经济学人: 搜寻火星生命 (2)

 Regardless of their source, any methane¹ molecules² in Mars's atmosphere would, on the basis of experiments on Earth, be expected to hang around for centuries. 不论它从何而来，根据地球的实验，火星大气中的任何甲烷分子将有望徘徊几个世纪。

It was to find signs of this more widespread material that a spectroscopic instrument called NOMAD³ (Nadir and Occultation for MArs Discovery), 正是为了发现更多关于这种普遍材料的迹象，一种搭载在ExoMars微量气体探测轨道飞行器上的

which is on board ExoMars Trace Gas Orbiter, was designed. And, as Ann Carine Vandaele of the Belgian Institute for Space Aeronomy told the AGU, 光谱仪器NOMAD被设计了出来。并且正如比利时航天航空研究所的安·卡林·凡达勒所告诉AGU的，

NOMAD has failed to find the slightest hint of methane in the Martian atmosphere. NOMAD并没有在火星大气中发现甲烷的任何最细微的线索。

Since NOMAD is 20 times more sensitive than the methane detector⁴ on board Curiosity, this is bad news. 由于NOMAD的敏感度是好奇号上所搭载的甲烷探测器得20多倍，因此这是个坏消息。

The findings are still under review, pending⁵ publication in a journal, and are therefore preliminary. 在结果发表于杂志期间，这些发现仍在审查之中，因此这些结果还在初级阶段。

But they do not surprise Kevin Zahnle of the Ames Research Centre, in California, a laboratory belonging to NASA, America's space agency. 但对于从属于美国太空署NASA的加利福尼亚艾姆斯研究中心的凯文·扎恩勒来说，这些结果并不惊讶。

Dr Zahnle has long argued that Curiosity's reports of Martian methane are artefacts. 扎恩勒博士长期以来都在争论称好奇号关于火星甲烷的报道是假象。

They are only marginally higher than control readings, 它们不过是在边缘函数上比控制读数稍高，

and those readings indicate the rover itself may be a source of methane (though nobody knows how), 并且那些读数表明探测车本身或许就是甲烷的一种来源（虽然没人知道其原理），

which further complicates⁶ taking accurate readings. 这进一步将获取正确读数复杂化。

The optimists⁷ will not be deflected⁸, though. They note that NOMAD can probe only the upper part of Mars's atmosphere. 虽然乐观派不会因此停止脚步。他们注意到NOMAD仅能探测火星大气的上层部分。

Air with an altitude of less than 5km is beyond its range. 海拔不足5千米的大气不在其探测范围内。

Moreover, when ExoMars Trace Gas Orbiter flew over Gale⁹, a dust storm obscured NOMAD's view of anything within 30km of the surface. 此外，当ExoMars微量气体探测轨道飞行器飞过盖尔山时，一场尘暴遮盖住了NOMAD 30千米范围内的视角。

Such optimists thus argue that the idea of methane seeping¹⁰ from the crater¹¹ cannot be discounted. 因此这些乐观主义者争辩称甲烷从火山口喷射出的这种想法是没有市场的。

What NOMAD does seem to show is that, if methane exists at all in Mars's air, it is rare and confined to low levels of the atmosphere. NOMAD似乎确实为我们展现了，如果甲烷存在于火星大气之中，那么它很稀少，并且限于大气的低层中。

But for now, neither side is willing to give way. 但目前，两边都不愿让步。

 

1 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。

2 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。

3 nomad   

n.游牧部落的人，流浪者，游牧民

参考例句：

• He was indeed a nomad of no nationality.他的确是个无国籍的游民。
• The nomad life is rough and hazardous.游牧生活艰苦又危险。

4 detector   

n.发觉者，探测器

参考例句：

• The detector is housed in a streamlined cylindrical container.探测器安装在流线型圆柱形容器内。
• Please walk through the metal detector.请走过金属检测器。

5 pending   

prep.直到，等待…期间；adj.待定的；迫近的

参考例句：

• The lawsuit is still pending in the state court.这案子仍在州法庭等待定夺。
• He knew my examination was pending.他知道我就要考试了。

6 complicates   

使复杂化( complicate的第三人称单数 )

参考例句：

• What complicates the issue is the burden of history. 历史的重负使问题复杂化了。
• Russia as a great and ambitious power gravely complicates the situation. 俄国作为一个强大而有野心的国家，使得局势异常复杂。

7 optimists   

n.乐观主义者( optimist的名词复数 )

参考例句：

• Even optimists admit the outlook to be poor. 甚至乐观的人都认为前景不好。 来自《简明英汉词典》
• Optimists reckon house prices will move up with inflation this year. 乐观人士认为今年的房价将会随通货膨胀而上涨。 来自辞典例句

8 deflected   

偏离的

参考例句：

• The ball deflected off Reid's body into the goal. 球打在里德身上反弹进球门。
• Most of its particles are deflected. 此物质的料子大多是偏斜的。

9 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。

10 seeping   

v.（液体）渗( seep的现在分词 )；渗透；渗出；漏出

参考例句：

• Water had been slowly seeping away from the pond. 池塘里的水一直在慢慢渗漏。 来自《简明英汉词典》
• Chueh-hui could feel the cold seeping into his bones. 觉慧开始觉得寒气透过衣服浸到身上来了。 来自汉英文学 - 家（1-26） - 家（1-26）

11 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。