The science of snowflakes: See how they form and why no two are ever alike Snow is made up of trillions of tiny ice crystals that make snowflakes, with not one alike.

When volcanic eruptions send towering plumes of ash into the atmosphere, they don’t just darken the sky or affect local air quality. New research shows that these eruptions can actually trigger the ...

As ice crystals grow and clump together, they become too heavy to stay aloft. With the help of gravity, they begin to fall back down through and eventually out of the cloud.

As the ice crystal falls to the ground, water vapor freezes onto the primary crystal, building new crystals. Microscopic view of snowflakes by Wilson Bentley. From the Annual Summary of the ...

The shape of the ice crystal is the key. It's called a plate, and it's shaped like a hexagon. They must be light enough to float very slowly down from the sky, or almost be suspended in the air.

Sundogs are formed when light passes through hexagonal plate crystals of ice, suspended in cirrus or cirrostratus clouds located at altitudes of around 20,000 feet (6,000 meters) and higher, up to ...