英语听力：自然百科 探索世界奥秘之Alien Neighbors (寻访外星人) Unit11

We have reasons to suspect, based on recent high resolution photography of the surface, that there may be a subsurface ocean there. And where we find water and where we find the right mix of organics, there is the possibility for life. So we have to entertain the idea then that Europa could provide in this subsurface ocean environment, a habitat that would be clement¹ for life and where life could have originated.

"I don't know whether we'll find life beyond single cell. And when I talk about life, I want to be very, very clear. Single cell life would be an unbelievable find. And any higher level, I just don't know, I just don't know. But I doubt that we'll find a human species. "

When our spacecraft eventually penetrated² Europa's icy sheets, they might find scenes like this, an undersea world where life prospers³ without sunlight or oxygen like our own deep ocean thermal⁴ beds. And beyond our own solar system, there is always the seductive possibility that an intelligent group of beings like ourselves exists somewhere. After all, our sun is one of billions of stars that shine in the universe, a universe that contains all the elements found in life on Earth. A distant star could be the sun of another civilization. Could aliens have paid us a visit already ? Maybe eons ago?

"It's always possible that there is something we haven't recognized that has been left here maybe a long time ago by alien visitation. But in the absence of presenting me with that evidence, I see no reason to, to believe this. I really think it's such an expensive exercise to physically⁵ travel from one star system to another. I can't imagine the motivation of any alien species that would do it. "

Humankind has explored the solar system, but we lack the technology to send men or robotic missions to another planetary system. But we've certainly left evidence of our own existance. The trail of debris⁶ from our space missions like Hansel and Gretel's breadcrumbs in the forest may one day mark the way for an alien group looking for us.

"Life probably does exist elsewhere in the universe, probably not sufficiently⁷, frequently in the universe for us ever to be likely to meet it. So that would be my guess is that life is present elsewhere in the universe, but is probably so spaced-out that we may never know about it. "

Out there, way out there, in other galaxies⁸, what is the likelihood? The president of the SETI Institute has developed a complicated equation to actually figure the odds⁹.

It's called the Drake Equation. It's based upon things we do know about the universe, and other things we can make educated guesses about, things like how often new stars form, how many stars have planets, how many planets have life, the chance of that life developing intelligence, the chances that intelligence will lead to technology.

words in this passage

clement:describes weather which is pleasant or not severe:温和的，温暖的（气候等）

例：It's very clement for the time of year.

Hansel and Gretel：a fairy tale, for more information,

Drake Equation:

1 clement   

adj.仁慈的；温和的

参考例句：

• A clement judge reduced his sentence.一位仁慈的法官为他减了刑。
• The planet's history contains many less stable and clement eras than the holocene.地球的历史包含着许多不如全新世稳定与温和的地质时期。

2 penetrated   

adj. 击穿的，鞭辟入里的 动词penetrate的过去式和过去分词形式

参考例句：

• The knife had penetrated his chest. 刀子刺入了他的胸膛。
• They penetrated into territory where no man had ever gone before. 他们已进入先前没人去过的地区。

3 prospers   

v.成功，兴旺( prosper的第三人称单数 )

参考例句：

• Whatever prospers my business is welcome. 凡使我生意兴隆者皆竭诚欢迎。 来自辞典例句
• Whatever prospers my business is good. 任何使我生意兴隆的都是好的。 来自辞典例句

4 thermal   

adj.热的，由热造成的；保暖的

参考例句：

• They will build another thermal power station.他们要另外建一座热能发电站。
• Volcanic activity has created thermal springs and boiling mud pools.火山活动产生了温泉和沸腾的泥浆池。

5 physically   

adj.物质上，体格上，身体上，按自然规律

参考例句：

• He was out of sorts physically,as well as disordered mentally.他浑身不舒服，心绪也很乱。
• Every time I think about it I feel physically sick.一想起那件事我就感到极恶心。

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 sufficiently   

adv.足够地，充分地

参考例句：

• It turned out he had not insured the house sufficiently.原来他没有给房屋投足保险。
• The new policy was sufficiently elastic to accommodate both views.新政策充分灵活地适用两种观点。

8 galaxies   

星系( galaxy的名词复数 )； 银河系； 一群（杰出或著名的人物）

参考例句：

• Quasars are the highly energetic cores of distant galaxies. 类星体是遥远星系的极为活跃的核心体。
• We still don't know how many galaxies there are in the universe. 我们还不知道宇宙中有多少个星系。

9 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？