Astronomers have captured(捕獲) the first direct image of a planet being born.
Adam Kraus, of the University of Hawaii’s Institute for Astronomy, said the planet is being formed out of dust and gas circling a 2-million-yea-old star about 450 light years from Earth.
The planet itself, based on scientific models of how planets form, is believed to have started taking shape about 50,000 to 100,000 years ago.
Called LkCa 15b, it’s the youngest planet ever observed. The previous record holder was about five times older.
Kraus and his colleague, Michael Ireland from Macquarie University and the Australian Astronomical Observatory, used Keck telescopes on Mauna Kea(a volcano on the island of Hawaii, US) to find the planet. Kraus presented the discovery Wednesday at NASA’s Goddard Space Flight Center in Maryland.
Observing planets while they’re forming can help scientists answer questions like weather planets form early in the life of a star or later, and whether they form relatively close to stars or father away.
Planets can change orbits(軌道) after forming, so it’s difficult to answer such questions by studying older planets.
“These very basic questions of when and where are best answered when you can actually see the planet forming, as the process is happening right now,” Kraus said.
Scientists hadn’t been able to see such young planets before because the stars they’re circling around outshine(光亮強(qiáng)過(guò)) them. Kraus and Ireland used two techniques to overcome this problem.
One method, which is also used by other astronomers, was to change the shape of the telescope mirrors to remove light distortion(扭曲) created by the Earth’s atmosphere. The other method they used, which was unique, was to put masks with several holes over most of the telescope mirrors. The combination of these techniques allowed the astronomers to obtain high-quality images that let them see the planet next to the bright star.
The star LkCa 15—the planet is named after its star—was the team’s second target. They immediately knew they were seeing something new, so they plan to gather more data on the star.
1.The research on younger planets helps scientists _____________.
A. study why planets change orbits after forming
B. understand how planets move around their stars
C. answer questions about the age of stars and planets
D. know the relationship between planets and their stars
2.Why are young planets like LkCa 15b hard to discover?
A. Their stars are brighter than them.. B. They are very far from the earth.
C. They are generally too small. D. They rarely form.
3.According to the text, Kraus and Ireland _____________.
A. have been working in the same university
B. observed the planet on a volcano in Hawaii
C. used two new methods in the observation
D. cut holes in the mirrors when observing
4.Which of the following would be the best title for the text?
A. Youngest planet seen as it’s forming.
B. Planet 450 light years away discovered.
C. World’s first direct image of a planet taken.
D. New technique helps discover young planets.
1.D
2.A
3.B
4.A
【解析】
試題分析:文章介紹了夏威夷天文學(xué)院的Adam Kraus和澳大利亞麥考瑞大學(xué)的Michael Ireland觀察到了一個(gè)行星的誕生過(guò)程并拍下了圖像。觀察這種行星的形成過(guò)程有助于科學(xué)家搞清楚這些行星與他們周?chē)男切侵g的關(guān)系。用通常的方法是很難觀察到這種星星的,因?yàn)橹車(chē)男切堑墓鈴?qiáng)過(guò)這種行星,兩位天文學(xué)家用了兩種現(xiàn)代的技術(shù)觀察了這顆行星。
