An international team of astronomers used a database combining observations from the best telescopes in the world
The Milky Way Galaxy
To test this theory, astronomers look at distant galaxies. Due to the limited speed of light, it takes time for light to travel across the void of space. The light we saw last night from an object 10 billion light years away
2 . With the fast development of astronomy, astronomers are eager to find a hint of the familiar: planets that resemble Earth. By pushing technology to the limits, astronomers are rapidly approaching the day when they can find another Earth.
The most direct approach is to take a picture of it with a telescope. However, a more effective way is to use “the Doppler technique”. This involves analyzing starlight for evidence that the star’s movement is affected by the gravitational pull of a planet. Nowadays, astronomers can tell when a planet is pulling its star by only one meter a second — about human walking speed. That’s enough to detect a giant planet in a big orbit, or a small planet if it’s close to its star.
Another approach is to watch a star for a slight dip in its brightness. This occurs when an orbiting planet passes in front of the star and blocks part of its light. At most, a tenth of all planetary systems are oriented so that these mini-eclipses (日食，月食) — called transits (凌日) — are visible from Earth. So, astronomers have to monitor a lot of stars to capture just a few transits.
The dream of astronomers is to discover a rocky planet roughly the size of Earth orbiting in a habitable zone, one that is neither too hot nor too cold to support life. If they succeed, they will have found what biologists believe could be a promising residence for life.
The best places to look may be dwarf stars. Smaller than the sun, dwarf stars are plentiful; seven of the ten stars nearest to Earth are dwarf stars. They also provide a steady supply of sunlight to any life-bearing planets within their habitable zone. Additionally, dwarf stars are dim, so the habitable zone lies closer in. If the planet is closer to the star, it’s easier for astronomers to detect a transit observation. A close-in planet also has a stronger pull on its star. That makes it easier to detect with the Doppler method.
1. According to paragraph two, astronomers analyze starlight with the aim of finding ________.| A．where we can detect a giant orbit |
| B．why a small planet is close to its stars |
| C．whether the motion of the stars is changed |
| D．how strong the power of the gravitational pull is |
| A．Transits last a very short period of time. |
| B．Most planetary systems don’t have transits. |
| C．Transits only occur for a small number of stars. |
| D．No more than 10% planetary systems have visible transits from Earth. |
| A．dwarf stars are limited in number |
| B．their planets are close to the Earth |
| C．the closeness of the habitable zone to dwarf stars aids detection |
| D．the brightness of dwarf stars to Earth improves their visibility |
| A．Confident. | B．Suspicious. | C．Ambiguous. | D．Unconcerned. |
Before the mid-20th century, most people felt travelling into space was an impossible dream. However, some scientists were d
Although scientists try to make sure nothing goes wrong, accidents can still happen. All the astronauts on the USSR’s Soyuz 11 and America’s Challenge died during their missions. These disasters made everyone sad and disappointed, but the desire to explore the universe never died. This is because people believe in the importance of c
4 . A new study suggests that dark markings on the planet Mars represent sand — not water. The research in 2015 suggested that lines on some Martian hills were evidence of water. Yet American scientists now say these lines appear more like dry flows of sand. If water is present, it is likely to be a small amount. Water in liquid form would be necessary for microbial (微生物的) life.
NASA, the American space agency, said more research is needed. Michael Meyer is the lead scientist for NASA’s Mars exploration programme. He noted that the latest study does not reject the presence of water. But he admitted, “It just may not be as exciting as the idea of rivers going down the sides of cliffs (悬崖).”
The new findings come from a team led by Colin Dundas of the United States Geological Survey. His team measured 151 of these lines in 10 areas. Most of the lines end with slopes (倾斜) between 28 degrees and 35 degrees. These measurements are similar to active sand dunes (沙丘) on both Mars and Earth. A small covering of dust that moves and sometimes becomes lighter might help explain the markings. They usually appear in the Martian summertime, and then disappear until the next year. If these lines are dry, this suggests that recent Mars bas not had large amounts of liquid water. Dundas and his research team say that many questions remain.
“I still think that Mars has great potential for having had life early on in its history,” Meyer said. “As long as that’s true, we also have a reasonable possibility of life still being on Mars. It just happens to be cryptic or well hidden.”
NASA currently has no robotic — either on Mars or in development — with the ability to climb steep slopes. The lack of such equipment has engineers coming up with ideas like Martian helicopters or planes without pilots.
