How Snow Forms

• Whether it is made in the clouds of the sky or in a laboratory, the basic structure of snow is always the same: Cold water condenses around particles of dust, salt or sand in the air. If the temperature is cold enough, that water freezes into an ice crystal nucleus around which more water condenses and freezes. Soon, the tiny ice formation grows large enough to become a snowflake, which then falls to the ground as precipitation. Artificial snow simply uses dry ice (solid carbon dioxide) as a freezing agent to speed up the process.
  
  

Creating Artificial Snow

• In the 1940s, a scientist named Vincent Schaefer invented artificial snow in a laboratory at the Mount Washington Observatory in New Hampshire. He was only attempting to create an artificial cloud inside a closed chamber, but he realized the temperature was too warm for a cloud to form. He used dry ice inside the chamber to lower the temperature, but water vapor began to appear around the dry ice. The dry ice crystals themselves acted as nuclei for snowflakes to form, eliminating the need to wait for water to condense around a particle of dust, salt or sand.
  
  

Implementing Artificial Snow

• In 1946, Shaefer took his experiment into the field, thus creating the modern method of producing artificial snow on a mass scale. In essence, he dumped dry ice into natural clouds already hanging over Mount Greylock. The dry ice crystals acted in much the same way they had in the laboratory, producing artificial snowflakes in the clouds, which then fell to the ground.