They live thousands of feet below the Earth’s surface. They eat hydrogen and exhale methane. And they may shape our world more profoundly than we can imagine.

它们生活在地表数千英尺以下的地方。它们吃着氢气，吐出甲烷。它们可能正以比我们想象的到更深的程度塑造着我们的世界。

Alexis Templeton remembers January 12, 2014, as the day the water exploded. A sturdy Pyrex bottle, sealed tight and filled with water, burst like a balloon.

亚历克西斯·坦普尔顿还记得2014年1月12日海水炸开的那一天。一个密封严密、里面灌满了水的结实的耐热瓶，就像气球一样爆裂了。

Templeton had just guided her Land Cruiser across the bumpy, rock-strewn floor of Wadi Lawayni, a broad, arid valley that cuts through the mountains of Oman. She parked beside a concrete platform that rose from the ground, marking a recently drilled water well. Templeton uncapped the well and lowered a bottle into its murky depths, hoping to collect a sample of water from 850 feet below the surface.

坦普尔顿刚刚驾驶着她的陆地巡洋舰穿过瓦迪·拉瓦尼崎岖不平、布满岩石的地面。瓦迪·拉瓦尼是横穿阿曼山脉的一条宽阔而干旱的山谷。她把车停在一个混凝土平台旁边，这个平台从地面升起，标志着这里有一口新钻的水井。坦普尔顿打开了井盖，把一个瓶子放进黑暗的深处，希望能从地下850英尺处收集到水的样本。

Wadi Lawayni is enclosed by pinnacles of chocolate-brown rock, hard as ceramic yet rounded and sagging like ancient mud-brick ruins. This fragment of the Earth’s interior, roughly the size of West Virginia, was thrust to the surface through an accident of plate tectonics millions of years ago. These exotic rocks—an anomaly on Earth—had lured Templeton to Oman.

瓦迪·拉瓦尼被像陶瓷一样坚硬，但又像古老的泥砖废墟一样圆润下垂的巧克力色岩石的尖顶包围着。这块地球内部的碎片大约有西弗吉尼亚那么大，是在几百万年前的一次板块构造事故中被冲到地表的。这些奇异的岩石——地球上的异类——吸引着坦普尔顿来到了阿曼。

Shortly after she hoisted her sample from the well, the bottle ruptured from internal pressure. The water gushed out through the cracks, fizzing like soda. The gas erupting from it was not carbon dioxide, as it is in soft drinks, but hydrogen—a flammable gas.

她刚把样品从井里提出来，瓶子就因内部压力而破裂了。水从裂缝里喷了出来，像苏打水一样嘶嘶作响。从中喷发出来的气体不是二氧化碳，而是一种可燃气体——氢气。

Templeton is a geobiologist at the University of Colorado at Boulder, and to her, the gas has special significance: “Organisms love hydrogen,” she says. They love to eat it, that is. The hydrogen in the sample was not, itself, evidence of life. But it suggested that the rocks beneath the surface might be the sort of place where life can flourish.

坦普尔顿是位于博尔德的科罗拉多大学的一位地球生物学家，对她来说，这种气体有着特殊的意义：“生物喜欢氢，”她说道。它们喜欢吃它，就是这样。样品中的氢气本身并不是生命存在的证据。但它表明，地表下的岩石可能是生命得以繁衍的地方。

Templeton is one of a growing number of scientists who believe that the Earth’s deep subsurface is brimming with life. By some estimates, this unexplored biosphere may contain anywhere from a tenth to one-half of all living matter on Earth.

越来越多的科学家相信地球的深层地下充满了生命，坦普尔顿就是其中之一。据估计，这个尚未开发的生物圈可能包含了地球上十分之一到二分之一的生物。

Scientists have found microbes living in granite rocks 6,000 feet underground in the Rocky Mountains, and in seafloor sediment buried since the age of the dinosaurs. They have even found tiny animals—worms, shrimp-like arthropods, whiskered rotifers—among the gold deposits of South Africa, 11,000 feet below the surface.

科学家在落基山脉地下6000英尺的花岗岩中发现了微生物，在恐龙时代以来埋藏的海底沉积物中也发现了微生物。他们甚至在南非地下11000英尺的金矿中发现了微小的动物——蠕虫、虾状节肢动物、须轮虫。

We humans tend to see the world as a solid rock coated with a thin layer of life. But to scientists like Templeton, the planet looks more like a wheel of cheese, one whose thick, leathery rind is perpetually gnawed and fermented by the microbes that inhabit its innards. Those creatures draw nourishment from sources that sound not only inedible, but also intangible: the atomic decay of radioactive elements, the pressure-cooking of rocks as they sink and melt into the Earth’s deep interior—and perhaps even earthquakes.

我们人类倾向于把世界看作一块覆盖着一层薄薄的生命的坚硬的岩石。但对像坦普尔顿这样的科学家来说，这个星球更像是一个奶酪轮子，它厚实的皮革外皮不断被居住在其内部的微生物啃咬和发酵。这些生物的营养来源不仅听起来是不可食用的，而且是无形的：放射性元素的原子衰变，岩石下沉并融化到地球内部深处时产生的压力——甚至还有地震。

Templeton had come to Oman in search of a hidden oasis of life. That fizz of hydrogen gas in 2014 was a strong sign that she was onto something. So this past January, she and her colleagues returned, intent on drilling 1,300 feet into these rocks and finding out what lived there.

坦普尔顿来到阿曼是为了寻找一个隐蔽的生命绿洲。2014年氢气的嘶嘶声是一个强烈的信号，表明她在做什么。所以今年1月，她和她的同事们回来了，打算在这些岩石上钻上1300英尺，看看那里到底生活着什么。

On a hot winter afternoon, a guttural roar reverberated across the sun-drenched expanse of Wadi Lawayni. A bulldozer sat near the center of the valley. Mounted on its front was a towering drill shaft, spinning several times per second.

