In the universe, as we know, there is the sun, the moon, the earth and many stars. Through our geography lessons, we know the earth goes round the sun, and the moon goes round 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 look smaller when they are farther, and small things look bigger when they are nearer.

The sun is bright 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(事实上) the stars are much bigger and brighter than the moon. They look smaller than the moon because they are farther away from the earth.

There are still many other planets in the universe. All of them move round the sun. But of all these planets, only on the earth are there living things and people can only live on the earth too. At 9:00 am, on October 15th, 2003, Chinese astronaut Yang Liwei was sent into space. He stayed there for 21 hours. It was the first time for Chinese to get into space.

A question has made the public think a lot for more than a century: Whether(是否) there is life on Mars.

A British spaceship and Europe’s Mars spaceship plan to land on Mars or enter the orbit(轨道) around it. One of the NASA’s spaceships is going to land on January 3, and the other is going to land on the opposite side of Mars on January 24.

Since 1960, over twenty spaceships sent to Mars have failed. Most were lost when they started flying up or landing because those were the most difficult time of any flights.

Scientists wanted to find out whether there was water on Mars. In October, a team of scientists reported that Mars was a dry wasteland(荒地). But weeks later, a second team reported differently that they had found some marks(痕迹). They showed clearly that they were made by the rivers. Such marks told us that Mars was a warmer place billions of years ago—just as life first appeared on Earth. Scientists at once asked the following questions: If it was true, what happened on Mars? Then what about the earth?

Maybe one day, in the near future, human beings will land on Mars, settle on Mars, and directly look for life.

Named after the “quest for heavenly truth”, Tianwen 1, China’s first Mars probe（探测器）, has given us impressive pictures of the red planet. The first high-resolution（高分辨率的）pictures of Mars taken by Tianwen 1 were made public by the China National Space Administration（CNSA） on March 4.

“These are the first close-up pictures of Mars’ surface taken by China, ” said Bao Weimin, a scientist of the Chinese Academy of Sciences.

The pictures were taken at different distances from Mars. The two black-and-white pictures were taken by the high-resolution camera on Tianwen 1 when the probe was about 330-350 kilometers above the Martian surface. As for the color picture, it was taken by Tianwen 1’s medium-resolution（中分辨率的）camera when the probe was about 5, 000 kilometers above the red planet. It shows Mars’ North Pole.

The high-resolution camera can take both color and panchromatic（全色的）pictures. Panchromatic pictures, which are black and white, are the clearest, having the largest amount of data for scientific study, said Liu Tongjie. The medium-resolution camera, can only produce lesser clear pictures. Scientists put the panchromatic and color pictures together to form a clear and beautiful color picture, Liu added.

Tianwen 1, the country’s first independent Mars task, was sent up on July 23, kicking off the nation’s planetary exploration program. The probe entered its preset orbit above Mars on Feb 24 and is looking for a landing site on the planet’s largest plain. The probe is expected to land on the red planet sometime between May and June.