In the next 18 minutes, I'm going to take you on a journey. And it's a journey that you and I have been on for many years now, and it began some 50 years ago, when humans first stepped off our planet. And in those 50 years, not only did we literally, physically set foot on the moon, but we have dispatched robotic spacecraft to all the planets -- all eight of them -- and we have landed on asteroids, we have rendezvoused with comets, and, at this point in time, we have a spacecraft on its way to Pluto, the body formerly known as a planet. And all of these robotic missions are part of a bigger human journey: a voyage to understand something, to get a sense of our cosmic place, to understand something of our origins, and how Earth, our planet, and we, living on it, came to be.
在接下来的18分钟里,我会带大家 踏上一个你我都没停下脚步的旅程, 50多年前,人类首度迈出地球。 在这50年间,人类不仅迈向月球, 还向所有8个行星发送机器人, 我们的足迹遍布小行星,我们还同彗星有亲密接触, 现在,我们正有一个飞船驶向冥王星, 过去冥王星也被认作行星之一。 所有这些机器人探测计划都是人类征程的一部分: 一个为理解而出发的征程,为理解我们置身的宇宙, 为理解人类的起源,为理解地球、 和人类的发展。
And of all the places in the solar system that we might go to and search for answers to questions like this, there's Saturn. And we have been to Saturn before -- we visited Saturn in the early 1980s -- but our investigations of Saturn have become far more in-depth in detail since the Cassini spacecraft, traveling across interplanetary space for seven years, glided into orbit around Saturn in the summer of 2004, and became at that point the farthest robotic outpost that humanity had ever established around the Sun.
在太阳系中我们足迹可以遍及的各个角落 我们寻找答案, 人类曾登上过土星-- 早在上世纪80年代初-- 人类对土星的探索变得更加深入、透彻 自打7年前罗西尼号探测器遨游在星际间 2004年罗西尼正式进入土星轨道, 成为当时 人类在太阳系走的最远的探测器。
Now, the Saturn system is a rich planetary system. It offers mystery, scientific insight and obviously splendor beyond compare, and the investigation of this system has enormous cosmic reach. In fact, just studying the rings alone, we stand to learn a lot about the discs of stars and gas that we call the spiral galaxies. And here's a beautiful picture of the Andromeda Nebula, which is our closest, largest spiral galaxy to the Milky Way. And then, here's a beautiful composite of the Whirlpool Galaxy, taken by the Hubble Space Telescope.
现在,土星是一个丰饶的行星系统。 她的神秘感、她带给科学的新视角及她无与伦比的光环 带给宇宙探索无限的新发现。 光是研究她的光环,我们就学到很多 我们把那些星星的环状聚集体称为螺旋星系 这张令人惊艳的照片是仙女座星系 仙女座星系距地球最近,同时也是银河中最大的螺旋星系 这是哈伯太空望远镜拍摄的漩涡星系 一张美丽的图片
So the journey back to Saturn is really part of and is also a metaphor for a much larger human voyage to understand the interconnectedness of everything around us, and also how humans fit into that picture. And it pains me that I can't tell you all that we have learned with Cassini. I can't show you all the beautiful pictures that we've taken in the last two and a half years, because I simply don't have the time. So I'm going to concentrate on two of the most exciting stories that have emerged out of this major exploratory expedition that we are conducting around Saturn, and have been for the past two and a half years.
所以去土星的旅程实际上是--打个比方 人类征程的放大 要了解与周围万物的内在关联性 以及人类在其中的作用 不能向大家展示所有卡西尼传回的信息,我很难受 因为时间缘故 我无法向大家展示过去两年半拍摄的美丽照片 不过,我会着重于 过去两年半 探索土星旅程中 两个最激动人心的方面
Saturn is accompanied by a very large and diverse collection of moons. They range in size from a few kilometers across to as big across as the U.S. Most of the beautiful pictures we've taken of Saturn, in fact, show Saturn in accompaniment with some of its moons. Here's Saturn with Dione, and then, here's Saturn showing the rings edge-on, showing you just how vertically thin they are, with the moon Enceladus. Now, two of the 47 moons that Saturn has are standouts.
