玄黄端现，太极混沌如鸡蛋，随着轰的一声, In the beginning there was darkness... And then... BANG!
诞生了无限膨胀的时间、空间和物质。 Giving birth to an endless expanding existence of time, space and matter.
现在所见超乎我们的想象，超越了客观认知极限， Now see further than we've ever imagined, beyond the limits of our existence,
那地方我们称之为“宇宙”。 in a place we call... THE UNIVERSE
在我们的太阳系以外有行星吗? Are there planets beyond our solar system?
这个问题很少有人敢探索 It's a question few have dared to probe.
实际上最初开始寻找行星的 The origin of hunting for planets started, really,
是些科学狂热份子 from the lunatic fringe of science.
现在数百个神奇的星球已经被发现 Now, hundreds of these exotic worlds have been found.
它们中会有存在生命吗? Could any of them be home to alien life?
目前 我们发现这类行星是些... Right now, the sort of planets we're discovering are kind of...
怪物 monsters.
你会立刻变为灰烬 You would be incinerated immediately
之前你真的有点对周围的环境感到兴奋 before you had a chance to really sort of groove on your surroundings.
然而有些行星还是很有希望 But some planets hold more promise.
我对格雷司43b星感到兴奋几乎要跳起来了 I'm so excited about Gliese 436, I'm almost jumping out of my clothes.
我们即将找到另外一颗地球了吗? Could we be on the verge of finding another Earth?
我们还是不知道我们的地球究竟是颗很普通的行星呢 We still don't know whether our Earth is a commonly occurring planet
还是十亿分之一的怪物 or a one-in-a-billion freak.
尖端的科学、陌生的星球、狂野的气候 Cutting-edge science, strange worlds, and wild weather,
伴随着我们在宇宙中探寻“日外行星” as we travel the Universe in search of“alien planets”.
宇宙第二季第一集
日外行星 Alien Planets
潜伏在飞马座里、距离地球50光年 Lurking in the constellation Pegasus, 50 light-years from Earth,
有一颗巨大的行星 is a monstrous planet.
高温气体巨星几乎跟木星一样庞大 A superheated gas giant almost as massive as Jupiter,
围绕着它的太阳快速运转运行一圈还不到四天的时间 whipping around its star in a little over four days.
在1995年它被命名为“51飞马B” It's called“51 Pegasi b” and in 1995,
发现它是第一颗围绕陌生的太阳运转的行星 it became the first planet detected orbiting an alien sun.
这是个里程碑式的发现 It was a landmark discovery,
然而这只是更大探索的起步 but just a stepping stone on an even greater quest
我们要找到和地球相似的行星 to find a planet that looks more like our own.
最终天文学家回避不了的目标 The ultimate but elusive goal for astronomers
就是要找到另一颗地球 is to find another Earth.
我们寻找的是：判断出地球在 What we're after is the appreciation
宇宙广袤的环境中适合呆的地方 of where our Earth fits in, in the grand context of our Universe.
我们乐意能够找到另外一个地球 And we'd love to be able to find other Earths.
然而那些地球真的难找 But Earths are so undetectable,
小小的星球不可能发出那么明亮的光 little chunks of rock that don't emit much light.
类地行星在宇宙中有多少可能? How common might Earth-like planets be in the Universe?
即使所有的恒星中只有1%存在地球那样的行星 Even if only one percent of all stars were circled by a planet like our own,
那也意味着有十亿颗地球等着被发现 that would still mean there are billions of other Earths waiting to be discovered.
我们相当有把握 We are almost sure
岩石构成的类地行星大量存在 that rocky Earth-like planets exist in abundance out there,
但是和地球有多象呢? but how Earth-like?
对地球的独特性还存在争论 There are still open questions about the uniqueness of our Earth,
我们还不知道我们的地球是否与众不同的 and we don't know whether our Earth is unusual or not.
我认为 这是个极其深远 令人烦恼的问题 It's an extremely profound and, I think, disturbing question.
在日外行星的领域里 In the realm of alien planets,
存在广泛的可以想象的星球 there is a wide range of imaginable worlds.
可以找到海洋星球 完全被水所覆盖 We might find ocean worlds, completely covered in water,
找到冰封的行星 frigid ice planets,
像火星一样的星球、但或许会有厚厚的大气层 mars-like worlds, but perhaps with thick atmospheres
布满了大量的活火山 fed by massive active volcanoes,
甚至还有行星天上有两颗太阳 and even planets with two suns in their skies.
可能有的行星对人类十分友好 There may be planets that humans would find hospitable,
而人类难以踏足其它行星 and others on which humans wouldn't dare tread
因为那里将只能是其他生物的栖息地 that could still be home to other types of creatures.
或许我们到目前为止的主要经验 Perhaps the major lesson we've learned so far
是寻找围绕太阳运转的行星 from looking the planets around the stars
那是我们能够考虑到的大多数行星所具有的性质 is that nature can make a lot more planets that we can dream of.
哪怕只找到一颗类地行星 Finding just one other truly Earth-like planet
都将暗示地球在宇宙中是很普通的星球 would hint that Earths are common in the Universe.
如果地球很普通那么或许生命也是普遍存在的 And if Earths are common, then perhaps life, too, is widespread.
然而在目前为止所发现的200多颗日外行星中 But of the over 200 alien planet detected so far,
就我们所知大多数似乎都完全不适合生命生存 most of them seem uttlerly hostile to life as we know it.
迄今为止我们发现了三类星球 So far, we found sort of three kinds of worlds.
一类行星、他们的轨道实在离恒星太近 One kind are the planets that are really close to the star that they orbit,
完全会被烤死 and they're totally baked to death.
接着是那些距离恒星相当远、非常寒冷 Then there are the ones that are quite far away, and they're pretty cold.
还有一些具有很大偏心轨道的行星 And then there are the ones in the highly eccentric orbits
它们有时离太阳很近 有时离太阳很远 which sometimes get close to the star and sometimes far away.
所以它们是冷热交替 So they're alternately very hot and cold.
到目前为止我们确实还没有发现有行星上存在森林 So far, we definitely haven't found any worlds with jungles and forests.
确实我们还没有发现有行星 Indeed, we haven't found any worlds
有直接的迹象表明有适合居住的 that are square smack in the habitable zone where there's
表面存在水和其它适宜条件的区域 liquid water on the surface and other nice conditions.
我们的观点是就是把这个地球作为参考 Our frame of reference for what we consider to be a nice planet is this one.
我们已经相当适应地球了 We like it quite a bit.
我们有可供呼吸的空气、舒适的温度、还有水 We've got breathable air, it's a pleasant temperature, and there is water.
即使是在我们的太阳系里还找不到象地球这样的行星 And even in our own solar system we don't see a lot of planets like that.
目前我们发现那种行星是些怪物 Right now the sort of planets we're discovering are kind of monsters.
换句话说是些很极端的行星 In other words, they're extremes.
