Aaron Kramer, age 9, of Patterson, N.J., for his question:
HOW HOT IS THE SAHARA DESERT?
The largest desert in the world is the Sahara. It extends across northern Africa from the Atlantic Ocean to the Red Sea, and from the Mediterranean Sea to the Sudan. Temperatures on the Sahara during summer are pushed up to between 120 and 130 degrees Fahrenheit by the hot equatorial sun.
The northeast trade wind blows constantly across Africa from the Red Sea to the Atlantic Ocean. This movement of air dries up the moisture of the Sahara.
In winter, the sand of the Sahara cools so quickly that there may be frost during the nights. The temperature falls quickly when the wind comes cutting and cold. It seldom snows in the lower areas of the desert but higher mountains are sometimes snow covered. Also, sandstorms occur often.
All parts of the Sahara get some rain, but in many places there are only occasional showers. Sometimes rain falls but it evaporates before it can hit the ground.
It is hard to believe, but the Sahara is almost as large as the United States. The desert covers about 3 million square miles. It is about 3,200 miles long from the east to the west and from 800 to 1,400 miles wide from north to south.
The Sahara covers most of Egypt, Libya and Algeria and parts of the Sudan, Tunisia and Morocco. The desert also includes large parts of Western Sahara, Mali, Mauritania, Niger and Chad.
A large part of the Sahara is covered with hot, shifting sand dunes. But other parts have a hard and rocky surface. The vast central plateau extends about three fourths of the distance across the desert from the northeast to the southwest. This plateau is from 1,900 to 2,500 feet above sea level.
Three mountain ranges, the Ahaggar, the Tibesti and the Air, rise above the central plateau of the Sahara.
You won't find too much animal life on the Sahara because of the small amount of natural food supply.
On the borders of the desert, where there is some water, there are lions, panthers, jackals, hyenas, foxes and several kinds of apes. There are also many snakes.
There are many oasis areas in the Sahara where water can be found. Some cover less than one square mile, but other oases are so large that several million date palms may grow by the use of irrigation.
Most of the oases are watered by springs that are fed from underground water. This water collects on a layer of clay beneath the sand.
Camel caravans have crossed the Sahara desert since early times. There is some evidence that the caravan routes are about 4,000 years old.
But thirst and starvation, sandstorms and attack by bandit tribes often threatened those who attempted to cross the desert before the motor truck was developed. Today motorbuses and trucks make regular trips across the Sahara. Service stations are situated at many of the oases and they provide fuel.