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KIDS: Our World!
EVAN: Hold on Globey, just one more cut should do it.
Here we go... and Ta Dah!!!
It’s a snowflake!! Snowflakes are a beautiful part of our
world and they also very fascinating.
One place that’s no stranger to snow is Lake Placid, New York.
Once a year NASA Goddard Space Flight Center co hosts a
program called the History of Winter. It’s there that
students and teachers can study...
You guessed it, snow! Let’s visit some experts there and
find out why NASA has such an interest in the
science of snow. TIM MCCOLLUM: The idea was that
the students would become engaged in scientific research.
It wouldn’t be a word problem in a book. It would be
something that they could literally be outside looking at
something that they could analyze. Something they could
study. They’d have to dress, they’d have to prepare for the
elements. When students look at a snowflake, because of what
they’ve learned and what we’ve learned about the structure and
everything that goes into forming a snowflake as it’s
falling from the sky and the different changes that it goes
through. That a snowflake represents a history of what
happened to that snowflake on the way down.
EVAN: So if I stare at a snowflake and find out exactly
what it’s been through, you could call me a snow detective!
But what causes snow and where does it come from?
TIM: Snow is not rain that freezes on the way down.
That’s how we end up with sleet. Snow is basically
something that forms directly from water vapor in the air.
PETE WASILEWSKI: The cloud conditions first of all have to
be cold enough and then you need a little bit of
dust to nucleate a little tiny ice crystal.
TIM: Then as those snowflakes fall, as they pass through
different layers of temperature, and different
percentages of humidity, and as the wind blows them around and
as they bump into other snowflakes on their way down-
all of those factors go into the actual shape and you wind
up getting more of these star like pattern that we’re
familiar with. Looking at a snowflake really does tell so
much about its history as it’s falling.
EVAN: So if no two snowflakes are alike, then what are the
different types of snowflakes? TIM: That is what the students
are most interested in. And they see there is such a wide
variety. Most snowflakes, or many snowflakes don’t look at
all like what most people think in terms of a snowflake.
Some of them look like bullets. They literally have a pointy
end. And when you walk into a driving snowstorm, and it’s
hitting your face and it kind of stings and you look at the
shape of those crystals, well that makes sense. Or they’ll
look like hourglasses, we call hollow columns. Or capped
columns which almost look like spools of thread. And there’s
such a wide variety, but they’re still all ice crystals.
EVAN: At the “History of Winter” event, teachers and
students look at the shape of snowflakes then record the
weather conditions. They’re building a huge database of
crystals and weather conditions to discover connections.
But why do all this research?
TIM: As much as we’ve learned about the Earth’s system and
what a complex system it is, the more we realize there’s so
much we don’t’ know. And as we learn more about something as
simple as a snowflake, and the conditions it takes to form a
snowflake, it helps all of us have a better understanding of
the way the atmosphere works. Hopefully we will learn more
about the conditions that change our climate.
EVAN: Who knew you could learn so much from something as small
as a snowflake? I think I’m going outside and be a snow
detective too. Come on Globey!
You can be a snow detective too, just go to the History of
Winter website and download the forms.
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KIDS: Our World!