Exploring The Last Green Valley: How to catch a snowflake

Silently, like thoughts that come and go, the snowflakes fall, each one a gem.” – William Hamilton Gibson

Wintertime tends to bring out the kid in me, or rather brings back so many snowy winter memories from long ago that remind me of when I was young.

One of my favorite wintertime memories came back to me last month when we had our first plowable snow. That storm had what I consider to be perfect snow conditions – dry and very cold air, light winds and gently falling snow.

I had ventured out to start the tractor and begin the seasonal task of keeping the driveway clear of snow and ice.

As I unlocked the barn door, I noticed a few snowflakes on my arm. I fumbled for my glasses to get a better look and there they were – perfect hexagon-shaped snowflakes.

As my warm breath melted them away, I remembered the time my mother taught me how to catch snowflakes.

There are a few ways you can catch snowflakes. Like most kids, my first attempts were with mouth agape, tongue stuck out and face to the clouds.

Squinting into the heavy falling snow, I would stumble around and leap like a frog snatching flies from the sky. I learned pretty quickly that snowflakes don’t really taste very good.

It was during one of those glorious snow days when school was cancelled that my mother decided to show us how to actually catch a snowflake – and learn something at the same time.

She sent us outside to shovel the driveway but we knew something was up when she said she would be joining us later.

She put a large piece of black construction paper in the freezer and about an hour later she put on her coat, hat and gloves, took the now-frozen paper from the freezer, grabbed a magnifying glass from her sewing basket, and joined us outside.

She called us around and then held the construction paper flat to the sky. We watched for about 15 seconds as light snowflakes covered the surface of the frozen paper.

Carefully holding the paper flat, she walked under the covered carport to get out of the falling snow. We gathered around the paper and she handed each of us the magnifying glass to behold the winter secrets and wonder of beautifully shaped hexagon snowflakes.

“Remember not to breathe on them and don’t get too close or they’ll melt” she said as we looked at the snowflakes, each frozen crystal different and distinct against the black paper. She told us that no two are alike and each is one of a kind. We tried in vain to find two that matched.

Before writing today’s column and providing a nice tip (thanks mom) about how to catch and look at snowflakes, I did a bit of research.

Here is some information I found from the Geology and Earth Science News and Information website, geology.com.

“A snowflake begins when a tiny dust or pollen particle comes into contact with water vapor high in Earth’s atmosphere. The water vapor coats the tiny particle and freezes into a tiny crystal of ice. This tiny crystal will be the ‘seed’ from which a snowflake will grow.

“The molecules of water that form each tiny ice crystal naturally arrange themselves into a hexagonal (six-sided) structure. The result will be a snowflake with six sides or six arms. Ice crystals are ‘minerals’ because they are naturally occurring solids with a definite chemical composition and an ordered internal structure.

“The newly-formed ice crystal (snowflake) is heavier than the surrounding air and it begins falling. As it falls towards Earth through humid air, more water vapor freezes onto the surface of the tiny crystal. This freezing process is very systematic. The water molecules of the vapor arrange themselves so that the hexagonal crystal structure of ice is repeated. The snowflake grows larger and larger as it falls, enlarging the hexagonal pattern.”

My mother said that no two snowflakes are alike, so I did some research on that question and here’s what I found from a 2007 article by John Roach for National Geographic News.

Scientists believe the chance that any two flakes are exactly alike is virtually zero.

Why?

The answer, according to New York-based writer Mariana Gosnell, is in the way snowflakes form and fall to Earth. The process is detailed in her book “Ice: the Nature, the History, and the Uses of an Astonishing Substance.”

A snowflake begins to form when water vapor condenses around a speck of dust high in the clouds – up to six miles up – and then crystallizes.

How the water vapor keeps on condensing and where the snowflake falls “is what determines the way the snowflake, or snow crystal, looks when it lands on your coat sleeve,” Gosnell said. “It is extremely sensitive to microenvironments.”

Between 27 and 32 degrees, for example, crystals take the form of six-sided plates. Below that, needles form. A few degrees colder yields hollow columns; chillier yet, fernlike stars.

If temperatures drop further, plates and columns form again.

These crystals – usually six-sided because of the way hydrogen atoms bond with oxygen to create water – may eventually sprout branches, which continue to grow as additional water molecules cluster on the crystals’ surfaces.

Humidity also plays a role. Drier air encourages growth across flat surfaces, for example, while higher humidity encourages growth at the tips, edges, and corners. More water vapor also leads to faster-growing and more intricate crystals.

 To further complicate matters, as a crystal falls, frost could freeze to it or another passing flake could break off some of the crystal’s branches. Even the approach of a water drop can influence how a branch grows.

“By the time it reaches Earth, it may not have any resemblance to the very simple crystal that it started out as six miles up,” Gosnell said.

That may be more information than you were looking for regarding snowflakes, but is seems pretty clear that there is little or no chance of two snowflakes being exactly alike.

Next time we have snow I hope you’ll go out to catch snowflakes just like we did with my mom many years ago.

Remember to put a piece of dark-colored construction paper in the freezer first, as this important step helps keep the snowflakes from melting when they land on the paper.

If conditions are just right, you’ll catch perfectly-shaped snowflakes. Most importantly, you’ll create memories to last a lifetime.

I hope you enjoy the winter season. It has just begun!

Bill Reid is chief ranger of The Last Green Valley National Heritage Corridor and has lived in the region for 35 years. He can be reached at bill@tlgv.org.

The Norwich Bulletin is granted first serial rights and associated electronic rights to publish the preceding article. The Last Green Valley, Inc. retains all other rights to the work.