火星的蓋爾隕石坑曾經(jīng)有一個巨大的咸水湖

我們剛得到更多的確鑿證據(jù)，火星的蓋爾隕石坑曾經(jīng)有一個巨大的咸水湖

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

從紅色崎嶇的表面看，火星像一個沒有生命的星球，既干燥又荒涼。但事實并非總是如此。

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.

美國宇航局的好奇號探測器現(xiàn)在收集到了更多的證據(jù)，證明在大約37億年前，蓋爾隕石坑的邊緣曾有過一個古老的咸水湖。

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.

加州理工學(xué)院的研究人員分析了從隕石坑基巖中采集的土壤樣本，發(fā)現(xiàn)了火星上其他巖石中沒有觀察到的各種鹽。

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.

該研究小組提出，這些硫酸鹽可以追溯到大約33億至37億年前，它們是從蒸發(fā)的水中殘留下來的，這表明存在著古老的鹽水或鹽池，它們可能曾經(jīng)有過微小的生命形式。

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.

衛(wèi)星對這顆紅色行星的觀測無疑表明，在這段時間內(nèi)，也就是我們所知的西方人時期，發(fā)生了某種氣候轉(zhuǎn)變。而現(xiàn)在，蒸發(fā)鹽的發(fā)現(xiàn)也表明，在類似的時間軸上，氣候正在向更干旱的方向轉(zhuǎn)變。

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.

據(jù)預(yù)測，所發(fā)現(xiàn)的鈣和鎂硫酸鹽來自火星玄武巖，產(chǎn)生的土壤富含硫酸鹽和氯化物，而鐵含量很低。

"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."

“硫酸鈣礦物的溶解度相對較低，這導(dǎo)致了它們在蒸發(fā)過程中廣泛存在，”作者解釋道，“而較不常見的硫酸鎂和氯化物礦物則代表了最終的蒸發(fā)過程。”

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.

眾所周知，地球上還存在著耐鹽或耐鹽的生物群，因此在這些結(jié)果出來之后，蓋爾隕石坑的生命探索無疑將繼續(xù)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.

蓋爾隕石坑是由大約35到38億年前的一顆流星形成的，它被選為“好奇號”的著陸點，因為科學(xué)家們甚至從遠(yuǎn)處就懷疑它是一個干涸的湖床。

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.

事實證明，這并不是那么糟糕的預(yù)感。自從好奇號著陸以來，它的發(fā)現(xiàn)有力地支持了湖泊假說。2013年，美國國家航空航天局宣布，蓋爾環(huán)形山曾經(jīng)包含可能有微生物生命的古老淡水湖。在接下來的幾年里，科學(xué)家們發(fā)現(xiàn)了更多關(guān)于火星上湖泊和溪流的線索。