【www.scabjd.com--雅思】
雅思网权威发布
雅思阅读模拟题:Search begins for Earth,更多雅思阅读模拟题相关信息请访问雅思考试(IELTS)网。
【导语】为大家准备了雅思阅读模拟题:Search begins for Earth。雅思模拟试题在雅思备考过程中所起的作用不可小觑,通过模拟练习题,我们可以很直接地了解到自己的备考状况,从而可以更有针对性地进行之后的复习。希望以下内容能够对大家的雅思备考有所帮助!更多雅思报名官网的最新消息,最专业的雅思备考资料,将为大家发布。
Search begins for "Earth" beyond solar system
Staff and agencies
Wednesday December 27, 2006
Guardian Unlimited
1. A European spacecraft took off today to spearhead the search for another
"Earth" among the stars.
2. The Corot space telescope blasted off aboard a Russian Soyuz rocket from
the Baikonur cosmodrome in Kazakhstan shortly after 2.20pm.
3. Corot, short for convection rotation and planetary transits, is the
first instrument capable of finding small rocky planets beyond the solar system.
Any such planet situated in the right orbit stands a good chance of having
liquid water on its surface, and quite possibly life, although a leading
scientist involved in the project said it was unlikely to find "any little green
men".
4. Developed by the French space agency, CNES, and partnered by the
European Space Agency (ESA), Austria, Belgium, Germany, Brazil and Spain, Corot
will monitor around 120,000 stars with its 27cm telescope from a polar orbit 514
miles above the Earth. Over two and a half years, it will focus on five to six
different areas of the sky, measuring the brightness of about 10,000 stars every
512 seconds.
5. "At the present moment we are hoping to find out more about the nature
of planets around stars which are potential habitats. We are looking at
habitable planets, not inhabited planets. We are not going to find any little
green men," Professor Ian Roxburgh, an ESA scientist who has been involved with
Corot since its inception, told the BBC Radio 4 Today programme.
6. Prof Roxburgh said it was hoped Corot would find "rocky planets that
could develop an atmosphere and, if they are the right distance from their
parent star, they could have water".
7. To search for planets, the telescope will look for the dimming of
starlight caused when an object passes in front of a star, known as a "transit".
Although it will take more sophisticated space telescopes planned in the next 10
years to confirm the presence of an Earth-like planet with oxygen and liquid
water, Corot will let scientists know where to point their lenses.
8. Measurements of minute changes in brightness will enable scientists to
detect giant Jupiter-like gas planets as well as small rocky ones. It is the
rocky planets - that could be no bigger than about twice the size of the Earth -
which will cause the most excitement. Scientists expect to find between 10 and
40 of these smaller planets.
9. Corot will also probe into stellar interiors by studying the acoustic
waves that ripple across the surface of stars, a technique called
"asteroseismology".
10. The nature of the ripples allows astronomers to calculate a star"s
precise mass, age and chemical composition.
11. "A planet passing in front of a star can be detected by the fall in
light from that star. Small oscillations of the star also produce changes in the
light emitted, which reveal what the star is made of and how they are structured
internally. This data will provide a major boost to our understanding of how
stars form and evolve," Prof Roxburgh said.
12. Since the discovery in 1995 of the first "exoplanet" - a planet
orbiting a star other than the Sun - more than 200 others have been found by
ground-based observatories.
13. Until now the usual method of finding exoplanets has been to detect the
"wobble" their gravity imparts on parent stars. But only giant gaseous planets
bigger than Jupiter can be found this way, and they are unlikely to harbour
life.
14. In the 2010s, ESA plans to launch Darwin, a fleet of four or five
interlinked space telescopes that will not only spot small rocky planets, but
analyse their atmospheres for signs of biological activity.
15. At around the same time, the US space agency, Nasa, will launch
Terrestrial Planet Finder, another space telescope designed to locate Earth-like
planets.
本文来源:http://www.scabjd.com/yingyu/187523/