那么有着岩石地壳、海洋和大量生物的地球 So is the Earth, with its rocky surface, oceans, and abundant life,
只是一个在宇宙中没有其它近亲的行星奇迹吗? just a planetary wonder with no close kin in the cosmos?
早期的日外行星的探索对此还没有答案 The early discoveries of alien planet have yet to answer that question,
但这些探索带来的合理的结论是过去所做的似乎是徒劳的 but they have brought legitimacy to what once seemed like a futile quest.
虽然许多人认为一定会有其它的地球 While many believe there had to be other worlds out there
存在于浩瀚的宇宙中 in the vastness of the Universe,
寻找它们被普遍认为是现在的科学做不到的 locating them was widely considered beyond the reach of modern science.
仅仅在几十年前 Only a few decades ago,
一位天文学家搜寻到了所谓的“日外行星” an astronomer hunting for these so-called“extrasolar planets”,
就被当作搜寻到UFO那样议论 was taken about as seriously as someone searching for UFOs.
搜寻行星开始于上世纪八、九十年代 The search for planets, as it started in the 1980s and 1990s,
一直被认为是跳出了权威的科学常规 was considered off of the beaten track of standard science.
80年代早期天文学家格夫·马尔西的事业一无成就 In the early '80s, astronomer Geoff Marcy's career was going nowhere.
他研究恒星的磁场进入了死胡同 His research into the magnetic fields of stars had reached a dead end,
他开始质疑自己的科学能力 and he was beginning to question his own abilities as a scientist.
当我第一次开始考虑搜寻行星时 When I first began thinking about looking for planets,
还处在自己认为事业已经结束了的时候 it was in a time in my career when I thought it was over.
我想..自己作为科学家已经没有希望了 I thought there were... There's no hope for me as a scientist, and I thought
我想熄灭怒火最好的一击 the best shot I had going out in flames
就是尝试大家都不会从事的实验... was to try an experiment that everybody thought would never work...
也就是去寻找其它恒星周围的行星 Namely, looking for planets around other stars.
大多数人认为我们我们永远都找不到哪怕是一颗行星 And most people thought we would never find any planets.
在格夫·马尔西之前 他的合作者保罗·巴特勒 Before Geoff Marcy, his collaborator, Paul Butler,
还有世界各地的少数天文学拓荒者 and a handful of pioneering astronomers around the globe
已经开始搜寻日外行星了 could begin the search for alien planets,
他们必须先完善搜寻的方法 they had to first perfect methods for finding them.
恒星很容易通过传统的望远镜找到 Stars are easy to locate using conventional telescopes,
但是找到行星需要一些技巧和恒心 but to find a planet takes some ingenuity and patience.
不同于恒星、他们在轨道上运转行星很小、发出的光很弱 Unlike the stars they orbit, planets are small and emit very little light.
即使是我们太阳系里的巨人--木星 Even the giant of our solar system, Jupiter,
也比太阳小1000倍 is a thousand times less massive than the Sun
发出的光要弱100亿倍 and 10 billion times fainter.
拍摄恒星周围的行星的一个巨大的困难是 A huge difficulty in taking a picture of a planet around a star is that
行星相对恒星是非常非常地暗淡 the planet is extremely, extremely faint compared to the star.
恒星明亮到几乎将非常非常 The star is so bright it almost completely obscures
暗淡的行星完全遮蔽 the much, much dimmer planet.
被恒星的光芒遮蔽了行星搜寻者意识到 Blinded by starlight, planet hunters realized
即使不能直接看到行星 that even if they couldn't see a planet directly,
但还是能够发现行星在运行时 they should still be able to detect its gravitational effect
对恒星的引力作用 on the star it orbits.
一颗没有行星的恒星应该平滑地在太空中通过 A star with no planets should drift smoothly through the sky,
而带有行星的恒星应该暴露出引力的摆动 while one with planets should exhibit a telltale gravitational wobble.
我们经常说行星围绕着太阳或恒星运转 We often say that planets orbit the sun or other stars,
但这并不完全属实:行星和恒星是围绕着 but that's not exactly true: the planets and the stars
它们共同的质量中心即重心运转的 orbit their common center of mass or center of gravity.
而这个重心不是在它们之间的中间 And this center of mass isn't halfway between them.
就象是跷跷板 质量较大的物体 Just like on a seesaw, the more massive object
必定靠近重心这样才能平衡整个系统 must be closer to the center of mass to bring balance to the system.
那么来看一下太阳和木星 So consider the Sun and Jupiter,
太阳的质量要比木星大1000倍 The Sun is about a thousand times more massive than Jupiter.
因此太阳在这、支点或平衡点在这 So the Sun is here, the fulcrum or balancing point is there,
木星距离这点要远1000倍 and Jupiter is way out here a thousand times farther away.
在太空里这就意味着 In space, this means that
行星围绕重心勾勒出大的轨道 planets trace out large orbits around the center of mass,
而恒星的轨道要小得多得多但还是能够被发现 while stars make much smaller but still detectable orbits.
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事实上它们是围绕共同的重心在运转 in fact, they're orbiting their common center of mass,
因此行星是在相对较大的轨道上运行 so the planet moves in a relatively large orbit,
而恒星也在运行 但是在很小的轨道上运行 but the star also moves, but in a much smaller orbit.
所以恒星的运行只有很小一点而行星的运行就要大许多 So the star moves only a little bit, and the planet moves a lot.
我对天文学有点独特的业余爱好 I have a somewhat unusual hobby for an astronomer.
我跳肚子舞和耍火把 I'm a belly dancer and fire performer.
然而结论是：舞动火把 But it turns out that spinning fire
是模拟行星的运行的好方法 is a great way of simulating the motion of a planet.
你施加在锁链上的离心运动 The centrifugal motion of your fire on the chain
与行星在引力作用下的运动非常相似 is very similar to the motion of a planet under gravity.
我手腕上的光代表恒星 The light on my wrist represents the star,
旋转的火盏代表行星 and the spinning ball of fire around that is a planet,
就象大家看到的那样火球划出大圆圈 and as you can see, the ball of fire draws out a large circle,
而我的手腕只在里面画出很小的圆圈 and my wrist is drawing out a smaller circle inside it.
通过这个星光的细小的晃动 It's this tiny wobble of starlight
科学家就可以找到日外行星 that scientists use to find extrasolar planets.
然而甚至这个晃动都无法被察觉除非是通过多普勒效应 But even this wobble would be undetectable if it wasn't for the doppler effect,
事实上朝你移动过来的物体发出的波长较短 the fact that wavelengths get shorter as the object emitting them moves toward you,
反之则较长 and longer as it moves away from you.
多普勒效应大家是很熟悉的只要听到过运行中的 The doppler effect is very familiar if you've ever heard a train
火车拉汽笛就知道了 going by blowing its whistle.
当然当火车朝你开来时、听到的声音会拉高 So when the train is coming toward you, you hear a high pitched whistle,
而当火车远离你时 and as the train recedes into the distance away from you,
听到的汽笛声的频率就会越来越低 you hear the pitch of the whistle get lower and lower in frequency.
