Snowflakes are not only a lovely, sparkly symbol of the holiday season, they're also scientifically extraordinary. The delicate, crystalline substance forms only when atmospheric conditions are exactly right, turning water vapor into beautiful, unique ice crystals. But because they melt so quickly, it's not always easy to get a glimpse of their majesty up close.

Now you can! The Griffin Museum of Science and Industry is where science sparkles with this season's Christmas Around the World and Holidays of Light exhibits highlighting the amazing science of snow, illuminated with stunning photography by Ken Libbrecht, physics professor from the California Institute of Technology. These up-close-and-personal images of individual snowflakes remind us of the wonders behind the formation of snowflakes, the factors influencing snowfall, and the vital role that snow plays in our environment.

The formation of snowflakes

Though it is not always recognizable with the naked eye, snowflakes are intricate ice crystals that form through crystallization. Water vapor transforms into solid ice crystals when the temperature drops below freezing, 32°F. The process begins when water vapor condenses onto tiny particles, such as dust or salt in the atmosphere. These particles act as nuclei, providing a surface for water molecules to adhere to.

As more water vapor freezes onto these nuclei, the ice crystals grow in size-and complexity. The shape of a snowflake depends on a range of factors including temperature, humidity, and the path the crystal takes through the atmosphere.

The factors influencing snowfall

While temperature is key to the crystallization process, it is not the only thing that impacts the formation of snow; several factors influence the type and amount of snowfall in a particular region:

• Humidity: Higher humidity levels create better conditions for snowfall. When the air is moist, there is more water vapor available for crystallization, leading to more substantial snowfall.
• Atmospheric Conditions: Calm air masses with gentle upward motion tend to produce large, fluffy snowflakes. Turbulent or rapidly rising air can lead to smaller, less uniform snowflakes.
• Altitude: Regions at higher altitudes tend to receive more snowfall than lowland areas at the same latitude. Mountains and elevated plateaus often see significant snowfall during the winter months.

Not all snowflakes are alike

Some snowflakes are made of a single ice crystal while other, more elaborate snowflakes are made of as many as 200 ice crystals fused together. The most iconic snowflake has a hexagonal or six-sided structure, and its intricate pattern results from the unique alignment of water molecules as they freeze.

Ken Libbrecht suggests that not all snowflakes look like traditional six-pointed stars. Many do, but there are also quite a few odd-looking crystals falling from the winter clouds—Libbrecht says you will see them if you go out looking. Plus, you can visit Griffin MSI to see his amazing snowflake photography.

The role of snow in the environment

Snow is not just a source of beauty; it plays crucial roles in the environment and our daily lives. For example, snow acts as a natural insulator, protecting the ground and the organisms beneath it from extreme cold temperatures.

Snowpack in mountainous regions serves as a vital source of freshwater for many communities. As the snow melts in the spring and early summer, it feeds into rivers and reservoirs, providing water for drinking.

And of course, snow can be fun! Skiing, snowboarding, ice skating, and other winter sports would not be possible without snow. Next time you head down a slope or look up at a snowy sky, consider the magnificent complexity happening to create those beautiful, one-of-a-kind snowflakes.