1 . Chinese scientists found Changesite-(Y)—the sixth new lunar mineral in moon samples (样品) brought back by the Chang’e 5 lunar probe (探测器) in December 2020. It has become the first lunar mineral found by Chinese scientists, making China the third nation in the world, after the United States and Russia, to have achieved such a success, reported China Daily.

Changesite-(Y) looks crystal clear like a diamond (钻石). But its chemical content (化学组成) is different from any other known mineral. It has a high level of rare earth, reported China Science Daily. Li Ziying, chief scientist of the lunar sample research, said that the finding of this new mineral will help researchers study the history and physical traits (特征) of the moon. The value of the rare earth in it will also be studied.

Besides the new mineral, scientists also measured the content of helium-3 (氦-3) from the Chang’e 5 samples. Helium-3 is a valuable fuel (燃料) that can provide safer nuclear energy (核能). It is not radioactive (放射性的) and would not produce dangerous waste. On Earth, we have only 15 to 20 tons of helium-3 that can be used. But after studying the moon’s soil, scientists said there could be at least 1 million tons of helium-3 on the moon. That’s enough for all people on Earth to have clean energy for 10,000 years!

In the minds of the Chinese, they always    1    the moon with gentleness and brightness, expressing their best wishes. On August 15 of the lunar calendar each year, the moon is full and it’s time to celebrate the Mid-Autumn Festival.

In Chinese traditional culture, the moon is a    2    of human’s feelings. In ancient times, from royalty to the ordinary family, it was an important custom    3    the full moon during the festival. Adults usually enjoyed delicious mooncakes with a cup of hot tea,    4    children ran around with bright lanterns. After nightfall, whole families went out for a walk under the stars, looking up at the full moon and thinking of their relatives or friends, as well as    5    was far from home. A line from a poem “The moon seen at home is brighter” expresses those feelings.

Besides, with respect to the history of Chinese civilization（文明）, China is the first nation to have the dream of flying to the sky.    6    the story of Chang’e to Dunhuang flying apsaras, all express Chinese ancestors’ desire to explore（探索）outer space. Many ancient Chinese poets also showed their great    7    in the moon through wonderful words. For example, the poet Li Bai, a    8    lover of the moon, wrote hundreds of poems about it.

The Chinese exploring moon project, named after Chang’e,    9    expresses this pursuit（追求）of the Chinese. The successful launch of Chang’e 1 not only    10    the groundwork（基础）for future exploration of the moon, but also made a long-held dream of the Chinese people come true.

3 . We have seen lots of science fiction movies about aliens. People travel to stars and even fight with aliens in the movies. But are there real aliens in the universe（宇宙）? Most of us think it is impossible, just like fairy tales. But the answer of some scientists is yes. So they have been searching for aliens in outer space for many years. They hope to find life signs of aliens.

Some scientists are used to using radio telescopes（望远镜）to search for aliens in space. In order to find aliens, they have worked hard for over half a century, but so far they have found nothing. Then some scientists guessed aliens might not want to connect us, but aliens could answer our messages. So some scientists sent radio signals into the universe. They hope one day they would be picked up by alien technology. These scientists want to prove（证明）that we are not alone in the universe.

But what should we do if the “alien phone” rings one day? Should we answer it? Stephen Hawking, the famous physicist, thought it could be dangerous to connect aliens. He said that the main purpose of aliens’ visiting to the earth could be searching for our resources（资源）. But other scientists think we have no need to worry. David Morrison, a NASA scientist, said, “If an alien radio signal reaches the earth from a planet thousands of light-years away, then they almost surely have solved all the problems we still have including the short of resources. Maybe they are much smarter than us, but why do they want to hurt us? I think we can try to connect them.”

5 . Mars is a neighboring planet in our solar system. Scientists study Mars because it could hold clues that could help us learn more about life on Earth. For decades, scientists have used robot technology to better understand Mars. In December 2020, scientists introduced a group of robots named Mars Dogs at a yearly meeting.

The Mars Dog is a four-legged robot created by the company Boston Dynamics. It, along with other similar robots, can move around in ways the wheeled rovers (探测器) that explored the planet never could. Traditional Mars rovers are limited mostly to flat surfaces. However, many scientifically interesting Martian regions are only reachable by crossing very rough (崎岖的) ground or going below ground. Walking Mars Dogs are well-suited for such challenges—even if they fall down, they can get back up again. These robots can also explore underground by walking around rocks and lowering themselves into caves. They are even capable of selecting which path to take. While they do this, they collect measurements to build a map of what they see.

A Mars Dog would also be about 12 times lighter than present rovers. It would be able to travel much faster, reaching normal walking speeds of 5 kilometers per hour during tests. Compare that to the Curiosity rover that is presently exploring Mars. Curiosity rolls along the Martian surface at about 0.14 kilometers per hour.

Before going to Mars, the team members are testing the robot. They even take the robot to outdoor locations similar to Martian landscapes. Those tests show that the robots, without any help, can walk around rocks and map deep caves. “These behaviors could one day enable significant scientific missions to take place on the Martian surface and subsurface,” the scientists said at the yearly meeting.

Our Milky Way Galaxy may be home to 2 billion planets that have the right conditions to support life. These planets have the correct temperature for liquid water. While no one knows what alien life would look like, if it is anything like life on earth, it would need water to keep alive. According to the research, there are nearly 2 billion habitable planets in the Milky Way Galaxy, which is just one of 100 to 200 billion galaxies in the universe.

The earth was formed 9 billion years after the Big Bang. Many of the planets in the Milky Way were formed millions and some even billions of years before the earth. If intelligent life had existed on any of these planets, they would be much more developed than humans. With that much time to develop the technology for space travel, we should have been visited by aliens many times.

So where is everyone? Some people believe that aliens have visited earth many times, and some governments of the world might have known very well. some believe that we have also been visited many times in the ancient past. They point to the Egyptian pyramids or the huge heads of Easter Island. They say that there was no way that ancient humans were able to create these structures without alien assistance.

According to Harvard professor Avi Loeb,        . For example, in 2017, a cigar-shaped object came within 33 million km of the earth as it passed through our solar system. It was named Oumuamua, which means “messenger from the distant past reaching out to us” in Hawaiian. Loeb says that its unusual shape and the fact that it sped up as it left our solar system sets it apart from anything else we’ve seen. He thinks it was a probe sent by an alien civilization. Jackie Fairey, says everyone should have reservation about this. She is one of many scientists who say there are more reasonable explanations for Oumuamua. That hasn’t stopped Professor Loeb. He has written a new book on Oumuamua called Extraterrestrial: The First Sign of Intelligent Life Beyond Earth.

7 . Venus, the evening star, is a brother planet of our earth.     1     It’s covered with air and clouds. Scientists once thought that there might be some kinds of life under the clouds. Recently, they have found that it’s too hot—400℃.     2     Why is it so hot then?     3     CO₂ allows the heat of the sun to go to the ground. At the same time, it prevents the heat from going out.     4     Thus（因此）most of the heat from the sun is kept in the air forever. The temperature goes up every year, and it’s 400%℃ now.

The United Nations suggested that all leaders in the world should meet to discuss cutbacks（缩减）of CO₂. Other people in Europe have started a battle called “Green Peace Movement”.     5     No one would like to change our green earth into a red hot planet like Venus.