Book 1, Question 68
Why Is Every Snowflake Different? One of a Kind!
Snowflakes all follow one family rule but each one turns out different. A snowflake begins as a tiny ice crystal in a cloud and grows by collecting water vapor as it falls. Changes in temperature and moisture make its arms grow in unique ways, from simple plates to lacy stars. Water molecules lock together in a hexagon shape, so every snowflake has six sides. Catch flakes on a cold, dark sleeve and draw the shapes you see!
From the book
Page from A Million Whys Book 1
More fun facts
- A snowflake starts when a super cold water droplet freezes onto a tiny bit of pollen or dust in the sky.
- As it falls, water vapor freezes onto the crystal and builds its six arms.
- Temperature mostly decides a snow crystal's basic shape. Long needles grow near 23 degrees Fahrenheit, and flat plates grow near 5 degrees.
- Tiny changes in temperature or humidity, even seconds apart, can make a crystal's arms branch in new directions.
- The six arms of one snowflake usually match each other, because they all go through the same conditions as they fall.
- In the 1880s, a Vermont farmer named Wilson Bentley took about 5,000 snowflake photos through a microscope and never found two alike.
- In 1635, the mathematician Rene Descartes sketched snowflakes he saw with his own eyes, including rare twelve-sided ones.
- Small raindrops are round, but large ones are shaped more like hamburger buns.
Questions kids ask
Why do snowflakes have six sides?
Water molecules line up in a six-sided pattern when they freeze, so the crystal grows six arms.
Has anyone found two identical snowflakes?
Wilson Bentley photographed about 5,000 snowflakes and never found two that were alike.