在一个炎热的冬日午后，一种喉咙咆哮的声音回荡在阳光普照的瓦迪·拉瓦尼广阔的土地上。一辆推土机停在山谷中心附近。安装在它前面的是一个高耸的钻杆，每秒能够旋转好几次。

Half a dozen men in hard hats, most of them Indian workers employed by a local company, operated the drill. Templeton and a half-dozen other scientists and graduate students congregated a few yards away, beneath the shade of a canopy that billowed in the gentle breeze. They bent over tables, examining the sections of stone core being brought up by the workers every hour or so.

六名戴着安全帽的男子操作着这台钻机，其中大多数人是当地一家公司雇佣的印度工人。坦普尔顿和其他六名科学家和研究生则聚集在几码远的一个树冠下，树冠在微风中翻腾。他们伏在桌子前，每隔一小时左右就检查工人们搬运上来的岩芯。

The rig had been running for a day, and the cores coming out of the ground were changing color as the drill penetrated deeper into the earth. The top few feet of stone were tinted orange and yellow, indicating that oxygen from the surface had turned the iron in the rock into rusty minerals. By 60 feet below the surface, those fingerprints of oxygen petered out, and the stone darkened to greenish-gray, spider-webbed with black veins.

钻机已经运转了一天，随着钻机深入地下，从地下钻出的岩心开始变色。最上面几英尺的石头被染成了橙色和黄色，这表明地表的氧气把岩石中的铁变成了生锈的矿物。在地下60英尺的地方，氧气的痕迹逐渐消失，石头变成了青灰色，布满黑色的蜘蛛网纹理。

“This is beautiful rock,” said Templeton, running a latex-gloved finger over its surface. Her sunglasses were pushed back over her straight brown hair, revealing cheekbones darkened from years of working outside on ships, on tropical islands, in the high Arctic, and everywhere else her work has taken her. “I’m hoping we see a lot more of this,” she said.

“这是一块美丽的岩石，”坦普尔顿说着，用戴着乳胶手套的手指抚摸着岩石表面。她把墨镜往后推，盖在一头笔直的棕色头发上，露出了因多年在船上、热带岛屿上、北极地区工作而变黑的颧骨。“我希望我们能看到更多这样的情况，”她说道。

The green-black rock was giving her a close look at something that is all but impossible to observe just about anywhere else on the planet.

这块青黑色的岩石让她近距离观察到了地球上其他地方几乎不可能观察到的东西。

These rocks from deep inside the Earth are rich in iron—iron in the form of minerals that don’t ordinarily survive anywhere near the planet’s surface. This subterranean iron is so chemically reactive, so eager to combine with oxygen, that when it comes in contact with water underground, it rips the water molecules apart. It yanks out the oxygen—the “O” in H2O—and leaves behind H2, or hydrogen gas.

这些来自地球深处的岩石富含铁——以矿物的形式存在的铁通常在地球表面的任何地方都无法幸存下来。这种地下存在的铁具有很强的化学活性，它非常渴望与氧气结合，当它与地下的水接触时，就会把水分子撕裂。它拉扯出氧，留下H2，也就是氢气。

Geologists call this process “serpentinization,” for the sinuous veins of black, green, and white minerals that it leaves behind. Serpentinization usually happens only in places inaccessible to humans, such as thousands of feet beneath the floor of the Atlantic Ocean.

地质学家将这一过程称为“蛇纹石化”，因为它遗留下了黑色、绿色和白色矿物的蜿蜒矿脉。蛇纹石化通常只发生在人类无法到达的地方，比如大西洋海底之下数千英尺的地方。

Here in Oman, though, deep-earth rocks have been lifted so close to the surface that serpentinization occurs only a few hundred feet underground. The hydrogen gas that burst Templeton’s water bottle in 2014 was a tiny sample of serpentinization’s yield; one water well, drilled a few years ago in this same region, released so much hydrogen that it was judged an explosion risk—prompting the government to seal it shut with concrete.

然而，在阿曼这里，地层深处的岩石被抬升到离地表如此之近的地方，以至于蛇纹石化就发生在地下几百英尺的地方。2014年，坦普尔顿的水瓶爆裂时产生的氢气只是蛇形石化产物的一个小样本；几年前在同一地区钻探的一口水井释放了非常多的氢气，以至于被判定为有爆炸的危险——从而促使政府用混凝土将其封堵住。

Hydrogen is special stuff. It was one of the fuels that propelled the Apollo missions, and the space shuttles, into orbit; ounce for ounce, it is one of the most energy-dense naturally occurring compounds on Earth. This makes it an important food for microbes below Earth’s surface.

氢是一种特殊的物质。它是推动阿波罗计划和航天飞机进入轨道的燃料之一；它是地球上能量密度最大的天然化合物之一。这使得它成为地表以下微生物的重要食物。

All told, the microbes living beneath the mountains of eastern Oman may consume thousands of tons of hydrogen each year—resulting in a slow, controlled combustion of the gas, precisely choreographed by the enzymes inside their water-filled cells.

总而言之，生活在阿曼东部山脉下的微生物每年可能消耗数千吨氢气——从而导致了这种气体缓慢的、可控的燃烧，而这些燃烧过程是由它们充满水的细胞内的酶精确控制的。

But that hydrogen supplies only half the equation of life: To produce energy from hydrogen, microbes need something to burn it with, just as humans inhale oxygen to burn food. Figuring out what the microbes are “breathing” so far underground, beyond the reach of oxygen, is a key part of Templeton’s mission.

但这些氢气只提供了生命方程式的一半：要从氢中产生能量，微生物就需要一些东西来燃烧它，就像人类吸入氧气来燃烧食物一样。弄清楚这些微生物在地下氧气无法到达的地方呼吸着什么，是坦普尔顿计划中的关键部分。

At two in the afternoon, a battered pickup truck trundled past the drill site on a dusty dirt track. Behind it, six camels trotted in tight formation, their heads bobbing in the air: local livestock, tethered on short leashes, being led to a fresh patch of rangeland somewhere up the wadi.

下午两点，一辆破旧的小卡车在一条尘土飞扬的小道上驶过钻井现场。在它后面，六只骆驼排成紧密的队形小跑着，它们的头在空中上下摆动：当地的牲畜被拴在短皮带上，被带到溪边某处的一块草地上。

Templeton, oblivious to the camels, called out in excitement: “Gold!” She pointed to a section of core lying on the table, and to a dime-sized cluster of yellow metallic crystals. Their cubic shapes revealed her little joke: The crystals were not real gold, but fool’s gold, also known as pyrite.