土星被一组庞大而多样的卫星所环绕 它们当中,有的仅几千米大,有的有美国从东南到北那么大 其实,最美丽的照片 是那些有卫星环绕的土星照片。这是一张土星和土卫四 这是一张土星光环侧向地球 这光环实际上纵向是很浅薄的,旁边是土卫二 土星47个卫星中有两个是很突出的
And those are Titan and Enceladus. Titan is Saturn's largest moon, and, until Cassini had arrived there, was the largest single expanse of unexplored terrain that we had remaining in our solar system. And it is a body that has long intrigued people who've watched the planets. It has a very large, thick atmosphere, and in fact, its surface environment was believed to be more like the environment we have here on the Earth, or at least had in the past, than any other body in the solar system. Its atmosphere is largely molecular nitrogen, like you are breathing here in this room, except that its atmosphere is suffused with simple organic materials like methane and propane and ethane. And these molecules high up in the atmosphere of Titan get broken down, and their products join together to make haze particles. This haze is ubiquitous. It's completely global and enveloping Titan. And that's why you cannot see down to the surface with our eyes in the visible region of the spectrum.
土卫六和土卫二。土卫六是土星最大的卫星 直到卡西尼进入其轨道 这是对太阳系未知领域的 又一次重大探索 对于研究行星的人这可是一个令人朝思暮想的形体 它有一个巨大、浑厚的大气 事实上它的气候 与地球大气非常接近 至少过去相较于其他行星来说是这样的 它的大气有分子态氮组成,就像我们现在这个房间一样 不过它的大气中充满 甲烷、丙烷和乙烷等有机材质 土卫六上这些分子含量很高 这些分子分解后形成烟雾 这些烟雾无处不在,弥漫于整个土卫六 在我们肉眼可辨识的范围内 其表面是不可见的
But these haze particles, it was surmised, before we got there with Cassini, over billions and billions of years, gently drifted down to the surface and coated the surface in a thick organic sludge. So like the equivalent, the Titan equivalent, of tar, or oil, or what -- we didn't know what. But this is what we suspected. And these molecules, especially methane and ethane, can be liquids at the surface temperatures of Titan. And so it turns out that methane is to Titan what water is to the Earth. It's a condensable in the atmosphere, and so recognizing this circumstance brought to the fore a whole world of bizarre possibilities. You can have methane clouds, OK, and above those clouds, you have this hundreds of kilometers of haze, which prevent any sunlight from getting to the surface. The temperature at the surface is some 350 degrees below zero Fahrenheit.
但这些雾气的存在不过是推测 在卡西尼探测的数亿年前 这些雾气悬浮于地表后附着其上 形成有机污垢 类似于地球上的焦油,或油什么的,我也不清楚 我们是这样推测的。这些分子 尤其是甲烷和乙烷,在土星地温下是液态的。 我们发现甲烷就是土星的水。 在大气里是可以凝缩的 这一发现 为许多稀奇古怪的设想提供了可能。土星有甲烷云层。 甲烷云层上有数百公里高的雾气层 光线无法穿透云层射向地面 土星地面气温仅为零下350华氏度
But despite that cold, you could have rain falling down on the surface of Titan. And doing on Titan what rain does on the Earth: it carves gullies; it forms rivers and cataracts; it can create canyons; it can pool in large basins and craters. It can wash the sludge off high mountain peaks and hills, down into the lowlands. So stop and think for a minute. Try to imagine what the surface of Titan might look like. It's dark. High noon on Titan is as dark as deep earth twilight on the Earth. It's cold, it's eerie, it's misty, it might be raining, and you might be standing on the shores of Lake Michigan brimming with paint thinner. (Laughter)
虽冷,但还有雨 就像地球一样,土星在雨的作用下形成溪谷河流 和大瀑布、峡谷、盆地和地坑。 雨洗净山顶的污垢 然后冲向地底。大家停下来想一想 土星的地表会是什么样子呢? 月光下的土星是黑暗的,就像黎明前的地球 此时寒冷、阴森、雾气缭绕 还有可能在下雨,想象站在雨中 面前是密歇根湖,闪闪发光
That is the view that we had of the surface of Titan before we got there with Cassini, and I can tell you that what we have found on Titan, though it is not the same in detail, is every bit as fascinating as that story is. And for us, it has been like -- the Cassini people -- it has been like a Jules Verne adventure come true. As I said, it has a thick, extensive atmosphere. This is a picture of Titan, backlit by the Sun, with the rings as a beautiful backdrop. And yet another moon there -- I don't even know which one it is. It's a very extensive atmosphere. We have instruments on Cassini which can see down to the surface through this atmosphere, and my camera system is one of them. And we have taken pictures like this. And what you see is bright and dark regions, and that's about as far as it got for us. It was so mystifying: we couldn't make out what we were seeing on Titan. When you look closer at this region, you start to see things like sinuous channels -- we didn't know. You see a few round things. This, we later found out, is, in fact, a crater, but there are very few craters on the surface of Titan, meaning it's a very young surface. And there are features that look tectonic. They look like they've been pulled apart. Whenever you see anything linear on a planet, it means there's been a fracture, like a fault. And so it's been tectonically altered.
