?Freak heavy rainstorms in 2015 and 2017 wiped out many dry-adapted microbes in the Atacama Desert, useful info in the search for life off Earth.在2015年和2017年,反常的風(fēng)暴抹去了阿塔卡馬沙漠里許多適應干燥的微生物,這對地球外生命搜尋工作來(lái)說(shuō)是個(gè)有用的信息。
? 撰文\播音:克里斯托弗?因塔利亞塔(Christopher Intagliata) 翻譯:陳美娟 校對:張藝簫
? The?Atacama desert in Chile?is one of the?driest spots on Earth. Sometimes, you can't see any life at all. 智利的阿塔卡馬沙漠是世界上最干燥的地方之一。在那里,有時(shí)你完全看不到任何生命的蹤跡。 "As I was a kid those drives were very boring…because there was nothing to see." “我還是個(gè)孩子的時(shí)候,這段路途是那么無(wú)趣……因為實(shí)在沒(méi)什么好看的。” Armando Azua-Bustos was born and raised in Atacama. He’s now an astrobiologist at the Spanish National Research Council's (CSIC) Center for Astrobiology.? 阿曼多?阿祖-烏巴斯圖斯(Armando Azua-Bustos)在阿塔卡馬地區出生、長(cháng)大。他現在是西班牙國家研究委員會(huì )天體生物學(xué)中心的一名天體生物學(xué)家。 But he says, with closer inspection, life?can?be found. "There is life around, but you have to take a microscope to see microorganisms in those driest places in the Atacama."? 但他說(shuō),隨著(zhù)進(jìn)一步觀(guān)察,現在能夠找到生命的蹤跡了。“這周邊有生命存在,但你需要在阿塔卡馬干燥的區域用顯微鏡來(lái)觀(guān)察微生物有機體。” Then in 2015, and again in 2017, freak storms from the Pacific flooded?the Atacama. Ten times the usual amount of rain fell, turning some of the driest parts of the desert into lagoons. 在2015年和2017年,從太平洋刮來(lái)的反常風(fēng)暴淹沒(méi)了阿塔卡馬地區。往常10倍量的降水,把這片沙漠最干燥的一些區域變成了小片淡水湖。 But the desert's hardy microbial life didn't exactly burst into bloom. "I start looking at the microscope and I couldn't see anything! That was surprising. I was expecting to see a zoo of little things moving all around. But I couldn't see anything." 然而在沙漠里有頑強生命力的微生物的數量并沒(méi)有爆發(fā)式增長(cháng)。“我一直盯著(zhù)顯微鏡但我什么也沒(méi)有發(fā)現!這太對出乎我的意料了。我原本還期待能看到一大堆小生命動(dòng)來(lái)動(dòng)去呢。但我什么也沒(méi)看到。” In fact, after sampling three of the newly submerged areas, his team found only a quarter of the microscopic species they'd previously isolated in the desert region—perhaps, he says, because the water killed the rest, through a process called "osmotic shock." "The cell doesn't have the mechanisms to get all the water that is going into the cell to get it out, so they start inflating like a small balloon until they burst out." 事實(shí)上,在對三個(gè)新增的淹沒(méi)區域進(jìn)行取樣時(shí),他的團隊發(fā)現,被他們從沙漠地區隔離到顯微鏡下的物種中,僅存四分之一。他說(shuō),有可能是因為水通過(guò)一個(gè)叫做“滲透休克”的過(guò)程把剩下的那些生命殺死了。“它們的細胞沒(méi)有那種讓全部進(jìn)入細胞的水全部出來(lái)的機制,所以它們像小氣球一樣不斷膨脹,直到炸裂。” The results are in the journal?Scientific Reports. [A. Azua-Bustos et al.,?Unprecedented rains decimate surface microbial communities in the hyperarid core of the Atacama Desert] 這項研究結果刊登在《科學(xué)報告》期刊上。 The microbial massacre should serve as a cautionary tale, he says, as we search for similar dry-adapted lifeforms on Mars. Because several of the life-detecting experiments performed by the Viking landers involved—you guessed it—adding water. And it would be tragic if we killed?the first extraterrestrial life we found. 他說(shuō),當我們在火星上搜尋類(lèi)似的適應干旱的生命形態(tài)時(shí),要把這場(chǎng)微生物大屠殺看做是一個(gè)前車(chē)之鑒。因為你知道的,一些維京號火星車(chē)參與的生命保護實(shí)驗中有加水這個(gè)步驟。要是我們把我們首次發(fā)現的外星生命殺死的話(huà),那將是個(gè)悲劇。