How Do Snowflakes Form?
Having just passed the Winter Solstice, I’ve been thinking a lot about the best and worst part of winter: snow! Snow can be beautiful, and it can be a pain in the butt. Snowflakes are especially cool - but how do they form? Why are they shaped like that? Why is each snowflake unique?
We know snow happens in winter, so we know it needs to be cold. Water won’t just freeze anywhere, though. First, it has to condense from water vapor to liquid water, and in order to do that, it needs a small particle to condense on. This very, very cold water droplet then freezes. Due to the molecular structure of water, the ice crystal that forms is always six-sided.
From there, water continues to freeze onto the ice crystal, especially on its six facets, forming a six-sided or six-branched shape. As the ice crystal falls to Earth, the environmental conditions along its journey and the shape of the crystal determine the way the ice crystal develops into a unique (and beautiful) snowflake!
Since each ice crystal has a slightly different journey down to Earth, but all of them have six facets, each ice crystal will develop into a different six-sided or six-branched snowflake.
I learned some tricks about how to catch and observe snowflakes from a children’s book I recently read with my daughter (and also learned a lot more about how they form!) (Amazon affiliate link):
Find a piece of dark cardboard and leave it outside for at least 10 minutes, so it’ll get cold and the snowflakes won’t immediately melt after landing on it.
Let some snowflakes fall onto the cardboard.
Grab a magnifying glass (or phone with a camera that zooms in) and enjoy!
Happy winter!
Sources:
https://www.noaa.gov/stories/how-do-snowflakes-form-science-behind-snow#:~:text=A%3A%20A%20snowflake%20begins%20to,six%20arms%20of%20the%20snowflake.
https://scijinks.gov/snowflakes/