坦普尔顿没有看见骆驼，她兴奋地喊道：“金子！”她指着桌子上的一段岩芯，还有一堆硬币大小的黄色金属晶体。它们的立方形状让她的小笑话露了馅：这些晶体不是真正的金子，而是傻瓜的金子，也叫黄铁矿。

Pyrite, composed of iron and sulfur, is one of dozens of minerals known to be “biogenic”: Its formation is sometimes triggered by microbes. The crystals coalesce from the waste products that microbial cells exhale. So these pyrite crystals could be a byproduct of microbe metabolism—a possibility Templeton calls “beautiful.”

黄铁矿是由铁和硫构成的，它是几十种已知的“生物成因”矿物之一：它的形成有时是由微生物触发的。这些晶体是由微生物细胞呼出的废物凝聚而成。所以这些黄铁矿晶体可能是微生物代谢的副产品——一种坦普尔顿称其为“美丽”的可能性。

Back home in Colorado, she’ll give these crystals the same careful attention that an archaeologist would devote to a Roman trash pile. She’ll cut them into transparent slices and view them under a microscope. If the pyrite is, in fact, the product of living cells, she says, then the microbes “might even be entombed in the minerals.” She hopes to find their fossilized bodies.

回到科罗拉多州的家中，她会像考古学家对待罗马的垃圾堆一样，对这些水晶给予细心的关注。她会把它们切成透明的薄片，放在显微镜下观察。她说，如果黄铁矿实际上是活细胞的产物，那么微生物“甚至可能就埋藏在矿物中”。她希望能找到它们的化石。

Not until the early 1990s did anyone suspect that abundant life might inhabit the deep earth. The first evidence came from the rocks that sit below the seafloor.

直到20世纪90年代初，才有人怀疑地球深处可能存在丰富的生命。第一个证据来自海底下的岩石。

Geologists had long noticed that volcanic glass, found in dark, basaltic rocks that lay hundreds to thousands of feet below the seafloor, was often riddled with microscopic pits and tunnels. “We had no idea that this might be biological,” says Hubert Staudigel, a volcanologist at the Scripps Institution of Oceanography in La Jolla, California.

地质学家早就注意到，在海床下数百至数千英尺深的玄武岩中发现的火山玻璃里，通常布满了微小的坑洞和隧道。加州拉荷亚市斯克里普斯海洋研究所火山学家休伯特·斯托迪格尔说:“我们当时还不知道这可能是生物学上的现象。”

In 1992, a young scientist named Ingunn Thorseth, of the University of Bergen in Norway, suggested that the pits were the geologic equivalent of tooth cavities: Microbes had etched them into the volcanic glass as they consumed atoms of iron. In fact, Thorseth found what appeared to be dead cells inside the cavities—in rock samples collected from 3,000 feet beneath the seafloor.

1992年，挪威卑尔根大学年轻的科学家因古恩·索塞斯提出，这些坑相当于地质上的蛀牙洞：微生物在吞噬铁原子时将它们蚀刻在了火山玻璃上。事实上，索赛斯在这些腔洞中发现了看似死亡的细胞——就是在海底3000英尺处采集的岩石样本中。

When these discoveries unfolded, Templeton had not yet entered the field. She finished a master’s degree in geochemistry in 1996, then took a job at the Lawrence Berkeley National Laboratory in California, where she studied how quickly microbes were eating the jet fuel embedded in the soil of a former U.S. Navy base. A few years later, for her Ph.D. research at Stanford, she studied how underground microbes metabolize lead, arsenic, and other pollutants.

当这些被发现时，坦普尔顿还没有进入这个领域。1996年，她获得了地球化学硕士学位，之后在加州的劳伦斯伯克利国家实验室找到了一份工作。在那里，她对微生物吞噬埋藏在前美国海军基地土壤中的喷气燃料的速度进行了研究。几年后，在斯坦福攻读博士学位时，她研究了地下微生物是如何代谢铅、砷和其他污染物的。

In 2002, she moved to Scripps to work with Bradley Tebo, a biology professor, and Staudigel, on a related question: How were microbes living off the iron and other metals in basaltic glass from the seafloor?

2002年，她搬到斯克里普斯，与生物学教授布拉德利·泰博和斯塔迪格尔一起研究一个相关问题：微生物是如何以海底玄武玻璃中的铁和其他金属为生的？

In November of that year, on the back deck of a research ship in the middle of the Pacific Ocean, she climbed down the hatch of the Pisces-IV, a car-sized submersible, and was lowered into the sea. Terry Kerby, a pilot with the Hawaii Undersea Research Laboratory, guided the craft to the southern slope of Loihi Seamount, an undersea volcano near Hawaii’s Big Island.

那年11月，在太平洋中部的一艘考察船的后甲板上，她从一辆汽车大小的潜水器“双鱼座四号”的舱口爬了下来，沉入了大海。夏威夷海底研究实验室的操纵员特里·克尔比驾驶着这台潜水器前往夏威夷大岛附近的海底火山——罗伊希海底火山的南坡。

At a depth of 5,600 feet, the sub’s floodlights dimly illuminated a bizarre undersea landscape: a jumble of what resembled black, bulging trash bags, haphazardly stacked into towering pinnacles. These so-called pillow basalts had formed decades or centuries before as lava oozed from cracks, encountered seawater, and flash-cooled into lobes of glassy rock. Templeton lay on her side on a bench, bundled up against the cold, and watched through a thick glass portal as Kerby broke off pieces of basalt with the craft’s robotic pincer arms. Eight hours after they were lowered into the ocean, they returned to the surface with 10 pounds of rock.

