宇宙射线大脑有害 火星移民获难成行

Going to Mars could be bad for astronauts’ brains, a new study using rodents has found.

一项关于啮齿动物的实验发现，前往火星可能会对宇航员的大脑造成损害。

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.

尽管地球的大气层可以最大限度地遮挡住宇宙射线，但是宇航员在前往火星的漫长旅途中将不得不暴露在有害的辐射之下。研究者将老鼠放置在充电粒子周围，结果发现实验鼠出现了大脑受损、神经系统发炎和记忆受损等症状。

"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.”

“对于两三年内经常在地球和火星之间往返的宇航员来说，这可不是什么好消息，”加州大学欧文分校医学院的放射肿瘤学教授查理斯·利莫里表示“宇航员在太空中会受到特殊的伤害，如果长期暴露在粒子辐射下，神经系统可能会出现包括身体多项机能下降、记忆缺陷、焦虑、抑郁和决策能力受损在内的并发症，还会留下持续时间极长的后遗症。”

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.

科学家们还发现，实验鼠因射线的作用变得越来越焦虑，受到了“恐惧消退”机能的影响。恐惧消退将人们过去的恐惧深埋心底，如果这一过程出现问题，宇航员会感受到更多的恐惧。

"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."

“恐惧消退出现缺陷，人们会更容易变得焦虑，”利莫里在声明中说到“这在地球与火星往返的三年时间里会成为一个大问题。”

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.

火星距地球约1.4亿英里，将成为未来太空旅行中地位显著的目的地。美国航空航天局计划于2018年执行无人探索任务，而2020年则将由探测车完成探测，而21世纪30年代将会有宇航员登上火星。同时美国太空探索技术公司创始人埃隆·马斯克曾宣布了大胆的火星殖民计划。

The study, which notes that cosmic radiation could possibly impair astronauts’ decision-making abilities, was published in the journal Science Reports.

这项研究发表在《Science Reports》期刊上，指出了宇宙射线对宇航员决策力造成的影响。

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.

这项研究的实验对象是鼠类而非人类（原因显而易见），而科学界普遍认为，在鼠类身上出现的现象不一定会同样在人类身上出现，研究报告也用了“可能地”这样的字眼。

“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.

研究报告指出：“老鼠在宇宙射线的作用下出现了认知障碍，而宇航员在火星的往返途中不免要接触到这些射线，因此在宇航员身上也很可能出现上述现象。”