英语听力：自然百科 已知的宇宙：外星生命 Alien_Contact-6

 To make sure Kepler's truely found a planet, scientists are using one of the largest earth-based telescopes for conformation. This telescope will also determine the planet's mass and distance from its star. Scientists are most interested in the small rocky worlds that sit in what's called the "Goldilocks" zone. 

 

Remember how important liquid water is to life? Well, if a planet is in the "Goldilocks" zone, it's not too close, and not too far from its star--it's just right. And it's possible for water to flow there as a liquid.We obviously sit in the "Goldilocks" zone, but in our solar system Mars and Venus also do, but we've yet to find life on either those two planets.

 

"Kowning if a planet is inhabitable, is not as straightforward¹ as saying, oh, we found a planet the size of the earth, and it's 90 million miles from a sun-like star. Venus are inhabitable, and Mars are inhabitable."

 

"Why is Venus such a harsh hideous² environment? Some 6,00 degrees celsius³ or so. And of course, the answer for Venus sadly is that some greenhouse effect, global warming, has overtaken Venus."

 

When it formed over four billion years ago, Venus had water, and probably vast oceans on its surface. But there was also a lot of the greenhouse gas water vapor⁴ in the atmosphere, which blanked it and heated the planet. And this Venus got hotter. More and more water on its surface evaporated into the atmosphere, trapping the heat even more. 

 

On earth, much of the green gas carbon dioxide is chemically bound to the rocks, and it was this way on young Venus too. But when it've come to about 750 degrees fahrenheit⁵, this carbon dioxide started getting out of the rocks and into the atmosphere. With an atomsphere of water vapour and carbon dioxide, this cycle kept going and going and the runaway⁶ greenhouse effect has left Venus dry, lifeless,and...

1 straightforward   

adj.正直的，坦率的；易懂的，简单的

参考例句：

• A straightforward talk is better than a flowery speech.巧言不如直说。
• I must insist on your giving me a straightforward answer.我一定要你给我一个直截了当的回答。

2 hideous   

adj.丑陋的，可憎的，可怕的，恐怖的

参考例句：

• The whole experience had been like some hideous nightmare.整个经历就像一场可怕的噩梦。
• They're not like dogs,they're hideous brutes.它们不像狗，是丑陋的畜牲。

3 Celsius   

adj.摄氏温度计的，摄氏的

参考例句：

• The temperature tonight will fall to seven degrees Celsius.今晚气温将下降到七摄氏度。
• The maximum temperature in July may be 36 degrees Celsius.七月份最高温度可能达到36摄氏度。

4 vapor   

n.蒸汽，雾气

参考例句：

• The cold wind condenses vapor into rain.冷风使水蒸气凝结成雨。
• This new machine sometimes transpires a lot of hot vapor.这部机器有时排出大量的热气。

5 Fahrenheit   

n./adj.华氏温度；华氏温度计(的)

参考例句：

• He was asked for the boiling point of water in Fahrenheit.他被问到水的沸点是华氏多少度。
• The thermometer reads 80 degrees Fahrenheit.寒暑表指出华氏80度。

6 runaway   

n.逃走的人，逃亡，亡命者；adj.逃亡的，逃走的

参考例句：

• The police have not found the runaway to date.警察迄今没抓到逃犯。
• He was praised for bringing up the runaway horse.他勒住了脱缰之马受到了表扬。