BBC Take Away English (Dangers f

地球已经存在了 46 亿年，在此期间它经受了一些灾难性的事件，比如陨石冲击和气候的巨大改变。那么未来又会是怎样呢？系好安全带，让我们一起探讨那些来自外星际对地球可能会造成的危险。

danger from the space

article

What is the greatest threat to life on our planet? Is it climate change? Shortages of food or water? Or might an altogether bigger danger come from somewhere further away: space?

We’re not talking about an invasion by little green men here. Instead, how about the prospect of being hit by a gigantic meteorite, zapped by lethal cosmic rays or fried by the deadly energy of an erupting star?

It wouldn’t be the first time. Good old planet Earth has had a rough ride over the last 3.7 billion years, with some spectacularly devastating events. The most famous mass extinction was 66 million years ago, when it’s widely believed a meteorite killed off the dinosaurs. A 110-mile-wide crater in Mexico with the same geological age supports this theory.

Believe it or not, this wasn’t the most brutal episode in our planet’s history. That was when a staggering 96% of life was wiped out at the end of the Permian period（二叠纪）, 252 million years ago. Scientists don’t know for sure why this happened, but any potential explanations carry with them the grim possiblity that similar events could happen again.

For example, some experts believe that our Sun has a very dense, dim twin star which is too far away to observe directly. This sleeping giant, dubbed the “Death Star”, could distort the paths of orbiting chunks of icy rock and hurl them towards the rest of the Solar System.

Is this what happened 252 million years ago? Or is there instead, perhaps, a distant, ninth planet in our Solar System which pulls in passing comets and sends them hurtling our way?

If that isn’t enough to put you off your breakfast, then consider what’s happening to our friend, the Sun. The star that has given us the warmth to sustain life is gradually turning into a deadly foe. Like all stars, it is slowing dying, burning through its energy supplies. As it does so, it expands, and in about 2 billion years it will have grown so much that the heat will make life on planet Earth unbearable.

While all this sounds a little macabre, take comfort from the fact that the chance of being hit by a giant interstellar projectile is incredibly slim, and that 2 billion years is a very long time.

And there’s another thing: if the dinosaurs had not snuffed it when they did, it’s extremely unlikely that human beings would have had the chance to evolve at all.

vocabulary

little green men （比喻）外星人
meteorite [ˈmi:tiəraɪt] 陨星、陨石
cosmic ray 宇宙射线
good old （赞美语气）老牌的、靠谱的
a rough ride 一段艰难的历程
spectacularly devastating events 惊人的毁灭性事件
Believe it or not, 信不信由你
mass extinction 物种大灭绝
to kill off 杀死、消灭
crater （火山口式的）圆坑
geological 地质的
brutal 残酷的
episode 小插曲

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staggering
adj. 蹒跚的;难以置信的，令人震惊的;犹豫的
adv. 难以置信地，令人震惊地
v. 错开;蹒跚(stagger的现在分词);使…感到震惊[担心]

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to wipe out 彻底灭绝
grim 冷酷的，残忍的; 严厉的; 阴冷的; 可怕的，讨厌的
dense 密度大的

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dim
adj. 暗淡的，昏暗的;不光明的;看不清的;（性质和特征上）不显著的
vt.& vi.（使）变暗淡;（使）变模糊;（使）减弱;变淡漠
n. 笨蛋，傻子

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dub
vt.（以剑触肩）封…为爵士;授予称号;起绰号;配音，转录
vi. 击鼓
n. 笨蛋;鼓声;混录进去的新声音;录音带的复制版

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distort
vt. 曲解;歪曲，扭曲;使变形
vi. 扭曲;变形

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to orbit 沿轨道围绕（行星或恒星）运行
Solar System 太阳系
comet 彗星
to hurtle 猛冲

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foe
n. 敌人，仇敌;危害物;反对者

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to put someone off (something) 丧失对某事的兴致
macabre 恐怖的，令人害怕的
interstellar 星际的
to snuff it （俗语）死亡，断气
macabre [məˈkɑ:brə] 可怕的，毛骨悚然的

make sentences

1. Last year was a rough ride. I’m glad to see the end of it.

2. Washing clothes in boiling water kills off bacteria.

3. Can we change the topic? Talking about it puts me off my food.

4. One day I’d love to travel to space! I’d even buy a one-way ticket to Mars.

5. Earth orbits the Sun.

question

What evidence is there that a meteorite wiped out the dinosaurs?

answer

A huge crater was discovered which struck Earth at the same time as when the dinosaurs became extinct.