2017年托福听力科学美国人60秒：未知星球

　　科学美国人60秒英文文本
　　This is Scientific American 60 Secomds, Space. I'm Clara Moskowitz, got a minute?
　　Solar system conspiracy theorists have long harbored suspicions that a hidden extra planet or dwarf star lies beyond the orbit of Pluto. As a planet, it’s been called Tyche or simply Planet X. As a star, Nemesis.
　　But an exhaustive search has found no hints of this long-rumored object. NASA's Wide-Field Infrared Survey Explorer has scanned the entire sky in infrared light—twice—and ruled out any hidden bodies larger than Saturn out to 10,000 times the distance from the Earth to the sun.
　　Furthermore, it found no evidence for anything bigger than Jupiter out to 26,000 times the Earth-sun distance. Pluto, for comparison, lies only 40 times farther from the sun than Earth.
　　The finding deals a blow to theories that a Planet X- or Nemesis-type object may have caused periodic mass extinctions on Earth. Some theorists have mused that a hidden planet might have swept through bands of comets in the solar system, sending them crashing into Earth. Now it seems that for such mass species die-offs, the fault lies not in the stars.
　　Thanks for the minute for Scientific American 60 Secomds, Tech. I'm Clara Moskowitz.
　　科学美国人60秒中文翻译：
　　这里是科学美国人60秒，太空系列。我是克拉拉·莫斯科维兹。
　　太阳系阴谋论者一直以来长期庇护这样一个观点，那就是在冥王星轨道深处还隐藏着一颗行星或是矮星。它曾被当做行星命名为堤喀或者简单的X行星。或者曾被当作一颗恒星命名为涅墨西斯星。
　　但是一个详细的调查已经发现这颗长期被传闻笼罩物体的真实面目。NASA的广谱红外调查探测设备已经第二次用红外线扫描出这颗星球的全部大气层,排除了任何可能比土星大，距离地球到太阳一万倍的任何隐藏物体。
　　此外，还发现没有比木星更大的，超过日地距离26000倍的任何可能存在物体。而冥王星比地球距太阳的间距只远40倍。这一研究发现对某些理论是个不小的冲击，比如X行星或涅墨西斯星之类的天体曾造成地球上的物种灭绝。
　　这一研究发现对某些理论是个不小的冲击，比如X行星或涅墨西斯星之类的天体曾造成地球上的物种灭绝。一些理论家已经考虑一颗隐藏的行星也许本该被太阳系存在的一个彗星带打扫干净，而且转而冲向地球。现在按照如此这般推论看来，大规模物种灭绝其实的罪魁祸首并不是这些行星。托福考试(TOEFL)