宇宙射線大腦有害 火星移民獲難成行
Going to Mars could be bad for astronauts’ brains, a new study using rodents has found.
一項關於齧齒動物的實驗發現，前往火星可能會對宇航員的大腦造成損害。
While the Earth’s magnetosphere mostly protects people on this planet from cosmic radiation, any trailblazers on a long-distance trek to Mars would have to contend with the harmful radiation of space. To study this, researchers exposed rodents to charged particles and then analyzed the results. They found that, among other issues, the rodents had brain damage, neural inflammation, and impaired memory.
儘管地球的大氣層可以最大限度地遮擋住宇宙射線，但是宇航員在前往火星的漫長旅途中將不得不暴露在有害的輻射之下。研究者將老鼠放置在充電粒子周圍，結果發現實驗鼠出現了大腦受損、神經系統發炎和記憶受損等症狀。
"This is not positive news for astronauts deployed on a two-to-three-year round trip to Mars," Charles Limoli, a professor of radiation oncology at the University of California, Irvine, School of Medicine, said in a statement. "The space environment poses unique hazards to astronauts. Exposure to these particles can lead to a range of potential central nervous system complications that can occur during and persist long after actual space travel - such as various performance decrements, memory deficits, anxiety, depression and impaired decision-making.”
“對於兩三年內經常在地球和火星之間往返的宇航員來說，這可不是什麼好消息，”加州大學歐文分校醫學院的放射腫瘤學教授查理斯·利莫里表示“宇航員在太空中會受到特殊的傷害，如果長期暴露在粒子輻射下，神經系統可能會出現包括身體多項機能下降、記憶缺陷、焦慮、抑鬱和決策能力受損在內的併發症，還會留下持續時間極長的後遺症。”
The scientists also found that radiation could lead to more anxiety, as the rodents had their sense of “fear extinction” affected. Since fear extinction tamps down fear associated with past events, if that process isn’t working properly, then the astronauts could feel more fear.
科學家們還發現，實驗鼠因射線的作用變得越來越焦慮，受到了“恐懼消退”機能的影響。恐懼消退將人們過去的恐懼深埋心底，如果這一過程出現問題，宇航員會感受到更多的恐懼。
"Deficits in fear extinction could make you prone to anxiety," Limoli said in the statement, "which could become problematic over the course of a three-year trip to and from Mars."
“恐懼消退出現缺陷，人們會更容易變得焦慮，”利莫里在聲明中說到“這在地球與火星往返的三年時間裏會成爲一個大問題。”
The red planet, about 140 million miles from Earth, is a prominent and tantalizing target for the future of space travel. NASA is looking at 2018 for the launch of its uncrewed Mars InSight mission, has plans for a next-gen Martian rover launching in 2020, and is eying a manned mission in the 2030s decade. Meanwhile, Elon Musk, the founder of SpaceX, has announced a bold vision to send people to Mars and colonize it.
火星距地球約1.4億英里，將成爲未來太空旅行中地位顯著的目的地。美國航空航天局計劃於2018年執行無人探索任務，而2020年則將由探測車完成探測，而21世紀30年代將會有宇航員登上火星。同時美國太空探索技術公司創始人埃隆·馬斯克曾宣佈了大膽的火星殖民計劃。
The study, which notes that cosmic radiation could possibly impair astronauts’ decision-making abilities, was published in the journal Science Reports.
這項研究發表在《Science Reports》期刊上，指出了宇宙射線對宇航員決策力造成的影響。
A caveat: the study used rodents, not people (for obvious reasons), and in general in science, just because something happens to mice during a study doesn’t mean it will be the same for humans. Indeed, the study uses the word “possibly”to couch their results.
這項研究的實驗對象是鼠類而非人類（原因顯而易見），而科學界普遍認爲，在鼠類身上出現的現象不一定會同樣在人類身上出現，研究報告也用了“可能地”這樣的字眼。
“The Mars mission will result in an inevitable exposure to cosmic radiation that has been shown to cause cognitive impairments in rodent models, and possibly in astronauts engaged in deep space travel,”the study states.
研究報告指出：“老鼠在宇宙射線的作用下出現了認知障礙，而宇航員在火星的往返途中不免要接觸到這些射線，因此在宇航員身上也很可能出現上述現象。”
