NASA发现7颗超近类地行星 星际移民或有盼头了

美国宇航局的科学家们称，他们在距地球40光年处发现围绕单一恒星“特拉普1号”(Trappist-1)运行的7颗系外行星。他们认为，这一酷似太阳系的行星系，堪称迄今寻找外星生命的最佳地点。

NASA scientists have discovered at least seven Earth-sized planets, each potentially capable of hosting life, orbiting a nearby star just outside the solar system.
美国宇航局的科学家们发现，至少有七颗地球大小的行星围绕着太阳系外的一颗临近恒星运行，每颗行星都可能适宜生命体生存。

The exciting discovery announced Wednesday has been deemed one of the first realistic opportunities to begin a search for alien life outside our system as well as the first time so many planets were discovered circling the same star.
22日公开的发现激动人心，被视为开启探索太阳系外外星生物的首批现实机遇之一，也是人类首次发现如此多的行星环绕在同一颗恒星周围。

“This discovery could be a significant piece in the puzzle of finding habitable environments, places that are conducive to life. Answering the question 'are we alone' is a top science priority and finding so many planets like these for the first time in the habitable zone is a remarkable step forward toward that goal,” associate administrator of the agency's Science Mission Directorate in Washington Thomas Zurbuchen said in a press release.
美国宇航局科学任务署副署长华盛顿•托马斯•祖博肯在一篇新闻稿中表示，“该发现可能给寻找适宜生存的栖居环境的谜题提供关键信息。科学界的首要任务是回答‘宇宙中只有我们吗’的问题，而在宜居地带首次发现这么多此类行星是科学家们向着该目标迈出的重大一步。”

科学家们给特拉普1号的七颗行星编号b、c、d、e、f、g、h

The cluster of planets orbit a dim dwarf star, just barely the size of Jupiter, called Trappist-1. The group of planets are about 40 light years away which isn't actually all that far away from Earth. The close proximity will allow the system to be studied in great detail, according to the release.
这群行星围绕的暗矮星和木星差不多大，被称为特拉普1号。行星与地球相距约40光年，这样的距离实际上并不算遥远。据新闻稿称，在这样靠近的距离下，人类可以对该行星系进行详细的研究。

科普：40光年有多远

科学家们表示，在如此靠近的行星系发现7颗类地行星真是可喜可贺。也有网友称，看来人类离太空移民不远了：

那么，“真的不算远”的40光年到底意味着什么呢？小编就来为大家科普一下。

一光年指的是光在真空中走一年的距离，折合成米数为：

9,460,730,472,580,800米

如果你数不清的话，那我们再折合成公里数，也就是：

大约94607亿公里

迄今为止，应用在实践中的最快人造飞行器是“新视野号”探测器，其实际飞行速度大约为16公里/秒。2006年1月升空的，2015年7月才掠过冥王星，花了9年半时间才飞48亿公里。

如果按照这个速度来计算，理论上飞到特拉普1号星系需要大概75万年……

不过别灰心，美国宇航局做了一个特拉普1号星系的模拟视频，下面一起来看看了解一下这个酷似太阳系的行星系：

Three of the planets or exoplanets as scientist call them, are receiving just the right amount of energy from the host star, meaning oceans of water could cover their surfaces. Scientists refer to the ideal zone just around the star as "the habitable zone," sometimes jokingly called the "Goldilocks Zone," as it is just right for supporting life.
其中三颗行星（科学家们也称之为系外行星）从恒星接受到的能量恰到好处，这意味着它们的表面可能覆盖了大面积的液态水。科学家们将该行星系恒星周围的理想地带称为“宜居地带”，由于这里正好适宜生命生存，他们有时也将其戏称为“金发美女地带”。

The other three bodies farther off from the star could feature smaller bodies of water and the seventh could even boast a puddle or two under ideal conditions.
另外三颗离恒星较远的行星表面覆盖的液态水可能较少，理想条件下第七颗行星甚至可能只有一两个水坑。

Based on their densities, all of the planets are believed to be rock, but scientists said they still need to study the atmospheres before determining whether or not the planets boast water and, ultimately, whether or not they could support any type of life form.
根据这些行星的密度可以判断它们是由岩石构成的，但科学家们需要对它们的大气进行研究，然后才能确定上面是否存在水、并最终确定它们是否适合生命体生存。

七颗行星的质量、体积、公转周期、与恒星距离都被算出来了，根据其密度被确定为固态行星。而且，他们的质量、体积都跟地球差别不是很大。

NASA's space telescope Spitzer, an infrared telescope that trails the earth as it orbits the sun, revealed the new system.
美国宇航局史匹哲天文望远镜发现了这个全新的行星系。史匹哲红外望远镜绕太阳运行，追踪地球。

"This is the most exciting result I have seen in the 14 years of Spitzer operations," said Sean Carey, manager of NASA's Spitzer Science Center at Caltech/IPAC. "Spitzer will follow up in the fall to further refine our understand of these planets so that the James Webb Space Telescope can follow up. More observations of the system are sure to reveal more secrets."
加州理工学院美国宇航局史匹哲科学中心负责人肖恩•卡雷称，“这是史匹哲运行14年以来，我看到的最令人兴奋的结果。”史匹哲将在秋季进一步完善我们对这些行星的了解，以便于詹姆斯•韦伯天文望远镜跟进。对该行星系的进一步观察必将透露出更多的奥秘。”

英文来源：纽约每日新闻
翻译&编辑：董静
审校：yaning