有点象声波、光波会出现频率的变化 Just like sound waves, light waves appear to shift in frequency
随着物体发出的光向你过来还是远离而变化 as the object emitting them comes toward or away from you.
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远离我们的物体发出的光看上去有点偏红 light from an object moving away from you will look slightly redder.
只要光波改变其波长 When the light waves shift their wavelength
偏蓝、偏红、接着又偏蓝 toward the blue and toward the red and back toward the blue again
那就说明恒星在左右晃动这种晃动是极其细微的 as the star wobbles around, the shift is excruciatingly tiny,
但是这种光波的波长的变化对于我们来说 but it's that difference in the wavelength of the light waves coming at you,
就可以进行测量 that is what we measure and it's what allows us
就可以发现围绕着其它恒星运行的行星了 to detect planets around other stars.
利用这个多普勒技术 马西和巴特勒化了十多年的时间 Using this doppler technique, Marcy and Butler spent over a decade
坚持研究了周围120颗恒星的任何一点晃动的迹象 patiently studying 120 nearby stars for any sign of a wobble.
经过了11年我没有发现一颗行星一无所获 I went 11 years without finding a single planet, nothing,
对此没人感到惊讶 and no one was surprised by that, it seemed
所有的旁观者似乎都认为是合乎常理的是徒劳的、无聊的 logical to everybody else that it was a fruitless, frivolous,
观察其它行星甚至还可能是愚蠢的举动 maybe even lunatic exercise to look for planets of any sort.
但后来在1995年传来了惊人的宣布 But then, in 1995, came the surprise announcement
瑞士天文学家米歇尔·麦耶和Diedre Queloz from Swiss astronomers, Michel Mayor and Diedre Queloz,
发现有颗巨大的气体行星围绕着飞马座51运行 that they had discovered a gas giant planet circling the star 51 pegasi.
马西和巴特勒冲上立克天文台 Marcy and Butler rushed up to Lick Observatory
天文台坐落在北加州汉密尔顿山上 他们用自己的望远镜瞄准那颗星 on Northern California's Mount Hamilton to aim their own telescope at the star
观察能否证实瑞士同行的成果 and see if they could confirm the Swiss team's results.
耶！看、好极了 Yup, there it is. Looks beautiful.
保罗·巴特勒和我都感到很震惊看到了那颗恒星的晃动 Paul Butler and I were shocked to see that the wobble of the star was precisely
跟瑞士人说的一样 as the Swiss had said it was.
我记得从立克天文台开车离开汉密尔顿山时 And I remember driving off Mount Hamilton from Lick Observatory
完全沉默了 保罗·巴特勒就坐在我旁边 in complete silence, Paul Butler next to me.
我们知道第一颗日外行星已经被发现了 We knew that the first extrasolar planet had been discovered.
知道吗这是个非常激动的时刻 It was a very moving, you know, personally moving moment.
尽管这是个非凡的发现 Despite the monumental nature of the discovery,
这个、和今后所有将被发现的日外行星一样 this, like all future extrasolar planets,
是不会用希腊或罗马神的名字来命名了 wouldn't get the name of a Greek or Roman god.
它将根据其宿主星的天文登记名字来命名了 It would take the astronomical catalogue name of its parent star,
飞马座51 51 pegasi,
加上小写字母b and add to it a lower case B.
在标准的命名法里 如果发现同一颗恒星的第二颗行星 In the standard nomenclature, if a second planet was found around the same star,
就将加上小写字母c等等用字母来表示 it would get a lowercase C and so on through the alphabet.
这个名字对飞马座51b来说是唯一朴实的 Its name was the only thing unassuming about 51 pegasi b.
这个发现震撼了人们对行星认识的基础 The discovery shook the foundations of our understanding of planets.
1995年天文学家艾伦·博斯应邀对 In 1995, astrophysicist Alan Boss was asked to review a paper
两位瑞士天文学家宣布的 announcing the discovery by two Swiss astronomers
发现了第一颗日外行星进行评论 of the first planet orbiting an alien sun.
回顾这个文件 造成了我多少个不眠之夜 Reviewing this paper caused me a fair number of sleepless nights
因为他们的发现相当惊人 because it was pretty stunning what they had found.
吃惊是因为瑞士人声称已经发现了类似木星的行星 Stunning because the Swiss claimed to have found a Jupiter-like planet.
但是木星围绕太阳一圈需要12年 But where Jupiter orbits the sun in 12 years,
而这颗行星围绕宿主星快速运转一圈仅仅4天时间 this planet zipped around its star in only four days.
这也意味着这颗行星必定距离其中央的恒星是非常非常的近 And that also meant that the planet had to be much, much closer to its central star,
要比木星距离太阳近100倍 roughly a hundred times closer than Jupiter is.
这实在是难以理解 And that just was hard to understand.
木星在距离太阳5亿英里的轨道上运行 Jupiter orbits the sun at a comfortable distance of around half a billion miles.
飞马座51b好象是距离其宿主星500万英里 51 Pegasi b is more like 5 million miles from its star.
如果把它放到我们太阳系里来 If it were dropped into our own solar system,
这颗日外行星将会比水星更靠近太阳 this alien planet would orbit much closer to the sun than Mercury,
将是最内部的行星了 our innermost planet.
既然如此靠近宿主星 那么那颗行星简直是在受煎熬 Being so close to the star means that the planet is being literally fried.
从宿主星上来的辐射是难以置信的 The radiation from the star is incredible
相对来说我们的地球离开太阳较远 compared to what we experience here on Earth, relatively far from our sun.
所以这完全是个意想不到的发现 So this was a completely unexpected discovery.
行星不可能在那里形成 It was a planet that could not have formed there.
天文学家知道它不应该在那里 Astronomers knew it didn't belong there.
同样的道理 如果在中央公园中心发现一棵红杉 In the same way that if we found a giant redwood in the middle of Central park,
我们就知道它不应该在那里的 we would know that it didn't belong there.
你必须要问一下自己:它是怎么会到那里去的? You'd have to ask yourself,“How did it get there?”
那是天文学家在发现这些巨大的行星后 and that's what astronomers were asking themselves about
对自己提出的疑问 these giant planets that they were finding.
飞马座51b不光具有怪异的性质 51 Pegasi b wasn't just a freak of nature.
它是几十个所谓的“烤箱”或“高温木星”中的第一个 It was the first of dozens of so-called“roasters” or“hot Jupiters”
被发现几乎不可能那么近地靠近宿主星运行 to be discovered in seemingly impossible close-in orbits.
不可能是因为气体行星形成的公认的理论 Impossible because the accepted theory for how gas planets form
指出石块和冰块在围绕着年轻的恒星罗旋云里 suggests that rock and ice, in a disk surrounding a young star,
结合成固体的核接着气体进行合并 coalesces into a solid core that then accretes gas,
越来越大 growing larger and larger
一直到它将自己区域里的行星物质清理干净为止 until it has cleared out all the planet-forming material in its area.
