英语听力：探索发现 2014-07-20 BBC 地平线：陨石的真相-30

 It came in in the daytime sky out of the Sun. We’ve got telescopes looking out there for these objects, but they only work at night. Radar¹ doesn’t help either because to really use radar to find these objects above the atmosphere, you have to know exactly where to look. If you don’t know what’s coming in, you don’t know where to look. 

 

Because of that then, this thing and objects like this, if they come in at that particular direction, they’re always going to take us by surprise at the moment without current survey system. But even if we can spot an asteroid² heading towards us and in good time to prepare, what if anything can we do? 

 

There’re different options for deflecting⁴ asteroids⁵ and it is a bit sci-fi at the moment.

 

The idea of shooting it out of the sky with a nuclear weapon would really be a dreadful idea. I mean, it would just shower us with radioactive debris⁶, and it would just, you know, do more harm than good. What would be much better would be to simply push it, nudge it slightly off its course, so that it wasn’t then going to collide. So how do you gently nudge an asteroid? 

 

There’re lots of different techniques to push it. So, the one I love is called a mass driver. There’s an object, a machine which sits on the asteroid, sits there and throws off rocks. So it is accelerating rocks that way and that makes the asteroid gradually move in the opposite direction. You can paint one side of the asteroid white. That reflects the Sun and there’s this weird⁷ effect that makes the asteroid gradually drift across. 

 

We can launch a mission now which essentially⁸ can impact an asteroid and then deflect³ it, a bit like a billiard shot or a snooker shot. We just hit the asteroid extremely fast with a spacecraft. And that small impact really is sufficient to just alter its course so that it misses the Earth. 

1 radar   

n.雷达，无线电探测器

参考例句：

• They are following the flight of an aircraft by radar.他们正在用雷达追踪一架飞机的飞行。
• Enemy ships were detected on the radar.敌舰的影像已显现在雷达上。

2 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。

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 deflecting   

（使）偏斜， （使）偏离， （使）转向( deflect的现在分词 )

参考例句：

• A variety of mechanical surfaces have been employed for deflecting the exhaust jets of solid-propellant rockets. 人们已经用过各种类型的机械控制面来偏转固体推进剂火箭的排气流。
• If she made a leading statement, he was expert deflecting her into more impersonal channels. 只要她一开口，他就会巧妙地把她的话题转到与个人无关的问题上去。

5 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。

6 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。

7 weird   

adj.古怪的，离奇的；怪诞的，神秘而可怕的

参考例句：

• From his weird behaviour,he seems a bit of an oddity.从他不寻常的行为看来，他好像有点怪。
• His weird clothes really gas me.他的怪衣裳简直笑死人。

8 essentially   

adv.本质上，实质上，基本上

参考例句：

• Really great men are essentially modest.真正的伟人大都很谦虚。
• She is an essentially selfish person.她本质上是个自私自利的人。