Electra

Rainbow

Rainbows are curved bands of colored light that appear in the sky. We see rainbows when the sun shines on raindrops. Sometimes both ends of the rainbow seem to touch the ground.

Rainbows usually appear at the end of the day, after a storm has passed. To find a rainbow, turn away from the sun, face the shadow of your head, and look up. If there is a rainbow, you will see it less than halfway between your shadow and a point straight above your head.

Usually, people see a primary (PRY mehr ee) rainbow, or main rainbow. It is red on top of the curve and violet on the inside, with other colors in between.

Sometimes a second, fainter rainbow appears higher up. This rainbow is violet on top and red on the inside.
Rainbows appear because of the way light behaves. White light is made up of all the other colors of light. Each color has light waves of a different length.

White light bends when it passes through a kind of glass called a prism (PRIHZ uhm). Light waves of some colors bend more than others.

This makes the white light separate into bands of colored light.When the light passes through raindrops, it separates in the same way. The bands of colored light make up the rainbow that people see.

Rain

Rain is water that falls in drops from the sky. It forms from droplets of water in the clouds. Droplets are tiny drops. Sometimes there is frozen water in clouds. When it melts, it falls to the ground as rain. Some raindrops are very small. Others are as big as a pencil eraser. They cannot get much bigger, because they break into smaller drops as they fall.

Large raindrops fall as fast as 30 feet (9 meters) per second. Raindrops form from water vapor (VAY puhr), or gas, in the air. The sun’s heat causes water from lakes, rivers, and oceans to rise into the air as water vapor. As it rises, the warm, moist air cools. Cool air holds less water than warm air can hold. As the air cools, the water vapor condenses, or forms droplets. The droplets form clouds. As the clouds cool, the droplets combine with other droplets. When they become too heavy for the air to hold, they fall to the ground as rain.

If the same amount of rain or snow fell everywhere, Earth would get about 34 inches (86 centimeters) each year. But some places get much more, and some get much less. Warm, tropical areas near the equator get more rain than cold areas in the far north and south. The equator is a make-believe line around Earth’s middle. Usually, seacoasts get more rain than other regions.