VOA常速英语2014--美国国家航空航天局寻找类地行星（在线收听）

NASA Focuses on Earth-Like Planets 美国国家航空航天局寻找类地行星

For decades, looking for life elsewhere in the universe meant listening for signals that could be from distant civilizations. But recent breakthroughs in space technology refocused some of that effort toward finding planets that may harbor life, even in its primitive form.

When NASA launched the Kepler Space Telescope in 2009, scientists learned something new-and quite significant, says the director of the Space Telescope Science Institute, Matt Mountain.

美国太空望远镜科学研究所所长马特·芒廷表示在2009年NASA发射开普勒太空望远镜时,科学家们已经了解到了新鲜且相当重要的事情。

“Our galaxy has at least 100 billion planets in it.

“我们的星系中有至少1000亿颗行星。

And we didn't know that five years ago."

而5年前,我们对此还一无所知。”

Of course, Kepler and today's other powerful telescopes cannot actually see those planets; they are too faint against the light of their stars.

当然,开普勒和现如今其他强大的望远镜无法实际观测到这些星体,相比自身行星它们发散的光太微弱。

But scientists can measure the change of light when they pass in front of the star and analyze the light passing through their atmosphere to determine what is in it.

但是当它们在星体前面通过时，科学家可以测量光的变化, 并针对通过它们大气所发出的光进行分析判断内部结构。

NASA's astrophysicist and former astronaut John Grunsfeld.“Well, if we were looking at Earth, we would see signs of our sky, our blue sky, we would see signs of oxygen, of carbon-dioxide, of sulfur dioxide from volcanoes and we might even see signatures that there was plant life.And we see that by dissecting the light into its component colors."

NASA的天体物理学家及前宇航员约翰·菲尔。“嗯,如果我们观察地球,我们会看到我们标志性的天空,蓝天,我们也会看到标志性的氧气,来自火山的二氧化硫, 二氧化碳等,我们甚至可能看到标志性这个星球的动植物。我们全部都是通过仔细研究光及其组成部分所得出。”

寻找类地行星.jpg

Most of the planets discovered so far are unlike Earth. They are too big, too small, too close to their sun, or too far away to support life. But astrophysicist Sara Seager says small planets the size of Earth are extremely common.

到目前为止所发现的大部分行星都并非类似地球。不是太大,就是太小,要么太接近太阳,抑或不能够让生命得到存续。但天体物理学家萨拉·西格尔表示地球这样的小行星非常常见。

“We're looking for biological signatures, gasses that are produced by life, gasses that don't belong in the atmosphere."

“我们正在寻找生命可存续的迹象, 生命所产生的气体, 不属于大气中的气体。”

In cooperation with the European Space Agency and scientists from other nations, NASA is building the next generation of space telescopes that may be able to find evidence of life.

通过与欧洲航天局及其他国家的科学家合作,美国宇航局正在建造次世代的太空望远镜,也许能够发现生命迹象。

The James Webb Space Telescope, scheduled to be deployed in 2018, will have unprecedented sensitivity and resolution that will greatly improve the spectroscopic analysis of distant stars and planets.

预计于2018年投入使用的詹姆斯·韦伯太空望远镜将配备前所未有的灵敏度和分辨率,将大大提高遥远的恒星和行星的光谱分析。

NASA's chief scientist Ellen Stofan says the agency also plans to look for life on Jupiter's moon Europa, which may have an ocean under its ice cover.

美国国家航空航天局的首席科学家艾伦·斯托芬表示他们的机构还计划寻找木星的卫星，被海洋冰层覆盖的欧罗巴上的生命迹象。

“In our own solar system we know where to go, we know what to measure it and we're in the process of doing just that. Looking out, beyond our solar system, we're on the right track, we're making the right measurements and we're just on the cusp of learning so much."

“在我们的太阳系,我们知道该去哪里,我们知道如何测量,我们一直在进行这个过程。而在我们的太阳系之外,我们在正确的轨道上,进行着正确的测量,我们还未深入就已经了解到这么多。”

Scientists say there's a very high probability that they will find a planet very much like Earth. That could help answer the question: how hard is it for life to get a foothold in the universe?

科学家们表示他们发现类地行星的概率非常高。这可能有助于解决生命在宇宙中立足到底有多难这个问题。