Rain, thunder and lightning are likely to follow if you spot one of these in the sky. What are dark clouds called? There are a few different types of dark clouds. Nimbostratus, ...

At low altitudes, fluffy cotton-like cumulous and dark-gray nimbostratus clouds garnish the sky, changing daily. Higher in the atmosphere, clouds become thinner and wispier, like cirrus clouds.

Part of the closest star-forming region to us, known as the Chamaeleon Complex, has been illuminated by the light of young ...

The dark appearance of the clouds is influenced by where you are looking at them from. A pitch black sky often appears before a storm strikes. Here's what gives these clouds their dark appearance.

He added that the cloud "grows so tall, but stays so narrow, that it blocks light from the setting sun and casts a shadow across the sky." Cappucci also said the dark band seen in the clip is ...