听力文摘：从小行星手里拯救世界

Okay, so there's an asteroid¹ heading toward the Earth. Whatdo we do?

我们来假设，有颗小行星要撞地球啦，我们怎么办呢？

Does our future really rest in the hands of Hollywood, Bruce Willis and a ragtag team ofminers like in the movie Armageddon?

难道真要想好莱坞电影《世界末日》里演的似的，把未来交到布鲁斯·威利斯和他那帮乌合之众手里？

Sure, we could wait until danger is imminent² and then hope that a well placed nuclear explosionwould shatter or deflect³ the monster asteroid threatening humanity, but is this our only option?

我们当然也能听任危机发展下去，在最后关头期待一枚核弹把带有毁灭威力的小行星击碎或者打偏。不过这难道是人类的唯一选择？

The answer is that it depends on how big the asteroid is, how far away it is, and How much timewe have before impact?

这个嘛，要看这颗小行星有多大，离地球有多远，我们有多少危机应对时间啦。

Because there's lots of space debris⁴ out there, odds⁵ are that the threatening object won't be oneof the giant Earth-destroying asteroids⁶ that NASA is already tracking, but a smaller meteoroid capable of causing regional devastation⁷.

足以毁灭地球的小行星早已上了NASA的定位追踪名单。但宇宙里到处是太空垃圾，很可能没等那些小行星威胁到地球，一些更小的流星就已足以造成地域性灾难了。

With enough warning, though, we could crash a robotic spacecraft into the object and change its trajectory⁸ so that it'll sail by Earth.

不过，有了充足的预警，我们可以发射一些无人太空飞行器，把这些小天体撞离原定轨道。

We know we have the technology for this, because NASA has already successfully rammed⁹ a spacecraft into a comet to study the comet's composition.

这种技术早就有了，NASA就曾把一架飞行器撞向颗彗星，用以研究彗星的成分。

There are also rare instances when space objects pass close by several years before returning on a collision course with Earth.

也有一种很少见的情况：一些天体早先只是擦过近地轨道，数年后飞回来时，却可能撞上地球。

Here even a tiny change in trajectory during the first pass would resultin big payoff later.

天体轨道极细微的变化都可能导致今后的大灾难。

In these cases, we could use a spacecraft's mass and gravitational field to nudge the space object off course without shattering it and creating potentially dangerous fragments.

这种情况下，利用太空飞行器的质量和重力场，能将致命天体引偏些。用不着击碎它，这样也就不会产生可能威胁到地球安全的一堆碎片了。

Obviously, early warning is key, which is why NASA has issued a grand challenge to scientists invarious disciplines, institutions and agencies to work together to uncover ways of detecting,characterizing and interacting with asteroids.

显然，早期预警是关键。这也是为什么NASA给学界和各大相关机构出了个大挑战，让大家联合起来，预先测算分析和处理各种小行星的运行情况。

Because when it comes to the future of the Earth,Bruce Willis can only do so much.

因为一旦真的等到灾难临头，布鲁斯·威利斯可救不了人类。

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 imminent   

adj.即将发生的，临近的，逼近的

参考例句：

• The black clounds show that a storm is imminent.乌云预示暴风雨即将来临。
• The country is in imminent danger.国难当头。

3 deflect   

v.(使)偏斜，(使)偏离，(使)转向

参考例句：

• Never let a little problem deflect you.决不要因一点小问题就半途而废。
• They decided to deflect from the original plan.他们决定改变原计划。

4 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。

5 odds   

n.让步，机率，可能性，比率；胜败优劣之别

参考例句：

• The odds are 5 to 1 that she will win.她获胜的机会是五比一。
• Do you know the odds of winning the lottery once?你知道赢得一次彩票的几率多大吗？

6 asteroids   

n.小行星( asteroid的名词复数 )；海盘车，海星

参考例句：

• Asteroids,also known as "minor planets",are numerous in the outer space. 小行星，亦称为“小型行星”，在外太空中不计其数。
• Most stars probably have their quota of planets, meteorids, comets, and asteroids. 多数恒星也许还拥有若干行星、流星、彗星和小行星。

7 devastation   

n.毁坏；荒废；极度震惊或悲伤

参考例句：

• The bomb caused widespread devastation. 炸弹造成大面积破坏。
• There was devastation on every side. 到处都是破坏的创伤。 来自《简明英汉词典》

8 trajectory   

n.弹道，轨道

参考例句：

• It is not difficult to sketch the subsequent trajectory.很容易描绘出它们最终的轨迹。
• The path followed by a projectile is called its trajectory.抛物体所循的路径称为它的轨道。

9 rammed   

v.夯实（土等）( ram的过去式和过去分词 )；猛撞；猛压；反复灌输

参考例句：

• Two passengers were injured when their taxi was rammed from behind by a bus. 公共汽车从后面撞来，出租车上的两位乘客受了伤。
• I rammed down the earth around the newly-planted tree. 我将新栽的树周围的土捣硬。 来自《简明英汉词典》