Question

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(光亮強過) 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.

 

Answer 1

【答案】

 

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院的Adam Kraus和澳大利亞麥考瑞大學的Michael Ireland觀察到了一個行星的誕生過程并拍下了圖像。觀察這種行星的形成過程有助于科學家搞清楚這些行星與他們周圍的星星之間的關系。用通常的方法是很難觀察到這種星星的，因為周圍的星星的光強過這種行星，兩位天文學家用了兩種現代的技術觀察了這顆行星。

1.D細節(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：當他們形成的時候，觀察這種行星有助于科學家回答一些問題，比方說，行星是形成于星星的生命之前還是之后，相對來說，他們的形成離星星是近還是遠。所以答案應為D，了解行星與星星之間的關系。

2.A細節(jié)理解題。Scientists hadn’t been able to see such young planets before because the stars they’re circling around outshine(光亮強過) them. Kraus and Ireland used two techniques to overcome this problem.以前科學家是沒有辦法看到這么年輕的行星的，因為環(huán)繞他們的星星的光亮強過他們自己的光。兩位天文學家用了兩種技術去克服這個問題。故答案應為A，他們周圍的星星比較亮。

3.B細節(jié)判斷題。夏威夷天文學院的Adam Kraus和澳大利亞麥考瑞大學的Michael Ireland，所以A是錯誤的；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，也是其他天文學家用的方法----，故答案C是錯誤的；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特的，就是放一個有幾個洞的面罩----，故D，在鏡子上弄洞是錯誤的。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上使用的望遠鏡，Mauna Kea是美國夏威夷島上的一個活火山，故B是正確的。

4.A綜合理解題。文章講述的是兩位科學家用兩種技術觀察到了一個最年輕的行星的形成過程，講述了他們的年齡，以及原來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，在他們形成的時候觀察到了一種行星。B的意思為：被發(fā)現的450億光年遠的行星,沒有強調是在形成的過程中，是不恰當的；C照的第一張行星的直接影像，文章沒有講述拍照的過程；D新的技術有助于發(fā)現年輕的行星，本文沒有詳細介紹這種技術。

【考點】考查科技類文章的閱讀理解。