Question

In how much time does moonlight reach the earth?
A. 1.3 seconds
B. 13 seconds
c. 1.3 minutes
D. 13 minutes

Answer 1

Hint: Moon is a large natural satellite of earth and is the only celestial body that is nearest to us in space. It is very small and is about one fourth the size of earth. It has a diameter of 3.476 km. Due to its small size, its mass is less and so is its gravity which is only one sixth of earth.

Complete answer:
The average distance of the moon from earth is 238,855 miles or 384,400 km. It orbits around the earth in 27 days 7 hours 43 minutes and 11.47 seconds and completes one revolution. The Moon does not have any light of its own rather, it reflects the light received from the sun. Of the total incident sunlight received, only 13.6 percent is reflected from the lunar surface.
We know, light travels through space or vacuum at about 186,282 miles per second (299,792 km per second). Sunlight takes approximately 8 minutes and 20 seconds to reach the Earth's surface. So, the time taken by moonlight to reach earth’s surface will depend on the product of distance of moon from the earth and the rate at which light travels through space. Thus, if we calculate this we will get 1.25 seconds or 1.3 seconds approximately.
So, the correct answer is option A.

Note: The time taken by moon to spin on its axis to complete one rotation matches with its revolution around the earth, i.e. 27.3 days. This is the reason why we are able to see the same side of the moon only. The earth facing side is called nearside while the face away from the earth is called farside.