---
url: https://gaojian.site/new-concept/book-3/55-from-the-earth-greetings.md
description: '新概念英语第三册：From the Earth: Greetings。精读、词块回忆、双向译练、句法、逻辑与FSRS复习。'
---

# 55 · 来自地球的问候

### 第1段

Recent developments in astronomy have made it possible to detect planets in our own Milky Way and in other galaxies. This is a major achievement because, in relative terms, planets are very small and do not emit light. Finding planets is proving hard enough, but finding life on them will prove infinitely more difficult. The first question to answer is whether a planet can actually support life. In our own solar system, for example, Venus is far too hot and Mars is far too cold to support life. Only the Earth provides ideal conditions, and even here it has taken more than four billion years for plant and animal life to evolve.
Whether a planet can support life depends on the size and brightness of its star, that is its "sun". Imagine a star up to twenty times larger, brighter and hotter than our own sun. A planet would have to be a very long way from it to be capable of supporting life. Alternatively, if the star were small, the life-supporting planet would have to have a close orbit round it and also provide the perfect conditions for life forms to develop. But how would we find such a planet? At present, there is no telescope in existence that is capable of detecting the presence of life. The development of such a telescope will be one of the great astronomical projects of the twenty-first century.
It is impossible to look for life on another planet using earth-based telescopes. Our own warm atmosphere and the heat generated by the telescope would make it impossible to detect objects as small as planets. Even a telescope in orbit round the earth, like the very successful Hubble telescope, would not be suitable because of the dust particles in our solar system. A telescope would have to be as far away as the planet Jupiter to look for life in outer space, because the dust becomes thinner the further we travel towards the outer edges of our own solar system. Once we detected a planet, we would have to find a way of blotting out the light from its star, so that we would be able to "see" the planet properly and analyze its atmosphere. In the first instance, we would be looking for plant life, rather than "little green men". The life forms most likely to develop on a planet would be bacteria. It is bacteria that have generated the oxygen we breathe on earth. For most of the earth's history they have been the only form of life on our planet. As Earth-dwellers, we always cherish the hope that we will be visited by little green men and that we will be able to communicate with them. But this hope is always in the realms of science fiction. If we were able to discover lowly forms of life like bacteria on another planet, it would completely change our view of ourselves. As Daniel Goldin of NASA observed, "Finding life elsewhere would change everything. No human endeavour or thought would be unchanged by it."

中文理解：天文学近来的发展，使人们有可能探测到银河系乃至其他星系中的行星。这是一项重大成就，因为相对来说，行星体积很小，而且本身不发光。发现行星已经够难，要在行星上找到生命，就会困难得多。首先必须回答一个问题：这颗行星是否真的具备孕育生命的条件？比如，在我们的太阳系中，金星太热，火星又太冷，都无法维持生命。只有地球提供了理想条件；而即便在地球上，动植物生命的演化，也经历了四十多亿年。
一颗行星能否维持生命，取决于它所围绕的恒星，也就是它的“太阳”，有多大、多亮。设想一颗恒星，大小、亮度和热度都高达太阳的二十倍，那么一颗行星就必须离它非常远，才可能适合生命存在。相反，如果恒星很小，宜居行星就必须沿着贴近恒星的轨道运行，同时自身还要提供适合生命发展的理想条件。可我们怎样才能找到这样的行星呢？目前还没有任何一架望远镜，能够探测生命是否存在。研制这样的望远镜，将成为21世纪天文学的重大工程之一。
利用地面望远镜寻找其他行星上的生命，是不可能的。地球温暖的大气层，以及望远镜本身产生的热量，都会使我们无法探测行星这样小的天体。即便是像哈勃这样成就卓著、绕地运行的望远镜，也会受到太阳系尘埃的干扰，并不适用。若要搜寻外太空的生命，望远镜得远到木星所在的位置，因为越接近太阳系边缘，尘埃越稀薄。一旦发现行星，我们还得想办法遮去它所围绕的恒星的光，才能真正“看清”行星，并分析其大气。最初，我们寻找的会是植物生命，而不是什么“小绿人”。行星上最有可能出现的生命形式，是细菌。地球上供我们呼吸的氧气，正是细菌产生的；在地球历史的大部分时间里，细菌都是唯一的生命形式。作为地球居民，我们总怀着一种希望：有朝一日，小绿人会来访，我们还能与它们交流。但这种希望始终属于科幻的领域。假如我们能在另一颗行星上发现细菌这样低等的生命形式，就会彻底改变我们对自身的认识。正如美国航天局的丹尼尔·戈尔丁所说：“在别处发现生命，将改变一切。人类的一切努力和思想，都将因此而改变。”

