Scientists have found the first evidence that briny water may flow on the surface of Mars during the planet’s summer months. The

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问题    Scientists have found the first evidence that briny water may flow on the surface of Mars during the planet’s summer months. The confirmation of water on the surface of Mars is important and would raise a host of questions, chief among them: Where is the water coming from, and what does it mean for the prospect of life, past or present?
   They found telltale fingerprints of salts that form only in the presence of water in narrow channels cut into cliff walls throughout the planet’s equatorial region. The slopes appear during the warm summer months on Mars, then vanish when the temperatures drop. Scientists suspected the streaks were cut by flowing water, but had previously been unable to make the measurements.
   The salt content of the water is important because without it, the water would freeze in Mars’ bone-chilling temperatures. The water could be coming from subsurface ice, from salts attracting water from the thin Martian atmosphere or possibly bubbling up from an aquifer.
   The discovery is important as it could affect thinking about whether the planet that is most like Earth in the solar system could support present-day microbial life.
   Mars reconnaissance orbiter makes its measurements during the hottest part of the Martian day, so scientists believed any traces of water, or fingerprints from hydrated minerals, would have evaporated. Also, the chemical-sensing instrument on the orbiting spacecraft cannot hone in on details as small as the narrow streaks, which typically are less than 16 feet wide.
   But scientists created a computer program that could scrutinize individual pixels. That data was then correlated with high-resolution images of the streaks. Scientists concentrated on the widest streaks and came up with a 100-percent match between their locations and detections of hydrated salts.
   Then, NASA declared "Mars mystery solved" in a press advisory without offering even a hint as to what mystery they meant. "It’s a little bit of an over-the-top announcement by NASA," Ojha said. "There are so many mysteries to be solved."
   Whatever the water’s source, the prospect of liquid water, even seasonally, raises the intriguing prospect that Mars could support life. Much more information about the water’s chemistry, however, would be needed before scientists could make that assessment.
   NASA’s ongoing Mars rover Curiosity has found evidence that Mars had all the ingredients and suitable habitats for microbial life to exist at some point in its past.

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答案 科学家们已发现首个表明夏季火星表面可能有卤水流动的证据。确认火星表面有水的存在十分重要。这将引出一系列问题,其中最主要的问题是:这些水从哪里来?它对发现过去和现在的生命迹象意味着什么? 科学家们发现在遍布火星赤道地区的斜坡上的狭窄沟槽内有盐存在的明显痕迹,而这些痕迹必须有水才能形成。温暖夏季,火星上出现坡地,一旦降温,坡地便消失。科学家们怀疑,火星上的这些沟槽是由水流冲刷而成,但以前一直无法对这些沟槽进行测量。 水里的盐分至关重要,因为没有盐分,在火星冰冷刺骨的环境中,水会被冻结。水可能源自地表之下的冰层,也可能是盐从火星周围稀薄的大气层里吸取的水分,或者可能是由含水层冒泡形成。 水的发现很重要,这会引发人们对于太阳系中最像地球的火星是否能够为现有微生物提供生命支持的思考。 火星侦察轨道器在火星最热时进行测量,因此,科学家们曾认为,即使有水痕或有水合矿物痕迹,也可能都蒸发了。而且,轨道航天器上的化学传感器尚且无法获取火星上现有的通常不到16英尺宽的狭窄缝隙的详细数据。 不过,科学家们开发了一个电脑程序,可以仔细观测单个像素。然后,将这些数据与高分辨率图像上的沟槽进行比对分析。科学家们集中观察最宽沟槽,结果沟槽的地理位置与检测到的水合盐完全匹配。 随后,美国国家航空航天局发布新闻公告,宣布“火星秘密已经揭开”,但却丝毫没有透露所谓的“秘密”。欧嘉(Ojha)说: “美国国家航空航天局的公告有点言过其实了。还有太多的谜团尚待解开。” 不管这些水从哪里来,如能确定液态水真实存在,哪怕只是季节性的,这一发现也展现了诱人的前景:火星能支持生命的存在。但是,科学家们还需要获得更多有关火星水的化学成分信息后,才能对此进行评估。 美国国家航空航天局在轨的火星探测器“好奇号”已发现证据,证明在过去的某个时间点,火星曾具有能支持微生物生命存在的所有物质和适宜环境。

解析    本文改编自科普评论性文章。改编后文章开篇直接呈现最新的、令人震惊的科学发现,引发读者阅读兴趣。随即引出要讨论的问题:火星上水产生的可能原因以及水的存在有何重要价值。文章第二部分包括第2至6自然段,逐步分析了火星上有水的可能原因、水中含有盐分的重要性、发现水的重要性,以及最新科学研究进展等细节问题,文章整体上逻辑清晰,衔接过渡自然。文章第三部分笔锋稍转,提到美国宇航局最新公告似有夸张之嫌,但无论如何,现有证据起码能证明火星曾经有过可能支持微生物存在的自然条件和生存要素。
   整篇文章虽然属于科普性论说文体,但总体上可读性较强,所探讨问题也易于引发读者兴趣。从翻译角度而言,译者需注意把握语体,做到文字正式但不古板,用词准确而不远奥。
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