火星的盖尔陨石坑曾经有一个巨大的咸水湖

我们刚得到更多的确凿证据，火星的盖尔陨石坑曾经有一个巨大的咸水湖

From its red and rugged surface, Mars looks like a lifeless planet, both dry and desolate. But that hasn't always been the case.

从红色崎岖的表面看，火星像一个没有生命的星球，既干燥又荒凉。但事实并非总是如此。

NASA's Curiosity Rover has now collected even more evidence of an ancient salty lake that once lapped the edges of the Gale crater some 3.7 billion years ago.

美国宇航局的好奇号探测器现在收集到了更多的证据，证明在大约37亿年前，盖尔陨石坑的边缘曾有过一个古老的咸水湖。

Analysing soil samples collected from the crater's bedrock, researchers from Caltech have turned up a diverse range of salts not observed in other rocks on Mars.

加州理工学院的研究人员分析了从陨石坑基岩中采集的土壤样本，发现了火星上其他岩石中没有观察到的各种盐。

Dating back roughly 3.3 to 3.7 billion years ago, the team proposes that these sulfates are left over from evaporated water, indicating the existence of ancient brines, or salty pools, that could have once held tiny forms of life.

该研究小组提出，这些硫酸盐可以追溯到大约33亿至37亿年前，它们是从蒸发的水中残留下来的，这表明存在着古老的盐水或盐池，它们可能曾经有过微小的生命形式。

Satellite observations of the Red Planet certainly suggest that during this time frame, known as the Hesperian period, some sort of climatic transition took place. And now, the discovery of evaporated salts also indicates a shift to more arid weather on a similar timeline.

卫星对这颗红色行星的观测无疑表明，在这段时间内，也就是我们所知的西方人时期，发生了某种气候转变。而现在，蒸发盐的发现也表明，在类似的时间轴上，气候正在向更干旱的方向转变。

The calcium and magnesium sulfates discovered are predicted to have come from Martian basalts, producing soils rich in sulfate and chloride and poor in iron.

据预测，所发现的钙和镁硫酸盐来自火星玄武岩，产生的土壤富含硫酸盐和氯化物，而铁含量很低。

"The relatively low solubility of calcium sulfate minerals results in their widespread production during evaporation," the authors explain, "while less common magnesium sulfate and chloride minerals represent terminal evaporation."

“硫酸钙矿物的溶解度相对较低，这导致了它们在蒸发过程中广泛存在，”作者解释道，“而较不常见的硫酸镁和氯化物矿物则代表了最终的蒸发过程。”

Other examples of such hypersaline lakes are known to house salt tolerant or 'halotolerant' biota on Earth, so after these results, the search for life in Gale crater will no doubt continue.

众所周知，地球上还存在着耐盐或耐盐的生物群，因此在这些结果出来之后，盖尔陨石坑的生命探索无疑将继续下去。

Formed by a meteor roughly 3.5 to 3.8 billion years ago, Gale Crater was chosen as the landing site for Curiosity because scientists suspected, even from afar, that it was a dried-up lake bed.

盖尔陨石坑是由大约35到38亿年前的一颗流星形成的，它被选为“好奇号”的着陆点，因为科学家们甚至从远处就怀疑它是一个干涸的湖床。

It turns out, that wasn't such a bad hunch. Ever since it landed, Curiosity's finds have strongly supported the lake hypothesis. In 2013, NASA announcedthat Gale crater once contained ancient freshwater lake that might have held microbial life. And in the following years, scientists have noticed even moreclues of lakes and streams on the Red Planet.

事实证明，这并不是那么糟糕的预感。自从好奇号着陆以来，它的发现有力地支持了湖泊假说。2013年，美国国家航空航天局宣布，盖尔环形山曾经包含可能有微生物生命的古老淡水湖。在接下来的几年里，科学家们发现了更多关于火星上湖泊和溪流的线索。