在5600英尺深的水下，潜艇的泛光灯隐隐约约地照亮了一幅奇异的海底景观：一堆乱七八糟的东西，像是鼓鼓囊囊的黑色垃圾袋，杂乱地堆在高耸的塔尖上。这些所谓的枕状玄武岩形成于几十年前或几百年前，当时岩浆从裂缝中渗出，遇到海水，然后闪冷形成玻璃状的岩石裂片。坦普尔顿侧身躺在一条长凳上，裹得严严实实的，抵御着寒冷。她透过一个厚厚的玻璃窗，看着克尔比用飞船的机械钳子手臂掰下玄武岩碎片。他们被放如海底8小时后，带着10磅重的岩石回到了海面上。

The same year, she and Staudigel visited Hawaii’s Kilauea volcano, hoping to collect microbe-free volcanic glass that they could compare with their deep-sea samples. Clad in heavy boots, they walked onto an active lava flow, treading on a black crust of hardened rock just half an inch thick. Staudigel found a spot where the orange, molten lava had broken through the overlying crust. He scooped up the glowing material with a metal pole and plopped it—like hot, gooey honey—into a bucket of water. It hissed and crackled, boiling the water as it hardened into fresh glass.

同年，她和斯塔迪格尔造访了夏威夷的基拉韦厄火山，希望在那里收集到没有微生物存在的火山玻璃，以便与深海样品进行比较。他们穿着笨重的靴子，踏上活跃的熔岩流，踩在一块只有半英寸厚的坚硬岩石的黑色外壳上。斯塔迪格尔发现了橙色的熔岩从覆盖着的地壳中喷发出来的地方。他用一根金属棒把发光的材料舀起来，扑通一声扔进一桶水里。它嘶嘶作响，噼啪作响，把水烧开了，而它则硬化成新的玻璃。

Back in the lab, Templeton isolated dozens of the bacterial strains that leach iron and manganese out of the deep-sea rocks. She and her colleagues remelted the sterile glass from Kilauea in a furnace, doped it with different amounts of iron and other nutrients, and grew the bacterial strains from the seafloor on it. She used sophisticated X-ray techniques to watch, fascinated, as the bacteria digested the minerals.

回到实验室中，坦普尔顿从深海岩石中分离出了几十种从铁和锰中滤出的细菌。她和她的同事们将基拉韦厄火山的无菌玻璃放到熔炉中重熔，加入不同数量的铁和其他营养物质，并在其上培养来自海底的细菌。她用复杂的X光技术，着迷地观察细菌消化矿物质的过程。

“I have a basement full of basalt from the seafloor because I can’t let it go,” she told me one day during a break in the drilling.

“我有一个地下室，里面装满了来自海底的玄武岩，因为我放不下它，”有一天，在钻探间歇，她告诉了我这件事。

But those rocks, and the critters that chew on them, had one major drawback for Templeton: They came from the seafloor, where the water contains oxygen.

但是对坦普尔顿来说，这些岩石，还有那些啃噬它们的动物，有一个主要的缺点：它们来自海底，那里的水中含有氧气。

Oxygen sustains every animal on Earth, from aardvarks to earthworms to jellyfish; our atmosphere and most of our ocean is chock-full of it. But Earth has only been highly oxygenated for a tiny fraction of its history. Even today, vast swaths of our planet’s biosphere have never encountered oxygen. Go more than a few feet into bedrock, and it’s virtually nonexistent. Go anywhere else in the solar system, including places like Mars that might harbor life, and you won’t find it, either.

氧气支撑着地球上的每一种动物，从非洲食蚁兽到蚯蚓再到水母；我们的大气层和大部分海洋中都充满了这种气体。但是地球只有一小部分的历史是富氧的。即使在今天，我们地球的生物圈的大片区域也从未遇到过氧气。只要深入基岩几英尺，它就几乎不存在了。如果去往太阳系的其他地方，包括火星这样可能孕育生命的地方，你也找不到它的踪迹。

As Templeton explored Earth’s deep biosphere, she had become interested in how life originated on Earth—and where else it might exist in the solar system. The subsurface could provide a window into those distant places and times, but only if she could delve deeper, below the reach of oxygen.

当坦普尔顿探索地球深层的生物圈时，她对地球上的生命起源以及太阳系中其他地方的生命起源产生了兴趣。地底可以提供一扇窗户，让她看到那些遥远的地方和时代，但前提是她能在氧气触及不到的地方挖得更深。

The mountains of east Oman seemed like the perfect place. This massive slab of slowly serpentinizing rock preserves, in its interior, the oxygen-deprived conditions and chemically reactive iron minerals that are thought to exist deep inside the planet.

东阿曼的群山似乎是一个完美的地方。这一大块缓慢蛇纹石化的岩石在其内部保存了被认为存在于地球深处的缺氧条件和化学反应性铁矿物。

Templeton and several other deep-biosphere researchers connected with a major effort that was in early planning stages—the Oman Drilling Project.

坦普尔顿和其他几个深海生物圈的研究人员参与了一项处于早期计划阶段的重要工作——阿曼钻探项目。

The effort was co-led by Peter Kelemen, a geologist at the Lamont-Doherty Earth Observatory in New York. He had his own mission: The deep-earth rocks in Oman react not only with oxygen and water but also with carbon dioxide, pulling the gas out of the atmosphere and locking it into carbonate minerals—a process that, if understood, could help humanity offset some of its carbon emissions.

这项工作是由纽约拉蒙特-多尔蒂地球观测站的地质学家彼得·克莱门一同领导的。他有自己的使命：阿曼的深部岩石不仅与氧气和水发生反应，还与二氧化碳发生反应，将气体从大气中拉扯出来，锁入碳酸盐矿中——如果能理解这一过程，就能帮助人类抵消部分的碳排放。

Kelemen was present during the drilling at Wadi Lawayni in January 2018. And he was bullish on the prospects of finding life. These rocks had originally formed at a temperature of more than 1,800 degrees Fahrenheit. But they would have rapidly cooled, and today the top thousand feet of rock hover around 90 degrees Fahrenheit. These rocks, he said, “have not been hot enough to kill microbes since the Cretaceous”—the age of the dinosaurs.

2018年1月，克莱门就在瓦迪拉瓦尼钻井现场。他对找到生命的前景很乐观。这些岩石最初形成的温度超过1800华氏度。但是它们很快就会冷却下来，而今天，顶部的1000英尺岩石的温度在华氏90度左右徘徊。他说，这些岩石“自白垩纪(恐龙时代)以来还没有热到足以杀死微生物的程度”。

At three in the afternoon at the drill site, half a dozen team members gathered near the rig for what had become an hourly ritual: a moment of suspense.

