Now that man has actually explored the surce of the moon, he has learned many new things about it. But one thing man knew before he ever reached the moon was that there was no life on it.
There is no atmosphere on the moon. Astronomers knew this because there is no twilight on the moon. On earth darkness comes gradually because the air reflects the sun’s light even after the sun sets. On the moon, one moment there is sunlight, the next moment night has arrived.
The lack of air means that the moon is not protected from any of the sun’s rays. The sun sends out heat and light radiation. Life on earth depends on heat and light.
But the sun also sends out dangerous kinds of radiation. The earth’s atmosphere protects us from most of them. On the moon, however, there is no atmosphere to stop the radiations. All the sun’s rays beat down on the sur&e of the moon.
Because there is no atmosphere, the moon’s surface is either extremely hot or extremely cold. As the moon rotates, the side of it that is lighted up by the sun becomes very hot. The temperature there reaches more than 150 degrees Centigrade. This is hotter than boiling water. The hot lunar day lasts two weeks.
It is followed by a night that is also two weeks long. At night the temperature drops to 125 degrees below zero. This is more than twice as cold as temperatures reached at the earth’s South Pole.
Under these conditions, no form of life that we know of here on earth could exist on the moon.