1.D細(xì)節(jié)理解題。Observing planets while they’re forming can help scientists answer questions like weather planets form early in the life of a star or later, and whether they form relatively close to stars or father away.句意為:當(dāng)他們形成的時(shí)候,觀察這種行星有助于科學(xué)家回答一些問(wèn)題,比方說(shuō),行星是形成于星星的生命之前還是之后,相對(duì)來(lái)說(shuō),他們的形成離星星是近還是遠(yuǎn)。所以答案應(yīng)為D,了解行星與星星之間的關(guān)系。
2.A細(xì)節(jié)理解題。Scientists hadn’t been able to see such young planets before because the stars they’re circling around outshine(光亮強(qiáng)過(guò)) them. Kraus and Ireland used two techniques to overcome this problem.以前科學(xué)家是沒(méi)有辦法看到這么年輕的行星的,因?yàn)榄h(huán)繞他們的星星的光亮強(qiáng)過(guò)他們自己的光。兩位天文學(xué)家用了兩種技術(shù)去克服這個(gè)問(wèn)題。故答案應(yīng)為A,他們周?chē)男切潜容^亮。
3.B細(xì)節(jié)判斷題。夏威夷天文學(xué)院的Adam Kraus和澳大利亞麥考瑞大學(xué)的Michael Ireland,所以A是錯(cuò)誤的;One method, which is also used by other astronomers, was to change the shape of the telescope mirrors to remove light distortion(扭曲) created by the Earth’s atmosphere.一種方法,也是其他天文學(xué)家用的方法----,故答案C是錯(cuò)誤的;The other method they used, which was unique, was to put masks with several holes over most of the telescope mirrors.他們使用的另一種方法是獨(dú)特的,就是放一個(gè)有幾個(gè)洞的面罩----,故D,在鏡子上弄洞是錯(cuò)誤的。Kraus and his colleague, Michael Ireland from Macquarie University and the Australian Astronomical Observatory, used Keck telescopes on Mauna Kea(a volcano on the island of Hawaii, US) to find the planet.在Mauna Kea上使用的望遠(yuǎn)鏡,Mauna Kea是美國(guó)夏威夷島上的一個(gè)活火山,故B是正確的。
4.A綜合理解題。文章講述的是兩位科學(xué)家用兩種技術(shù)觀察到了一個(gè)最年輕的行星的形成過(guò)程,講述了他們的年齡,以及原來(lái)很難觀察到這種行星的原因,還有了解這種行星的意義等,所以A是正確的,在他們形成的時(shí)候觀察到了一種行星。B的意思為:被發(fā)現(xiàn)的450億光年遠(yuǎn)的行星,沒(méi)有強(qiáng)調(diào)是在形成的過(guò)程中,是不恰當(dāng)?shù);C照的第一張行星的直接影像,文章沒(méi)有講述拍照的過(guò)程;D新的技術(shù)有助于發(fā)現(xiàn)年輕的行星,本文沒(méi)有詳細(xì)介紹這種技術(shù)。
【考點(diǎn)】考查科技類(lèi)文章的閱讀理解。
年級(jí) | 高中課程 | 年級(jí) | 初中課程 |
高一 | 高一免費(fèi)課程推薦! | 初一 | 初一免費(fèi)課程推薦! |
高二 | 高二免費(fèi)課程推薦! | 初二 | 初二免費(fèi)課程推薦! |
高三 | 高三免費(fèi)課程推薦! | 初三 | 初三免費(fèi)課程推薦! |
科目:高中英語(yǔ) 來(lái)源: 題型:閱讀理解
Once in a blue moon there is one on New Year's Eve. Revelers ringing in 2010 will be treated to a so-called blue moon. According to popular definition, a blue moon is the second full moon in a month. But don't 1 it to be blue - the name has nothing to 2 the color of our closest celestial(天體) neighbor.
A full moon 3 on December 2. It will appear again on Thursday in time for the New Year's countdown.
"If you're in Times Square, you'll see the 4 moon right above you. It's going to be that brilliant," said Jack Horkheimer, director emeritus of the Miami Space Transit Planetarium and host of a weekly astronomy TV show.
The New Year's Eve blue moon will be 5 in the United States, Canada, Europe, South America and Africa. For partygoers in Australia and Asia, the full moon does not show up 6 New Year's Day, making January a blue moon month for them.
However, the Eastern Hemisphere can celebrate with a partial lunar eclipse(月蝕) on New Year's Eve when 7 of the moon enters the Earth's shadow. The 8 will not be visible in the Americas.
A full moon occurs 9 29.5 days, and most years have 12. 10 , an extra full moon in a month - a blue moon - occurs every 2.5 years. The 11 time there was a lunar double take was in May 2007. New Year's Eve blue moons are rarer, occurring every 19 years. The last time was in 1990; the next one won't 12 again until 2028.
Blue moons have no astronomical 13 , said Greg Laughlin, an astronomer at the University of California, Santa Cruz.
"`Blue moon' is just a 14 in the same sense as a `hunter's moon' or a `harvest moon,'" Laughlin said in an e-mail.