在卡西尼问世前,我们是这样想象土星的 我们的发现,虽细节上有差异 但同样令人神往 对于我们来说,对热爱卡西尼的人来所 这就像凡尔纳的小说变成现实 正如我所说的,土星有一个厚重的大气 这张是土星在太阳的光辉下光环奕奕生彩的照片 这是另一个卫星 我也不清楚是哪一个。它的大气面积很大 卡西尼上的设备可以穿过大气看清土星地表 我的设备也在上面 我们的照片中有这样的 其中有光明和黑暗的区域,我们的设备也只能达到这个水平 这很神秘--我们怎样也无法弄清土星地表 仔细观察你会有所发现 比如蜿蜒的渠道,这是我们以前所不知的,你还能看到环状物 后来我们这是一个地坑 但土卫六上却没有几个 所以这个地表是新形成的 同时还有地质构造 有些似乎是被撕裂的 在任何行星上看到线形地质 就说明有断层 这里的地质结构被改变过
But we couldn't make sense of our images, until, six months after we got into orbit, an event occurred that many have regarded as the highlight of Cassini's investigation of Titan. And that was the deployment of the Huygens probe, the European-built Huygens probe that Cassini had carried for seven years across the solar system. We deployed it to the atmosphere of Titan, it took two and a half hours to descend, and it landed on the surface. And I just want to emphasize how significant an event this is. This is a device of human making, and it landed in the outer solar system for the first time in human history. It is so significant that, in my mind, this was an event that should have been celebrated with ticker tape parades in every city across the U.S. and Europe, and sadly, that wasn't the case. (Laughter).
但我们无法理解这些图片 直到6个月后卡西尼进入土星轨道 一个发现可以被称为 卡西尼土星征程的里程碑 这是惠更斯号探测器的投入使用 卡西尼携带的欧洲制造的惠更斯号 傲游了7年。我们将它步入土卫六大气中 经过两个半小时的降落,最终着陆与土卫六 我想强调一下其重要性 这是人造的设备 在人类历史上首次着陆与太阳系外 这对我很重要 我们应该在欧美用彩车 大肆庆祝 虽没实现 (笑)
It was significant for another reason. This is an international mission, and this event was celebrated in Europe, in Germany, and the celebratory presentations were given in English accents, and American accents, and German accents, and French and Italian and Dutch accents. It was a moving demonstration of what the words "united nations" are supposed to mean: a true union of nations joined together in a colossal effort for good. And, in this case, it was a massive undertaking to explore a planet, and to come to understand a planetary system that, for all of human history, had been unreachable, and now humans had actually touched it. So it was -- I mean, I'm getting goose bumps just talking about it. It was a tremendously emotional event, and it's something that I will personally never forget, and you shouldn't either. (Applause).
重大的原因还有一个,那就是,这是一次国际任务 在欧洲,德国,人们举国欢庆 庆祝演讲在英国 美国、德国、法国、意大利和荷兰进行 这是你个激动人心的对 “联合国”的定义 一个真正的各个国家参与的,致力于人类共同未来的联合体 这样,探索一颗行星是一个极大的任务 并且,实现探索了一个人类历史上不曾踏足的 行星系统 是多么一个壮举 一说的这儿,我都起鸡皮疙瘩了 这是几个激动人心的时刻 我会永远铭记,大家也应铭记在心 (鼓掌)
But anyway, the probe took measurements of the atmosphere on the way down, and it also took panoramic pictures. And I can't tell you what it was like to see the first pictures of Titan's surface from the probe. And this is what we saw. And it was a shocker, because it was everything we wanted those other pictures taken from orbit to be. It was an unambiguous pattern, a geological pattern. It's a dendritic drainage pattern that can be formed only by the flow of liquids. And you can follow these channels and you can see how they all converge. And they converge into this channel here, which drains into this region. You are looking at a shoreline. Was this a shoreline of fluids? We didn't know. But this is somewhat of a shoreline.
