Blog Dog Dan: GET YOUR HEAD OUT OF THE CLOUDS by Blog Dog Dan

Well, he can't really help it - he's so tall! When someone says this to you, they're telling you to "be practical, come back down to Earth." The highest clouds are located in the Earth's mesophere at altitudes of 47-53 miles (250,000-280,000 feet). These are called noctilucent clouds or "night-shining clouds" because they can only be seen at deep twilight. They are made of crystals of water ice and occur from mid-May to mid-August in the northern hemisphere and between mid-November and mid-February in the southern hemisphere. They are normally too faint to be seen, colorless or pale blue, and can only be observed in twilight around sunrise and sunset when the clouds of the lower atmosphere are in shadow but the noctilucent cloud is illuminated by the sun. They are considered a "beautiful natural phenomenon."

Photographed by the crew of the International Space Station

Luke Howard (1772-1864) developed the International Cloud Atlas which classified 10 types of clouds. Number 9 was the white fluffy cumulonimbus (cumulus + nimbus). This is where we get the expression "on cloud nine," which means floating free on a downy white cushion, presumably without a care in the world.

These are the four main types of clouds:

Cumulus - These look like clouds that are piled on top of each other. They are fluffy and can be white or gray. When they’re white and puffy, that usually means it’s not going to rain right away. If they grow into big gray clouds, you can usually expect rain.

Stratus: These look like a huge gray blanket that hangs low in the sky. If it’s warm, then you will get rain; if it’s cold, you will get snow. When stratus clouds are near the ground or on the ground, this is called fog.

Cirrus: These are very high in the sky and look very thin and wispy. These are made of ice crystals, not water drops, because they are formed where it is high enough to be cold and freeze the water drops into ice. If the sky is blue with only cirrus clouds present, it’s going to be a nice day!

Nimbus: These clouds mean that a thunderstorm is brewing and there may be thunder and lightning soon. When you see a nimbus cloud, rain or snow will likely be falling out of it.

A rainbow occurs when the sun shines onto drops of water (rain, mist, and dew) in the atmosphere that takes the form of an arc. Rainbows caused by sunlight always appear in the section of the sky directly opposite the sun. It is impossible to see any rainbow from water droplets at any angle other than the customary one (which is 42 degrees from the direction opposite the sun). Every rainbow contains these colors in order: red, orange, yellow, green, blue, indigo, and violet.

Rainbow Brite was a character introduced by Hallmark Cards in 1983, with the animated television series starting in 1984. Here's the Rainbow Brite premise: A little orphan girl named Wisp is taken by an unknown force to the Colorless World. She must find the Sphere of Light, but upon doing so, she befriends a sprite, Twink, and a majestic white horse known as Starlite. She rescues the seven Color Kids (one for each color of the rainbow) and finds the Color Belt, which is the tool she needs to bring color to the land. After using it to defeat the King of Shadows (also known as the Evil Force and the Dark One), an evil hooded being with twitchy fingers, the unknown force renames Wisp as Rainbow Brite. She and the Color Kids (and their helpers, the Sprites) live in Rainbow Land and are in charge of all the colors on Earth.