* **have made it possible**：已使……成为可能；make it possible to do，it 先占宾语位置，真正行动在后。

* **in relative terms**：相对而言；需理解比较尺度，不表示绝对小或大。

* **emit light**：发光；emit 与 reflect 区别：原文说行星不自行发光，不等于完全不可见。

* **support life**：维持生命；本课指环境容许生命生存，不是赞助生活。

* **provides ideal conditions**：提供理想条件；provide conditions for + 活动，ideal 不等于唯一条件。

* **depends on**：取决于；说清影响条件，不等于必然因果。

* **have a close orbit**：有一条距离很近的轨道；轨道远近与讨论对象相连，不把本课年代性科普当最新科学定论。

* **At present**：目前；说明目前的情况；比口语里的 right now 稍正式。

* **in existence**：现存的；存在的；in existence 说存在状态，需明确时间与范围。

* **earth-based telescopes**：地面望远镜；earth-based 是复合形容词，课文可作为技术条件比较的语言材料。

* **because of**：由于；因为；后面接原因，不直接接完整陈述句；because 后面才可直接接主语和谓语。

* **the outer edges of**：……的外围边缘；the edge of + 对象，outer 强调远离中心。

* **blotting out**：遮住；遮蔽；blot out light / a view；本课指遮去恒星强光以观测行星。

* **In the first instance**：首先；起初；交代第一步，未必意味着永远只做这一项。

* **rather than**：而不是；两端结构尽量平行，明确替代的两种选择。

* **have generated the oxygen**：产生了氧气；generate + 产物；原文将某作用概括给 bacteria，理解语言与完整科学机制分开。

* **cherish the hope**：始终怀着希望；cherish the hope that… / of doing，语气比 hope 更郑重。

* **communicate with**：与……交流；communicate with + 对象，communicate information to + 接收者。

* **change our view of ourselves**：改变我们对自身的认识；change one's view of + 对象，ourselves 回指看待自己的主体。

* **would be unchanged**：将会保持不变；本课 No… would be unchanged 双重语义为一切都会改变，不能漏 No。

#### 原文注释 · Recent developments in astronomy have made it possible to detect planets in our own Milky Way and in other galaxies.

注释：①detect = discover, find。②in relative terms = relatively (speaking) , in relation to other things。③emit = send out。 ④ideal conditions = an environment which is perfect (for the development of life)。

#### 原文注释 · Whether a planet can support life depends on the size and brightness of its star, that is its "sun".

注释：①capable of = able to。②alternatively = on the other hand。③presence = existence。

#### 原文注释 · It is impossible to look for life on another planet using earth-based telescopes.

注释：①在because 引导的原因状语从句中还有一个“the further…system”作比较状语从句。②小绿人这个单词本身在英语语境中就是指代外星人，是想象的外星小绿人。

#### Summary 摘要

Finding life on other planets with earth based telescopes is impossible because of the heat of our planet and the dust particles throughout the solar System. A telescope would need to be as far away as Jupiter. Even then, the problem will be how to blot out the light from a planet's sun to study it. The most likely forms of life will be plants and bacteria. Even the discovery of lowly life forms would change our view of ourselves. (80 words)

#### Composition 作文

\[1]Do you remember ET in the film ET, the Extraterrestrial(n.天外来客)? If you do, you will know that the common picture of extraterrestrials is that they will look rather strange-for instance, they might have big eyes and funny feet and be a strange colour-but they will still somehow look like living creatures from earth. At the same time, of course, we believe that they will probably have incredible powers-like ET's power to heal injuries and to come alive again. Many science-fiction stories and films have shown aliens or extraterrestrials like this. They may somehow look like strange earth creatures, therefore, but they are benevolent.

\[2]But what if extraterrestrials-beings from other planets-are creatures with incredible intelligence and with no form, that is, with no body form like earthly creatures? They might be almost "living thoughts". How would we greet them? How would we deal with them? And what if they are not benevolent? In other words, what if they really want to take over the earth?

\[3]There are stories that extraterrestrials or aliens have already crashed on earth in spacecraft (flying saucers) and that scientists have studied them. There are even more fantastic stories that scientists are already learning from extraterrestrials new knowledge which will help us build incredible spacecraft to fly to other planets and beyond. Stories like that must surely be just rumours.

\[4]Perhaps one day we will know if there really are extraterrestrials out there in space, and if there are, we will know what they look like and what they think of us. Will they really be little green men? Or will they begiants? Or Perhaps they will be so small that we can hardly see them? Will they be friendly? Or will they want to take over the earth? Who knows? One thing is certain. If we were ever to discover that there are extraterrestrials out there, the discovery would completely change our view of the universe and ourselves. (329 words)

## 学完这一课

用 Doing A is hard, but doing B… 比较两项任务的难点。

[Nce · 本册复习台](/new-concept/book-3/review) · [三册选择地图](/new-concept/)

*译文依据整理稿，由本站按中文表达重新校订；解析据吴应时、何景霖整理资料及首轮审校稿；词伙与练习提示为本站学习设计。原PDF第197—200页，2022年2月第3版。*