英语听力：自然百科 探索世界奥秘之Life On Mars(火星生命)Unit14

Well, hearing that Odyssey¹ had found subsurface water on Mars was enormously exciting for somebody who is involved in planning to send humans to Mars. Water has a number of important uses for us. At the most basic, it provides drinking water once it's been purified, and it provides water for hygiene² purposes as well. More important than that, we can electrolyze it, we can actually split it into hydrogen and oxygen, oxygen obviously we can use for breathing and we can also use it as a fuel stock with the hydrogen for our vehicle to come back home. And we can also use the hydrogen itself in fuel cells to power our rover vehicles. So the ability to use water that exists on Mars is tremendously important to human missions on Mars.

But any colonizing³ of Mars would require extreme action. Some believe it would need what scientists call'terraforming', transforming the entire planet into an artificial Earth. This involves growing plants to create more oxygen, and an atmosphere.

It requires raising the temperature of the planet, raising the atmospheric⁴ density⁵ through melting the icecaps and freeing up the carbon dioxide. But the key thing about the water ice on Mars is once we've done that, then we can let that water exist free form on surface of the planet, it again will create rivers, lakes, oceans which we can use and the plants can use to survive.

But plants grown on Mars may be very different from those on Earth. The lower gravity on Mars, one third of that on Earth means that both plants and animals might grow taller and thinner.

I think we're all familiar with seeing the giant redwood trees of California. They are somewhat unusual here on Earth. They only occur in a few localized places. On Mars, it would be the norm. You would see these tremendously tall, slim trees, possibly with very high canopies⁶ on them as well. Animal life could be affected⁷ the same way as well. We could see new breeds of animal that we haven't seen before, very tall, thin sheep living on Mars. But again early days, very much speculative⁸.

This lower gravity would also have implications for any people born there.

If humans live on Mars for many generations, they might develop into different forms than humans on Earth. They might be taller, they might be thinner, they might have weaker muscles and weaker bones. It might even be possible that they would not be able to function very effectively on the gravity of Earth. In that case, Mars' society and Earth's society might split and become effectively two different species.

subsurface water(also underground water): water that is found in cavities beneath the surface of the land

electrolyze(also electrolyse): separate a substance using electric currents, chemically separate a substance

terraforming: is the theoretical process of modifying a planet, moon, or other body to a more habitable atmosphere, temperature, or ecology. It is a type of planetary engineering. The term is sometimes used broadly as a synonym⁹ for planetary engineering in general. The concepts of terraforming are rooted both in science fiction and actual science

localized(also localised): confined to a particular place; concentrated in particular location

canopy¹⁰: The uppermost layer in a forest, formed by the crowns of the trees. Also called crown canopy

1 odyssey   

n.长途冒险旅行；一连串的冒险

参考例句：

• The march to Travnik was the final stretch of a 16-hour odyssey.去特拉夫尼克的这段路是长达16小时艰险旅行的最后一程。
• His odyssey of passion, friendship,love,and revenge was now finished.他的热情、友谊、爱情和复仇的漫长历程，到此结束了。

2 hygiene   

n.健康法，卫生学 （a.hygienic）

参考例句：

• Their course of study includes elementary hygiene and medical theory.他们的课程包括基础卫生学和医疗知识。
• He's going to give us a lecture on public hygiene.他要给我们作关于公共卫生方面的报告。

3 colonizing   

v.开拓殖民地，移民于殖民地( colonize的现在分词 )

参考例句：

• The art of colonizing is no exception to the rule. 殖民的芸术是� 有特例的。 来自互联网
• A Lesson for Other Colonizing Nations. 其它殖民国家学习的教训。 来自互联网

4 atmospheric   

adj.大气的，空气的；大气层的；大气所引起的

参考例句：

• Sea surface temperatures and atmospheric circulation are strongly coupled.海洋表面温度与大气环流是密切相关的。
• Clouds return radiant energy to the surface primarily via the atmospheric window.云主要通过大气窗区向地表辐射能量。

5 density   

n.密集，密度，浓度

参考例句：

• The population density of that country is 685 per square mile.那个国家的人口密度为每平方英里685人。
• The region has a very high population density.该地区的人口密度很高。

6 canopies   

（宝座或床等上面的）华盖( canopy的名词复数 )； （飞行器上的）座舱罩； 任何悬于上空的覆盖物； 森林中天棚似的树荫

参考例句：

• Golf carts with bright canvas canopies wandered the raingreen fairways. 一场雨后显得愈加葱绿的高尔夫球场草地上，散放着一些带有色彩缤纷的帆布华盖的高尔夫小车。
• Rock permitted seven canopies, cornices floors, decorative glass, Ambilight, momentum magnificent, magnificent. 七檐佛殿背倚山岩，楼层飞檐翘角，殿顶琉璃装饰，流光溢彩，气势恢宏，蔚为壮观。

7 affected   

adj.不自然的，假装的

参考例句：

• She showed an affected interest in our subject.她假装对我们的课题感到兴趣。
• His manners are affected.他的态度不自然。

8 speculative   

adj.思索性的，暝想性的，推理的

参考例句：

• Much of our information is speculative.我们的许多信息是带推测性的。
• The report is highly speculative and should be ignored.那个报道推测的成分很大，不应理会。

9 synonym   

n.同义词，换喻词

参考例句：

• Zhuge Liang is a synonym for wisdom in folklore.诸葛亮在民间传说中成了智慧的代名词。
• The term 'industrial democracy' is often used as a synonym for worker participation. “工业民主”这个词常被用作“工人参与”的同义词。

10 canopy   

n.天篷，遮篷

参考例句：

• The trees formed a leafy canopy above their heads.树木在他们头顶上空形成了一个枝叶茂盛的遮篷。
• They lay down under a canopy of stars.他们躺在繁星点点的天幕下。