When droplets of water in a cloud come into contact with tiny particles specks of dust, tiny pollutants, minuscule pieces of vegetation that have been carried up by wind they freeze into ice crystals and begin to fall. Traveling through a cloud, these ice crystals may pass by air containing super cooled droplets, which is water that is below the freezing point but remains a liquid. These droplets attach themselves to the sides of the ice crystals, where they freeze, forming snowflakes. When water freezes it forms flat, six-sided ice crystals (though the way the crystals clump together accounts for a number of different snowflake shapes). As these crystals increase in size, they fall to Earth. If the cloud from which they fall is low in the sky, the snowflakes are likely to stay frozen and will fall to the ground as snow. Although itís hard to imagine, each snowflake does seem to be unique, with a shape or size unlike any other. One American who enjoyed studying the weather, W. A. Bentley, spent nearly 50 years of his life making microphotographs of snowflakes to see if this was true. He never found two snowflakes that were alike.