托福阅读机经背景材料：移居到外星

　　其它星球可能存在着生命一直以来都是科幻电影的主题。现在，这种可能性有可能变成现实。据天文学家说，他们已经发现了一个适合人类居住的星球。这个星球围绕着临近恒星运转且距地球只有20光年。

　　The possibility of life on other planets has been a staple of science fiction for decades. Now that possibility has taken a step closer to reality as astronomers say they have found a planet orbiting a star a mere 20 light-years away that has the right conditions for life to exist.

　　Scientists are calling it the first "Goldilocks" planet, as its temperature seems to be just right to harbor life.

　　由于这个行星可能具备适合生命居住的条件，于是科学家便把这个新发现的行星叫做“Goldilocks”。

　　"The planet has to be the right distance from the star so it's not too hot and not too cold that liquid water can exist," says Paul Butler of the Carnegie Institution of Washington. "And then the planet has to have the right surface gravity."

　　来自华盛顿卡内基学院的保罗?巴特勒说：“由于这颗行星距临近恒星的距离恰好合适，所以这个星球上的温度既不太热也不太冷。这正好使液态水能很好的保存下来。如此以来，这个星球表面就有一定的重力存在。”

　　Butler spoke Wednesday afternoon at a news conference organized by the National Science Foundation, the organization that funded Butler's research. Astronomers have found hundreds of planets orbiting other stars in the past decade, but they have all been so far from their suns that any water would be solid ice or so close that liquid water would boil away.

　　星期三下午，巴特勒在由美国国家科学基金会组织的新闻招待会上发表了上述演讲。这个组织给他的项目研究提供了一定资金上的支持。其实在过去的几十年里，科学家已经发现了成百上千围绕其它恒星运转的行星，但它们都因距离太阳太远而致使其星球上的液态水都凝固成了固态水，或蒸发不见了。

　　The new planet, called Gliese 581-g, is different. But Butler has no direct evidence that Gliese 581-g actually has water.

　　这个叫做Gliese 581g的行星很特别。但巴特勒目前还没有获得任何证明这个行星上存在水的直接证据。

　　"What we know is that this planet exists at the right distance for liquid water, and that it has the right amount of mass to hold onto an atmosphere and to protect its liquid water on the surface," he says. "And of course, any subsequent discussion about life is purely speculative."

　　巴特勒说：“据我们所知，现在这个行星所处的位置正好位于保留住液态水存在的最好位置。这样，这个行星就具备合适的质量以支撑大气层并维持其地面上液态水的存在。当然，任何关于这个星球上存在生命这类的后续话题都纯属人们的推测罢了。”

　　But then he couldn't resist speculating: "That being said, on the Earth, anywhere you find liquid water you find life in abundance."

　　但随后，他也不禁预测道：“人们都说，在地球上，只要有水的地方，就有生生不息的生命体存在。”

　　A Solar System Like Our Own

　　跟我们的太阳系类似的星系

　　There are six planets orbiting around star Gliese 581. And even if planet 581-g doesn't have life, Steven Vogt, a professor of astronomy and astrophysics at the University of California, Santa Cruz, says the solar system around Gliese 581 has an eerie resemblance to the one around our sun.

　　在Gliese 581星系中一共有六颗行星在围绕临近的恒星转动。来自美国加州圣克鲁兹大学研究天文和天体物理学的教授斯蒂芬?沃格特说，即使Gliese 581行星里尚未发现有生命的迹象，但是这个行星周围的太阳系却跟我们地球所在的太阳系有着惊人的相似。

　　"It has an inner clutch of rocky, sort of terrestrial-like planets," he says. Those are planets like Mercury, Venus, Earth and Mars. "And then this sort of loner that's sitting on the outside, kind of like our Jupiter. But it's scaled down. This entire solar system would fit within our own Earth's orbit."

　　巴特勒说：“这个星系中有一些里面多岩石的，有点像陆地的行星。这些行星跟水星，金星，地球和火星类似。这些行星跟其它行星孤立开来，就像木星一样。但如果让这个星系按比例缩小，那么这整个星系就可以被容纳进地球旋转的轨道中。”

　　That's because Gliese 581 is a red dwarf — a pipsqueak of a star compared to our sun.

　　这是由于Gliese 581行星属于红矮星——跟我们的太阳相比，它就算得上是微不足道了。

　　"If you think of the sun as a 100-watt light bulb, this is a 1-watt light bulb. It's like a Christmas tree light," says David Charbonneau, a planet hunter at the Harvard-Smithsonian Center for Astrophysics. "So to have the same temperature, a planet needs to be much closer to that star than it would be from the sun, where you'd have a temperature where you might have light and liquid water."

　　哈佛—史密森天体物理学研究中心的天体探测者大卫?夏博诺说：“如果你把太阳比作100瓦的电灯泡，那么Gliese 581行星则等同于是一只只有一瓦的电灯泡，就跟悬挂在圣诞树上的灯泡差不多。所以一个行星上要有足够的温度，那么这个行星距恒星的距离就得比它距离太阳的距离近，这样，这个行星上才能具备合适的温度，维持一定的光照和液态水。”

　　Charbonneau says the next step will be to try to analyze the atmosphere of this planet and other Goldilocks planets that are probably out there to see if they contain oxygen, another key chemical for life. Those findings are probably some years off, but Charbonneau predicts they will come.

　　夏博诺还说：“接下来要做的是对这个行星及其他Goldilocks行星的大气层进行分析，以检测其中是否含有氧气，或其他维持生命存在的关键的化学物质。这些发现可能要等上几年后了，但一定会有所发现。”