The golden, glowing sun glares down on a vast sea of sand. As far as the eye can see, the sand stretches in great yellow-brown ripples. The air is so hot you can see it shimmer as it rises from the sand. There is not even the tiniest green plant anywhere in sight.
Whenever most people think of a desert, they usually think of an endless, hot sandy land. But there are actually many different kinds of deserts.
Some deserts are rolling, sandy places where hardly any kind of plant can grow. Some are flat plains that are covered with many kinds of plants. Even the world's biggest, hottest desert, the Sahara, has small patches of trees and grass in some places. Such a patch of greenery is called an oasis.
Some deserts are hot all year round. Others are hot in the summer and cold in the winter. Some deserts are great bare places on the shores of seas. Others are rocky places high up in mountains. But all deserts, wherever they may be, are the earth's dry places - places where little rain falls.
It does rain in deserts, but usually only a tiny bit. Some parts of deserts go for many years without rain, then get just a sprinkle. Sometimes a desert is so hot that the rain dries up before it reaches the ground !
But some deserts get cloudbursts. Than, rain pours down on parts of the desert. In fact, the heavy rain may cause sudden floods. The dry earth can't soak up the water fast enough, and water quickly fills up the desert's low places. But soon, the ground is again as dry as an old bone
Scientists can tell that the deserts now on earth were not always here. Most of them are probably only a few million years old. At one time, most of the places we now know as deserts were green and fertile. But something happened. Changes in the wind and weather made rain stop falling on these places. Then, year after year, these lands were baked and dried by the sun until they became the deserts they are today.
Whenever most people think of a desert, they usually think of an endless, hot sandy land. But there are actually many different kinds of deserts.
Some deserts are rolling, sandy places where hardly any kind of plant can grow. Some are flat plains that are covered with many kinds of plants. Even the world's biggest, hottest desert, the Sahara, has small patches of trees and grass in some places. Such a patch of greenery is called an oasis.
Some deserts are hot all year round. Others are hot in the summer and cold in the winter. Some deserts are great bare places on the shores of seas. Others are rocky places high up in mountains. But all deserts, wherever they may be, are the earth's dry places - places where little rain falls.
It does rain in deserts, but usually only a tiny bit. Some parts of deserts go for many years without rain, then get just a sprinkle. Sometimes a desert is so hot that the rain dries up before it reaches the ground !
But some deserts get cloudbursts. Than, rain pours down on parts of the desert. In fact, the heavy rain may cause sudden floods. The dry earth can't soak up the water fast enough, and water quickly fills up the desert's low places. But soon, the ground is again as dry as an old bone
Scientists can tell that the deserts now on earth were not always here. Most of them are probably only a few million years old. At one time, most of the places we now know as deserts were green and fertile. But something happened. Changes in the wind and weather made rain stop falling on these places. Then, year after year, these lands were baked and dried by the sun until they became the deserts they are today.
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