文/梅根·巴特爾斯 譯/陳棟

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.”

在毛伊島，一架位于火山頂?shù)耐h(yuǎn)鏡每晚都會通過世界上最大的數(shù)碼攝像機(jī)來捕捉宇宙中的光子。通常它會尋找那些在宇宙中飄蕩的小行星，但去年10月的一個晚上，它把目光鎖定在了一個非同尋常的物體上，一個似乎來自另一個太陽系的不明飛行物正在太空中快速移動。

[2]或者至少這是夏威夷大學(xué)的天文學(xué)家們在發(fā)現(xiàn)它時得出的結(jié)論。起初，他們以為它是顆彗星，后來又認(rèn)為它是顆小行星。但未出一個月，他們意識到這個物體又長又薄，根本不像任何科學(xué)界已知的小行星。他們將其命名為Oumuamua——這是一個夏威夷詞，意為“來自遙遠(yuǎn)過去的使者”。

[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，瘋子。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探空氣球，把探空儀器帶到高空進(jìn)行溫度、大氣壓力、濕度、風(fēng)速風(fēng)向等氣象要素測量的氣球。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]數(shù)千英里外，一位名叫阿維·羅卜的哈佛天文學(xué)家也得知了關(guān)于這個神秘物體的消息。很快，他便開始考慮一種十分吸引人的可能性：Oumuamua實際上是一艘用來給它的創(chuàng)造者回傳信號的外星飛船。這一理論乍一聽有點不著邊際，但羅卜并非是一個要在飛船里尋找小綠人的怪人。他和他的同事們所在的頂尖科學(xué)家隊伍不斷壯大，這些科學(xué)家們正在用與對待其他科學(xué)問題同等嚴(yán)苛的標(biāo)準(zhǔn)研究人類面臨的最重要問題之一：我們是這個宇宙中孤獨的存在嗎？

[4]美國人一直以來對外星訪客的存在充滿幻想。2001年的蓋洛普民意調(diào)查（可取得的最近一次調(diào)查）發(fā)現(xiàn)，33%的美國人相信外星人已經(jīng)到訪過地球。但是，不管是來自政府內(nèi)部還是外部的科學(xué)家們，一直都把此類說法當(dāng)作兒戲。從1947年新墨西哥城羅斯威爾的探空氣球墜毀事件到英格蘭的麥田怪圈，他們參加了諸多辯論，但只是為了揭穿一些非?？梢傻恼f法。他們還感嘆大多數(shù)人缺乏辨別能力，外星could indeed happen).

[5] But while UFO claims are often hoaxes5hoax騙局；惡作劇。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.人登陸——實際并未發(fā)生——和未來可能與外星人聯(lián)絡(luò)（這確實有可能發(fā)生）完全是兩回事。

[5]但盡管關(guān)于不明飛行物的各種說法通常是惡作劇或是陰謀論者的杰作，尋找外星智慧——和人類一樣聰明且擁有先進(jìn)科技的外星生命——卻是正當(dāng)合理的科學(xué)領(lǐng)域。

[6]專家們對智能生命會以何種方式聯(lián)系人類各持己見。但這一復(fù)蘇的領(lǐng)域，亦被稱作SETI （搜尋地外文明計劃），很大程度上基于這一假設(shè)，即外星人（如果他們確實存在而且實際上在試圖與我們聊天）可能會使用和我們用于彼此溝通同類型的技術(shù)——從無線電信號到閃光。

Look Who’s Talking

[7] Instruments like radio telescopes7radio telescope射電望遠(yuǎn)鏡?！猤iant, 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，誰在說話

[7]各種儀器，譬如射電望遠(yuǎn)鏡（巨大、超靈敏的盤形物，可用來接收極遠(yuǎn)處傳來的微弱信號）被用來搜索宇宙中的光。無線電波構(gòu)成了光譜的一部分——許多科學(xué)家認(rèn)為，外星科技最有可能用這一波段與我們聯(lián)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的俚語表達(dá)，表示寒暄打招呼。?”

[9] Scientists classify radio waves by how often they crest10crest達(dá)到波峰，到達(dá)頂點。; 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此處指radio window，射電窗。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]外星人搜尋者們尋找無線電波是因為人類非常喜歡使用它們。無線電波可以傳播到很遠(yuǎn)的距離，使我們在開車時也能收聽到最愛的脫口秀。他們還可以穿越光年并且滿載信息，這也是為何它們可以傳送我們的電視廣播、移動電話和GPS位置。由于無線電波如此萬能，SETI 科學(xué)家們認(rèn)為我們的銀河系鄰居可能也會用它們和我們打招呼說：“最近怎樣？”

[9]科學(xué)家們通過達(dá)到波峰的頻率對無線電波進(jìn)行分類；該測量結(jié)果便是此電磁波的頻率。波峰之間靠得越近，頻率就越高。當(dāng)無線電波來自地球以外時，科學(xué)家們會把頻道調(diào)到1到10千兆赫之間。低于這個射電窗會捕捉到太多來自銀河系其余部分的噪音，譬如行星的輻射甚至是遠(yuǎn)處某個黑洞的嗡嗡聲。大氣層會阻隔高于10千兆赫的頻率。而在這個安靜的射電窗內(nèi)，有90億個頻率或頻道可供外星人使用。

[10] 20世紀(jì)60年代外星智慧現(xiàn)代化搜索剛開始時，科學(xué)家們每次只能收聽到一個頻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，他們可以一次收聽數(shù)以千萬乃至億計的頻道，重復(fù)百萬次地聆聽某個遠(yuǎn)方傳來的音符。這種巨大的容量增加了我們捕捉到外星人信息的機(jī)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無法克服的，無法超越的。, 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. ■

外星人表情符號

[11]然而SETI科學(xué)家們認(rèn)為，“外星人可能會使用和我們在地球使用的類似科技”這一假設(shè)會給他們的搜尋構(gòu)成一個根本的、可能無法克服的挑戰(zhàn)：我們?nèi)祟惖拿芗ㄐ艜顾褜ぷ兊脽o比困難。手機(jī)、Wi-Fi和GPS都依賴無線電波。這些電磁波占據(jù)了研究人員用以收聽外星人信號的相同頻道。而且因為我們的設(shè)備與射電望遠(yuǎn)鏡距離近得多，所以信號也要強(qiáng)很多。我們每發(fā)一次表情符號，都可能使SETI研究變得更加困難。加州大學(xué)伯克利分校SETI研究中心主任安德魯·西米昂表示，從糠皮樣繁亂的人類信號中分揀出小麥般有用的外星人信號是尋找外星智慧中最難的部分。 □