Chapter 5

                                              The Discovery of Moon


1.Who were the first men to set foot on the moon, and when did this happen?

Ans: On July 20, 1969, the American astronauts Neil Armstrong and Edwin “Buzz” Aldrin became the first men to set foot on the moon, emerging from the spacecraft Apollo-11.

2.What was the significance of Apollo-11’s mission?

Ans: Apollo-11’s mission opened new avenues in space exploration. It collected lunar soil samples, left instruments on the moon to send observations to Earth, and marked the first time humans walked on another celestial body.

3.Who stayed aboard the spacecraft Eagle-2 during the moon landing?

Ans: Michael Collins stayed aboard Eagle-2, orbiting the moon while Armstrong and Aldrin were on its surface, waiting for their return.

4.What instruments did the astronauts leave on the moon, and what was their purpose?

Ans: They left machines and scientific instruments that continued sending observations about the moon’s surface and environment to observatories on Earth, aiding long-term study.

5.What misconception about the moon was corrected by Apollo missions?

Ans: Apollo missions removed myths and misconceptions, proving the moon is a barren, airless, and desolate place, contrary to earlier imaginative ideas about it.

6.Why was the moon exploration considered an important part of the space program?

Ans: It was the only celestial body besides Earth that humans had landed on, giving direct observation of a heavenly body and valuable scientific information.

7.What approach did the USSR take for moon exploration?

Ans: The USSR chose not to send humans but sent robotic spacecraft like Luna-16 to conduct experiments and gather data, which was safer and less expensive.

8.Describe the role of the Luna-16 spacecraft.

Ans: Luna-16 carried a robot to the moon in September 1970. The robot performed experiments on the moon’s surface effectively, demonstrating that machines could substitute humans in such missions.

9.What did lunar research reveal about the moon’s habitability?

Ans: The moon is desolate, has no water or air, and is unfit for human habitation, though some metals like aluminum, titanium, and iron exist on its surface.

10.Can humans make the moon inhabitable, according to scientists?

Ans: Some scientists believe it might be possible by extracting oxygen from compounds containing oxygen, but this remains theoretical.

11.What is the size of the moon relative to Earth?

Ans: The moon is about a quarter of the Earth’s diameter, measuring 3,476 km, making it large compared to the satellites of other planets.

12.How far is the moon from Earth?

Ans: The moon is approximately 384,405 km away from Earth.

13.What is unique about the moon’s rotation?

Ans: The moon keeps the same face towards Earth while orbiting it, completing one rotation per month.

14.What causes the moon’s craters?

Ans: Craters on the moon’s surface are caused by meteorite impacts over billions of years.

15.How old is the moon, and how does this compare to Earth?

Ans: The moon is about 4,600 million years old, roughly the same age as Earth.

16.Is the moon self-luminous?

Ans: No, the moon does not emit its own light; it reflects sunlight.

17.What is meant by “phases of the moon”?

Ans: As the moon orbits Earth, the varying portion of its sunlit surface visible from Earth creates phases, including new moon, crescent, half-moon, and full moon.

18.Why is the moon’s temperature extreme?

Ans: In sunlight, lunar rocks reach 110°C, but in shadow, temperatures drop below -100°C due to the absence of an atmosphere and water to moderate temperature.

19.What is the effect of cosmic dust on the moon?

Ans: A very light “rain” of cosmic dust continually falls on the moon, slightly altering its surface over time.

20.What metals have been found on the moon?

Ans: Metals like aluminum, titanium, and iron have been discovered on the lunar surface.

21.Why did the Soviet Union prefer robotic exploration over human exploration?

Ans: Robots were safer, cheaper, and avoided risking human life while still providing accurate scientific data.

22.What are the main benefits of lunar exploration?

Ans: Lunar exploration provides scientific knowledge, helps correct misconceptions, and aids the development of technology for space missions.

23.How did Apollo-11 contribute to future space missions?

Ans: It provided data, collected soil samples, and demonstrated that humans could safely land and return from another celestial body, paving the way for future missions.

24.What role do instruments left on the moon play?

Ans: They continuously send data to Earth, allowing scientists to monitor lunar conditions without human presence.

25.What is the significance of Michael Collins’ role aboard Eagle-2?

Ans: He maintained orbital support for Armstrong and Aldrin, ensuring their safe return to Apollo-11, demonstrating the teamwork required for manned missions.

26.How did space exploration change global perception of the moon?

Ans: It shifted beliefs from myth and imagination to scientific understanding, revealing its true barren nature.

27.What is the common center of gravity between Earth and the moon?

Ans: Earth and moon revolve around a shared center of gravity, affecting their orbital dynamics and tidal forces.

28.How does the moon affect timekeeping on Earth?

Ans: Its orbit determines lunar months and visible phases, which have historically guided calendars and cultural events.

29.How often do full moon and new moon occur?

Ans: They occur approximately once a month as part of the lunar phase cycle.

30.How much does moon-rise and moon-set change daily?

Ans: Moon-rise and moon-set are delayed by about 50 minutes each day.

Answer by Mrinmoee