下午三点，在钻井现场，六名队员聚集在了钻井平台附近，开始了一项每小时都进行一次的仪式：悬疑时刻。

A new section of core, freshly raised from the borehole, was lowered onto a sawhorse—a stone cylinder 10 feet long and as big around as the fat end of a baseball bat, concealed in a metal pipe.

一段刚从钻孔中挖出的岩芯被放入锯木机中，锯木机是一个石质圆柱体，长10英尺，和棒球棒的粗头一样大，并被隐藏在金属管中。

Workers lifted one end of the pipe. And out slid the core—along with a gush of black gunk. Glops of thick, dark sludge dripped on the ground. The core was covered from end to end.

工人们抬起了管子的一端。随着一股黑色粘稠物喷涌而出，岩芯滑了出来。一团又浓又黑的污泥滴在地上。岩芯从头到尾都被它包裹住了。

“Oh my god,” someone said. “Oya.” Murmurs all around.

“哦，我的上帝，呕”有人说道。周围的人都在窃窃私语。

A worker wiped down the core, and pinprick bubbles erupted on its smooth, sheeny surface—reminiscent of the bubbles in hot cooking oil. The stone, no longer pressurized underground, was degassing before our eyes, the bubbles squirting out through pores in the rock. The odor of sewer and burnt rubber rose into the air—a smell that had instant meaning for the scientists present.

一名工人擦干了堆芯，它光滑、光亮的表面上冒出了小气泡，让人想起热食用油里的气泡。石头不再在地下加压，而是在我们眼前冒气，气泡从岩石的孔隙中喷出。下水道的气味和烧焦的橡胶味散发到了空气中，这种气味对在场的科学家们来说立刻就有了意义。

“That rock is seriously alive,” said Templeton.

“那块岩石真的还有生物存在，”坦普尔顿说道。

“Hydrogen sulfide,” said Kelemen.

“硫化氢，”克莱门说道。

Hydrogen sulfide—a gas found in sewers, in your intestines, and, apparently, underground in Oman—is produced by microbes living in the absence of oxygen. Deprived of that life-giving gas, they pull a trick that no animal on Earth can do: They breathe something else. In other words, they burn their food using some other chemical that is available underground.

硫化氢是一种存在于下水道、肠道——显然还有阿曼地下的气体，它是由生活在缺氧环境中的微生物产生的。没有了那种能维持生命的气体，它们就会做出地球上任何动物都做不到的事情：呼吸其他东西。换句话说，它们用地下可利用的其他化学物质燃烧食物。

The sections of core brought up so far offered clues about what they might be breathing. The gassy core was crisscrossed by bands of orange-brown stone—marking the places where hot magma had spurted through deep fissures in the Earth millions of years before, when this rock lay miles underground.

到目前为止发现的岩芯提供了它们可能是怎样呼吸的线索。这个冒气的岩芯上面是纵横交错的橘黄色的条纹，这些条纹标识出了数百万年前炽热的岩浆从地下几英里处的深裂缝中喷出来的地方。

Those bands of fossil magma would have gradually bled their chemical components into the groundwater—including a molecule called sulfate, which consists of a single sulfur atom studded with four oxygen atoms. The microbes were probably using this molecule to digest hydrogen, said Templeton: “They eat the hydrogen and they breathe the sulfate.” And then, they exhale fart gas.

这些化石岩浆带的化学成分会逐渐渗入地下水，其中包括一种叫做硫酸盐的分子，它由一个硫原子和四个氧原子组成。坦普尔顿说，这些微生物可能利用这种分子来消化氢，“它们吃掉氢，呼吸硫酸盐”。然后，它们呼出的是屁。

Hydrogen sulfide isn’t just stinky. It is also toxic. So the very microbes that produce it also run the risk of poisoning themselves as it accumulates underground. How did they avoid doing so? Once again, the rock provided clues.

硫化氢不仅是臭的，它还是有毒的。因此，产生这种物质的微生物也有让自己中毒的危险，因为它会在地下积聚。它们是如何避免这种结果的呢？岩石再次提供了线索。

As drilling continued over the next several days, the black goo petered out. Each new section of core was dry and stink-free. But the stone itself had changed: Its mosaic of veins and serpentine minerals had darkened into shades of gray and black, like a plaid shirt soaked in ink.

在接下来的几天里，随着钻探的继续，黑色粘稠物逐渐消失。每一段岩芯都是干燥无味的。但是石头本身已经发生了变化：它那由纹理和蛇纹石化矿物组成的马赛克已经变成了灰色和黑色，就像一件浸透了墨水的格子衬衫。

“All of that blackening is a bio-product,” Templeton said one afternoon, as she and her research associate, Eric Ellison, crowded inside a cramped laboratory trailer, packing samples of rock to send home. Some of the rocks sat in a sealed Plexiglass box, and Ellison handled them with his hands inserted through gloves mounted in the walls of the box—giving the appearance that the rocks contained something sinister. But the precaution wasn’t intended to protect humans; it was meant to keep the delicate microbes out of contact with oxygen.

“所有这些变黑的结果都是一种生物产品，”一天下午，邓普顿和她的研究助理埃里克·埃里森挤在一辆狭窄的实验室拖车里，她如此说道。他们正在打包岩石样本，准备送回家。有些石头放在一个密封的有机玻璃盒子里，埃利森把戴着手套的手伸进盒子取石头，看上去石头里藏着什么凶恶的东西。但这种预防措施并不是为了保护人类；它的目的是让这些脆弱的微生物远离氧气。

Templeton speculated that the microbes had stained the most recent rock samples: The hydrogen sulfide they exhaled had reacted with iron in the surrounding stone, creating iron sulfide—a harmless black mineral. The pyrite minerals we’d seen earlier were also composed of iron and sulfide, and could have formed the same way.

坦普尔顿推测这些微生物对最近的岩石样本进行了染色：它们呼出的硫化氢与周围岩石中的铁发生了反应，生成了硫化铁——一种无害的黑色矿物。我们之前看到的黄铁矿矿物也是由铁和硫化物组成的，它也可能是以同样的方式形成的。

These black minerals are more than an academic curiosity. They provide a glimpse of how microbes have not only survived inside the Earth’s crust, but also transformed it, in some cases forming minerals that might not otherwise exist.

