Question

How has the earth's moon changed over time?

Answer 1

Hint : The earth is the only planet with life. It is because the earth is at the right distance from the sun and is protected from solar radiation by the magnetic field. Also, the Earth is kept warm by an insulating atmosphere and has the right chemical ingredients for life including water and carbon.

Complete Step by step answer:
The present theory states that the Moon was formed when another planet hit the earth. The Moon would have been the molten rock and was much closer to the Earth and is rotating quite quickly when it was formed.
Over time, the Moon cooled and as it had no atmosphere there was nothing to stop the meteorites from hitting the surface. Thus it has a large number of impact craters. Moreover, the Earth’s gravity has a tidal effect on the Moon and this has resulted in the Moon’s rotation period too slow. Also, it has the effect of making the Moon’s orbit get further from the Earth.
Over time, the Moon became tidally locked to the Earth which indicates that the Moon’s rotation period is the same as that of its orbital period. Hence the Moon always shows the same face to the Earth.

Note:
1. The name Earth is derived from Anglo Saxon word erda. It means the ground or the soil. It became later eorthe and later erthe in Middle English.
2. Earth is the third planet from the sun and it takes 24 hours to rotate.
3. There is no sound on the moon.