这个过程只能发生在与恒星有足够距离的地方 This process can only occur at a distance far enough from the star
在那里温度要低到足以结成冰 where it's cold enough for ice to exist.
距离恒星这么近是不可能形成那么大的物体的 You can't form something that massive, that close into a star.
需要过冰点才能形成冰 It needs to form past the snow line where ice can form.
在我们的太阳系里木星所处的位置是 And in our solar system, that's about where Jupiter is:
他距离太阳比地球距离太阳大5倍 about five times further out from the Sun than the Earth.
所以在距离其宿主星这么近、这么热的地方 So how could a gas giant planet like 51 Pegasi b
怎么能够形成飞马座51b的呢? form so scorchingly close to its star?
我是有事会在半夜里醒来的人 I was one of these things where I woke up in the middle of the night, and
有个晚上我对自己说可能这意味着 one night I said to myself,“Maybe what this means
那个物体是从它原来形成的地方转移到那里的 is that this object had to have migrated inwards from where it originally formed.”
我认为我们现在已经了解了 We now, I think, have an understanding
那颗行星是在一派混沌中的形成过程 that planet formation is an almost chaotic process,
一些翻滚的小块、有许多小行星准行星形成 a sort of roll of the dice, with many planetesimals, wannabe planets forming,
强化、竞争、一种万有引力的争夺 Building up, and a competion, a sort of gravitational musical chairs, takes place
发生在行星之间 为了自己地盘的争夺 in which the planets compete for their own space.
在这个竞争中一些行星被抛离了太阳系 In this competion, some planets are flung out of the solar system
而有一些被抛向了中心 and some are tossed toward the center.
相信有些行星坠落到宿主星上燃烧了起来 It's believed some planets crash and burn on their parent star,
而其它一些则在很近但稳定的轨道上幸存了下来 while others survive in a close but stable orbit.
这些幸存者就是热的木星 These survivors are the hot Jupiters.
发现了围绕飞马座51的热的木星 The discovery of the hot Jupiter circling 51 Pegasi
让行星搜寻者杰夫·马西和保罗·巴特勒 sent planet hunters Geoff Marcy and Paul Butler
回过头来分析他们过去十年里收集的数据 back to analyze the data they'd been collecting for the past decade.
他们的团队一直在期待发生由大行星引起的长期晃动 Their team had been looking for the expected long-term wobbles caused by a giant planet.
我们突然意识到应该用稍微不同的方法来分析自己的数据 We ourselves suddenly realized we should analyze our data
寻找那些短周期的行星 in a slightly different way, look for the shorter period planets, not just
不只是那些围绕宿主星运行较长周期的行星 planets that take a long time to go around their star.
这就让我们在现有的数据里发现 And that led us to discover within an existing data
那些行星已经被埋没了好多年了 all of these planets that had been buried there for years.
我回忆起那天就象是昨天一样 I remember the day like it was yesterday,
1995年12月30日 December 30, 1995,
上午8:00 电话响了 and at 8:00 a.m. the phone rings.
一接听是保罗·巴特勒 I pick it up, it's Paul Butler,
我的王牌合作者至今已经合作20个年头了 my ace collaborator for 20 years now,
保罗对我说：“杰夫、快过来” and Paul just said,“Jeff, come over here.”
所以、当然啦我立刻跳上车一直开到这个了不起的办公室 So, of course, I immediately got in my car. I drove right to this very office,
直接到这里坐下在加州大学伯克利分校的坎贝尔大厦里 right here where I'm sitting now, in Campbell Hall at UC Berkeley,
他让我看他的电脑屏幕 and he showed me his computer screen.
屏幕上清楚地出现了 And there on that screen was the unmistakable graph
室女座70上下晃动的图象 of the wobble of the star 70 Virginis
那颗星在上下来回晃动 going up and down, and up and down the star, wobbling to and fro,
这正是能够在我们的数据里想象得到的行星的签名 exactly as we had imagined a planet signature would look in our data.
所以那一刻我们两人的眼睛都睁得大大的 So that was the moment with both of our eyes opened this wide
我们知道我们已经发现了自己的第一颗行星... that we knew we had discovered our first planet...
第二颗行星已经被发现了 the second planet ever discovered.
室女座70b距离地球59光年 70 virginis b is 59 light-years from Earth,
在室女座里 in the constellation Virgo.
由于它的质量至少比木星大7倍 With a mass at least seven times larger than Jupiter,
这个行星马上被冠以在已知的宇宙中 this world immediately claimed the title
重量级行星中的冠军 as the planetary heavyweight of the known universe.
现在实际上它就在眼前就是那颗行星 Here right before our eyes, essentially, is a planet
7倍 可能比我们的木星大10倍 seven, maybe 10 times bigger than our own Jupiter,
直接告诉我们大自然创造的行星 telling us immediately that, yes, nature does make planets even bigger
要比太阳系里最大的行星还要大 than the largest ones we have here in the solar system.
它不是热的木星 Rather than a hot Jupiter,
这颗行星是第一颗新的日外行星种类叫做“偏心巨星” this planet was the first of a new class of alien worlds called“eccentric giants”
因为它们有偏心狭长的轨道 because of their eccentric or elongated orbits.
室女座70b的远端距离宿主星6300万英里 70 Virginis b swings out as far as 63 million miles from its star
近端只有2700万英里 and passes as close as 27 million miles.
这颗围绕室女座70的行星的可怕方面 The frightening aspect of the planet around 70 Virginis
是我们大家从小学习就已经形成的概念 is that we all grew up in kindergarten learning
即行星以近乎圆形的轨道围绕太阳运转 that planets go around the sun in nearly circular orbits,
那么世界上有这种行星围绕其宿主星 So what in the world is a planet doing going around its star
在这么长的古怪的轨道运行的吗? in one of these elongated, wacky orbits?
首次发现的两颗围绕其宿主星的行星 Already the first two planets discovered around alien suns
已经向人们对行星的运行的认识发起了挑战 were challenging our view of how planets should behave.
在接下来的十年里的进一步探索显示出 Further discoveries over the next decade would show
偏心轨道在宇宙中是很普遍的现象 that eccentric orbits are common in the universe,
而我们太阳系里的圆形轨道似乎倒是很罕见的 while the circular orbits of our solar system seem to be rare.
这让人有点尴尬 坦率说 It's embarrassing, frankly, when you think about
这是我们人类自己想象的行星围绕恒星的运行规律 how we humans imagined planets would orbit other stars,
是普遍的现象、是它们具有的特性在猜测 how common they would be, what properties they would have. Guess what?
我们在想象那些行星看上去 We imagined that those planets would look
就象是在围绕着我们的太阳运行 just like the planets that orbit our Sun,
回想起来真是目光短浅 extraordinarily nearsighted in retrospect.
对于科学家来说我作为当事人之一感到很尴尬 And for a scientist, I find it embarrassing that I was a party to this.
但事实上我们已经认识到了日外行星 But, in fact, what we've learned is that planets around other stars are
和我们太阳系里的行星非常不同 remarkably different from the representatives we have around our Sun.