这些黑色矿物不仅仅是学术上的奇闻轶事。它们让我们得以一窥微生物是如何在地壳内部生存下来的，它们是如何改造地壳的，在某些情况下，它们形成了原本不可能存在的矿物质。

Some of the world’s richest deposits of iron, lead, zinc, copper, silver, and other metals formed when hydrogen sulfide latched onto metals that had dissolved deep underground. The sulfide locked the metals in place, concentrating them into minerals that accumulated for millions of years—until they were exhumed by miners. The hydrogen sulfide that formed those ores often came from volcanic sources, but in some cases, it came from microbes.

一些世界上含量最丰富的矿藏——铁、铅、锌、铜、银和其他的金属——是在硫化氢与溶解在地下深处的金属结合时形成的。硫化物将金属固定在原地，将它们浓缩成矿物，这些矿物积累了数百万年，直到被矿工挖掘出来。形成这些矿石的硫化氢通常来自火山，但在某些情况下，它来自微生物。

Robert Hazen, a mineralogist and astrobiologist at the Carnegie Institution in Washington, D.C., believes that more than half of Earth’s minerals owe their existence to life—to the roots of plants, to corals and diatoms, and even to subsurface microbes. He has even speculated that the world’s seven continents may owe their existence, in part, to microbes gnawing on rocks.

罗伯特·哈森是华盛顿卡内基研究所的矿物学家和天体生物学家。他认为，地球上一半以上的矿物的存在都归功于生命——植物的根、珊瑚和硅藻，甚至地下微生物。他甚至推测，世界上七大洲存在的部分原因可能就是微生物啃噬岩石。

Four billion years ago, Earth had no permanent land—just a few volcanic peaks jutting above the ocean. But microbes on the seafloor may have helped change that. They attacked iron-rich basalt rocks, much as they do today, converting the volcanic glass into clay minerals. Those clays melted more readily than other rocks. And once melted, they resolidified into a new kind of rock, a material lighter and fluffier than the rest of the planet: granite.

40亿年前，地球上没有永久性的陆地——只有几座火山山峰突出海面。但是海底的微生物可能帮助改变了这一点。它们攻击富含铁的玄武岩，就像它们今天所做的一样，将火山玻璃转化为粘土矿物。这些粘土比其他岩石更容易熔化。一旦融化，它们就会重新凝固成一种新的岩石，一种比地球上的其他部分更轻、更松软的材料：花岗岩。

Those buoyant granites piled into heaps that rose above the ocean, creating the first permanent continents. This would have happened to some degree without the help of microbes, but Hazen suspects that they accelerated the process. “You can imagine microbes shifting the balance,” he says. “What we’re arguing is that microbes played a fundamental role.”

那些浮力大的花岗岩堆积在海面上，形成了第一个永久性的大陆。如果没有微生物的帮助，这种情况在某种程度上也是会发生的，但是哈森怀疑微生物加速了这一进程。“你可以想象微生物改变了平衡，”他说道，“我们认为微生物扮演了一个基本性的角色。”

The emergence of land had a profound effect on Earth’s evolution. Rocks exposed to the air broke down more quickly, releasing trace nutrients such as molybdenum, iron, and phosphorus into the oceans. These nutrients spurred the growth of photosynthetic algae, which absorbed carbon dioxide and exhaled oxygen. Just over 2 billion years ago, the first traces of oxygen appeared in Earth’s atmosphere. Five hundred and fifty million years ago, oxygen levels finally rose high enough to support the first primitive animals.

陆地的出现对地球的演化产生了深远的影响。暴露在空气中的岩石分解得更快，向海洋中释放微量营养物质，如钼、铁和磷。这些营养物质刺激了光合藻类的生长，光合藻类吸收二氧化碳并呼出氧气。就在20亿年前，地球大气中出现了最初的氧气痕迹。五亿五千万年前，氧气水平终于上升到足以支持第一批原始动物的水平。

Earth’s abundant water, and its optimal distance from the sun, made it a promising incubator for life. But its evolution into a paradise for intelligent, oxygen-breathing animals was never guaranteed. Microbes may have pushed our planet over an invisible tipping point—and toward the formation of continents, oxygen, and life as we know it.

地球上丰富的水，以及它与太阳的最佳距离，使它成为一个有希望的孕育生命的地方。但它能否进化成为了聪明的、呼吸氧气的动物的天堂却从未是确证无疑的。微生物可能已经把我们的星球推过了一个看不见的临界点——朝着我们所知道的大陆、氧气和生命的形态推进。

Even today, microbes continue to make, and remake, our planet from the inside out.

即使在今天，微生物仍然在从内到外地塑造和改造我们的星球。

In some ways, the microbe underworld resembles human civilization, with microbial “cities” built at the crossroads of commerce. In Oman, the thriving oasis of stinky, black microbes sat 100 feet underground, near the intersection of several large rock fractures—channels that allowed hydrogen and sulfate to trickle in from different sources.

在某些方面，微生物的地底社会与人类文明相似，微生物的“城市”建立在商业的十字路口。在阿曼，繁荣的臭气腾腾的黑色微生物绿洲位于地下100英尺处，它靠近几处大型岩石裂隙的交汇处——这些裂隙允许氢和硫酸盐从不同来源流过来。

Elisabetta Mariani, a structural geologist from the University of Liverpool in England, spent long days under the canopy, mapping these breaks in the rock. Late one morning, she called me over to see something special: a break cutting diagonally across a core, exposing two rock faces streaked in paper-thin layers of green-and-black serpentine.

英国利物浦大学的结构地质学家伊丽莎白花了很长时间在树冠下测绘岩石上的这些裂缝。一天上午的晚些时候，她叫我去看一些特别的东西：一条斜切岩芯的裂缝，其中露出了两块岩石的表面，上面布满了像纸一样薄的绿黑相间的蛇纹。

“Can you see here these grooves?” she asked, in English accented with her native Italian, pointing out scratches that raked the two serpentine faces. They showed that this was more than just a passive break; it was an active fault. “Two blocks of rocks have slipped past each other along this direction,” she said, gesturing along the grooves.