1. What do American scientists find on Mars now according to their study?| A．A lot of little life. | B．An amount of water. |
| C．Some Martian hills. | D．Dark markings are sand. |
| A．In Martian spring. | B．In Martian summer. |
| C．In Martian autumn. | D．In Martian winter. |
| A．Doubtful. | B．Trustful. | C．Unconcerned | D．Objective. |
| A．Undiscovered. | B．Strange. | C．Magical. | D．Icy. |
5 . As we all know, the universe includes the Sun and Earth, the planets and moons, the galaxies and stars.
Within the universe are billions of galaxies. A galaxy such as our own Milky Way contains billions of stars.
Cosmologists (宇宙学家) think that before the universe existed, all matter and energy were gathered in a tiny point. Then the point exploded. This explosion is called the Big Bang. After the Big Bang, the universe expanded at an amazing rate.
We still have much to learn about the universe. One important question remains unanswered: Does life exist beyond Earth? Scientists do not have the answer.
| A．One of those stars is the Sun. |
| B．The Sun and the Earth are in the solar system. |
| C．That is, the universe includes space and everything in it. |
| D．Some people believe that people have a good life on Earth. |
| E．The expansion then slowed and, over time, the universe cooled. |
| F．Some think that Earth is the only planet in the universe with intelligent life. |
| G．Cosmologists are also trying to determine what the likely future of the universe will be. |
6 . 阅读下面短文，在空白处填入1个适当的单词或括号内单词的正确形式。
American scientists are working to develop a telescope to deploy(部署) on the moon. The telescope is designed to search for ancient radio waves
7 . Mars is truly a fascinating planet for those of us here on Earth.
The Red Planet has the largest volcano in the solar system-Olympus Mons.
Mars also has an atmosphere, but it is very thin and made up mostly of carbon dioxide. Because of its thin atmosphere and greater distance from the Sun, Mars is much colder than Earth.
Scientists believe that studying Mars can help answer some of the key questions about our planet Earth, or even the universe.
| A．It is roughly 27 kilometres high. |
| B．Missions to Mars have never been easy. |
| C．Mars, however, today has no active volcanoes. |
| D．The temperature at the planet’s surface varies widely. |
| E．However, Mars does have weather, with clouds and winds. |
| F．China will continue to explore the mysteries of the universe. |
| G．It is one of the few planets that we can see with our own eyes. |
8 . Two high school students have identified four new planets in distant space about 200-light-years from Earth, making them “the youngest astronomers” to make such a discovery.
Kartik Pingle, 16, and Jasmine Wright. 18, who both attend schools in Massachusetts, participated in the Student Research Mentoring Program (SRMP). With the help of Tansu Daylan, an MIT doctor for Astrophysics and Space Research, the students studied and analyzed data from the Transiting Exoplanct Survey Satellite (TESS). Together they focused on Tess Object of Interest (TOI) 1233, a nearby, bright sun-like star and here they found four planets rotating（旋转）around the star. “We were looking to see changes in light over time,” Pingle explained, “the idea is that if the planet transits the star, or passes in front of it, it would periodically cover up the star and decrease its brightness.”
While studying 1233, Pingle and Wright had at least hoped to find one planet but were overwhelmed with joy when a total of four were spotted. “I was very excited and very shocked.” Wright said. “We knew this was the goal of Daylan’s research, but to actually find a multi-planetary system, and be part of the discovering team, was really cool.” Three of the newly discovered planets are considered as “sub-Neptunes”, which are gaseous, but smaller than the Neptune that lives in our solar system. While observing the planets, the team determined each one completes their orbit around 1233 every six to 19.5 days. However, the fourth planet is called a “super-Earth” for its large size and rockiness this one orbits around the star in just under four days.
“We have long been studying planets beyond our solar system and with multi-planetary systems, the two young students are kind of hitting the jackpot. They are really blessed.” Daylan said. “The planets originated from the same disk of matter around the same star, but they ended up being different planets with different atmospheres and different climates due to their different orbits. So, we would like to understand the basic processes of planet formation and evolution using this planetary system.”
Daylan added that it was a “win-win” to work with Pingle and Wright on the study. “As a researcher, I really enjoy interacting with young brains that are open to experimentation and learning and have slightest bias（偏见）.”he said, “I also think it is very beneficial to high school students, since they get exposure to cutting-edge research, and this prepares them quickly for a research career.”
