『新东方在线托福听力』为托福考生准备了ETS托福TPO/Official 72 Lec1听力练习：What is the lecture mainly about?原文题目答案解析，TPO/Official 72 Lec1听力原文范文音频翻译。

托福TPO/Official 72 Lec1听力原文What is the lecture mainly about?【新东方在线】

旁白：请听一段天文学课堂中的讲座片段。

Narrator:Listen to part of a lecture in an astronomy class.

教授：好，这是一个有趣的词：天体生物学。

Professor: OK, here's an interesting word: astrobiology.

你以前听说过“天体生物学”这个词吗？

Have you came across the term astrobiology before?

学生：啊……听起来像是生物学和天文学的结合？

Student: Ah…it sounds like a cross between biology and astronomy?

学生：所以是研究生命的？“Astro”是星星、太空……所以是和研究太空生命有关？

Student: So the study of life, Astro, stars, space… so something to do with studying live in space?

教授：没错。完全正确。这是一门相对较新的科学。

Professor: Yes.Precisely.It's a relatively new science.

它以前还不被太多人重视，但现在已经得到认可了。

It’s on the margins for a while, but it has now reached respectability.

它涉及生物学、天文学和地质学的内容，但可能也跟哲学有关？

It has aspects of biology, astronomy, and geology, but maybe it's also philosophy?

我的意思是，我们在处理未知的事物，进行假设和推测，有些人认为这超出了科学的传统范畴。

I mean we're dealing with the unknown, making assumptions, speculations which while the some think this goes a little beyond the usual role of science,

但无论如何，我们在天体生物学中做的一件事就是我们非常仔细地观察微生物。

but anyway, one thing we're doing in astrobiology is that we are looking very carefully at microbes.

它们是非常微小的生物体，需要显微镜才能看到。

They are tiny organisms you need a microscope to see them.

因此，天体生物学家对微生物是否可能从其他行星的岩石上带到地球很感兴趣，对南极洲发现的陨石的研究似乎表明了这种可能性。

So astrobiologists are interested in whether microbes might have been carried to earth on rocks from other planets, and studies of meteorites found in antarctica seem to suggest that possibility.

但科学家应该研究的不仅仅是来自其他行星的微生物。

But it's not just microbes from other planets traveling to earth that scientists should study.

从另一个方向来看，他们正在研究地球上的微生物是否被带到其他行星上。

Going in the other direction, they're looking at whether microbes from earth might have been carry to other planets.

学生：那么从这里来的生命会存在于其他地方吗？

Student: So could life that traveled from here exist somewhere else?

教授:是的。这就是它的迷人之处，但首先，我们最好后退一点。

Professor: Yes. that's what's fascinating about this, but first, well, we better back up a bit.

这是怎么发生的？微生物从一个星球到另一个星球。

How could this happen? microbes going from one planet to another.

一种可能是小行星和彗星对行星的撞击。

One possibility is from the impact of asteroids and comets on planets.

当这些物体撞击行星表面时，它们会形成一个陨石坑，一个洞，物质，岩石从陨石坑中喷射出来，被抛到行星的大气层中。

When these objects hit a planet surface, they form a crater, a hole, and material, well rocks get ejected from that crater and thrown up into the planet’s atmosphere.

一些岩石甚至可能逃脱地球的引力，进入外太空。

Some of the rocks might even escape the planet‘s gravity and go into outer space.

被抛出的岩石中的大多数生命都会死于极高的压力和岩石被抛向太空时的高速。

Ok, most of the life in the ejected rocks would die due to the extremely high pressure and the high speed of the rocks as they're being thrown into space.

但是，如果生物在行星表面的岩石中，而不是在小行星撞击的地方，岩石上的压力就不会那么大，当岩石被喷射到太空中时，生物可能会存活下来。

But, if the living organism was inside a rock on the surface of the planet but not right where the asteroid hit, there wouldn't be as much pressure on the rock and the organism might survive when the rock gets ejected into space.

然后就是在太空中生存的问题。啊,是吗?

Then there's the question of survival in space.Ah, yes?

Student: I don't see how that could happen.

我以为任何生物在外太空都会死去。

I thought anything living would die in outer space.

教授：是的，而且还有极端的温度、宇宙射线、紫外线辐射。

Professor: Yes, and there's extreme temperatures, cosmic rays, ultraviolet radiation.

但在太空中进行的细菌实验表明，它们确实可以在这些条件下生存。

But experiments involving bacteria in space have shown that they can survive these conditions.

如果微生物藏得足够深，它们就能免受紫外线的伤害，尤其是紫外线非常致命。

If a microbe is deep enough inside a rock, it'll be protected from ultraviolet light, which is particularly deadly.

另外，如果微生物形成了孢子，它们的生存几率会更高。

Also, if a microbe forms a spore, it has an even better chance of survival.

我得解释一下，孢子是一种休眠结构，一些生物用来繁殖或自我保护。

I should explain that a spore is a dormant structure formed by some organisms for reproduction or to help them survival.

它们有一层保护壳，可以抵御恶劣环境。

They have a protective coating to help resist harsh environments.

事实上，低温似乎有助于孢子存活。

Cold temperatures actually seem to help spores survive.

因此，一种已经发育成孢子的微生物甚至可能在岩石中存活数百万年。

So, a microbe that has developed to spore might even survive in rocks for millions of years.

好吧，想象一下，由于我们太阳系的行星受到撞击，岩石被抛向太空。

OK, so imagine rocks being thrown up into space because of an impact on the planet in our own solar system.

在这些岩石中，有些可能携带生物，最终可能会遇到另一个星球。

Of these rocks, some of which might carry organisms, might eventually encounter another planet.

现在，当岩石与大气摩擦而加热时，它们能在进入行星大气层时幸存下来吗？

Now, could they survive the entry into the planet’s atmosphere when the rock gets heated from friction with the atmosphere?

如果岩石足够大，它内部的温度将保持相对较低，微生物可能能够生存。

If the rock is big enough, the temperature inside it will remain relatively low and microbes might be able to survive.

But then there's the impact on the planet surface.

如果岩石更小，如果含有微生物的大岩石在大气中破碎，那么这些小碎片撞击地表的力就会更小，如果岩石保持完整，微生物就能存活下来。

There it helps if the rock is smaller if that same large rock with microbes in it shatters in the atmosphere, then these smaller pieces would hit the surface with less force
If the rock stayed intact and microbes might survive.

学生：那在宇宙飞船上旅行的微生物呢？比如发射到火星上的太空探测器？

Student:
what about microbes traveling on spacecraft? like a space probe sent on Mars?

教授：我们来看看伽利略号太空探测器，它被派往木卫二执行任务，木卫二是木星的卫星之一。

Professor：
Well, let's look at the space probe Galileo, which was sent on a mission to Europa, one of Jupiter’s moons.

嗯，木卫二冰冷的表面下似乎有一片海洋，可能有生命存在。

It’s… well, Europa seems to have an ocean of water just below its icy surface and it might be capable of supporting life.

负责伽利略号任务的人不希望探测器撞向木卫二，并被它可能携带的地球微生物污染。

The people in charge of the Galileo mission didn't want the probe to crash into Europa and contaminated with microbes from earth that it might've been carrying.

所以在任务结束时，他们引导伽利略号飞向木星的大气层，燃烧起来。

So at the end of the mission, they steered Galileo toward Jupiter's atmosphere, burned up.

According to the professor, which microbes are most likely to survive after being ejected into space because of the impact of an asteroid?

What condition would make it more likely that microbes would survive entry into a planet's atmosphere?

Why does the professor mention the space probe Galileo?

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