“你能看到这些凹槽吗？”她用带着母语意大利语口音的英语问道，同时指着那两块蛇形表面上的划痕。它们证明了这不仅仅是一次被动的断裂；这是一个活动断层。“两块岩石沿着这个方向相互滑过，”她指着凹槽说道。

Tullis Onstott, a geologist at Princeton University not affiliated with the Oman drilling, believes that such active faults may do more than just provide routes for food to move underground—they may actually produce food. In November 2017, Onstott and his colleagues began an audacious experiment. Starting from a tunnel 8,000 feet down in the Moab Khotsong gold mine in South Africa, they bored a new hole toward a fault that lay nearly half a mile deeper still. On August 5, 2014, the fault had sparked a magnitude-5.5 earthquake. By drilling into it, Onstott hoped to test the provocative idea that earthquakes supply food to the deep biosphere.

普林斯顿大学的地质学家图利斯·奥斯多特认为，这些活动断层不仅为食物在地下的移动提供了通道，它们还可能会生产食物。2017年11月，奥斯多特和他的同事们开始了一项大胆的实验。他们从南非摩押·霍特松金矿8000英尺深的一个隧道开始，朝着一个更深近半英里的断层挖了一个新洞。2014年8月5日，该断层引发了5.5级地震。通过钻探，奥斯托特希望测试这个具有颠覆性的想法，即地震为地层深处的生物圈提供了食物。

Scientists have long noticed that hydrogen gas seeps out of major faults such as the San Andreas in California. That gas is produced in part by a chemical reaction: Silicate minerals pulverized during a quake react with water and release hydrogen as a byproduct. For microbes sitting next to the fault, that reaction could result in something like a periodic sugar rush.

科学家们早就注意到氢气会从主要的断层中渗出，比如加州的圣安德烈亚斯断层。这种气体部分是由化学反应产生的：在地震中粉碎的硅酸盐矿物与水发生反应，释放出副产品氢。对于断层附近的微生物来说，这种反应可能会引发周期性的糖果大战。

In March 2018, four months after the drilling in the Moab Khotsong mine began, workers brought up a stone core that crossed the fault.

2018年3月，摩押·霍特松金矿开始钻探四个月后，工人们挖出了一段穿过断层的岩芯。

The rock along the fault was “pretty banged up,” says Onstott—torn with dozens of parallel fractures. The stone lining some of those cracks was crushed into fragile clay, marking recent earthquakes. Other cracks, filled with veins of white quartzite, marked older ruptures from thousands of years before.

奥斯多特说道：断层沿线的岩石“被撞得粉碎”，同时还有数十处平行的裂缝。其中一些裂缝里的石头被压成易碎的粘土，标志着最近发生的地震。其他的裂缝则填满了白色石英岩脉，标志着几千年前更古老的断裂。

Onstott is now searching those quartzite veins for fossilized cells and analyzing the rock for DNA, in hopes of finding out what kind of microbes—if any—inhabit the fault.

奥斯多特目前正在这些石英岩脉中寻找化石细胞，并对岩石进行DNA分析，希望能找到栖息在断层中的微生物(如果有的话)。

More importantly, he and his colleagues have kept the borehole open—monitoring water, gases, and microbes in the fault, and taking new samples each time there’s an aftershock. “You can then see whether or not there’s a gas release,” he says, “and whether or not there’s a change in the microbial community because they’re consuming the gas.”

更重要的是，他和他的同事们保持了钻孔的开放状态，监测断层中的水、气体和微生物，并在每次余震发生时采集新的样本。他说:“然后你就可以看到是否有气体释放出来，以及微生物群落是否因为消耗了气体而发生了变化。”

Even as Onstott awaits those results, he is starting to consider an even more radical possibility: that deep-dwelling microbes don’t just feed off of earthquakes, but might also trigger them. He believes that as microbes attack the iron, manganese, and other elements in the minerals that line the fault, they could weaken the rock—and prime the fault for its next big slip. Exploring that possibility would mean doing laboratory experiments to find out whether microbes in a fault can actually break down minerals quickly enough to affect seismic activity. With a scientist’s characteristic understatement, he contemplates the work ahead: “It’s a reasonable hypothesis to test.”

即使在奥斯多特等待这些结果的同时，他也已经开始考虑一种更激进的可能性：深海微生物不仅以地震为食，还可能引发地震。他相信，当微生物攻击沿断层排列的矿物中的铁、锰和其他元素时，它们会让岩石变得脆弱，并为下一次大滑坡做好准备。探索这种可能性意味着要进行实验室实验，以查明断层中的微生物是否能够迅速分解矿物质，从而影响到地震活动。带着科学家特有的轻描淡写，他思考着未来的工作：“这是一个需要验证的合理假设”。

By January 30, the drill in Wadi Lawayni had reached a depth of 200 feet. Its motor growled in the background as Templeton and her colleague, Eric Boyd, rested in camp chairs under an acacia tree. Strewn at their feet lay the signs of other travelers who had paused in this rare island of shade—nodules of camel dung, smooth and round like leathery plums.

到1月30日，瓦迪·拉瓦尼的钻井已经达到200英尺的深度。当坦普尔顿和她的同事埃里克·博伊德坐在一棵相思树下的野营椅上休息时，机器的马达在背景中轰鸣。在他们的脚下，散落着其他旅行者在这个罕见的阴岛停留过的痕迹——一堆堆光滑圆润的骆驼粪，就像闪耀着皮革般光泽的李子一样。

“We think that this is an environment that’s important for understanding the origins of life,” said Boyd, a geobiologist from Montana State University in Bozeman. That potential, he said, is part of what lured him and Templeton to these deep-earth rocks in Oman: “We like hydrogen.”

位于博兹曼的蒙大拿州立大学的地质学家博伊德说，“我们认为，这是一个对理解生命起源非常重要的环境。”他说，正是这种潜力吸引着他和坦普尔顿来到阿曼寻找这些深埋地下的岩石：“我们喜欢氢气”。

Both Boyd and Templeton believe that life on Earth started in an environment similar to that which lies a few yards beneath their camp chairs. They believe that life began within subsurface fractures, where iron-rich minerals gurgled out hydrogen gas as they reacted with water.

