If you dream of a frosty landscape (or your kids just can't get enough of Frozen II), here are some fun ways to learn more about snow and even create a crystal snowflake.
The December holiday season means many of us have kids to entertain while they're out of school. For those of us in the northern hemisphere, where December also means cold temperatures, we talked on a previous episode about fun science experiments to do like freezing bubbles, deflating balloons without letting the air out, and making maple syrup candy. But you can also do some fun science experiments with the snow itself, including making your own. And that's a bonus if your kids can’t get enough of Frozen II.
The study of snow
Scientists study snow and the role it plays in our ecosystems. Ever heard of watermelon snow? According to the National Snow and Ice Data Center, a form of cryophilic (that means cold-loving), freshwater algae found in the Alps gives the snow it lives in a pinkish hue. The Taylor Glacier in Antarctica is home to Blood Falls, so named for its blood-red snow. Saltwater from an ancient reservoir underneath the glacier seeps out, and when it hits the air, the iron-rich water oxidizes, giving it a deep red color.
And even though it doesn’t snow everywhere on our planet, snow contains information about global climate conditions. For example, researchers dig deep snow pits in places like Greenland and Antarctica to observe old layers of snow and ice that can tell us about the amount of carbon dioxide that was in the atmosphere when that snow was closer to the surface. Scientists also study snow to understand how to predict snowstorms better
How to Catch Snowflakes
For something so small, snowflakes have incredibly intricate shapes that always have six sides because the oxygen and hydrogen atoms that make up the water molecules in snow fit together most efficiently in a hexagonal pattern. (Keep that in mind if you want to keep your cut-out paper snowflakes scientifically accurate!)
To get a better look at this detail, you can try catching a few snowflakes to investigate them up close.
Snowflakes have incredibly intricate shapes that always have six sides because the oxygen and hydrogen atoms that make up the water molecules in snow fit together most efficiently in a hexagonal pattern.
If the snow is fluffy enough, you may be able to catch snowflakes using just some dark construction paper. It helps if the paper is already cold so that it doesn’t melt the snow on contact, so here's a pro tip—store the paper in the freezer before you try this out.
Once you catch some snowflakes, you’ll want to take a peek at them with a magnifying glass quickly. The flakes won’t last long on the paper.
If you want to preserve those flakes a little longer, you can use microscope slides (which only cost a few dollars) or other small, flat pieces of clear glass. Again, stick the slides in the freezer beforehand, so they don’t melt the flakes before you have a chance to view them. Spray the slides with hairspray to make them sticky and set a trap for the snowflake. If you leave the slide to sit for a few hours, the flake will leave behind an imprint in the layer of now dried hairspray once the water that makes up the flake melts away. You don’t need a microscope to see the detail in your science art piece, but it helps.
How to make your own snow
If you live in a place where it doesn’t snow, don’t let that stop you. You can make your own, or at least something approximating it.
If you live in a place where it doesn’t snow, don’t let that stop you. You can make your own!
Snowscapes and snowballs
If you want to make something that looks like snow for a winter scene, or you'd like to roll some snowballs and maybe even make a miniature snowman or two, here's how.
Combine equal parts of baking soda and water in a bowl. Then, add water a tablespoon at a time and mix with your hands to form crumbly snow that holds its shape when squeezed. Just be careful not to add too much water. If you do, your mixture will have a consistency more like glue or paste than snow.
Create a crystal snowflake
If you want to make something shaped like actual flakes, you can do that with a little more effort by making borax crystals form on a snowflake shape you create as a framework. You'll need some pipe cleaners, scissors, borax, a wide-mouth jar, a pencil, and some string. A few drops of blue food coloring are an optional wintry touch.
A quick note: Because borax isn't safe to ingest, and you'll be working with boiling water, this project is for older or closely supervised kids.
First, you'll need to make the snowflake framework. I created a snowflake-like shape using pipe cleaners. For a more scientifically accurate flake, you can make a six-pointed star. Just remember that the color of the pipe cleaner will show up in your finished snowflake, so white pipe cleaners are best. (Unless, of course, watermelon snow is what you're after!)
When you mixed the borax with water, you created something called a supersaturated suspension by stirring in borax until the water couldn't dissolve anymore.
Next, you'll need a way to suspend the snowflake in a liquid mixture of borax and water. (You may already have borax lying around if you and your kids have used it in their favorite slime recipe.) Tie a string to one of the points of your snowflake so you can suspend it in a jar without the framework touching the sides or bottom of the jar. I tied the other end of my snowflake's string to a pencil and laid the pencil across the top of my jar to suspend it.
Now, mix up your snow solution. Recipe queen Martha Stewart suggests three tablespoons of borax and one drop of food coloring for every one cup of boiling water that it takes to fill your jar.
Suspend the snowflake in the jar and leave it to sit overnight. When morning comes, check out your masterpiece! It should appear crystalized and be ready to remove from the jar. Let the snowflake dry before hanging it.
And here's where the science comes in. You created something called a supersaturated suspension by stirring borax into boiling water until no more would dissolve. The hot water allowed more borax to dissolve into the solution by separating its molecules more than is normal. But as the mixture cooled, the molecules connected again in a repeating pattern that caused the crystal shapes to form and cling to your pipe cleaner snowflake. How cool is that? (Pun totally intended.)