual snowflakes form when water vapor freezes around a tiny airborne particle (e.g. dust or pollen).
10. The largest individual snow crystal ever photographed was 10 millimeters (a little over 3/8 inch) wide.