In ancient times the moon was worshipped as a goddess who ruled the night. Since those ancient days, man has learned a great deal about the moon. and now, at last, it is possible for human beings to land there. They can now “explore” it and solve many of its mysteries.
The only reason we can see the moon from earth, or that it “shines”, is because light from the sun strikes its surface and is reflected us. Strangely enough, we can only see one side of the moon from the earth. This is because the moon rotates on its axis in the same length of time it takes for it to make its journey around the earth. Of course, man has seen the other side from television pictures sent back by the various Apollo crews as they orbited the moon.
Since the moon has no atmosphere, or air, the light from the sun which hits it has rather interesting effects. For about 14 days, the surface of the moon is heated by the direct rays of the sun to a temperature above that of boiling water. The other half of the lunar month, it is exposed to the cold of the long dark night because there is no air to stop the heat from the sun radiating away again. The Earth does reflect light back on to the Moon, this is called ‘Earthshine”, but it does little to help raise the temperature of the lunar night which can fall to about-200 degrees Centigrade.
Is There Gravity On The Moon?
There is gravity on or in every single object that exists in the universe. For gravity is simply the force which pulls every object in the universe towards every other object in the universe.
But the force of gravity depends on two things. The mass of the objects involved, and their distance from each other. For example, there is a force of attraction between you and the earth. But the earth is so enormous compared to you, that it pulls on you. The force of this pull is what you weigh at the earth’s surface. But if you were twice as far from the centre of the earth as you are now (or 4,000 miles in the air), you would weigh only one-quarter of what you weigh here on earth.
Earth’s moon is a huge object but compared to the earth it is rather small. It weighs only 1/81 as much as the earth. So its gravity, or pull, on its surface is much less than that of the earth.
So is a man were on moon, his weight would be only one-sixth of his weight on the earth. If he were able to make a jump while standing on it, he could jump six times as high. And if he were able to throw a ball, it would go up six times as far, because the pull of the moon’s surface is so weak.
Since man first appeared on earth, Moon has been a mystery to him. In ancient times it was even worshipped as a goddess who ruled the night. Right now, we are living in the days when more is being found out about the earth’s moon than ever before in the whole history of mankind. Pictures of the other side of the moon have already been taken by the Americans and the Russians.
The fact that we cannot see the other side from the earth is due to a simple fact. Moon is a satellite of the earth, a small body that revolves about it, just as the earth moves in an orbit about the sun.
This journey of the moon around the earth takes a certain definite period, about 29 1/2 days. The moon rotates on its axis, but the time it takes to rotate is the same length of time it takes for it to go around the earth. So we only see one side of this remarkable satellite.
If you want to get a picture of how this works, try this.
Hold your left hand in front of you and clench your fist. Imagine that is the earth. Now take an apple or orange and mark around it with a pencil to indicate two halves. Imagine that it is the moon.
Now face one side of the “moon” towards the “earth. Keeping that same side facing the earth, make a complete circle around the earth. You will see that not only did the moon go around the earth, but it also made a complete rotation on its axis. And yet only one side ever faced the earth.
Most scientists believe that when we finally do explore the moon and definitely know all about the other side, it will be pretty much like the sideman has always seen.