文/梅根·巴特尔斯 译/陈栋

Every evening in Maui, a telescope perched atop a volcano captures particles of light in the universe with the world’s largest digital camera. Normally it searches for asteroids1asteroind小行星。dancing across the cosmos. But one night last October, it locked its gaze onto something remarkable, an unidenti fi ed fl ying object moving quickly through space,seemingly from another solar system.

[2] Or at least that’s what astronomers at the University of Hawaii concluded when they discovered it. At first, they thought it was a comet, then an asteroid.But within a month, they realized the object was long and thin and unlike any asteroid known to science. They named it “Oumuamua”—a Hawaiian word that means “messenger from the distant past.”

在毛伊岛，一架位于火山顶的望远镜每晚都会通过世界上最大的数码摄像机来捕捉宇宙中的光子。通常它会寻找那些在宇宙中飘荡的小行星，但去年10月的一个晚上，它把目光锁定在了一个非同寻常的物体上，一个似乎来自另一个太阳系的不明飞行物正在太空中快速移动。

[2]或者至少这是夏威夷大学的天文学家们在发现它时得出的结论。起初，他们以为它是颗彗星，后来又认为它是颗小行星。但未出一个月，他们意识到这个物体又长又薄，根本不像任何科学界已知的小行星。他们将其命名为Oumuamua——这是一个夏威夷词，意为“来自遥远过去的使者”。

[3] Thousands of miles away, a Harvard astronomer named Avi Loeb learned of the mysterious object as well.Soon, he began pondering an enticing possibility: that Oumuamua was actually an alien spacecraft sending signals back to its creators. This theory may sound a bit out there. But Loeb isn’t some crackpot2crackpot怪人，疯子。looking for little green men in a spaceship. He and his colleagues are part of a growing number of top-tier scientists who are applying the same rigorous standards they use on other scientific issues to tackle one of the biggest questions facing humanity:Are we alone in the universe?

[4] Americans have long been fascinated by the possibility of alien visitors.A 2001 Gallup Poll (the most recent one available) found that 33 percent of Americans believed aliens have visited the Earth. But scientists—both inside and outside the U.S. government—have been reluctant to take such claims seriously. From the 1947 weather balloon3weather balloon探空气球，把探空仪器带到高空进行温度、大气压力、湿度、风速风向等气象要素测量的气球。crash in Roswell, New Mexico, to crop circles in England, they’ve largely joined the debate only to debunk44 debunk揭露，揭穿。some very dubious claims. They’ve also lamented the lack of distinction most people make between alien landings—which haven’t occurred—and the possibility of future alien contacts (which

[3]数千英里外，一位名叫阿维·罗卜的哈佛天文学家也得知了关于这个神秘物体的消息。很快，他便开始考虑一种十分吸引人的可能性：Oumuamua实际上是一艘用来给它的创造者回传信号的外星飞船。这一理论乍一听有点不着边际，但罗卜并非是一个要在飞船里寻找小绿人的怪人。他和他的同事们所在的顶尖科学家队伍不断壮大，这些科学家们正在用与对待其他科学问题同等严苛的标准研究人类面临的最重要问题之一：我们是这个宇宙中孤独的存在吗？

[4]美国人一直以来对外星访客的存在充满幻想。2001年的盖洛普民意调查（可取得的最近一次调查）发现，33%的美国人相信外星人已经到访过地球。但是，不管是来自政府内部还是外部的科学家们，一直都把此类说法当作儿戏。从1947年新墨西哥城罗斯威尔的探空气球坠毁事件到英格兰的麦田怪圈，他们参加了诸多辩论，但只是为了揭穿一些非常可疑的说法。他们还感叹大多数人缺乏辨别能力，外星could indeed happen).

[5] But while UFO claims are often hoaxes5hoax骗局；恶作剧。or the work of conspiracy theorists, the search for extraterrestrial6extraterrestrial地球外的。intelligence—alien life just as smart and technologically advanced as humans—is a legitimate scienti fi c fi eld.

[6] Experts disagree on how intelligent life might try to contact humans.But the resurrected field, known as SETI (Search for Extraterrestrial Intelligence), is largely based on the assumption that extraterrestrials—if they are out there and actually trying to chat—might use the same type of tech that we use to communicate with one another—from radio signals to fl ashes of light.人登陆——实际并未发生——和未来可能与外星人联络（这确实有可能发生）完全是两回事。

[5]但尽管关于不明飞行物的各种说法通常是恶作剧或是阴谋论者的杰作，寻找外星智慧——和人类一样聪明且拥有先进科技的外星生命——却是正当合理的科学领域。

[6]专家们对智能生命会以何种方式联系人类各持己见。但这一复苏的领域，亦被称作SETI （搜寻地外文明计划），很大程度上基于这一假设，即外星人（如果他们确实存在而且实际上在试图与我们聊天）可能会使用和我们用于彼此沟通同类型的技术——从无线电信号到闪光。