从90年代开始行星搜寻的重大改变 The planet-hunting revolution that began in the 1990s
同样也彻底改变了行星在宇宙中是很稀有的概念 has also obliterated any notion that planets are rare in the universe.
随着日外行星数量的不断增加 With an ever-growing catalogue of alien planets,
天文学家们现在正在努力全面研究 astronomers are now trying to learn all they can
已经发现的200多颗行星 about the more than 200 worlds they have already discovered.
杰夫·马西和其他天文学家利用多普勒技术 The doppler technique used by Geoff Marcy and other astronomers
来确定所发现的行星的质量 tells them the mass of the planet they found,
但无法确定其大小 but it doesn't tell them the size.
要搞明白日外行星的大小需要碰运气 To figure out just how big an alien planet is requires a bit of good luck.
行星的轨道必须是这样 The orbit of the planet has to be aligned in such a way
即从地球上能看到它直接经过它的宿主星 that from Earth, we can see it pass directly in front of its star.
这叫做“凌日” This is called“transiting”.
在行星经过时 测量恒星亮毒的变化 By measuring how much the starlight dims during this transit,
天文学家实际上就可以确定它的大小了 astronomers can actually determine the size of the planet.
2007年秋季天文学家在观察 In the fall of 2007, astronomers were watching
一颗叫做Tres-4的热木星经过它的宿主星 when a hot Jupiter called“Tres-4” transited its star.
这颗行星的质量和木星差不多 The planet was about the same mass as Jupiter
所以其大小也应该差不多 and, therefore, should have been roughly the same size.
但是天文学家得到了一个意外的发现 But astronomers were in for a surprise.
结果Tres-4的个头几乎是木星的两倍 Tres-4 turned out to be almost twice as big as Jupiter.
事实上 这是迄今为止发现的最大的行星 It was, in fact, the largest planet ever discovered,
有点象服了激素的木星 sort of, a Jupiter on steroids.
某些日外行星真是虚胖 Some of these extrasolar planets are
{\c they're really expanded in size.
我们认为其中的原因是 And we think that the reason why that's happening
因为它们的中心有个热源 is because they have an internal source of heat,
行星的内部压力升高、造成了体积膨胀 which is raising the pressure inside the planet, causing it to expand.
这和火车的蒸汽锅炉非常相象 That's very similar to a steam boiler on a steam train.
在蒸汽锅炉里 里面有水通过热源得到加热 In a steam boiler, you have water, which is being heated by a heat source.
水变成了蒸汽、压力升高 That water is turning to steam, the pressure is increasing
就引起锅炉的活塞移动、伸展 and that's causing the piston of the boiler to move out, to expand.
假如没有气体的膨胀 If you didn't have the gases' ability to expand,
{\c
我们就爬不上这座山 we wouldn't be climbing up this mountain.
虽然内部的加热可能是所谓的“蓬松的木星”的起因 While internal heating is the likely cause of the so-called“fluffy Jupiters”
但是这个日外行星的情况还是非常陌生的 something much stranger is happening on this alien world.
在日外行星的领域里 In the field of extrasolar planets,
似乎每一个新发现都会创造科学思维的新世界 it seems each new discovery creates a brand-new world of scientific intrigue.
在亚利桑那大学 At the university of Arizona,
行星学家Adam Showman在思考其它行星的天气 planetary scientist Adam Showman ponders the weather on other planets.
最近 Showman帮助生成了有史以来 Recently, Showman helped generate the first ever forecast
第一个日外行星的天气预报 for a planet beyond our solar system.
他发现那里的天气真的与那个行星相配 And what he found was weather truly befitting an alien world.
我们认为那里的风速大概是每小时6000英里 We think that the winds are probably about 6,000 miles per hour,
可能还不止 possibly even more.
这和我们太阳系里任何一颗行星的风速形成了巨大的反差 This is huge compared to the wind speed on any planet in our solar system.
这是HD 189733 b This is HD 189733 b.
是颗热木星、距离地球60多光年 It's a hot Jupiter, more than 60 light-years from Earth.
围绕其宿主星运转一周两天多一点时间 That races around its sunlike star in a little over two days,
距离宿主星只有300万英里 at a distance of only three million miles.
从370万亿英里外 怎样才能预测那颗行星上的天气呢? How is it possible to divine the weather on a planet 370 trillion miles away?
首先必须测到行星的温度 First, you have to take the planet's temperature.
科学家知道因为行星太靠近其宿主星了 Scientists knew that since the planet orbits so close to its star,
它将会被潮汐锁定 it would be tidally locked,
引力效应将会造成固定的一面 a gravitational effect that would cause it to show the same
始终对着宿主星 face to the star at all times.
一面始终沐浴在宿主星的炽热的阳光下 One side would always be bathed in the burning hot light of the alien sun,
而另外一面则隐蔽在永久的黑暗中 while the other would be cloaked in perpetual darkness.
假如那些行星上没有风 那么就意味着 If there was no wind on these planets, then that would mean
光照面会非常非常的热 that the dayside would then be very, very hot
而阴暗面则非常非常的冷 and the night side would be very, very cold.
在2007年春天科学家利用史匹哲太空望远镜 In the spring of 2007, scientists used the Spitzer space telescope,
可以观察到与热相连的红外线波长 which sees in infrared wavelengths associated with heat
生成一张行星正反两面 to generate a crude map of the temperature
粗糙的温度图象 on both the day and nightside of the planet.
现在大家看到的是第一张日外行星的全景图象 You are actually looking at the first map of any kind made of an alien world.
图象显示行星的光照面 What the map shows is that the dayside of the planet
{\c
一点都不奇怪 它离宿主星太近了 no surprise, given how close the planet orbits to its star.
令人吃惊的是 What was surprising was how hot
行星的阴暗面的温度 the nightside of the planet turned out to be.
尽管终日不见阳光 但温度却高达1000度 Despite being in total darkness, it swelters at around a thousand degrees.
显然有什么通过行星的大气层在分配着温度 Clearly, something was distributing heat throughout the planet's atmosphere,
将光照面的热能带到行星的另一面 carrying thermal energy from the dayside, clear around the other side of the planet.
根据掌握的太阳系里的气象知识 From his knowledge of weather in our own solar system,
Showman知道罪魁祸首是什么 Showman knew what the culprit was.
他通过计算 得出这颗日外行星 He ran the numbers, and that's when he figured out
存在规模空前的极速风暴 that this alien world had jet streams of unprecedented magnitude.
其每小时6000英里的狂风让太阳系里的所有风暴都是小巫见大巫了 Their 6,000 mile per hour winds dwarf anything in our own solar system.
地球上的风实际上是太阳系里最慢的 Earth, actually, has the slowest speeds of any planet in our solar system,
标准速度为每小时20英里 with a typical speed of about 20 miles per hour.
