A distant, oversize world causes cosmic confusion
The discovery of planets around distant stars has become like space-shuttle launches--newsworthy but just barely. With some 50 extrasolar planets under their belt, astronomers have to announce something really strange to get anyone's attention.
Last week they did just that. Standing in front of colleagues and reporters at the American Astronomical Society's semiannual meeting in San Diego, the world's premier planet-hunting team--astronomer Geoffrey Marcy of the University of California, Berkeley, and his colleagues--presented not one but two remarkable finds. The first is a pair of planets, each about the mass of Jupiter, that whirl around their home star 15 light-years from Earth in perfect lockstep. One takes 30 days to complete an orbit, the other exactly twice as long. Nobody has ever seen such a configuration. But the second discovery is far stranger--a solar system 123 light-years away, in the constellation Serpens, that harbors one "ordinary" planet and another so huge--17 times as massive as Jupiter--that nobody can quite figure out what it can be. It is, says Marcy, "a bit frightening."
What's frightening is that these discoveries make it clear how little astronomers know about planets, and they add to the dawning realization that our solar system--and by implication Planet Earth--may be a cosmic oddball. For years theorists figured that other stars would have planets more or less like the ones going around the sun. But starting with the 1995 discovery of the first extrasolar planet--a gassy monster like Jupiter but orbiting seven times as close to its star as Mercury orbits around our sun--each new find has seemed stranger than the last. Searchers have found more "hot Jupiters" like that first discovery. These include huge planets that career around their stars not in circular orbits but in elongated ones; their gravity would send any Earthlike neighbors flying off into space. Says Princeton astronomer Scott Tremaine: "Not a single prediction for what we'd find in other systems has turned out to be correct."
Last week's giant was the most unexpected discovery yet. Conventional theory suggests that it must have formed like a star, from a collapsing cloud of interstellar gas. Its smaller companion, only seven times Jupiter's mass, is almost certainly a planet, formed by the buildup of gas and dust left over from a star's formation. Yet the fact that these two orbs are so close together suggests to some theorists that they must have formed together--so maybe the bigger one is a planet after all.
Or maybe astronomers will have to rethink their definition of "planet." Just because we put heavenly objects into categories doesn't mean the distinctions are necessarily valid. And as Tremaine puts it, "When your classification schemes start breaking down, you know you're learning something exciting. This is wonderful stuff."
By Michael D. Lemonick Time; 01/22/2001, Vol. 157 Issue 3, p51, 2/3p, 1 diagram
注(1):本文选自Time; 01/22/2001, p51;
注(2):本文习题命题模仿对象:第1题模仿1998年text5第1题;第2题模仿text4第2题;第3题模仿1993年text2第1题;第4题模仿1999年text1第3题;第5题模仿1997年text4第4题;
1. The author believes that ____________.
[A] the discovery of planets is as important as the launch of space shuttles
[B] astronomers have been making a lot of discoveries of planets
[C] the public have no interest in astronomical discoveries
[D] there is little for astronomers to discover now
2.The two finds are remarkable in that ___________.
[A] the planets are far from our solar system
[B] the sizes of the plants are too huge.
[C] astronomers have never seen similar orbiting pattern and size before
[D] scientists can not figure out what they can be
3. By saying that our solar system “may be a cosmic oddball”, the author intends to render the idea that ______________.
[A] other stars have planets more or less like the one going around the sun
[B] the orbits of extrasolar planets around their stars are elongated ones
[C] the way planets orbiting around the sun in our solar system is quite unique
[D] planets in other systems are generally huger than the ones in ours
4. The case of the giant heavenly body demonstrates that _________.
[A] conventional theory can not explain such astronomical phenomenon satisfactorily
[B] it is either a star or a planet
[C] it was formed like a star and orbits like a planet
[D] theorists give a wrong definition of “planet”
5. The best title for this passage could be ___________.
[A] New Planetary Puzzlers
[B] Two Remarkable Finds
[C] A Redefinition of “Planet”
[D] “Hot Jupiters” Challenging Conventional Theory
答案:B C C A A
篇章剖析:
本篇文章讲述了安第斯山区的最新考古发现以及这一发现的重大意义。第一段想象了当年印加人参加活人祭祀前后的场景,引出话题;第二段简要介绍考古学家莱茵哈德及他这次发现的三具印加儿童遗体。第三段、第四段描述了同时发现的陪葬品,最后一段则说明这次发现对于考古学家的重要意义。文章层次分明,结构清晰。
词汇注释:
semiannual: [5semi5AnjuEl] adj. 半年一次的
premier: [5premjE] adj. 第一的, 首要的
Jupiter: [5dVu:pitE] n. 木星
lockstep: [`lCkstep] n. 前后紧接, 步伐一致
configuration: [kEn7fi^ju5reiFEn] n. 【天】(行星等的)相对位置, 方位
constellation: [kCnstE5leiFEn] n. [天]星群, 星座
Serpens: [5sE:penz] n. [天]巨蛇座
oddball:[ 5RdbC:l] n. 古怪的人;古怪的事物
Mercury: [5mE:kjuri] n.〈天〉水星
elongate: [5i:lCN^eit] v. 拉长, (使)伸长, 延长
interstellar: [5intE(:)5stelE] adj. 星际的
orb: [C:b] n. 球, 天体, 圆形物
难句突破:
What’s frightening is that these discoveries make it clear how little astronomers know about planets, and they add to the dawning realization that our solar system --- and by implication Planet Earth --- may be a cosmic oddball.
主体句式:what’s frightening is that …
结构分析:本句是个复杂句,包含主语从句(what’s frightening),表语从句(is 后面的部分),宾语从句(how little引导的部分),同位语从句(realization后面that引导的部分),插入语等,另外一些成语词组的出现也增加了句子的难度,比如dawning realization(渐渐认识到),by implication(含蓄地, 用寓意)等。阅读本句的时候应该先看各个分句在句中的成分以及相互之间的关系,然后再看各部分具体的意义。
句子译文:真正令人震惊的是,这些发现说明天文学家对于行星的了解十分有限,并且让人们清醒地认识到我们的太阳---不言而喻,还有地球这颗行星---也许是宇宙中的异数。
题目分析:
1. 答案是B,属事实细节题。文章中提到“with some 50 extrasolar planets under their belt” 来说明为什么天文发现已经很多,难以吸引公众,所以应该选B。
2. 答案是C,属事实细节题。文中第二段指出第一个发现里的两颗行星的运行轨道排列方式前所未见,第二个发现里面有一颗是木星体积17倍的巨大星体。其它各项在原因方面都罗列的过于简单,只有C把这两点都包括了,所以是正确答案。
3. 答案是C,属推理判断题。文中第三段举了几个例子说明1995年之后天文发现的太阳系外行星围绕母星运行的方式跟太阳系行星的运行方式大不相同,由此解释我们的太阳系是一个宇宙中的异数。
4. 答案是A,属推理判断题。文中介绍了传统理
阅读(515)
(责任编辑:城市网)