但是,探测器在着陆过程中收集了数据 拍摄了全景照片 那第一张土卫六地表的照片真的是无法形容的 它是这样的 挺让人震惊的,这就是我们期待已久的 轨道上的照片 这是一个清晰的、地理的图像 这种树枝状的格局只会是水流形成的 你可以在水道中航行 看看他们是如何覆盖地表的 水道进入这个流域后又注入那个地区 你看到的是滨线 是液态的吗?我们不得而知 但这是某种形态的滨线
This picture is taken at 16 kilometers. This is the picture taken at eight kilometers, OK? Again, the shoreline. Okay, now, 16 kilometers, eight kilometers -- this is roughly an airline altitude. If you were going to take an airplane trip across the U.S., you would be flying at these altitudes. So, this is the picture you would have at the window of Titanian Airlines as you fly across the surface of Titan. (Laughter)
这张照片是在16千米的高空拍摄的 这张是8千米。好,再看滨线 好,16千米,8千米-- 这大约就是在美国的 飞机飞行高度 这就是飞行在土卫六上的飞机 窗外的景色(笑)
And then finally, the probe came to rest on the surface, and I'm going to show you, ladies and gentlemen, the first picture ever taken from the surface of a moon in the outer solar system. And here is the horizon, OK? These are probably water ice pebbles, yes? (Applause). And obviously, it landed in one of these flat, dark regions and it didn't sink out of sight. So it wasn't fluid that we landed in. What the probe came down in was basically the Titan equivalent of a mud flat. This is an unconsolidated ground that is suffused with liquid methane. And it's probably the case that this material has washed off the highlands of Titan through these channels that we saw, and has drained over billions of years to fill in low-lying basins. And that is what the Huygens probe landed in.
最后,探测器着陆 女士们、先生们,我将向你们展示 首张太阳系外行星卫星地表照片 这是地平线 这些是小冰块 (鼓掌) 很明显,探测器着陆与平坦、黑暗的区域 探测器没有下沉消失。所以它没有落在水路上 实际上这是 土卫六版的泥巴地 这片疏松的土地上充满了液态的甲烷 大概这就是为何这些物质 冲下土卫六的高地 流下那些我们看过的水道 万年不变的注入低洼的盆地 惠更斯号就着陆于此
But still, there was no sign in our images, or even in the Huygens' images, of any large, open bodies of fluids. Where were they? It got even more puzzling when we found dunes. OK, so this is our movie of the equatorial region of Titan, showing these dunes. These are dunes that are 100 meters tall, separated by a few kilometers, and they go on for miles and miles and miles. There's hundreds, up to a 1,000 or 1,200 miles of dunes. This is the Saharan desert of Titan. It's obviously a place which is very dry, or you wouldn't get dunes.
但我们的照片中 惠更斯号传回的照片中还是没有一点水的迹象 水在哪儿呢?当我们发现沙丘的时候,这一切变得更加扑朔迷离。 这是我们土卫六赤道区域的影象 这些视频中的沙丘都有100多米高 每个相间几千米 它们延绵不绝 这是1000到1200公里长的沙丘 可以称得上是土卫六的撒哈拉 很明显,要是不干燥就不会有沙丘
So again, it got puzzling that there were no bodies of fluid, until finally, we saw lakes in the polar regions. And there is a lake scene in the south polar region of Titan. It's about the size of Lake Ontario. And then, only a week and a half ago, we flew over the north pole of Titan and found, again, we found a feature here the size of the Caspian Sea. So it seems that the liquids, for some reason we don't understand, or during at least this season, are apparently at the poles of Titan. And I think you would agree that we have found Titan is a remarkable, mystical place. It's exotic, it's alien, but yet strangely Earth-like, and having Earth-like geological formations and a tremendous geographical diversity, and is a fascinating world whose only rival in the solar system for complexity and richness is the Earth itself.
所以,让人费解的是没有水 但后来我们在两极地区找到湖泊 这是一张土卫六南极湖区的景致 大概有安大略湖那么大 就在10天前 探测器在土卫六北极上空飞行时 找到有里海那么大的图像 我们不解的是,那液体 在某些季节会出现在土卫六极地地区 你也会觉得土卫六 很奇妙、神秘。充满异域风情。但有处处与地球相似 有地球一样的地貌 以及繁多的地形 这个神奇的行星在太阳系里 唯一可以与之在复杂性和丰富性上相抗衡的只有地球
And so now we go onto Enceladus. Enceladus is a small moon, it's about a tenth the size of Titan. And you can see it here next to England, just to show you the size. This is not meant to be a threat. (Laughter). And Enceladus is very white, it's very bright, and its surface is obviously wrecked with fractures. It is a very geologically active body. But the mother lode of discoveries on Enceladus was found at the south pole -- and we're looking at the south pole here -- where we found this system of fractures. And they're a different color because they're a different composition. They are coated. These fractures are coated with organic materials. Moreover, this whole, entire region, the south polar region, has elevated temperatures. It's the hottest place on the planet, on the body. That's as bizarre as finding that the Antarctic on the Earth is hotter than the tropics.
