Comprehension: Our Unusual Planet

Topic Content:

• Title: Our Unusual Planet
• Text: New Oxford Secondary English Course for SS1 pages 57-59
• Questions and Answers

     It is easy to take for granted the climate and resources of the earth. Why should we not do so? The reason is that in fact, our planet is unique in the solar system. This is not to say it is unique in the universe. That cannot be said as Man has not yet explored the whole universe in detail and indeed, by reason of its immensity, may never succeed in doing so.

     Nevertheless, our planet, although it is small compared with the solar system and tiny in comparison with the whole universe, possesses very special advantages. It is on account of these special advantages that it is able to provide us with a wide variety of natural resources. What are these advantages and what are the reasons why they are of great importance to us?

     Over most of the earth’s surface, the range of temperature is suitable for the formation of living matter and carbohydrates. This narrow range of temperature is due to the fact that the earth’s mass through gravity holds down a layer of gases which we call the atmosphere; and since the atmosphere is neither too thick nor too thin, it both moderates the amount of heat from the sun that reaches the earth’s surface by day and also acts as a blanket retaining heat by night. Given the suitability of the Earth’s temperature range for the formation of living matter and carbohydrates, life can be maintained on Earth today. Moreover, the oxygen in the atmosphere, being continually renewed by plants, is kept at a level sufficient for human and animal life.

     The sun emits deadly ultraviolet rays and there are many other harmful radiations in outer space. However, largely absorbed by the atmosphere, these rays and radiations are prevented from harming and destroying life on Earth.

Life on land cannot continue without water. That it does continue is owing to rain, evaporated water from the seas that cover seventy per cent of the earth’s surface. The regulation of the earth’s temperature is also partly due to the seas, for they absorb heat in summer and warm the atmosphere in winter.

Because of its size and weight, high pressures have been produced deep inside the earth. Thanks to these pressures and the resultant heat, volcanic action in the past has brought to the surface minerals and other natural resources. Owing to this activity many minerals that would otherwise remain buried beyond our reach are available for our use.

Thus, because of the high proportion of water on the earth’s surface, because of the particular thickness of its atmosphere and because of volcanic activity, the earth alone of all the bodies in our solar system is capable of maintaining life.

(Source: NOSEC Book 4, pp 29-31)