In drawings, clouds look like they are made of cotton. But do you know what they are really made of? Water!

Clouds are lots of tiny water drops all grouped together. The drops are so light they can float in air. Even though they float, clouds can actually weigh hundreds of tons.

Clouds are formed when warm air rises. The water vapor cools off. The air turns to water drops. Clouds are made!

There are many kinds of clouds. Scientists group them based on how high they float in the sky. Cirrus clouds are the highest. Stratus clouds are the lowest.

Fog is a special kind of cloud that forms on the ground. Another special kind of cloud is called an asperitas cloud. It looks like waves in the sky.

Clouds often look white. They are reflecting the sunlight. Clouds with more water in them block the sun. They start to look dark. Then they release the water as rain.

Sometimes during thunderstorms clouds look green. No one knows why. It’s a cloud secret.

Except for Mercury, every planet in our solar system has clouds. Earth is the only planet whose clouds are made of water. Clouds on Venus are made of sulfuric acid. Clouds on Jupiter are made of hydrogen.

Nephology is the study of clouds. There is a lot to learn about these natural wonders. Maybe you will be a cloud expert someday!