英语听力：自然百科 探索世界奥秘之Alien Neighbors (寻访外星人) Unit14

"...what's more, You can start to say perhaps what the planet's made of, and you can follow it in its orbit. You can understand it in much more detail."

In the future, the revamped Hubble Space Telescope may even detect planetary systems more like our own. Telescopes yet to be invented may one day confirm that we are not alone in the universe.

"It is conceivable within the next 10 to 15 years that we can directly detect these earth-sized planets that could have atmospheres, that could have oceans, we don't know. And we might also be able to sense their atmospheres from earth with telescopes to see if there is water, carbon dioxide and oxygen. And if we find carbon dioxide and oxygen, where the oxygen is in much greater abundance than the carbon dioxide, we will then speculate that photosynthesis¹ takes place. That's the process on earth where trees and leaves convert carbon dioxide to oxygen, and then we could really begin to think there could be life. But right now, we don't even know if there’s an earth-sized planet around a star other than our own.

Future generations might witness scenes like these from an alien world. The discovery of an earth-like planet is a real possibility.

"There is no question that having discovered planets tremendously enhances our interest and the prospects² of discovering intelligent life in the galaxy³. And the reason is up until a few years ago, we didn't know there were any planets around any other stars. We might've been the only thing going in our galaxy."

Today, earth is still the only place where we know for sure that life exists. Humankind has the only intelligence civilization that we know about. But, there could be life out there. The mounting evidence motivates scientists to keep searching.

"Are we alone? I rather doubt it. Uh, if we are, that would be almost more fascinating to me. Uh, and so, I'm eager to continue the search and even if it's a lowly microbe that we find as our cohort in the, in the cosmos⁴, I'll be, I'll be satisfied."

Perhaps, these are the fingerprints⁵ of a simple life form, perhaps not. Mars holds out the most hope in the solar system but then there are more than 100 billion stars in our galaxy and there are countless⁶ galaxies⁷. If it could be shown, beyond doubt, that life evolved somewhere, anywhere other than our own home planet, then life on earth would never be the same again.

words and expressions

revamp:to change or arrange something again, in order to improve it修补, 翻新；改装.

eg:We revamped all the management system, but the business is doing no better than it was before.

in abundance:充裕

eg:Carpets are available in abundance.可供地毯货源充足。

photosynthesis :the process by which a plant uses the energy from the light of the sun to produce its own food光合作用

lowly :low in position and importance, or not respected:地位低的；级别低的

cohort:a group of people who share a characteristic, usually age:同党,同伴

beyond doubt：[常作插入语]毫无疑问

1 photosynthesis   

n.光合作用

参考例句：

• In apple trees photosynthesis occurs almost exclusively in the leaves.苹果树的光合作用几乎只发生在叶内。
• Chloroplasts are the structures in which photosynthesis happens.叶绿体就是光合作用发生的地方。

2 prospects   

n.希望，前途(恒为复数)

参考例句：

• There is a mood of pessimism in the company about future job prospects. 公司中有一种对工作前景悲观的情绪。
• They are less sanguine about the company's long-term prospects. 他们对公司的远景不那么乐观。

3 galaxy   

n.星系；银河系；一群(杰出或著名的人物)

参考例句：

• The earth is one of the planets in the Galaxy.地球是银河系中的星球之一。
• The company has a galaxy of talent.该公司拥有一批优秀的人才。

4 cosmos   

n.宇宙；秩序，和谐

参考例句：

• Our world is but a small part of the cosmos.我们的世界仅仅是宇宙的一小部分而已。
• Is there any other intelligent life elsewhere in the cosmos?在宇宙的其他星球上还存在别的有智慧的生物吗？

5 fingerprints   

n.指纹( fingerprint的名词复数 )v.指纹( fingerprint的第三人称单数 )

参考例句：

• Everyone's fingerprints are unique. 每个人的指纹都是独一无二的。
• They wore gloves so as not to leave any fingerprints behind (them). 他们戴着手套，以免留下指纹。 来自《简明英汉词典》

6 countless   

adj.无数的，多得不计其数的

参考例句：

• In the war countless innocent people lost their lives.在这场战争中无数无辜的人丧失了性命。
• I've told you countless times.我已经告诉你无数遍了。

7 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。