The popular definition of blue moon 15 after a writer for Sky & Telescope magazine in 1946 misunderstood the Maine Farmer's Calendar and marked a blue moon as the second full moon in a month. In fact, the calendar 16 a blue moon as the third full moon in a season with four full moons, not the usual three.
Though Sky & Telescope corrected the 17 decades later, the definition caught on. For purists(語(yǔ)言純正癖者), however, this New Year's Eve full moon doesn't even qualify as a 18 moon. It's just the first full moon of the winter season.
In a tongue-in-cheek essay 19 on the magazine's Web site this week, senior contributing editor Kelly Beatty wrote: "If skies are clear when I'm 20 celebrating, I'll take a peek(瞇著眼睛看) at that brilliant orb(天體) as it rises over the Boston skyline to see if it's an icy shade of blue. Or maybe I'll just howl."
( ) 1. A. wish B. wait C. hope D. expect
( ) 2. A. deal with B. do with C. develop with D. form into
( ) 3. A. occurred B. came C. ran D. went
( ) 4. A. full B. half C. bright D. part
( ) 5. A. out of sight B. visible C. big D. clear
( ) 6. A. until B. when C. before D. since
( ) 7. A. part B. all C. any D. none
( ) 8. A. moon B. eclipse C. sun D. shadow
( ) 9. A. each B. every C. either D. all
( ) 10. A. On the whole B. Generally speaking C. On average D. In addition
( ) 11. A. last B. next C. other D. another
( ) 12. A. go B. see C. come D. look
( ) 13. A. point B. evident C. theory D. significance
( ) 14. A. name B. object C. phenomenon D. tradition
( ) 15. A. created B. came about C. made D. copied
( ) 16. A. named B. called C. introduced D. defined
( ) 17. A. error B. name C. reality D. number
( ) 18. A. blue B. red C. yellow D. grey
( ) 19. A. published B. posted C. printed D. written
( ) 20. A. in B. out C. away D. on
查看答案和解析>>
科目:高中英語(yǔ) 來(lái)源:2012-2013學(xué)年遼寧省沈陽(yáng)同澤女中高二下學(xué)期第一次月考英語(yǔ)試卷(帶解析) 題型:單選題
The newly-discovered star was named ________ a Chinese astronomer ________ honor of his contributions to astronomy.
A.for;in | B.a(chǎn)fter;for |
C.a(chǎn)s;in | D.a(chǎn)fter;in |
查看答案和解析>>
科目:高中英語(yǔ) 來(lái)源:2013屆黑龍江齊齊哈爾實(shí)驗(yàn)中學(xué)高三三模英語(yǔ)試卷(帶解析) 題型:閱讀理解
Still waiting for little green men to make contact? Don't hold your breath.
A leading astronomer has concluded there probably aren't any aliens out there – meaning we are absolutely alone in the universe.
Even though there may be tens of thousands of other distant planets similar in size to Earth, the conditions on them are likely to be too hard to support life-forms such as ET.
Dr Howard Smith, a senior astrophysicist at Harvard University, believes there is very little hope of discovering aliens and, even if we did, it would be almost impossible to make contact.
So far astronomers have discovered a total of 500 planets in distant solar systems – known as extrasolar systems – although they believe billions of others exist.
But Dr Smith points out that many of these planets are either too close to the sun or too far away, meaning their surface temperatures are so bad that they could not support life. Others have unusual orbits which cause vast temperature variations, making it impossible for water to exist – the most important thing for life.
Dr Smith said, "We have found that most other planets and solar systems are wildly different from our own. It means it is highly unlikely there are any planets with intelligent life close enough for us to make contact." But his suggestions contradict other leading scientists who have claimed aliens almost certainly exist.
Only last month Professor Stephen Hawking said the fact that there are billions of galaxies out there made it reasonable to think there were other life-forms in the universe.
Researchers from the University of London have recently suggested that aliens could be living on as many as 40,000 other planets. But Dr Smith said: "Any hope of contact has to be limited to a relatively tiny space around the Earth, reaching maybe 1,250 light years out from our planet, where aliens might be able to pick up our signals or send us their own. But communicating would still take decades or centuries."
