Did You Know THIS About Snow?

The snow has begun to fly here in New England.  I am reminded of cold, calm nights watching large flakes build up in the trees, as well as blustery, cold, dreary days when tiny snow crystals fly sideways and sting my face.

You may not know it, but there is a scientific difference between snow crystals and snowflakes.  Most people are familiar with the classic, six-pointed shape of snow.  This image is immortalized in holiday decorations and thick scarfs.  What most people don’t realize is that image is of a snow crystal, not a snow flake. 

A snow crystal is formed when a tiny drop of water forms and freezes.  As more molecules of water impact the original frozen drop, the snow crystal begins to form and grow.  The classic six-pointed snow crystal only forms when the temperature of the air around it is approximately -15°C.  This temperature allows the snow crystal to grow outwards, forming into star-shapes with six arms, or perhaps a plate form with six sides (because of the molecular structure of water, all snow crystals have six sides).

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You may have also heard that no two snow crystals are alike.  This may not be entirely true, but it is true that there are an enormous amount of shapes that snow crystals can take.  From plates and stars to bullet and needle shapes, different conditions in the atmosphere can produce extraordinarily different snow crystals.

So, you may be asking yourself, what is a snowflake?  Quite simply, a snowflake is a group of crystals that have gotten stuck together.  When we see those big, wet clumps of crystals falling, we are looking at snowflakes.


Snow Crystal Identification

Materials:

  • Hand lens / Magnifying Glass
  • Snow Crystal ID card

Instructions:

  • Head outside when the snow is falling.
  • Allow a snow crystal to fall on your arm.
  • Use the hand lens to examine the snow crystal.  What shape is it?  Is it a star or plate, or perhaps a needle?
  • Use the ID card to find the type of snow crystals you found.  You can now match the type of crystal to the atmospheric conditions in which it was made!
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Figure 1: By Charles Schmitt - Own work, CC BY-SA 4.0
Figure 2: Kenneth Libbrecht CC BY-NC-SA