1. How did the two students identify the four planets？| A．By helping professor Tansu Daylan with the data. |
| B．By analyzing the change of brightness of star 1233. |
| C．By studying Neptune that lives in our solar system. |
| D．By interacting with other young talented brains. |
| A．It was made by two high school students. |
| B．It was made with an innovative approach. |
| C．It was meant to be made by Tansu Daylan. |
| D．It found the largest number of planets at a time. |
| A．Making a discovery difficultly. | B．Achieving the goal easily. |
| C．Succeeding in something luckily. | D．Performing a task carefully. |
| A．It allows the scientists to work with young people without prejudice. |
| B．It equips future astronomers with better researching abilities. |
| C．It provides more perspectives and thus boosts more discoveries. |
| D．It arouses students’ interest in exploring the unknown universe. |
9 . Unusually bright light in the sky that appeared suddenly last June has got astronomers in great excitement, After months of study, they still aren’t sure what the object — university referred to as the “Cow” — is, whatever it is, says astronomer Lilian Rivera Sandoval or Texas Tech University in Lubbock, “It’s super strange and we are obsessed with its study.”
The Cow first appeared in telescope observations on 16 June 2018, in what turned out to be small galaxy about 200 million light years away. “When we saw that we thought, let’s get on this.” says Daniel Perley, an astronomer at Liverpool John Moore University.
The early observations confirmed the Caw was truly strange. It didn’t show the obvious changes in its light output that an exploding star would make. Sandoval ways as soon as she and colleagues Anew the Cow was truly distant, they requested time on NASA’s Neil Gehrels Swift Observatory to see what the Cow was doing in X-rays. Although the X-ray brightness varied over the early weeks, “the spectrum didn’t change, which is very unusual,” she notes. After 3 weeks, the X-ray signal began to vary more wildly while also dropping off in brightness.
Many astronomers agree that the long and steady duration of the event means that it was powered after an initial explosion by some form of central engine. But what that engine may be is also far from clear. Some argue that it could be a very unusual star whose central part has collapsed inward after it exploded. Others say it is a tidal disruption event — a star being torn apart by a black hole. But that usually requires the supermassive black hole in the center of a galaxy, and the Cow is situated in its galaxy’s arm. So, some say, il could be a tidal disruption event generated by an intermediate mass black hole, although evidence for the existence of such smaller black holes remains controversial. “All explanations have problems,” Sandoval says, “I hope there are more Cows.”
1. What is astronomers’ main concern about the Cow?| A．When it appears. | B．How it forms. |
| C．What it is. | D．Where it is from. |
| A．The Cow is a not typical exploding star in the galaxy. |
| B．The changes of X-rays brightness proved the Cow unique. |
| C．The Cow is not far from the Earth and easy to study. |
| D．The X-ray test helped find accurate features of the Cow. |
| A．The research results help little. | B．More Cows will appear. |
| C．Extra attention should be paid to the Cow. | D．More information is needed. |
| A．Astronomers conducted an interesting experiment at NASA. |
| B．The Cow has aroused astronomers’ passion in its research. |
| C．There exists a wide range of changes in the galaxies. |
| D．The discovery of the Cow is a great achievement. |
10 . Scientists know quite a lot about stars. After centuries of pointing telescopes at the night sky, astronomers and amateurs alike can figure out key traits of any star, such as its mass or its composition.
To calculate a star’s mass, just look at the time it takes to orbit a companion star. Then do a bit of calculation. To determine what it’s made of, look to the spectrum of light the star sends out. But one question scientists haven’t quite cracked yet is how to calculate the exact time of a star.
“The sun is the only star we know the age of,” says astronomer David Soderblom. He works at the Space Telescope Science Institute in Baltimore, Md. We use what we know about it and how it compares to others, he says, to figure out the age of other stars.
Even well-studied stars surprise scientists every now and then. In 2019, the red supergiant Betelgeuse became gradually dark. At the time, astronomers weren’t sure if this star was just going through a phase. The alternative was more exciting: It might be ready to explode as a supernova. (Turns out it was just a phase.) The sun also shook things up when scientists noticed that it wasn’t behaving like other middle-aged stars. It’s not as magnetically active as other stars of its age and mass. That suggests astronomers still might not fully understand the timeline of middle age.
Using physics and indirect measurements, scientists can make a rough estimate of a star’s age. Some methods, it turns out, work better for different types of stars.
Why do we even care? Galaxies are huge collections of stars of different ages. Star ages might help us figure out how such galaxies grow and evolve or how planets within them form. Knowing star ages might even assist in the search for life in other solar systems.
1. What may scientists want to research about stars most now?| A．Their companions. | B．Their types. |
| C．Their ages. | D．Their characteristics. |
| A．Discussed. | B．Described. | C．Touched. | D．Solved. |
| A．To show scientists still have puzzles about stars. |
| B．To prove scientists have studied stars to the full. |
| C．To provide facts for scientists’ researches on stars. |
| D．To warn scientists to notice some surprising stars. |
| A．The reasons for caring about the space. | B．The significance of researching star ages. |
| C．The ways of measuring a star’s age. | D．The benefits of figuring out solar systems. |