Look Who’s Talking

[7] Instruments like radio telescopes7radio telescope射电望远镜。—giant, ultra-sensitive dishes that receive faint signals from very far away—are used to search the cosmos light. Radio waves constitute a portion of the light spectrum—the band8band波段。that

瞧，谁在说话

[7]各种仪器，譬如射电望远镜（巨大、超灵敏的盘形物，可用来接收极远处传来的微弱信号）被用来搜索宇宙中的光。无线电波构成了光谱的一部分——许多科学家认为，外星科技最有可能用这一波段与我们联系。alien technology would most likely use to reach us, many astronomers believe.

[8] Alien hunters look for radio waves because humans are so fond of using them. Radio waves can travel miles, letting us hear our favorite talk show while we drive. They can also traverse lightyears and be crammed with information, which is why they carry our television broadcasts, our mobile calls and GPS locations. Because radio waves are so versatile, SETI scientists believe our galactic neighbors might use them to reach out and say, “Sup9Sup即What’s up的俚语表达，表示寒暄打招呼。?”

[9] Scientists classify radio waves by how often they crest10crest达到波峰，到达顶点。; that measurement is the wave’s frequency. The tighter the crests, the higher the frequency.When it comes to radio waves from beyond Earth, scientists tune to frequencies between 1 and 10 gigahertz11gigahertz千兆赫。.Going below that window12此处指radio window，射电窗。catches too much noise from the rest of the galaxy,like radiation from planets or even the humming of a distant black hole. The atmosphere blocks frequencies higher than about 10 gigahertz. But nestled in that quiet window are 9 billion possible frequencies, or channels, that aliens could be using.

[10] When the modern search for extraterrestrial intelligence began in the 1960s, scientists could listen to just one

[8]外星人搜寻者们寻找无线电波是因为人类非常喜欢使用它们。无线电波可以传播到很远的距离，使我们在开车时也能收听到最爱的脱口秀。他们还可以穿越光年并且满载信息，这也是为何它们可以传送我们的电视广播、移动电话和GPS位置。由于无线电波如此万能，SETI 科学家们认为我们的银河系邻居可能也会用它们和我们打招呼说：“最近怎样？”

[9]科学家们通过达到波峰的频率对无线电波进行分类；该测量结果便是此电磁波的频率。波峰之间靠得越近，频率就越高。当无线电波来自地球以外时，科学家们会把频道调到1到10千兆赫之间。低于这个射电窗会捕捉到太多来自银河系其余部分的噪音，譬如行星的辐射甚至是远处某个黑洞的嗡嗡声。大气层会阻隔高于10千兆赫的频率。而在这个安静的射电窗内，有90亿个频率或频道可供外星人使用。

[10] 20世纪60年代外星智慧现代化搜索刚开始时，科学家们每次只能收听到一个频channel at a time. Today, they can tune in to tens or even hundreds of millions of channels at once, listening for a single note from faraway millions of times over. This vast capacity increases the odds of us catching an alien message when it arrives.道。如今，他们可以一次收听数以千万乃至亿计的频道，重复百万次地聆听某个远方传来的音符。这种巨大的容量增加了我们捕捉到外星人信息的机率。

Alien Emojis

[11] Though SETI scientists believe,that assumption aliens would likely use similar technology as we do on Earth poses a fundamental, possibly insurmountable13insurmountable无法克服的，无法超越的。, challenge to their search: Our own chatter makes it immensely difficult. Cellphones, Wi-Fi and GPS all rely on radio waves. Those waves occupy the same channels researchers use to listen to for E.T. And because our devices are so much closer to the telescopes, the signals are much stronger. Every time we text an emoji, we potentially make SETI research more difficult. Sorting the alien wheat from the human chaff is the hardest part of the search for extraterrestrial intelligence, says Andrew Siemion, director of the University of California, Berkeley’s SETI Research Center. ■

外星人表情符号

[11]然而SETI科学家们认为，“外星人可能会使用和我们在地球使用的类似科技”这一假设会给他们的搜寻构成一个根本的、可能无法克服的挑战：我们人类的密集通信会使搜寻变得无比困难。手机、Wi-Fi和GPS都依赖无线电波。这些电磁波占据了研究人员用以收听外星人信号的相同频道。而且因为我们的设备与射电望远镜距离近得多，所以信号也要强很多。我们每发一次表情符号，都可能使SETI研究变得更加困难。加州大学伯克利分校SETI研究中心主任安德鲁·西米昂表示，从糠皮样繁乱的人类信号中分拣出小麦般有用的外星人信号是寻找外星智慧中最难的部分。 □