Following is a transcript of the video. Narrator: From thin and wispy to big and puffy, clouds cover about 70% of the planet at any given moment. But what if, in the next minute, poof, they all ...

Cirrus clouds are high-level clouds that are composed of ice crystals. They’re characterized by their thin, wispy appearance. Mares’ tails are a type of cirrus cloud, also known as cirrus uncinus.