What's a spacewalk? Any time an astronaut gets out of a spacecraft while in space, it is called a spacewalk. Astronauts go on spacewalks for many reasons. For example, experiments can be placed on the outside of a spacecraft. This lets scientists learn how being in space affects different things. By going on spacewalks, astronauts can also fix certain things instead of bringing them back to the earth to fix.

When astronauts go on spacewalks, they wear spacesuits to keep themselves safe. Inside spacesuits, astronauts have the oxygen they need to breathe and the water they need to drink. To keep the astronauts and the spacecraft safe, the astronauts must leave and go back to the spacecraft through a special door. When on a spacewalk, astronauts use safety tethers to stay close to their spacecraft, which connect the spacewalkers with the spacecraft. They keep astronauts from floating away into space. Another way astronauts stay safe during spacewalks is by wearing a SAFER. SAFER is worn like a backpack. It helps an astronaut move around in space.

How do astronauts train for spacewalks?  One way is by going for a swim. Floating in space is a lot like floating in water. Astronauts practice spacewalks underwater in a huge special swimming pool. For every one hour they will spend on a spacewalk, astronauts need to train seven hours in the pool. Another way astronauts practice for a spacewalk is by using virtual reality(虚拟现实). It looks and feels just like a spacewalk.

Today, only three countries have finished spacewalks independently. They are Russia, the United States and China. The first person to go on a spacewalk in the world was Alexei Leonov from Russia. Zhai Zhigang is the first Chinese astronaut to go on a spacewalk. The world record of spacewalks is held by Russian astronaut Anatoly Solovyev. He has been on 16 spacewalks and spent more than 82 hours outside in space.

A New Trend of Micro Museums

Is Making Science Portable

Science museums are amazing. You can see large dinosaur bones from the huge creatures that disappeared thousands of years ago or take a look at cells under a microscope. .

You can learn so much at a science museum if living close enough to one. However, for those who don't live in a city, getting a chance to visit science museums is not easy. ", their influence is limited. There just aren't enough science museums," said Charles Philipp. "And due to the high costs, it's unlikely that we'll be seeing a bunch of new traditional science museums popping up all over the country anytime soon."

Philipp and his partner Amanda Schochet have decided to reinvent science museums by getting them small. They founded MICRO, a nonprofit organization that builds tiny 6-foot-tall science museums, which are portable and replicable (可复制的). . They can get access to it for free in such places as waiting rooms of hospitals, libraries, airports, and even shopping malls.

, they made it with the help of a team of engineers, storytellers, and designers. Each of the micro museums has a scientific topic. The first museum is the Smallest Mollusk (软体动物) Museum showing the world of mollusks, which has won great popularity as the only museum devoted just to mollusks. A second museum is the Perpetual Motion Museum that focuses on physics and engineering and will officially open next year. It asks why things move, and why they stop. Hopefully one will come to a neighborhood near you soon.

Photographic self-portraits have existed for as long as cameras have been in human hands. But what about selfies in space? On Twitter last year, NASA astronaut Edwin Aldrin, who famously became the second man to walk on the moon in July 1969, laid claim to a spaceflight first: taking the first selfie in space during the Gemini XII mission in 1966.

"For me, it needs to be digital to be selfie, " argues Jennifer Levasseur, a director at the Smithsonian National Air and Space Museum. According to Levasseur, the concept of a selfie is directly linked to internet culture. "The thing that makes a selfie is sharing it," she says.

Still, astronauts have been carrying cameras aboard space vehicles since the 1960s. In 1966, Aldrin used a Hasselblad camera designed specifically for space. Hasselblad also painted the first camera in space a matte(不光亮的)black to reduce reflections in the orbiter window. But cameras used in space need to survive extreme conditions, like temperature swings from -149 F to 248 F, so Hasselblad painted later model silver.

Astronauts visiting the moon then had to take out the film and leave their camera bodies behind when they returned to Earth, because early space missions were limited by a weight limit on the returned trip. Then a big change in space camera technology came after the space shuttle Columbia broke apart on its return to Earth in 2003, Levasseur notes. "Fear that they'd never be able to bring film back from space and lose all that hard work accelerated the push for digital," she says.

Today, astronauts also have access to internet and social platforms in space and can post true space selfies made using digital cameras. Similarly, space robots are participating in selfie culture, capturing remote pictures of themselves in space or on other planets and sending them back to Earth.

Study Abroad

Every year, thousands of students choose to study abroad for the summer, six months, a year or longer. Here are some things you need to know before you make such a decision.

Why do it?

Living in another country will help you learn about the culture of another land. You will see the world in a new way. Many companies today want employees who speak a second language or who have experienced living or working in another country.

Making the right choice.

To choose the right country or school, ask yourself these questions： Do I want to live with a host family(寄宿家庭)，with roommates, or alone? How much do I want to pay?

Get your passport and visa(签证)early! Before you go，learn as much of the language as you can，and read about the customs of your host country. Also，talk with people who have experienced studying abroad. Call the school to make sure someone can meet you when you get there.

Once you are there.

After the first few weeks it's usual to feel a little homesick. Just be open to meeting new people and having new experiences. Remember that it takes time to get used to a new place with new customs. Talk to your new friends and write about your feelings.
 

L=Lily P=Peter

L: Peter, this morning, I learned from a magazine that China's Chang'e 5 lunar probe successfully returned with samples from the Moon in 2020.

P: Yes. The successful return (被认为是一个很大的进步)in humans' space exploration.

L: I can't agree more. And because of that, China became the third country in the world to bring the samples back from the Moon.

P: You said it, and (人们相信那些样本可以帮助科学家们 更多地了解月球的起源和形成)。

L: You're right. Actually, it's said that (中国不但自己研究那些样本，还把一些送给了其他国家)。

P: I think it's really a great idea. (月球属于全世界是不言而喻的)。Just as one expert says, international cooperation is one of the best ways to carry out scientific research, so China is willing to share its achievements with other countries.

B: Are you kidding? My six-year-old daughter (has been able to/ has to) make sentences freely with about 300 words.

B: Really? In that case, you (should/could) call the police immediately.