博伊德和坦普尔顿都相信，地球上的生命便始于一个类似于他们露营椅下面几码的环境中。他们认为生命起源于地下裂缝，富含铁的矿物与水发生反应时会喷出氢气。

Of all the chemical fuels that existed on Earth 4 billion years ago, hydrogen would have been one of the easiest for early, inefficient cells to metabolize. Hydrogen wasn’t only produced by serpentinization, either; it was also produced—and still is, today—by the radioactive decay of elements such as uranium, which constantly splits apart water molecules in the surrounding rock. Hydrogen is so labile, so willing to break apart, that it can even be digested using sluggish oxidants, like carbon dioxide or pure sulfur. DNA studies of millions of gene sequences suggest that the forerunner of all life on Earth—the “last universal common ancestor,” or LUCA—probably did use hydrogen as its food, and burned it with carbon dioxide. The same might be true for life in other worlds.

在40亿年前地球上存在的所有化学燃料中，氢是早期低效细胞最容易代谢的燃料之一。氢不仅是由蛇纹石化产生的；它也是由铀等元素的放射性衰变产生的，至今仍是如此。铀等元素不断地分解周围岩石中的水分子。氢是如此不稳定，如此容易分解，以至于它甚至可以被缓慢的氧化剂消化，如二氧化碳或纯硫。对数百万个基因序列的DNA研究表明，地球上所有生命的先驱者——“最后的共同祖先”(或称之为“卢卡”)——可能确实以氢气为食物，并将其与二氧化碳一起燃烧。其他世界的生命可能也是如此。

The iron minerals that exist here in Oman are common across the solar system, as is the process of serpentinization. The Reconnaissance Orbiter, a space probe now circling Mars, has mapped serpentine minerals on the Martian surface. The space probe Cassini has found chemical evidence of ongoing serpentinization deep within Saturn’s ice-covered moon, Enceladus. Serpentine-like minerals have been detected on the surface of Ceres, a dwarf planet that orbits the sun between Mars and Jupiter. Serpentine minerals are even found in meteorites, the fragments of embryonic planets that existed 4.5 billion years ago, just as Earth was being born—raising the possibility that the cradle of life’s origin actually existed before our planet did.

存在于阿曼的铁矿在整个太阳系都很常见，蛇纹石化的过程也是如此。目前环绕火星运行的太空探测器“勘测轨道飞行器”绘制了火星表面蛇纹石化矿物的分布地图。太空探测器卡西尼号在土星被冰覆盖的卫星土卫二深处发现了蛇纹石化的化学证据。在谷神星——一颗围绕太阳运行的矮行星，位于火星和木星之间——表面也发现了蛇纹石化矿物。蛇纹石化矿物甚至在陨石中也被发现了踪迹，而陨石则是45亿年前存在的行星胚胎的碎片，当时地球才刚刚诞生——这增加了生命起源的摇篮实际上比我们的星球更早存在的可能性。

Hydrogen—an energy source for nascent life—was produced in all of these places. It is probably still being produced throughout the solar system.

所有这些地方都产生了氢——一种生命初期的能源。它可能仍在整个太阳系的各处产生。

To Boyd, the implications are breathtaking.

对博伊德来说，其影响是惊人的。

“If you had rock like this, at a temperature similar to Earth, and you had liquid water, how inevitable do you think life is?” he asked. “My personal belief is, it’s inevitable.”

“如果你有像这样的岩石，温度和地球相似，还有液态水，你认为生命是不可避免的吗？”他问道，“我个人认为，这是不可避免的。”

Finding that life will be a challenge. With existing technologies, a probe sent to Mars could drill no more than a few feet below its hostile surface. Those shallow rocks might contain signs of past life—perhaps desiccated carcasses of Martian cells, sitting inside the microscopic tunnels that they chewed into the minerals—but any living microbes are likely to be buried hundreds of feet deeper. Templeton has grappled with the problem of detecting past signs of life—and of distinguishing those signs from things that happened without the influence of life—ever since she started looking at basaltic seafloor glasses 16 years ago.

发现这种生命将是一个挑战。根据现有技术，发射到火星的探测器只能钻探到其不友好的表面以下几英尺的地方。这些浅层岩石可能含有过去生命存在的迹象——也许是干燥的火星细胞尸体，躺在它们咀嚼矿物的显微隧道里——但是任何活着的微生物都可能被埋在更深的几百英尺的地方。自从16年前坦普尔顿开始研究玄武岩海底玻璃以来，她一直在努力解决探测过去的生命迹象的问题，以及如何将这些迹象与不受生命影响的事物区分开来。

“My job is to find bio-signatures,” she says. As she studies the rocks drilled out of Oman, she’ll subject them to some of the same tools that she used on the glasses. She will bounce X-rays off the mineral surface in order to map how the microbes are altering the minerals, and whether they are leaving metals in place or etching them away. By learning how living microbes chew on minerals, she hopes to find reliable ways of identifying those same chemical chew marks in extraterrestrial rocks that haven’t held living cells for thousands of years.

“我的工作是寻找生物的签名，”她说道。当她研究从阿曼钻出来的岩石时，她会使用一些她在眼镜上用过的工具来对付它们。她将从矿物表面反射X光，以绘制微生物如何改变矿物，以及它们是将金属留在原地还是蚀刻它们。通过研究活微生物如何咀嚼矿物质，她希望能找到可靠的方法来识别外星岩石中那些数千年来没有活细胞的化学咀嚼痕迹。

One day, these tools might be packed onto a Mars rover. Or they might be used on rocks that are brought back from other worlds. For now, she and her colleagues have plenty to do in Oman, figuring out what inhabits the dark, hot, hidden biosphere below their feet.

有一天，这些工具可能会被打包到火星探测器上。或者它们可能被用在从其他世界带回来的岩石上。目前，她和她的同事们在阿曼有很多事情要做，他们要弄清楚在他们脚下黑暗、炎热、隐秘的生物圈里栖息着什么。

【英翻】Meet the Endoterrestrials 遇见地底生物