1 . A satellite is an object in space that orbits around another. It has two kinds — natural satellites and artificial satellites. The moon is a natural satellite that moves around the earth while artificial satellites are those made by man.
Despite their widespread impact on daily life, artificial satellites mainly depend on different complicated makeups. On the outside, they may look like a wheel, equipped with solar panels or sails. Inside, the satellites contain mission-specific scientific instruments, which include whatever tools the satellites need to perform their work. Among them, high-resolution cameras and communication electronics are typical ones. Besides, the part that carries the load and holds all the parts together is called the bus.
Artificial satellites operate in a systematic way just like humans. Computers function as the satellite’s brain, which receive information, interpret it, and send messages back to the earth. Advanced digital cameras serve as the satellite’s eyes. Sensors are other important parts that not only recognize light, heat, and gases, but also record changes in what is being observed. Radios on the satellite send information back to the earth. Solar panels provide electrical power for the computers and other equipment, as well as the power to move the satellite forward.
Artificial satellites use gravity to stay in their orbits. Earth’s gravity pulls everything toward the center of the planet. To stay in the earth’s orbit, the speed of a satellite must adjust to the tiniest changes in the pull of gravity. The satellite’s speed works against earth’s gravity just enough so that it doesn’t go speeding into space or falling back to the earth.
Rockets carry satellites to different types and heights of orbits, based on the tasks they need to perform. Satellites closer to the earth are in low-earth orbit, which can be 200-500 miles high. The closer to the earth, the stronger the gravity is. Therefore, these satellites must travel at about 17,000 miles per hour to keep from falling back to the earth, while higher-orbiting satellites can travel more slowly.
1. What is Paragraph 2 of the text mainly about?| A．The appearance of artificial satellites. | B．The components of artificial satellites. |
| C．The basic function of artificial satellites. | D．The specific mission of artificial satellites. |
| A．Providing electrical power. | B．Recording changes observed. |
| C．Monitoring space environment. | D．Processing information received. |
| A．By relying on powerful rockets to get out of gravity. |
| B．By orbiting at a fixed speed regardless of gravity’s pull. |
| C．By changing speed constantly based on the pull of gravity. |
| D．By resisting the pull of gravity with advanced technologies. |
| A．They are more affected by earth’s gravity. |
| B．They take advantage of rockets more effectively. |
| C．They have weaker pull of gravity in higher orbits. |
| D．They are equipped with more advanced instruments. |
2 . For children, space is magical — a whole world is out there, with so many things to learn and stories to read. Here are some children’s books about space and the solar system.
Mae among the Stars by Stasia Burrington
This beautifully illustrated picture book is attractive to young kids. It was inspired by the first African American woman in space, Mae Jemison. It tells the story of Mae as a little girl, who always knew she had big dreams about space. This is a great addition to a young kid’s collection, as a reminder to hold tight to dreams and never give up.
Space by Libby Jackson
This beautifully illustrated book gives kids a look at 50 women from around the world who were involved in exploring space in some way, from the 19th century to the present day. This is a perfect gift for young kids who want to know more about some of the lesser-known scientific achievements related to space exploration.
Chasing Space by Leland Melvin
This is Melvin’s story about being a football player-turned-astronaut, along with his recovery from an injury that nearly left him deaf. Kids will love reading his story about how he faced challenges and advanced ahead, and he also includes DIY experiments for kids to try, and a section of full-color photographs.
System and Beyond by David A. Aguilar
The book is full of beautiful illustrations of space, and is perfect for kids of all ages, exploring various planets and the solar system. Unlike other kids’ space book, this is a National Geographic book written and illustrated by an award-winning astronomer and space artist. Aguilar is also the former Director of Science Information and Public Outreach at the Harvard-Smithsonian Center for Astrophysics.
