Before the mid-2th century,
2 . 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. |
3 . Have you ever got the thought or feeling that you’re being watched? Well, guess what? You might be right.
According to a study published in Nature on June 23, astronomers have found that 1,715 stars have had a direct view of Earth since humans have been here.
In order to do this, scientists used a previous method that looked for life on other planets. But instead, they changed the method so it could try to determine what places could see us.
The team looked at 331,312 stars within 326 light-years of Earth, with each light-year equaling 9.4 trillion kilometers. Out of all those stars, only 1,715 of them could see Earth within the last 5,000 years, with an extra 319 stars that will be able to see us in the next 5,000 years.
“When I look up at the sky, it looks a little bit friendlier because it’s like, maybe somebody is waving,” said Lisa Kaltenegger, director of the Carl Sagan Institute (研究所) at Cornell University, US, and the study’s lead writer.
If a planet circling around one of those 1,715 stars is home to advanced life, they could easily see that there is life here because of the oxygen on Earth. If that didn’t give it away, then the radio waves we have sent out into space would also be an indicator (标志). In fact, human-made radio waves have already traveled through 75 of the closest stars on Kaltenegger’s list.
Why haven’t we heard from anyone yet, then?
It takes a long time for messages to travel between star systems. By the time a message could be received, that advanced civilization (文明) would probably not exist anymore.
Alan Boss, a scientist at the Carnegie Institution for Science in the US who wasn’t part of the study, wrote in an email that this long time would limit the chances for different life to exchange “emails and TikTok videos”.
“So we should not expect aliens to show up anytime soon,” Boss said.
1. Which word can best describe Lisa Kalteneggers’ attitude towards the sky that he looked up at?| A．Objective | B．Indifferent | C．Critical | D．Positive. |
| A．The oxygen on Earth. | B．Human-made radio waves. |
| C．Advanced life in other planets. | D．A planet circling around one of those 1,715 stars. |
| A．Aliens don’t exist. | B．They cannot understand each other. |
| C．It takes a long time for messages to travel. | D．Human-made radio waves cannot travel far. |
| A．To present new findings published in a study. |
| B．To raise readers’ interest in aliens and the universe. |
| C．To discuss if there is advanced life on other stars. |
| D．To explain how messages travel between different star systems. |
NASA announced that it would make 366 precious images of the universe available to the public in April
NASA launched the Hubble Space Telescope
In the past three decades, scientists
Throughout history, mankind have been working hard on the space
With the first satellite launched and orbiting around Earth successfully, Yuri became the first astronaut
Following Russia and America, China became the third country in the world to
All in all,
Chinese scientists have contributed to the global effort
Experts believe the image of Sagittarius A will help people better understand the extreme celestial objects
Sagittarius A
The black hole is now mostly dormant and only
Black holes typically form when the nuclear fusion of a very massive star fizzles out
The Event Horizon Telescope held a news conference on Thursday
7 . Imagine a warm spring day 66 million years ago. These could have been the very last moments of the dinosaur era when a city-sized asteroid struck Earth, killing off three quarters of all species on the planet. According to a study published in Nature on Feb 23,the asteroid hit in springtime.
Scientists have long been confused over the time of year the asteroid hit, and how some animals managed to survive while dinosaurs didn’t, according to USA Today.
Researchers in 20l9 discovered fossilized fishes in North Dakota that died shortly after the asteroid hit Earth. They examined the fossils with a particle accelerator and found out there was seasonal growth on the bone. All fish bone cell densities and volumes can indicate the season. Because the accelerator also could capture the sizes, researchers were able to determine when in the year the asteroid hit, Dennis Voeten told USA Today.
“I think spring puts a large group of the late Cretaceous biota in a very unprotected spot because they were out and about looking for food, tending to offspring after the winter,” Melanie During, the main author of the study.
In the Southern Hemisphere, it was autumn. Therefore, life in the Southern Hemisphere was a lot more prepared for this event.
