Snowflakes

Ice has usually started to fall from the sky by mid-November in central
Maine, so brace yourself.
Snowflakes are intricate crystals of ice which form from when water
vapor in the clouds condenses directly into ice. All snowflakes are based
on the same six-armed pattern, but the chances of finding two identical
snowflakes is extremely small. Though the basic formula is the same, the
possible shapes are almost infinite.
In order for snow crystals to form, the top of the cloud must be at least 32
degrees Fahrenheit. However, the crystals do not actually start to form
until about 14 degrees. The complexity of a snow crystal also depends on
the humidity of a cloud. The lower the humidity, the simpler the shape is,
and the higher the humidity is, the more complex they are.
Snowflakes are not actually white. They are clear. The reason people
think they are white is because when you see a snowbank, the light
passes through the crystals. All the colors are evenly distributed
throughout the crystals, combining to give the mirage of a white color.
Snowflakes also help heat space itself! In the north and south poles, the
ice is very reflective, and when the sun's heat hits it, it is reflected back
into space.
One cubic foot of snow can contain 10 million flakes. If all the snow
that's ever fallen were accumulated at one time, it would be 50 miles deep
over the entire Earth.
Welcome to winter.
- By Jack Wilde and Dana Wilde

Maine Nature Notes