【小題1】By saying "don’t hold your breath", the author advised the reader not to _____.
A.keep silent | B.give up | C.expect so | D.be afraid |
A.a(chǎn)re too far away from the earth |
B.a(chǎn)re different from the Earth in size |
C.don’t have rich natural resources |
D.don’t have a suitable living environment |
A.they have better explanations about aliens |
B.a(chǎn)liens certainly exist on many planets |
C.they disagree with Dr Smith’s suggestion |
D.a(chǎn)liens can pick up signals from the earth |
A.There must be other life forms in the universe. |
B.We can communicate with aliens in decades. |
C.The chances of finding aliens are slight. |
D.Many other planets are quite different from the Earth. |
查看答案和解析>>
科目:高中英語(yǔ) 來(lái)源:河南省濮陽(yáng)市2010屆高三下學(xué)期第一次模擬考試 題型:閱讀理解
(D)
Inventor,physicist,surveyor,astronomer,biologist,artist…Robert Hooke was all these and more.Some say he Was the greatest experimental scientist of the 17th century.In the course of his work,he cooperated with famous men of science like Isaac Newton,and the great architect, Chrish@ler Wren.
Hoocke's early education began at home,under the guidance of his father.He entered Westnfinster School at the age of 13,and from there went to Oxford,where he came in contact with some of the best scientists in England.Hooke impressed them with his skills at designing experiments and inventing instruments.In 1662,at the age of 28, he was named Curator of
Experiments at the newly formed Royal Society of London—meaning that he was responsible for demonstrating new experiments at the society’s weekly meetings.Hooke accepted the job,even though he knew that the society had no money to pay him!
Watching living things through a microscope was one of his favorite pastimes.He invented a compound microscope for this purpose.One day while observing a cork(軟木塞)under a microscope,he saw honeycomb-like structures.They were cells—the smallest units of life.In fact,it was Hooke who invented the term“cell” as the boxlike ceils of the cork reminded him of the cells of a monastery(修道院).
Another achievement Of Hook’s was his book Micrographi which introduced the.Enormous potential of the microscope.It contains fascinating drawings of the things he saw under the microscope.The book also includes,among other things,ideas on gravity,light and combustion(燃燒)that may have helped scientists like Newton when they were developing their own theories on these phenomena.
Hooke made valuable contributions to astronomy too.A crater(坑)on the moon is named after him in appreciation of his services to this branch of science.
68.Why possibly did Hooke accept the job as Curator of Experiments?
A. Because his parents couldn’t afford his education.
B.Because his family needed his support.
C.Because he wanted to please the famous scientists in England.
D.Because he liked designing experiments.
69.The cell got its name because of .
A.its use B.its shape C.Hooke’s favorites D.Hooke’s experiences
70.The last paragraph is to prove that .
A.Hooke was the greatest experimental scientist of the 17th century
B.Hooke was good at making discoveries
C.Hooke’s contributions were not limited to one field
D.Hooke was one of the greatest astronomers
71.The best title for the text may be .
A.The Greatest Scientist B.A Helper of Newtom
C.A Brief Introduction to Hooke D.Achievements of Hook
查看答案和解析>>
科目:高中英語(yǔ) 來(lái)源:2010-2011學(xué)年四川省高三第一次月考英語(yǔ)卷 題型:單項(xiàng)填空
The newly discovered star was named a Chinese astronomer honour of his contributions to astronomy.
A. for; in B. after; for C. as; in D. after; in
查看答案和解析>>
百度致信 - 練習(xí)冊(cè)列表 - 試題列表
湖北省互聯(lián)網(wǎng)違法和不良信息舉報(bào)平臺(tái) | 網(wǎng)上有害信息舉報(bào)專(zhuān)區(qū) | 電信詐騙舉報(bào)專(zhuān)區(qū) | 涉歷史虛無(wú)主義有害信息舉報(bào)專(zhuān)區(qū) | 涉企侵權(quán)舉報(bào)專(zhuān)區(qū)
違法和不良信息舉報(bào)電話:027-86699610 舉報(bào)郵箱:58377363@163.com