太阳系里的巨大的气体行星上的风 The gas giants in our solar system
其实要比地球上的风快一点 actually have somewhat faster winds than the Earth
主要是因为其表面没有摩擦来降低风速 simply because there's no surface to have friction to slow down the winds.
例如 在木星和土星上风速每小时有几百英里 On Jupiter and Saturn, for example, the winds are a few hundred miles per hour.
所以它们还是要比那些热木星 So they're still about almost a factor of 10 lower
低一个小数点 than on these hot Jupiters.
热木星上的天气可能很极端 The weather on hot Jupiters may be extreme,
然而另一个等级的日外行星即偏心巨星的天气预报 but the forecast for another class of alien planets,
是为灾难大片特制的. the“Eccentric Giants”, is tailor-made for a disaster movie.
这是HD 80606 b This is HD 80606 b
大概距离地球200光年 a gas-giant planet located roughly 200 light-years from Earth,
围绕着大熊座里一颗恒星 orbiting a star in the constellation Ursa Major.
这颗怪异星球的一年相当于地球的111天 A year on this bizarre world lasts 111 days,
它是已知的轨道最偏心的行星 and it has the most eccentric orbit of any known planet.
由于轨道近似圆形 With its nearly circular orbit,
地球相对太阳的距离一年里变化较少 Earth's distance from the Sun changes relatively little throughout the year,
变化只有400万英里左右 varying by only about four million miles.
然而在HD 80606 b上 一年里 But during its year, HD 80606 b
与其宿主星近的时候有300万英里 comes as close as three million miles to its sun
远的时候达到7800万英里 and as far as 78 million,
相差有7500英里 a difference of 75 million miles.
荒唐的轨道导致完全荒唐的天气 Its crazy orbit leads to completely crazy weather.
它的温度在几个小时里几百度 The planet heats up by hundreds and hundreds
几百度地上升 of degrees in a matter of a few hours,
就完全造成了可怕的风暴 and that drives just absolutely tremendous storms.
由于它近距离地在其宿主星旁摇晃 As the planet swings in close to its star,
宿主星可怕地在空中变得越来越大 the alien sun looms ever larger in the sky.
因此在行星的一面有巨大的热量 And so you get a huge amount of heating on one side of the planet,
而另一面则是黑暗 the other side of the planet is in the night.
是什么引起剧烈的风暴的呢? What that does is it drives an intense storm.
通常行星的两面存在冲击波 It's basically a shockwave around both sides of the planet
以超音速喷射的速度运动 that is moving roughly at the speed of a supersonic jet.
这个炙热的风暴急速绕星球一周只需12个小时 This fiery hurricane rips around the planet in only 12 hours.
随着冲击波的慢慢消亡 As the shockwave slowly dies down,
过热的大气层翻腾形成巨大的气旋 the superheated atmosphere churns into a giant vortex
吞没了整整半个星球 that engulfs an entire hemisphere,
形成巨大的红斑 a sort of greater Red Spot.
随着行星远离其炽热的宿主星 As the planet moves away from the heat of its Star,
风暴逐渐丧失其能量和强度 the storm gradually loses energy and intensity.
然而在这个偏心巨星上平静从来不会持续很久 But on this eccentric giant, the calm never lasts for long.
每隔111天 冲击波重新燃起狂暴再次卷土重来 Every 111 days, the shockwave is reignited, and the violent cycle begins anew.
这要比我们太阳系里的所有风暴陌生得多 It's much stranger than anything that we have in our own Solar System.
如果你在那里 将会立刻被焚化 If you were there, you would be incinerated immediately
之前你会有点兴赏周边的环境 before you had a chance to really, sort of, groove on your surroundings.
宇宙似乎擅长于缔造怪异的世界 The Universe seems adept at creating strange worlds
即使是在最不可能的地方 even in the most unlikely of places.
这是颗脉冲星 This is a pulsar,
迅速旋转的奇怪的星体叫做“中子星” a rapidly spinning variety of an exotic stellar object called a“neutron star.”
中子星是巨大的恒星爆炸成 Neutron stars are the remnants left behind
超新星后的残留部分 after a massive Star explodes in a Supernova.
没人会预料到能发现行星 No one expected to find planets
在如此恶劣的宇宙环境中运行 circling in such a treacherous cosmic neighborhood.
我做梦都没想到 我们什么时候会在一颗行星围绕中子星运行 Never in my wildest dreams, did I think we would ever find planets orbiting a neutron star, a pulsar.
我是说毕竟中子星是超新星爆炸形成的 I mean, after all, neutron stars are formed as a result of Supernova explosions,
在那里恒星都炸飞了 where the Star just blows up.
因此可以确定 已经在那里的所有行星 So, certainly any planets that might have been there to begin with
都已经吹跑了 would have been blown away.
然而在90年代早期 And yet, in the early 1990s,
天文学家发现有两颗岩石行星围绕着一颗脉冲星 astronomers discovered two rocky planets around a pulsar,
距离地球有7000万亿英里 7,000 trillion miles from Earth.
事实上他们的发现早于飞马座51b Their discovery, in fact, predates 51 Pegasi b,
通过技术他们有史以来第一次发现了日外行星,但是因为它们围绕如此怪异的恒星运行 making them technically the first alien worlds ever detected. But since they orbit such strange stars,
许多天文学家认为脉冲星的行星会自成体系 many astronomers consider pulsar planets to be in a category of their own.
脉冲星的行星非常有趣 The pulsar planets were very interesting.
其实它们的质量很小 They're actually very low in mass and
比地球的质量小很多 more similar to the Earth's mass.
它们形成了一个有趣的 与众不同的行星家族 They form an interesting, exotic classification or a family of planets,
但是一点都不是主流 but it's by no means the mainstream.
然而大多数行星是和其宿主星一起 While most planets are believed to have formed out of
在同一个气体和尘埃的圆盘上形成的 the same disc of gas and dust as their parent stars,
显然 这些脉冲星的行星是以另外一种方式形成的 clearly, these pulsar planets formed a different way.
已经发现的行星必定是在超新星爆炸后形成的 The planets that have been found must have formed after the supernova explosion.
真是奇怪 And that's really bizarre
因为我们以为那里所有的东西都已经吹跑了 because we would think that all of the material was blown away,
但是显然一些碎片必然是以某种方式一直在圆盘里 but apparently, some of that debris must have somehow been in a disc,
圆盘的碎片结合成了行星 and parts of that disc coalesced into planets.
而这非常出人意料 But that's extremely surprising.
我不知道有谁真的明白这个过程 I don't know that anyone really understands that process yet.
尽管脉冲星的行星被认为具有岩石的地壳 Although the pulsar planets are believed to have rocky surfaces,
然而它们不可能成为生命的舞台 it's unlikely they would be a platform for life,
谁去都会折寿的 and any visit by humans would be short-lived.
由于脉冲星不停地旋转 As the pulsar rotates,
从它的两极发出集中的带电粒子束 it emits well-focused beams of charged particles from its poles,
产生可怕的旋转辐射束 creating a rotating spotlight of horrific radiation.
