5 facts about clouds

1. High clouds are usually made up of ice crystals, and have a base somewhere between 5,500 and 14,000 meters.
Clouds are made up of tiny water droplets or ice crystals, usually a mixture of both. The water and ice scatter all light, making clouds appear white. If the clouds get thick enough or high enough all the light above does not make it through, hence the gray or dark look. Also, if there are lots of other clouds around, their shadow can add to the gray or multicolored gray appearance.

2. Clouds move with the wind. High cirrus clouds are pushed along by the jet stream, sometimes traveling at more than 100 miles-per-hour. When clouds are part of a thunderstorm they usually travel at 30 to 40 mph.
Saturn has clouds. In fact, any planet or moon with an atmosphere has clouds.
3. Clouds are not always white. When cast in specific light conditions, they can adopt a beautiful rainbow iridescence. These gorgeous polychromatic swaths in the sky typically appear early in cloud formation, when individual cloud droplets are far enough apart that they can diffract light in different directions. These clouds resemble the oil film that forms in puddles on the street and are very rare, but are most often observed in altocumulus, cirrocumulus and lenticular clouds.
The classic white cloud is known as “Cumulus”. Hindu’s and Buddhist’s believe that Cumulus clouds are the spiritual cousins of elephants.

4. The cloudiest place on earth is South Africa’s Prince Edward Islands in the Antarctic Indian Ocean. Parts of the islands see just 800 hours of sunshine all year. To put that in context, it’s much less than the 4,019 hours that Yuma, Arizona — otherwise known as the sunniest place on earth — experiences annually.
There are currently a number of projects in motion to create and modify clouds. NASA’s ATREX Cloud project involves launching rockets 65 miles into the atmosphere, where they eject a cocktail of chemicals into the atmosphere that react with the oxygen and water to create clouds. This study aims to understand the movement of the upper-level jetstream.

5. It makes sense that “shooting” those so called “seeds” to clouds should make them rain out.
People have actually tried to do that, on several occasions, with an attempt to end global warming by shooting crystal salt seeds at clouds, causing a permanent low hanging cloud cover that will deflect the sunlight and stop global warming.