美国国家公共电台 NPR NASA's Curiosity Rover Finds Chemical Building Blocks For Life On Mars

 

DAVID GREENE, HOST:

This seems big. Scientists say for the first time they have clear evidence that the chemical building blocks of life exist on Mars. So is this the moment we can say there is life on the red planet? Well, NPR's Joe Palca says not yet.

JOE PALCA, BYLINE¹: About three years ago, NASA's six-wheeled rover called Curiosity drilled into two rocks at the bottom of Gale² Crater³. Powder from the rocks went into an onboard analyzer to see what they were made of. But the analyzer results were garbled⁴ so NASA astrobiologist Jennifer Eigenbrode spent the intervening years removing the junk that was messing things up. Then she looked at the analyzer results again.

JENNIFER EIGENBRODE: And there was signals there that were telling us that we had detected different types of organic molecules⁶.

PALCA: Organic molecules contain carbon, the chemical element central to life. That raises the obvious question, where was the carbon coming from?

EIGENBRODE: We don't know.

PALCA: Eigenbrode sees three possibilities.

EIGENBRODE: It could have been from meteorites⁷.

PALCA: Meteorites are constantly pummeling Mars, and many contain organic molecules.

EIGENBRODE: It could be from rock processes.

PALCA: Processes that have been going on in the billions of years since Mars formed. And then there's the most intriguing⁸ possibility. Eigenbrode says the analyzed⁹ rocks came from the bottom of what was once a lake at a time when Mars was a much warmer, wetter place.

EIGENBRODE: Because this lake had everything the organisms needed to be happy, it could have supported life. Maybe there was life in the lake.

PALCA: And that life decayed, leaving behind the organic molecules the rover detected. Penn State astrobiologist Kate Freeman agrees the new evidence makes that interpretation¹⁰ possible, but...

KATE FREEMAN: It's not standing¹¹ up and waving a flag saying, I'm life.

PALCA: Freeman isn't ruling out the possibility.

FREEMAN: I don't believe there's life on Mars at the present, although whether there was in the past or not is certainly an open question.

PALCA: In addition to finding organic molecules in the rocks in Gale Crater, rover scientists are reporting another intriguing finding. Chris Webster is a rover scientist at NASA's Jet Propulsion Laboratory. He says the rover has been seeing seasonal¹² changes in the amount of methane¹³ in the Martian atmosphere. Methane is another organic molecule⁵. Webster says he and his colleagues think the methane is coming from underground.

CHRIS WEBSTER: It's coming from subsurface reservoirs.

PALCA: So what's making the methane? Is it strictly¹⁴ chemical processes involving rocks alone, or could living or formerly¹⁵ living bacteria have generated the methane?

WEBSTER: We can't tell which one of those.

PALCA: Clearly, there are more questions about Mars that need answering. The rover results appear in the journal Science.

Joe Palca, NPR News.

1 byline   

n.署名；v.署名

参考例句：

• His byline was absent as well.他的署名也不见了。
• We wish to thank the author of this article which carries no byline.我们要感谢这篇文章的那位没有署名的作者。

2 gale   

n.大风，强风，一阵闹声（尤指笑声等）

参考例句：

• We got our roof blown off in the gale last night.昨夜的大风把我们的房顶给掀掉了。
• According to the weather forecast,there will be a gale tomorrow.据气象台预报，明天有大风。

3 crater   

n.火山口，弹坑

参考例句：

• With a telescope you can see the huge crater of Ve-suvius.用望远镜你能看到巨大的维苏威火山口。
• They came to the lip of a dead crater.他们来到了一个死火山口。

4 garbled   

adj.（指信息）混乱的，引起误解的v.对（事实）歪曲，对（文章等）断章取义，窜改( garble的过去式和过去分词 )

参考例句：

• He gave a garbled account of what had happened. 他对所发生事情的叙述含混不清。
• The Coastguard needs to decipher garbled messages in a few minutes. 海岸警卫队需要在几分钟内解读这些含混不清的信息。 来自辞典例句

5 molecule   

n.分子，克分子

参考例句：

• A molecule of water is made up of two atoms of hygrogen and one atom of oxygen.一个水分子是由P妈̬f婘̬ 妈̬成的。
• This gives us the structural formula of the molecule.这种方式给出了分子的结构式。

6 molecules   

分子( molecule的名词复数 )

参考例句：

• The structure of molecules can be seen under an electron microscope. 分子的结构可在电子显微镜下观察到。
• Inside the reactor the large molecules are cracked into smaller molecules. 在反应堆里，大分子裂变为小分子。

7 meteorites   

n.陨星( meteorite的名词复数 )

参考例句：

• Small meteorites have left impact craters all over the planet's surface. 这个行星的表面布满了小块陨石留下的撞击坑。 来自《简明英汉词典》
• One theory about the existence of extraterrestrial life rests on the presence of carbon compounds in meteorites. 地球外存在生命的理论是基于陨星上存在碳化合物质这一事实的。 来自《简明英汉词典》

8 intriguing   

adj.有趣的；迷人的v.搞阴谋诡计(intrigue的现在分词)；激起…的好奇心

参考例句：

• These discoveries raise intriguing questions. 这些发现带来了非常有趣的问题。
• It all sounds very intriguing. 这些听起来都很有趣。 来自《简明英汉词典》

9 analyzed   

v.分析( analyze的过去式和过去分词 )；分解；解释；对…进行心理分析

参考例句：

• The doctors analyzed the blood sample for anemia. 医生们分析了贫血的血样。 来自《简明英汉词典》
• The young man did not analyze the process of his captivation and enrapturement, for love to him was a mystery and could not be analyzed. 这年轻人没有分析自己蛊惑著迷的过程，因为对他来说，爱是个不可分析的迷。 来自《简明英汉词典》

10 interpretation   

n.解释，说明，描述；艺术处理

参考例句：

• His statement admits of one interpretation only.他的话只有一种解释。
• Analysis and interpretation is a very personal thing.分析与说明是个很主观的事情。

11 standing   

n.持续，地位；adj.永久的，不动的，直立的，不流动的

参考例句：

• After the earthquake only a few houses were left standing.地震过后只有几幢房屋还立着。
• They're standing out against any change in the law.他们坚决反对对法律做任何修改。

12 seasonal   

adj.季节的，季节性的

参考例句：

• The town relies on the seasonal tourist industry for jobs.这个城镇依靠季节性旅游业提供就业机会。
• The hors d'oeuvre is seasonal vegetables.餐前小吃是应时蔬菜。

13 methane   

n.甲烷，沼气

参考例句：

• The blast was caused by pockets of methane gas that ignited.爆炸是由数袋甲烷气体着火引起的。
• Methane may have extraterrestrial significance.甲烷具有星际意义。

14 strictly   

adv.严厉地，严格地；严密地

参考例句：

• His doctor is dieting him strictly.他的医生严格规定他的饮食。
• The guests were seated strictly in order of precedence.客人严格按照地位高低就座。

15 formerly   

adv.从前，以前

参考例句：

• We now enjoy these comforts of which formerly we had only heard.我们现在享受到了过去只是听说过的那些舒适条件。
• This boat was formerly used on the rivers of China.这船从前航行在中国内河里。