It is unclear whether small animals in the Northern Hemisphere actually did worse than those in the south. There is evidence that Northern Hemisphere turtles were wiped out in the asteroid strike, after which their habitats were later repopulated by turtles from the south, Voeten told The Guardian.
Nothing much larger than a house cat survived the asteroid impact and many species would have been killed whenever it hit, Daniel Field, a professor at the University of Cambridge, told The Guardian.
1. Which probably helps find the time of year the asteroid hit?| A．The types of fossilized fishes. | B．The location of fossilized fishes. |
| C．The number of fish fossils in the area. | D．The volume and density of the fish bone cells. |
| A．The season of the hit. | B．The size of asteroid. |
| C．The group size of species. | D．The body shape of animals. |
| A．Chances of survival depended on it where the species lived at the time. |
| B．Many species could have survived the asteroid strike but for the season. |
| C．Many species had little chance to survive even if it was a different season. |
| D．Animals from the Southern Hemisphere were less affected by asteroid strikes. |
| A．The Science behind the Asteroid | B．Occurrence of the Natural Disaster |
| C．The Effect of Dinosaurs’ Extinction | D．New Research on the Asteroid Strike |
8 . 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. |
9 . If Mars were the popular kid in school, Venus (金星) would be the unwelcome one sitting in the corner, largely ignored. Venus has nearly the same mass and size as Earth, but being closer to the sun, it gets nearly twice as much heat from the sun.
However, instead of having a climate that is just a warmer version of Earth’s, Venus’s surface and atmosphere are unbearable: clouds of sulphuric acid (硫酸) blanket the planet, while at ground level, it is hot enough to melt lead. Despite this, there is now a sign that Venus may harbour life. Jane Greaves at Cardiff University, UK, and her colleagues recently detected (发现) phosphine (磷化氢) in Venus’s atmosphere, with one potential explanation that it is the by-product of biology. That is because the only way this gas is made on Earth is in laboratories or by microbes (微生物). Though this doesn’t mean it was produced by life on Venus, attempts to find non-biological explanations for its presence have so far failed. Our best way of confirming or rejecting the possibility of life on Venus is to go and have a proper look. While Mars has been the focus of interplanetary (行星间的) exploration efforts lately, the phosphine discovery lets people look at Venus in a new light. As NASA administrator Jim Bridenstine tweeted: “It’s time to prioritize Venus.”
In the months and years to come, computer simulations(模拟) will be used to further study the possible chemistries of the atmosphere on Venus. More laboratory experiments will be conducted to try to identify other ways the phosphine there could be produced. However, there is no guarantee that these efforts will reveal the true nature of this substance on Venus. A newly-proposed strategy is to directly sample the atmosphere and surface of Venus. By doing so, we would be able to take direct measurements of phosphine.
The discovery of phosphine in Venus’s atmosphere is a great accomplishment. The scientific efforts may be just what we need to finally refocus on this neglected world. Possibly, the quiet kid in the corner may get the last laugh
1. Which description about Venus is NOT true?| A．It has the unbearable surface and atmosphere. |
| B．It has nearly the same mass as Earth. |
| C．It is almost as large as Earth. |
| D．It has a warmer Earth-like climate. |
| A．This kind of gas is very common. | B．There might exist signs of life. |
| C．Many products can be made with it. | D．Experiments were once conducted there. |
| A．The necessity to analyse phosphine. |
| B．The power of computer simulations |
| C．The importance of observations. |
| D．The approaches to exploring phosphine |
| A．Casual | B．Doubtful. | C．Supportive. | D．Unclear. |
1. What does the woman think is the problem living on the moon?
| A．Money. | B．Distance. | C．Technology. |
| A．A space pioneer. | B．A moon settler. | C．A shuttle designer. |
| A．It is very cool. | B．It isn’t practical. | C．It is reasonable. |
