Astronomers have captured(捕获) 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(轨道) 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(光亮强过) them. Kraus and Ireland used two techniques to overe this problem.[来源:学+科+网]
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 bination 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.
【小题1】The research on younger planets helps scientists .A．study why planets change orbits after formingB．understand how planets move around their starsC．answer questions about the age of stars and planetsD．know the relationship between planets and their stars【小题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.【小题3】According to the text, Kraus and Ireland . A．have been working in the same universityB．observed the planet on a volcano in HawaiiC．used two new methods in the observationD．cut holes in the mirrors when observing【小题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.D
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(答案→)D
解析：文章介绍了夏威夷天文学院的Adam Kraus和澳大利亚麦考瑞大学的Michael Ireland观察到了一个行星的诞生过程并拍下了图像。观察这种行星的形成过程有助于科学家搞清楚这些行星与他们周围的星星之间的关系。用通常的方法是很难观察到这种星星的，因为周围的星星的光强过这种行星，两位天文学家用了两种现代的技术观察了这颗行星。
【小题1】D细节理解题。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.句意为：当他们形成的时候，观察这种行星有助于科学家回答一些问题，比方说，行星是形成于星星的生命之前还是之后，相对来说，他们的形成离星星是近还是远。所以答案应为D，了解行星与星星之间的关系。
【小题2】A细节理解题。Scientists hadn’t been able to see such young planets before because the stars they’re circling around outshine(光亮强过) them. Kraus and Ireland used two techniques to overe this problem.以前科学家是没有办法看到这么年轻的行星的，因为环绕他们的星星的光亮强过他们自己的光。两位天文学家用了两种技术去克服这个问题。故答案应为A，他们周围的星星比较亮。
【小题3】B细节判断题。夏威夷天文学院的Adam Kraus和澳大利亚麦考瑞大学的Michael Ireland，所以A是错误的；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.一种方法，也是其他天文学家用的方法----，故答案C是错误的；The other method they used, which was unique, was to put masks with several holes over most of the telescope mirrors.他们使用的另一种方法是独特的，就是放一个有几个洞的面罩----，故D，在镜子上弄洞是错误的。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上使用的望远镜，Mauna Kea是美国夏威夷岛上的一个活火山，故B是正确的。
【小题4】A综合理解题。文章讲述的是两位科学家用两种技术观察到了一个最年轻的行星的形成过程，讲述了他们的年龄，以及原来很难观察到这种行星的原因，还有了解这种行星的意义等，所以A是正确的，在他们形成的时候观察到了一种行星。B的意思为：被发现的450亿光年远的行星,没有强调是在形成的过程中，是不恰当的；C照的第一张行星的直接影像，文章没有讲述拍照的过程；D新的技术有助于发现年轻的行星，本文没有详细介绍这种技术。
【考点】考查科技类文章的阅读理解。