科学美国人60秒 SSS 2014-08-29_在线英语听力室

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From the depths of space, an asteroid¹ hurtles toward Earth. [Well, our general vicinity.] But this is no ordinary hunk of galactic debris². Because the body of this asteroid seems to defy gravity. It’s bound by forces never observed on this scale in space.

That’s not the plot of a new summer blockbuster. It’s the result of a study in the journal Nature.

The asteroid in question is actually a kilometer-sized collection of rubble³. In most cases, such space-faring pebble⁴ piles are held together by a combination of gravity and friction⁵. But not so for our rocky interloper, dubbed⁶ “1950 DA.” This asteroid is rotating so rapidly that its pieces should have flung apart long ago.

Now, by analyzing⁷ the 1950 DA’s temperature and density⁸, researchers conclude that cohesive⁹ forces called van der Waals attractions must be keeping the pieces clustered. Van der Waals forces may sound mysterious, but they’re well known on the small scale for their weak influence within and between molecules¹⁰.

Blasting the asteroid, Hollywood style, could overcome these forces. But that might leave us with hundreds of smaller killer¹¹ space rocks to dodge¹². The good news is, the asteroid won’t be in our area until 2880. So we have some time to figure it out.

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1 asteroid
n.小行星；海盘车(动物)
参考例句：
Astronomers have yet to witness an asteroid impact with another planet.天文学家还没有目击过小行星撞击其它行星。 It's very unlikely that an asteroid will crash into Earth but the danger exists.小行星撞地球的可能性很小，但这样的危险还是存在的。

2 debris
n.瓦砾堆，废墟，碎片
参考例句：
After the bombing there was a lot of debris everywhere.轰炸之后到处瓦砾成堆。 Bacteria sticks to food debris in the teeth,causing decay.细菌附着在牙缝中的食物残渣上，导致蛀牙。

3 rubble
n.（一堆）碎石，瓦砾
参考例句：
After the earthquake,it took months to clean up the rubble.地震后，花了数月才清理完瓦砾。 After the war many cities were full of rubble.战后许多城市到处可见颓垣残壁。

4 pebble
n.卵石，小圆石
参考例句：
The bird mistook the pebble for egg and tried to hatch it.这只鸟错把卵石当蛋，想去孵它。 The pebble made a ripple on the surface of the lake.石子在湖面上激起一个涟漪。

5 friction
n.摩擦，摩擦力
参考例句：
When Joan returned to work,the friction between them increased.琼回来工作后，他们之间的摩擦加剧了。 Friction acts on moving bodies and brings them to a stop.摩擦力作用于运动着的物体，并使其停止。

6 dubbed
v.给…起绰号( dub的过去式和过去分词 )；把…称为；配音；复制
参考例句：
Mathematics was once dubbed the handmaiden of the sciences. 数学曾一度被视为各门科学的基础。 Is the movie dubbed or does it have subtitles? 这部电影是配音的还是打字幕的？来自《简明英汉词典》

7 analyzing
v.分析；分析( analyze的现在分词 )；分解；解释；对…进行心理分析n.分析
参考例句：
Analyzing the date of some socialist countries presents even greater problem s. 分析某些社会主义国家的统计数据，暴露出的问题甚至更大。来自辞典例句 He undoubtedly was not far off the mark in analyzing its predictions. 当然，他对其预测所作的分析倒也八九不离十。来自辞典例句

8 density
n.密集，密度，浓度
参考例句：
The population density of that country is 685 per square mile.那个国家的人口密度为每平方英里685人。 The region has a very high population density.该地区的人口密度很高。

9 cohesive
adj.有粘着力的；有结合力的；凝聚性的
参考例句：
She sealed the parcel with cohesive tape.她用粘胶带把包裹封起来。 The author skillfully fuses these fragments into a cohesive whole.作者将这些片断巧妙地结合成一个连贯的整体。

10 molecules
分子( molecule的名词复数 )
参考例句：
The structure of molecules can be seen under an electron microscope. 分子的结构可在电子显微镜下观察到。 Inside the reactor the large molecules are cracked into smaller molecules. 在反应堆里，大分子裂变为小分子。

11 killer
n.杀人者，杀人犯，杀手，屠杀者
参考例句：
Heart attacks have become Britain's No.1 killer disease.心脏病已成为英国的头号致命疾病。 The bulk of the evidence points to him as her killer.大量证据证明是他杀死她的。

12 dodge
v.闪开，躲开，避开；n.妙计，诡计
参考例句：
A dodge behind a tree kept her from being run over.她向树后一闪，才没被车从身上辗过。 The dodge was coopered by the police.诡计被警察粉碎了。

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科学美国人60秒 SSS 2014-08-29