呆在脉冲星的行星上是个非常危险的主张 Standing on a pulsar planet would be a very dangerous proposition.
会有高能辐射包围你 There would be high energy radiation all around you,
就是粒子和波的冲击 just an onslaught of particles and waves, and
辐射场强到 the radiation field would be so strong that
可能会摧毁你的身体组织 it would probably destroy your living tissue
肯定会很快引起癌变 and it would certainly cause cancer and mutations very quickly,
大概会让你死亡 but it would probably kill you.
如果你真的倒霉或走运 我想如果你一定要死 If you are really unlucky, or lucky, I suppose, if you're gonna die anyway,
倒不如死得壮观些... might as well die in a spectacular way...
接受脉冲星的光束吧因此每次旋转 you would be in the beam of the pulsar. So, every rotation,
光束会一闪而过 你将看到这个难以置信的灯塔 the beam would flash past you and you would see this incredibly bright beacon,
就象一座很近的灯塔在你脸上一闪而过 like a lighthouse really close to you, just flashing in your face.
这不是一个友好的环境根本不是 It would not be a very hospitable environment. No way.
虽然脉冲星不可能是逗留的好地方 While the pulsar planets might not be nice places to visit,
但是它们已经告诉了我们行星在宇宙中形成的基本的情况 they have taught us something fundamental about planet formation in the universe.
这些围绕着中子星的可怕的行星已经告诉我们 These planets, weird planets, around the neutron star have taught us that
行星的形成似乎相对比较容易 planetary formation appears to be relatively easy.
引力似乎喜欢将物体拉到一块 Gravity appears to like to pull stuff together
只要在特定的区域里有足够的东西 when there's enough stuff in a given region.
只要大自然如此擅长制造行星即使是在困难的条件下 If nature is so good at making planets, even under difficult circumstances,
那么宇宙中布满行星的概率还是很高的 then the odds are fairly high that the universe is full of planets,
宇宙中到处都会出现 and that somewhere out there in the cosmos,
其它地球正等着被发现 other Earths are waiting to be discovered.
然而真是这种情况那么那些地球究竟在哪里? But if that's the case, then where are the Earths?
为什么我们还没有找到呢? Why haven't we found them yet?
90年代末发现的第一颗行星是巨大的行星 The first planets that were found in the late 1990s were massive planets,
是地球质量的300倍 300 times the mass of our Earth.
最早发现最大的巨星实在是不奇怪 And it's really not a surprise that we found the most massive ones first.
就象我身后的大红杉树 Like the giant Redwood trees behind me,
从远处最容易被看到 they were the easiest to see from the enormous distances that we were looking.
所以一旦找到我们就会说：“啊！这有一颗巨大的行星 So when we find stars, where we say,“ah, there's just one
一棵大红杉树” single massive planet, one giant Redwood”
可以肯定这是不对的几乎可以肯定 that's almost certain to not be true. There almost certainly
围绕着恒星有一大群行星、小行星还有彗星 a forest of planets and asteroids and comets also orbiting that star.
随着天文学家们继续细查日外太阳系 As astronomers continue to scrutinize alien solar systems,
正在日益接近找到类地行星 they are edging ever closer to finding Earth-like planets.
这是红矮星格雷司436 b This is Gliese 436 b.
是颗行星、质量大约是地球的20倍 It's a world, roughly 20 times the mass of Earth,
质量和大小相当于海王星 similar in mass and size to Neptune.
在30光年以外的狮子星座里 It orbits a star 30 light-years away in the constellation Leo.
对格雷司436 我非常激动我几乎跳了起来 I'm so excited about Gliese 436. I'm almost jumping out of my clothes.
它是飞马座51以来最重大的发现 It's the most important discovery since 51 Pegasi,
可能还要重要 maybe even more important.
让杰夫·马西如此兴奋的是 What has Geoff Marcy so excited
发现这颗行星的密度是每立方厘米2.1克 is that this planet was found to have a density of 2.1 grams per cubic centimeter.
这意味着什么?是个了不起的数字 What does that mean? it's a spectacular number,
因为每个小学生都知道 because every schoolchild knows that
水的密度是每立方厘米1克 the density of water is one gram per cubic centimeter,
我们同样知道从街上随便拾起来的石块 and we also know that rocks that you pick up on the street,
我们地球的密度 例如这石块 the density of our Earth, for example, as a rock,
每立方厘米大约为5克 is about five grams per cubic centimeter.
因此 这颗行星 围绕着格雷司436 And therefore, this planet, around 436,
是石头和水的混合体 is composed of a mixture of rock and water.
由石头和水组成的行星听起来象地球 A planet made of rock and water sounds tantalizingly Earth-like,
但格雷司436 b的水太多 but gliese 436 b has so much water
根本就不会有陆地 that there would be no landmasses exposed at all.
你不会想去那个水世界游泳的吧 And you wouldn't wanna take a swim in the oceans of this watery alien world.
可能其表面有层液态水 There may be a layer of liquid water on the surface,
但是下面的东西就有点神秘了 but below that, things begin to get a little weird.
有如此多的水 There's so much water
水分子很轻的 that the sheer gravitational force
引力将向中心挤压 of the water molecules pressing down toward the center
将水紧紧地挤压在一起 will crush the water so tightly
水分子将相互紧挨着 that the water molecules are almost touching each other.
这是种很奇怪的水--事实上即使它不冷我们也称它为“冰” It's a very odd type of water. In fact, we call it“ice” even though it's not cold
因为水分子将被排列组合成冰的结构 because the water molecules will be arranged
但是仅仅是因为高压 in a structure like ice, but only due to its high pressure.
显然格雷司436 b不完全是类地行星 Clearly, gliese 436 b isn't quite an Earth-like planet,
那么这颗日外行星是什么呢? but what about this alien world?
什么样的行星才是真正的类地行星呢? What would make an alien planet truly Earth-like?
应该是主要由岩石构成 It should be made primarily of rock
有充分的水组成的海洋 with enough water for oceans,
但水又不能太多、陆地不能完全被淹没 but not so much water that the land masses are completely submerged.
也必须在它的恒星系里是适宜居住的地方 It would also have to be in its star's habitable zone.
适宜居住的典型的概念是 The typical idea for a habitable zone
它与恒星的距离能够在其 is the range of distances from a star where an Earth-like planet
表面存在液态水 could have liquid water at its surface.
这个概念就是如果将地球推近点 The idea would be that if you took Earth and pushed it in too far,
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而如果将地球推远点 or if you took the Earth and pushed it out too far,
海洋将通通接成冰也不利于生存 the oceans would all freeze, and that's bad for life.
在我们的太阳系里 In our own solar system,
适宜居住的区域是从火星的轨道 the habitable zone ranges from Mars' orbit
到金星的轨道之间 into as close as to where Venus orbits.
然而日外太阳系里的可居住区域各不相同 But the habitable zone in alien solar systems varies
有赖于其宿主星的温度有多高 depending on how hot the star is.