1. What do Mae among the Stars and Space have in common?| A．They include less-known astronauts. | B．They tell about scientists’ childhood. |
| C．They cover women exploring space. | D．They are suitable for children of all ages. |
| A．Stasia Burrington’s. | B．Libby Jackson’s. |
| C．Leland Melvin’s. | D．David A. Aguilar’s. |
| A．It has beautiful pictures. | B．It tells about space artists. |
| C．It has won many grand awards. | D．It was written by an astronomer. |
3 . A new study focuses on K2-18b, an exoplanet(系外行星) discovered in 2018, which orbits a red dwarf star close enough to receive about the same amount of radiation from its star as Earth does from our sun.
Recently, scientists have discovered gas giants that have water in their atmospheres, but this is the least giant planet ever to have water detected in its atmosphere. “The water detection was quite clear to us relatively early on,” lead author Bjorn Benneke, a professor at the Institute for Research on Exoplanets at the Universite de Montreal, told Space.com in an interview.
“Studies have suggested that planets with hydrogen-rich atmospheres could host certain forms of life.” Benneke said. However, “K2-18b’s large atmosphere is extremely thick and creates high-pressure conditions, which likely prevents life as we know it from existing on the planet’s surface.” a news release reads. While these researchers found evidence for liquid water clouds on K2-18b, because of its lack of surface, rain wouldn’t pool on the planet. Without a real surface, so to speak, landing on the planet would also be nearly impossible to land on, especially because the gas is so thick and has such an incredibly high pressure that any Earth-created spacecraft sent there would be destroyed.
Benneke suggests that, possibly, this planet formed by rock absorbing large amounts of gas, “like a vacuum cleaner,” he said. The gas absorbed would have more than doubled the planet and increased its volume Warren eightfood.
To come to these conclusions, the research team analyzed data from Hubble Space Telescope observations that they made between 2019 and 2020 of the K2-18b planet passing in front of its star eight times. This type of research, Benneke said, is leading toward a final goal of “being able to study real, true earth-like planets.” We are not quite there yet, he said, but this is really exciting.”
1. Why is it impossible to land on the K2-18b?| A．It has thin gas. | B．It doesn’t have a real surface. |
| C．It has too much water. | D．It is too far from the earth. |
| A．By releasing gas itself. | B．By receiving radiation from the sun. |
| C．By taking in much gas by rocks. | D．By getting away from the red dwarf star. |
| A．Scientists are making progress in studying real earth-like planets. |
| B．It is impossible for humans to land on other earth-like planets. |
| C．Scientists have succeeded in exploring K2-18b completely. |
| D．The K2-18b planet has passed before its star eight times between 2019 and 2020. |
| A．The exploration of the outer space. |
| B．The study of solar systems’ environment. |
| C．The discovery of the K2-18b planet. |
| D．The research on the K2-18b planet. |
4 . For years, planet-hunters have been searching for a planet other than Earth that can support life. They may have found one.
The planet is the sixth found orbiting a star called Gliese 581. Steven Vogt, one of the scientists involved, expects the new planet to have water. On Earth, when we find water, we find life.
A planet that can support life has to be just the right size for its system and just the right distance from its star. Some planets orbit so close to their stars that they’re much too hot for liquid water—or for life as we know it.
But a right-sized planet that's neither too close nor too far might be just right for water. Gliese 581 is probably just right. It is about three times as huge as Earth.
The new planet is 20 light years away, which is as far as 250 million trips to the Moon and back.
Gliese 581 is an exciting discovery—and astronomers are likely to find more soon, thanks to new, powerful telescopes specifically designed to look for planets.
| A．We can’t travel at the speed of light. |
| B．It’s pretty hard to imagine that water wouldn't be there. |
| C．Human beings won’t be visiting this planet any time soon. |
| D．So scientists looking for life on other planets look for water first. |
| E．It orbits its star so closely that it goes all the way around in only 37 days. |
| F．Astronomers will probably find more potential life-supporting planets soon. |
| G．Other planets keep their distance from the stars—where they’re too cold to have water or life. |
