We all know that the moon goes around the earth. But do you know you can always only see one side of the moon while the other side always turns away from us? The side that we can see from the earth is called the near side, while the other side is called the far side. Some people call it the dark side, but that's not correct, as the sun is shining on it brightly on the other side. The gravity(重力) on the moon is only one sixth of that on the earth. When a person is on the moon, he will weigh one sixth of his weight on the earth. So the moon is the place to go if you want to feel like you're weightless.
Astronauts have been on the moon several times since 1969 and they left a lot of rubbish behind. Scientists estimate that there are about 181, 437 kilograms of man-made materials lying around the moon.
As the nearest neighbor of the earth, the moon has a lot of effects on us. The scientists have found that around a full moon, people may take longer to fall asleep and sleep less.
Therefore, next time if you can't get to sleep, it could be the full moon.