再来看看土卫二。土卫二是个很小的星球 大有只有土卫六十分之一大,这是它和英国做比较 只是比较大小,不是地球安全威胁 (笑) 土卫二很白,很亮 其地表充满断裂层 土卫二地质活动活跃 但其南极上的母矿 --这是南极 我们在此发现地质断裂 这块儿颜色不一样是因为组成不同 这些断层上附着这有机物质 同时,着整个区域,南极区域 温度升高。是土卫二上温度最高的地区 这很怪,就像哪天地球上的南极变得比赤道地区还热
And then, when we took additional pictures, we discovered that from these fractures are issuing jets of fine, icy particles extending hundreds of miles into space. And when we color-code this image, to bring out the faint light levels, we see that these jets feed a plume that, in fact, we see, in other images, goes thousands of miles into the space above Enceladus. My team and I have examined images like this, and like this one, and have thought about the other results from Cassini. And we have arrived at the conclusion that these jets may be erupting from pockets of liquid water under the surface of Enceladus.
再看看其他照片 从这些断层中喷射出冰物质 喷向空中 经过图像处理呈现出的光线渐变 我们可以看到喷射出的冰状物形成羽毛形状 在其它图像中,有上千里 直入土卫二的空中 我和我的小组对图像进行分析 就像这张,还有其他卡西尼传回的照片 我们得出结论 这些喷出物可能是从小区域喷出的 土卫二地下的液体
So we have, possibly, liquid water, organic materials and excess heat. In other words, we have possibly stumbled upon the holy grail of modern day planetary exploration, or in other words, an environment that is potentially suitable for living organisms. And I don't think I need to tell you that the discovery of life elsewhere in our solar system, whether it be on Enceladus or elsewhere, would have enormous cultural and scientific implications. Because if we could demonstrate that genesis had occurred not once, but twice, independently, in our solar system, then that means, by inference, it has occurred a staggering number of times throughout the universe and its 13.7 billion year history.
可能是液体,有机物或余热 这是意外的发现 现代星系探索的圣杯 也就是另一个生命体可以存活的环境 不用我说,大家都知道在太阳系内其他行星 不管是土卫二还是其他什么地方 发现生命迹象 在文化和科技上是多么重大的啊 要是我们可以证明创世纪的存在 不知是一次,还是两次,在太阳系中其他星球 意味着,通过推断, 在宇宙137亿年的历史上不断发生过
Right now, Earth is the only planet still that we know is teeming with life. It is precious, it is unique, it is still, so far, the only home we've ever known. And if any of you were alert and coherent during the 1960s -- and we'd forgive you, if you weren't, OK -- you would remember this very famous picture taken by the Apollo 8 astronauts in 1968. It was the first time that Earth was imaged from space, and it had an enormous impact on our sense of place in the universe, and our sense of responsibility for the protection of our own planet.
现在,地球是我们唯一知道的充满生机的行星 是珍贵、独特的 同时也是我们唯一的家园 对于警觉思辨的人来说上世纪60年代 要不是那样的人也没关系 要是你还记得那令人难忘的 1968年阿波罗8号宇航员拍下的照片 那是首张从太空中拍下的地球照片 这张照片对我们行星的位置 以及保卫家园的责任感有了深刻冲击
Well, we on Cassini have taken an equivalent first, a picture that no human eye has ever seen before. It is a total eclipse of the Sun, seen from the other side of Saturn. And in this impossibly beautiful picture, you see the main rings backlit by the Sun, you see the refracted image of the Sun and you see this ring created, in fact, by the exhalations of Enceladus. But as if that weren't brilliant enough, we can spot, in this beautiful image, sight of our own planet, cradled in the arms of Saturn's rings.
可以说卡西尼第一条做到了 人类肉眼看不到的照片 这是土星另一面看到的日蚀 在这张没得令人窒息的照片中 那些光环被太阳的光辉点亮 这是太阳的折射成像 这些光环是土卫二的散发物 创造出来的 要是这些还不够美,那看看这些 我们行星的图片 被土星的光环所环抱
Now, there is something deeply moving about seeing ourselves from afar, and capturing the sight of our little, blue-ocean planet in the skies of other worlds. And that, and the perspective of ourselves that we gain from that, may be, in the end, the finest reward that we earn from this journey of discovery that started half a century ago. And thank you very much. (Applause)
从远处看我们的家园 是很感人的 在外太空 拍下我们海蓝的行星 也许这场长达半个世纪的探索 追中给我们的奖励是 对我们自己更深的认识 非常感谢 (鼓掌)