The Discovery of Moon Lesson Summary Notes and Explanation in English Class 9th


This chapter talks about earth’s wonderful satellite, the moon. It is based on “The Discovery of Moon” from the book World Famous Discoveries published by Pustak Mahal. We get to know about the first moon landing as well as many facts about the moon here.

The Moon Landing

On July 20, 1969, two American astronauts, Armstrong and Edwin, from the spacecraft Apollo-11, became the first men on the moon. After collecting samples of the lunar soil, these two astronauts returned to their spacecraft. They left instruments and machines on the moon which continued to send observations to the observatories on the earth. Apollo-11 was locked with another spacecraft, Eagle-2. As Apollo-11 remained on the surface of the moon, Eagle-2 revolved round the moon. On Eagle-2 was Michael Collins, who waited for the return of his companions.

After this successful mission, a series of Apollo spacecraft for flights to the moon was started. These made available useful and wonderful information about the moon which removed misconceptions about it.

Besides earth, the moon was the only heavenly mass that man had landed at and seen. Spacecrafts have been landed on the other planets but man has yet to set his foot on them. The USSR and the USA had worked out programmes for the exploration of the moon. The USSR sent just its spaceships whereas the USA also sent its astronauts. 

The Soviet Union did not feel it necessary to land man on the moon. It sent spaceships to carry on exploration with the help of scientific instruments. Soviet scientists sent a spacecraft called Luna-16 to the moon in September 1970. It carried a robot that was placed on the surface of the moon. It was less expensive and human life was not endangered.

Facts About the Moon

Research on the moon for over thirty years have shattered many old beliefs about it. There is no water and air on the moon. Soviet scientists have declared it unfit for human inhabitation. Some useful metals like aluminium, titanium and iron have been found there. Some scientists still feel that humans can live on the moon by separating oxygen from elements which contain oxygen.

Today we know all the important facts about the moon. It is the earth’s only natural satellite, very large in relation to its parent planet. It is a quarter of the earth’s diameter measuring 3476 km. Its distance from the earth is 384,405 km. It orbits the earth once a month, keeping the same face turned towards earth as it does so. Its surface is pitted with craters caused by meteorites. The moon is the same age as the earth at about 4,600 million years.

The moon is not a self-luminous body. The earth and the moon travel around a common centre of gravity in space. As the moon orbits the earth, different parts of its sunlit surface are visible from the earth, producing the cycle known as the phases of the moon. The average daily delay in the moon-rise and the moon-set is about 50 minutes. A very light ‘rain’ of cosmic dust continually falls on the moon. In the sun, lunar rocks reach a temperature of 110° but in the shadows the temperature goes down to less than -100 °C.

In spite of knowing these ‘dull’ facts about the moon, poets and lovers continue to sing of its beauty and compare the faces of their beloveds to this lovely satellite.


The moon landing shows us the potential of human knowledge and innovation. Humans were able to build spaceships to send men to the moon, and eventually uncovered its secrets. Yet, the moon continues to fascinate human imagination and inspire human emotion.