The Moon----Earth's Satellite

The Moon is the only satellite of the Earth and its diameter is 0.27 times of the Earth. Its mass is 0.012 times than that of the Earth and the gravity is 1/6 times of the Earth. Thus, if we do high and long jump exercises on the Moon, we will have better performance.

Owing to the influence of tides on the Earth, the Moon spans away the Earth 3 centimeters each year but it will not rotate away without any limit. The largest distance is 1.4 times of the current one. It takes more than billion years to maintain the largest distance.

The surface of the Moon is littered with craters. Scientist analyzed moon rocks and assumed that about 380-450 million years ago, the Moon had been bombarded by big meteorites and bombardments were left since then.