激动人心！科学家发现罕见类地球行星系中或有两颗宜居

Scientists have identified two planets circling round a dim dwarf star as especially likely candidates to have habitable conditions, with probable water and a source of heat, attributes thought necessary for life beyond Earth.

科学家已经发现了两颗围绕超冷矮星运行的行星。这两颗行星可能有适宜居住的条件，水资源和适宜的地表温度，这些都是地球生命所必需的。

Since their discovery last year, the seven planets and their star, called Trappist-1, have thrilled astronomers hunting for a world resembling Earth. Never before had scientists found so many Earth-sized planets around a single star, or in a zone where the extreme temperatures of space would not obliterate the chances of life.

自从去年发现了这被命名为“Trappist-1”的七颗行星和他们的恒星系统后，天文学家们为寻找到了这个类似地球的世界而兴奋不已。科学家们从来没有在一颗单独的恒星周围、或者是在这样一个太空的极端温度没有毁灭生命的空间里——发现过如此多的地球大小的行星。

The finding suggested that there may be planets as rocky and large as Earth all over the Milky Way, and scientists quickly set to work analyzing the Trappist-1 system.

这一发现表明，银河系中可能存在着像地球一样多岩石、大小相似的行星，科学家们很快开始着手分析Trappist-1系统。

With colleagues in Hungary, Dr Amy Barr of the Planetary Science Institute built mathematical models of the seven planets and their interiors, and found that six of the seven worlds probably have water, as liquid or ice, with a global ocean possible on one. The team then modeled the planets’ orbits to determine a likely surface temperature on the worlds.

匈牙利行星科学研究所的艾米.巴尔博士及其同事建立了一个关于七颗行星及其内部条件的数学模型，并发现其中六颗行星上可能有以液体或冰的形式存在的水，其中一颗甚至可能有海洋。该团队还模拟了行星的运行轨道，来确定其可能的地表温度。

“That’s one of the main innovations of the paper,” Barr told the Guardian. “The planets are also on eccentric orbits – kind of egg-shaped – so every time the planet goes around the star it gets stretched and squeezed.”

巴尔博士接受《卫报》采访时说，“这是论文最大的创新点之一，这些行星都沿着类似鸡蛋形状的椭圆轨道运行，所以围绕恒星运转时，会被拉伸和挤压。“

Barr said, those planets have a “very reasonable surface temperatures”. Planet d, the team estimates, has a temperature around 15C (59F) or perhaps as low as slightly warmer than the melting point of ice. Planet e was colder, Barr said: “the temperatures you would get in Antarctica, but also reasonable”.

巴尔说，这些行星有着“非常合理的地表温度”。研究小组估计，行星d的地表温度也许在15摄氏度(59华氏度)左右，或者低至0摄氏度上一点儿；行星e的地表温度更低一些，“是你在南极感受到的温度，但也是在合理范围的”，巴尔说。

The likelihood of tidal heating is encouraging to scientists in search of planets with the conditions for life.

潮汐加热的可能性促使科学家们寻找具有生命条件的行星。

Because Nasa has yet to launch its next-generation space telescope, the James Webb, scientists like Barr and her colleagues have turned to computers to investigate puzzles with limited data.

由于NASA尚未启用其新一代太空望远镜詹姆斯.韦伯，巴尔等科学家只能结合有限的数据在电脑上解开谜团。

Should the James Webb launch on schedule this year, it will provide far more data about specific exoplanets.

如果该望远镜能在今年能投入使用，将会提供外星球更多的细节数据。

“It’s hard to write a paper about seven planets all at once,” Barr said.

巴尔说，“同时写一篇关于7颗行星的论文是很困难的。“