What will astronauts eat when a space trip takes years?

“Lots of fresh vegetables,” says Dr. Janet Williams, whose team have spent the last 10 years learning how to grow plants in a space station. And it’s a good thing that she has already started her work, because space gardening can be really hard.

As usual, astronaut George White looked into the closed plant room. He had planted Dr. Williams’s quick-growing seedlings none of the stems were showing. He opened the room to check and found the problem. The stems weren’t growing upward and the roots weren’t growing downward. On Earth, gravity (重力) helps a plant’s stems and in it, but roots (根) to find “up” and “down”. However, in the space station, there was almost no gravity.

Dr. Williams suggested a method: give the plants more light, as plants also use sunlight to find their way. And it worked. When the plants had more light, the stems turned up and the roots went down.

Now Dr. Williams was free to worry about the next problem: Would her baby plants live to flower? Can we grow food on a space journey?

Many plants died in the space station. Dr. Williams thought she knew why: the space plants were hungry for air. Plants live by taking up CO₂ from the air. Since a plant uses it up in the air around, the plant needs moving air to bring more CO₂ close to its surface! On Earth, the air is always moving. Gravity pulls down cold air, and warm air rises. And with these air movements, plants get enough CO₂.

Many earlier experiments (实验) with plants in space had used closed rooms. Dr. Williams tried a new greenhouse that had a fan (电扇) to keep the air move. The plants loved it. They flowered and even produced more seeds. Using Dr. Williams’s method, astronaut George completed the first seed-to-seed experiment in space, and moved one plant closer to a garden in space.

“And this,” says Dr. Williams, “is good news for long-term space travel.”

2 . Do stars only appear at night? The answer is no. Venus（金星）is the one and only star that can be seen in the daytime. It shone at its brightest in the night sky on February 17, 2017.

Venus is the second planet in order from the sun. It is the second brightest natural object（物体）, behind the moon, in the night sky. Why is it so bright? First of all, Venus is the closest planet to the earth. It is also covered by highly reflective（反射的）clouds, which can reflect about 70 percent of the sunlight shining it, almost twice as much as the earth doe.

Some people called 2017 the year of Venus, because the planet was at its brightest twice in the year. Venus gets brighter when it goes further away from the sun, and nearer to the earth. The brightest moment happened once in February, and happened again during daylight on April 30th.

Venus is closer to the earth than Mars and it’s closer to the earth in size. Isn’t it a better choice for human exploration（探索）than Mars? However, with a temperature of about 465℃ on the surface, Venus is the hottest planet in our solar system! So people haven’t explored Venus yet. But scientists never give up. Recently, a team of NASA and Russian scientists created a new computer equipment that can stand temperatures of 480℃. It can work under Venus-like conditions for almost 22 days. The next step, according to the scientists, is to send a probe（探测器）to Venus by 2025.

3 . For thousands of years, humans have explored the Earth. Nowadays, we are exploring space. Astronomers (天文学家) are modern—day explorers. Now, many astronomers are looking for new planets and new places of humans to live in the future. But where do astronomers start looking?

First of all, astronomers look for a star. That’s because our own Earth moves around a star (the Sun). More importantly, it is the correct distance (距离) from the Sun for heat and light. So when astronomers have found the star, they look at the planets around it. In recent years, astronomers have found nearly 400 new planets with stars. However, many of these planets are either too near to the star or too far away.

However, if the planet is in a good position, astronomers look for three key things: water, air and rock. Water is important because all life needs water. Humans can drink it and they can also grow plants with water. And plants produce air for humans to breathe and food to eat. Rock on a planet is also important. That’s because there is often water under the rock.

After many years of scrutinizing, astronomers have found a planet that is similar to the Earth. It’s Gliese 581g and it’s near a star. The astronomers think it has water and rock and the average (平均的) temperature is between -31℃ and -12℃. That’s cold，but not colder than Antarctica or Arctic Circle, for example, Gliese 581g is bigger than the Earth. A year on Gliese 581g is only 37 Earth days instead of 365. But astronomers do not think there are big differences and some them thing Gliese 581g will be a new Earth. However, Gliese 581g is twenty light years from the Earth.

