VOA标准英语2008年-Study Finds Mars Water Too Salty to Sustain Lif

By Jessica Berman
Washington
29 May 2008

As the newly deployed¹ Phoenix² spacecraft begins its mission in search of life near Mars' northern pole, scientists say an analysis of Martian deposits suggest there was once water on the planet, but it was too salty to sustain life. VOA's Jessica Berman reports.

Scientists at Harvard University in Massachusetts and Stony³ Brook⁴ University in New York analyzed⁶ salt deposits in a four-billion-year-old rock that was explored by the U.S. space agency's Mars exploration rover, Opportunity, and by using information from spacecraft orbiting the Red Planet.

The data confirm that water once existed on Mars. Scientists have eagerly sought evidence of water because it is necessary for life.

But in a new study published in the latest issue of the journal Science, researchers conclude that the water that existed on Mars billions of years ago was too salty for any life form to tolerate, at least in Meridiani Planum, a vast region where the rock was found.

"Meridiani Planum, this locality where the Mars rover landed, may have actually been the best place for life to have existed on early Mars," said Nicholas Tosca, the study's lead author. "But the interesting thing is it itself was a pretty harsh place in terms of salinity⁷ because when we looked elsewhere [in] other localities where we had information about salt minerals, we found the salinity was much, much worse."

Tosca says the salt content of the water in Meridiani - which scientists believe was the consistency⁸ of a thick brine - does not completely rule out that life once existed there.

"If there was any opportunity for life on Mars, it happened when Mars was a very young planet - so it happened very long ago - and the window of opportunity was short," he said. "The conditions were very harsh in terms of salinity and so life needed to get its act together and grab a foothold before the climate turned quite cold and dry like it is today."

Tosca adds it is always possible Mars harbored ancient life forms unfamiliar⁹ to scientists on Earth.

Tosca says the Phoenix mission to scoop¹⁰ up and analyze⁵ ice beneath the Martian surface near the planet's northern pole will provide more evidence of the planet's chemistry, helping¹¹ to rule in or out the existence of life on Mars.

1 deployed   

（尤指军事行动）使展开( deploy的过去式和过去分词 )； 施展； 部署； 有效地利用

参考例句：

• Tanks have been deployed all along the front line. 沿整个前线已部署了坦克。
• The artillery was deployed to bear on the fort. 火炮是对着那个碉堡部署的。

2 phoenix   

n.凤凰，长生(不死)鸟；引申为重生

参考例句：

• The airline rose like a phoenix from the ashes.这家航空公司又起死回生了。
• The phoenix worship of China is fetish worship not totem adoration.中国凤崇拜是灵物崇拜而非图腾崇拜。

3 stony   

adj.石头的，多石头的，冷酷的，无情的

参考例句：

• The ground is too dry and stony.这块地太干，而且布满了石头。
• He listened to her story with a stony expression.他带着冷漠的表情听她讲经历。

4 brook   

n.小河，溪；v.忍受，容让

参考例句：

• In our room we could hear the murmur of a distant brook.在我们房间能听到远处小溪汩汩的流水声。
• The brook trickled through the valley.小溪涓涓流过峡谷。

5 analyze   

vt.分析，解析 (=analyse)

参考例句：

• We should analyze the cause and effect of this event.我们应该分析这场事变的因果。
• The teacher tried to analyze the cause of our failure.老师设法分析我们失败的原因。

6 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》

7 salinity   

n.盐分；咸度；盐浓度；咸性

参考例句：

• In the sea water sampled the salinity is two parts per thousand.在取样的海水中，盐度为千分之二。
• In many sedimentary basins the salinity of the formation water increases with depth or compaction.在许多沉积盆地中，地层水的含盐量随深度或压实作用而增高。

8 consistency   

n.一贯性，前后一致，稳定性；(液体的)浓度

参考例句：

• Your behaviour lacks consistency.你的行为缺乏一贯性。
• We appreciate the consistency and stability in China and in Chinese politics.我们赞赏中国及其政策的连续性和稳定性。

9 unfamiliar   

adj.陌生的，不熟悉的

参考例句：

• I am unfamiliar with the place and the people here.我在这儿人地生疏。
• The man seemed unfamiliar to me.这人很面生。

10 scoop   

n.铲子，舀取，独家新闻；v.汲取，舀取，抢先登出

参考例句：

• In the morning he must get his boy to scoop it out.早上一定得叫佣人把它剜出来。
• Uh,one scoop of coffee and one scoop of chocolate for me.我要一勺咖啡的和一勺巧克力的。

11 helping   

n.食物的一份&adj.帮助人的，辅助的

参考例句：

• The poor children regularly pony up for a second helping of my hamburger. 那些可怜的孩子们总是要求我把我的汉堡包再给他们一份。
• By doing this, they may at times be helping to restore competition. 这样一来, 他在某些时候,有助于竞争的加强。