But germs are the most common snowflake starters and lie at the heart of 85 percent of all flakes.2
So next time you gaze at a lovely snowstorm, inform your favorite germophobe or hypochondriac that living bacteria sit shivering in most of those untold billions of flakes. Then hand him or her a snow cone or organize a catch-a-snowflake-on-your-tongue party.
Once the ice-forming process is started, more molecules join the party, and the crystal grows. It can ultimately become either a snowflake or a rough granule of ice called by the odd name graupel. A snowflake contains ten quintillion water molecules. That’s ten million trillion. Ten snowflakes—which can fit on your thumb tip—have the same number of molecules as there are grains of sand on the earth. Or stars in the visible universe. How many flakes, how many molecules fashioned the snowy landscape I was observing as I drove east? It numbed the brain.

Bob Berman