Ice crystals. Photo: Rowan Butler

Just as each person is a unique compilation of many millions of parts, so is each snowflake. However, there are seven basic snowflake shapes, with each snowflake a variation on one of these. Some are quite different from the 'traditional' pinwheel shape. Snowflakes that fall on Antarctica contain information about the atmospheric conditions at the time of their formation - in the dust, chemicals and gas trapped in the ice. This means that the Antarctic ice sheet, which has been built up from snowfalls over hundreds of thousands of years, is like a museum holding long-term climatic and environmental information.

• Students can create their own snowflake shapes to decorate the classroom by folding a piece of paper four or six times and then cutting designs in it.
• View the display of amazing photomicrographs of snowflakes by Wilson Bentley.
• And visit snow crystals and snowflakes for all you ever wanted to know about them, including wonderful galleries of snowflake photographs and a short course in snow crystal physics.
• An activity for those very few Australian students who live in a region that experiences snowfall:
  Take a sheet of black paper outside, allowing it to cool to air temperature. Then place it on the ground and collect snowflakes. Examine the flakes through a magnifying glass before they melt. Try to find two that are the same. Then try to find all seven basic snowflake shapes. When you are back inside, draw them.