At 9:00 am on 15th October, 2003, our country     1     （send）its first manned spaceship, Shenzhou V, into space at Jiuquan Satellite Launch Centre.     2     took Yang Liwei and his spaceship about 21 hours to go around the earth 14 times. Yang Liwei is China’s     3     （one）astronaut. He comes from Liaoning Province and

The life of     5     astronaut is not easy. To put on a spacesuit takes him 15 minutes     6     the help of others.

China has become the third country in the world to send a person     10     space. We are all proud of our motherland.

6 . At 9:00 am on 15th October 2003, our country     1    （send）its first manned spaceship, Shenzhou V, into space at Jiuquan Satellite Launch Centre.     2     took Yang Liwei and his spaceship about 21 hours to go around the Earth 14 times, Yang Liwei is China’s     3    （one）astronaut. He comes from Liaoning Province and     4    （be）an air force pilot（飞行员）for many years.

The life of     5     astronaut is not easy. To put on a spacesuit takes him 15 minutes     6     the help of others.     7    （sleep）in space is not easy, either. He has to sleep in a special sleeping bag on the wall     8     there is no gravity（重力）. “I’m feeling very good in space, and it looks wonderful here,” said Yang. “I have looked at our beautiful Earth and recorded（记录）    9     I have seen there."

China has become the third country in the world to send a person     10     space. We are all proud of our motherland.

7 . Will humans someday live and work on Mars（火星）? Many scientists think so. In fact, they are already working on plans to turn Mars into a new Earth.

Humans need three basic things to live: water to drink, air to breathe and food to eat. Because of the shortage of those above, it is impossible to live on Mars right now. Then how can we make Mars a right place for humans to live on? The answer is to change the environment of the planet so that it is similar to Earth’s.

On Mars, the temperature is about —60℃. So one of the main purposes is to warm it up. One idea for warming Mars comes from a problem here on Earth ——climate change. Most scientists agree that Earth is becoming warmer because of increased levels of greenhouse gases（气体）in our atmosphere（大气）. We might create similar conditions on Mars by building factories that give off greenhouse gases. The gas will change the atmosphere on Mars. Rain will fall, and it may be possible to grow plants for food. There will be many difficulties in changing Mars. The program could take many centuries, and the cost will be high. We have some of the technology, such as the ability to create greenhouse gases, but not the money. Anyway, life on Mars is a real possibility for future people.

Xinhua news－China’s Chang’e-5 probe (探测器) will get to the earth from the moon on December 17th, 2020.

On December 3rd, 2020, a Chinese spaceship, Chang’e-5 probe, took off from the surface of the moon. It carried the country’s first samples (样本) of the soil and rocks on the moon.

Chang’e-5 probe is the first Chinese spaceship to take off from a star in space except the earth. On November 24th, Chang’e-5 probe was launched from Wenchang, Hainan Province in China. It landed safely on the moon on December 1st.

The takeoff from the moon overcame a lot of difficulties, including the different environments between the earth and the moon. “But luckily, we made it.” Xing Zhuoyi, a designer of Chang’e-5 probe said excitedly. Before the takeoff, a Chinese national flag was unfolded from the probe. “Everybody in the science hall clapped their hands together warmly.” Xing said. At that time, he felt so proud of his work and his country.

Chang’e-5 is one of the most important and challenging tasks in Chinese space history. It has also been the world’s first moon-sample task in more than 40 years. If successful, the task will help improve China’s science and technology development. It will play an important part in China’s future moon landing and deep-space exploration (探索).

A group of scientists discovered a gas called phosphine(磷化氢) on Venus(金星). That means there may be living things on the planet, which made many people start to imagine the talk between aliens and humans. A reporter from Washington Post wrote a letter to people of Earth on behalf of(代表) the citizens on Venus.