Many hundreds of years ago, the moon was a mystery to people on the earth. What was that glowing ball came out at night? Why did it keep getting smaller, then larger? Why didn't it fall from the sky? Through the ages, people have tried to come up with answers.

    To the native people of Bolivia, in South American, the moon was a great chief who once lived on the earth. The Abaluyian people of Kenya, in Africa, believe the moon and the sun were brothers who fought in the sky. In other parts of the world, people believed they saw different pictures in the moon. The Haida Indians of Canada saw a woman carrying a bucket. The Chinese saw a road.

    People in the past also used the moon to mark time as a kind of calendar. In fact, in some languages, the word for moon meant “month”. A Native American nation called the Sioux made a calendar of 13 moons, or months. Each moon had a name, such as Moon of Black Cherries, Moon of Green Corn, and Moon of Severe Cold.

    Though people of the past found the moon was helpful, mysterious and interesting, they didn't know much about it. They only knew what they could see with their own eyes.

    Then almost 400 years age, an Italian scientist named Galileo made a new telescope(望远镜) that was more powerful than any telescope made before. Galileo decided to take his new implement to look at the moon. He discovered that the moon was not the smooth, shiny ball. The brighter places were mostly hills and mountains. The flat areas were lower, which is why they appeared darker.

    As more people saw the moon through telescopes, they discovered more about it. Yet, people still had much to learn about the moon.

    Robots seem very new to most people. But they have a long history. The first one was made by a Greek inventor. You may have seen robots in some films. The robots in these films are stronger, faster and more clever than people in real life. Most robots are used in factories. They are used to do many dangerous, difficult or boring jobs. Some people can't look after themselves and move around. They need dogs to help them. These dogs are called guide dogs. Scientists are making robot dogs to help them. In the future, robot dogs might take the place of these guide dogs.

    Robots are also used in American hospitals. At one hospital, a robot takes meals from the kitchen to the sick people's rooms,   it never loses its way because it has a map of the hospital in its computer system.

    In the future, robots will work in space. But robots will never take the place of human beings, though they can help us in a lot of different ways.

    Today there are robots working in factories. Some can help to build cars, and they do easy jobs over and over again. Few people will do such jobs in the future because they are boring, but robots will never get bored.

    Scientists are now trying to make robots look like people. Some robots in Japan can walk and dance. However, some scientists believe that it will be difficult to make them really think like people. For example, scientist James White thinks that robots will never be able to wake up and know where they are. But many scientists don't think so. They think that robots will even be able to talk in 25 to 50 years.

    Some scientists believe that there will be more robots in the future. These new robots will look very different. Some will look like people, and others might look like animals. In India, for example, scientists made robots that look like snakes. When buildings fall down with people inside, these snake robots can help look for people under the buildings. This was not possible 20 years ago, but computers and rockets also seemed impossible 100 years ago. We never know what will happen in the future!

    In the universe, as we all know, there is the Sun, the Moon, the Earth and a good many stars. Through our geography lessons, we know the Earth goes around the Sun, and the Moon goes around the Earth. We have day and night because the Earth keeps turning all the time. When our part of the Earth turns to the Sun, it is day. When our part of the Earth turns away from the Sun, it is night.

    Just because the Moon is closer to the Earth than the Sun, it looks much bigger than the Sun. Big things will look smaller when they are further, and small things also look bigger when they are nearer.

    The Sun is big enough to give out very strong light. The Moon can't give out any light at all, but it looks quite bright, too. Why? In fact, the light from the Moon comes from the Sun. The Moon looks much bigger and brighter than the stars. But actually the stars are much bigger and brighter than the Moon. They look smaller than the Moon also because they are farther away from the Earth.

    There are many other planets in the universe. But of all the planets, only on the Earth there are living things and people can only live on the Earth, too. But at 9: 00 a. m. on October 15th, 2003, Chinese pilot Yang Liwei was sent up to space. He stayed there for over 21 hours. It was the first time for Chinese to get into space.