当前我们找到可居住的类地行星的最大希望 Currently, our best hope for finding habitable Earth-like planets
是针对相对较冷、较暗的恒星进行调查 is to look around cool, dim stars
此类恒星叫做“红矮星”即“中矮星” called“red dwarfs” or“m dwarfs.”
中矮星本身是种很特殊的恒星 The m dwarfs themselves are very special stars.
如果我们的太阳是100W的灯泡的话 So our sun might be 100-watt lightbulb,
中矮星大概就是10W的灯泡 an m dwarf is perhaps a 10-watt light bulb,
因此就意味着还是够温暖的 and so what that means is that to stay warm enough
会有液态的水而不是冰 so that you have liquid water, not ice,
但是还是不够热 行星要靠得很近才行 but still not too hot, you move the planet in much closer.
那些靠得很近的行星很容易通过手段被发现 And those close planets are easier for us to detect
因为它们拽拉宿主星会更强些 with our technique because they tug on the star a bit more.
其中一颗中矮星 格雷司876 One of these m dwarfs, called“Gliese 876”
已经发现至少有3颗行星 has been found to have at least three planets orbiting it.
其中两颗是气体巨星 Two of them are gas giants,
但是第三颗、格雷司876 d but the third, Gliese 876 d,
是到目前为止发现的最小的行星 is one of the smallest planets discovered so far,
大概是地球质量的6到7倍 at roughly six or seven times the mass of the Earth.
它也刚好处在其宿主星的可居住区的边缘 It's also just on the edge of its star's habitable zone.
它绕宿主星一圈只需要1.9天 The planet orbits in just 1.9 days around its host star,
但是因为宿主星的亮度很暗 but because the host star is so low in luminosity,
它所处的位置 可以想象得出可居住区域是什么样子 it puts it on the edge of what you might imagine a habitable zone to be.
会有一些地方 绕着行星背后一圈 There could be some region, a ring around the planet towards the backside
那里的温度刚好使得液态水存在 where the temperature's actually just right for liquid water to exist.
当它第一次被发现时 When it was first discovered,
科学家们高度称赞它是第一颗超级行星 scientists hailed this planet as the first of the super Earths.
是地球质量的7倍 Seven times the mass of the Earth
听起来很接近我们地球 sounds so close to the size of our Earth
怀疑它可能是颗岩石行星 that you wonder whether or not it's a rocky planet,
或许还有厚厚的大气层 maybe with a thick atmosphere.
然而现在 专家学者还是没有把握 But today, the experts are unsure
究竟是不是颗岩石大行星 whether this is a large, rocky planet at all.
格雷司876 b Like Gliese 436 b,
可能完全覆盖着致密水的海洋 it may be completely covered in an ocean of super dense water.
把它称为超级行星暗示着 To call it a“super Earth” is to suggest
我们已经找到了一颗地球亲密的堂兄了 that we've found a planet that's a close cousin of our Earth.
现在我宁愿它是个远房亲戚 I would now rather think of it as a distant cousin,
与地球不无关系 not unrelated to our Earth,
但是离得太远 其实 它更象是太阳系里的海王星 but far enough away, indeed, more like neptune
有个大的岩石核 in our own solar system, that has a big, rocky core,
但是包裹着水的外壳 but surrounded by a big envelope of water.
因此发现类地行星的竞赛在继续进行 So the race continues to discover the first truly
在亚利桑那大学 Earth-like planet.
天文学家莱尔德·克洛斯正期待 At the university of Arizona, astronomer laird close is hoping to capture
获得第一颗日外地球的照片 the first picture of an alien Earth.
然而要达到这个目标 望远镜技术需要有个大的飞跃 But to do that will take a giant leap in telescope technology.
这里是斯图尔特天文镜面实验室 Here at the steward observatory mirror lab,
在大学足球场看台 in a cavernous space underneath the bleachers
下面的大空间里 of the university's football stadium,
工程师们正在制作下一代的天文望远镜 engineers are working on the next generation of supertelescopes.
这是迄今为止最大的镜面 This is the largest mirror that's ever been made.
镜面直径8.4米 This mirror is 8.4 meters across,
然而这只是 but it's just 1/7th
巨型麦哲仑望远镜的7块镜面中的一块 of the size that's needed for the giant magellan telesce.
当把7块这样大小的镜面拼起来 And together, when combined with seven other mirrors like it
组合成巨型麦哲仑望远镜后 with the giant magellan telescope,
我们就能够直接看到 we will be able to actually directly image
日外行星 extrasolar planets and maybe even
甚至还可能看到日外类地行星了 Earth-like planets around alien suns.
预计会在2016年完成 Scheduled for completion in 2016,
这个望远镜拍到的会比哈勃太空望远镜拍到的 this telescope will be able to make images up to 10 times sharper
图象清晰10倍 than the hubble space telescope.
美国航天局和欧洲航天局 Nasa and the European Space Agency
也正在进行几项任务 are also developing several missions
用太空望远镜 that will use space-based telescopes
来搜索我们的行星亲戚 to search the stars for our planetary kin.
这对人类来说 无法想象会有多么振奋 This will be incredibly exciting for humankind
不管那些小光点周围是否存在行星 to know whether or not around those little points of light
我们观察夜晚的星空 that we see in the night sky, whether there's Earth-like planets
不管那些恒星周围有没有类地行星 tied in an orbit around those stars.
随着技术的提高 As technology improves,
我们将会找到更象地球的行星 we're gonna be able to find planets that look much more like the Earth,
或许那些行星上会有生命存在 planets that, perhaps, have life on them,
甚至还可能存在森林、火车 and maybe even planets that have forests and steam trains.
天文学家们已经将自己的毕生奉献在这个事业中了 The astronomers who have dedicated their lives to this quest
大家都相信找到第一颗真正的类地行星 all believe it's only a matter of time before we find
唯一重要的就是时间 the first truly Earth-like planet.
我可以告诉你最让人激动的是 The most exciting thing I can tell you is that
我们现在经常发现 we are now routinely discovering,
普遍发现那种 commonly discovering planets
是地球质量5到10倍的行星 that are a mere five or 10 times the mass of our Earth.
我们不会满天空地去找行星 We're not quite to the point where we're finding Earths,
而是完全有目标的去找的 and that's where we really want to be.
我们在找和我们的地球家园 But we're finding planets that are ever so close
非常亲近的行星 to our home planet.
所以说其实一旦跨过最后的一道槛 So when we actually do cross that final threshold and do find evidence
找到存在可居住行星的证据 that there's a habitable planet out there,
那对人类来说将是个划时代的事件 this is gonna be a quite an epochal event for humanity.
然而大家不必过多地担心 People should not worry too much yet,
我们还没有发现任何的类地行星 that we haven't found any Earth-like planets, because, well,
因为很多努力正在往前进 a lot of effort is going into it right now,
我认为在未来的10年里会达到目标的 and i think it will be done in the next 10 years.
是啊 敬请期待 Yeah, stay tuned.
谢谢观赏 Thanks For Viewing