I'd like to take you on the epic quest of the Rosetta spacecraft. To escort and land the probe on a comet, this has been my passion for the past two years. In order to do that, I need to explain to you something about the origin of the solar system.
我想带你们进入罗塞塔号 史诗般的探险中去。 护送这个探测器在一颗彗星上着陆, 是我过去两年以来的热情所在。 为了实现这个目标, 我需要向你们解释 关于太阳系起源的一些东西。
When we go back four and a half billion years, there was a cloud of gas and dust. In the center of this cloud, our sun formed and ignited. Along with that, what we now know as planets, comets and asteroids formed. What then happened, according to theory, is that when the Earth had cooled down a bit after its formation, comets massively impacted the Earth and delivered water to Earth. They probably also delivered complex organic material to Earth, and that may have bootstrapped the emergence of life. You can compare this to having to solve a 250-piece puzzle and not a 2,000-piece puzzle.
让我们回到45亿年前, 有一个充满气体和灰尘的云团。 在这个云团的中心, 我们的太阳在那里形成并燃烧。 与此同时,那些现在被我们称为行星、 彗星和小行星的天体也形成了。 随后,根据理论, 在地球形成并且温度 开始降低了一些的时候, 彗星极大地影响了地球, 并向地球输送了水分。 它们可能还向地球输送了 复杂的有机物质, 而那有可能诱导了生命的出现。 你们可以将这一过程与完成一个 250块的拼图相比, 而不是完成一个2000块的拼图。
Afterwards, the big planets like Jupiter and Saturn, they were not in their place where they are now, and they interacted gravitationally, and they swept the whole interior of the solar system clean, and what we now know as comets ended up in something called the Kuiper Belt, which is a belt of objects beyond the orbit of Neptune. And sometimes these objects run into each other, and they gravitationally deflect, and then the gravity of Jupiter pulls them back into the solar system. And they then become the comets as we see them in the sky.
然后,像木星和土星这样的大行星, 它们当时并不在今天所处的位置, 它们会通过引力相互作用, 并将整个太阳系内部打扫干净了, 而我们现在称为彗星的天体 最终到了一个叫做“柯伊伯带”的地方, 这是一个海王星轨道以外的天体聚集带。 有时这些天体会相互碰撞, 并且发生了重力转移, 木星的引力随后将它们拉回了太阳系。 然后它们就变成了 我们在天空中所见到的彗星。
The important thing here to note is that in the meantime, the four and a half billion years, these comets have been sitting on the outside of the solar system, and haven't changed -- deep, frozen versions of our solar system.
需要注意的重点是,在此期间, 这45亿年间, 这些彗星一直安坐在太阳系之外, 并且从没变过—— 深沉、冻结版的太阳系。
In the sky, they look like this. We know them for their tails. There are actually two tails. One is a dust tail, which is blown away by the solar wind. The other one is an ion tail, which is charged particles, and they follow the magnetic field in the solar system. There's the coma, and then there is the nucleus, which here is too small to see, and you have to remember that in the case of Rosetta, the spacecraft is in that center pixel. We are only 20, 30, 40 kilometers away from the comet.
在空中,它们看起来是这样的。 我们通过它们的尾巴认识它们。 这里事实上有两条尾巴。 一条是尘埃尾,是被太阳风吹出来的。 另一条是离子尾,是带电粒子, 它们受太阳系磁场的影响。 可以看到慧发, 还有慧核,小到几乎看不见, 但是你们要记住在罗塞塔号的案例中, 航天器就在那个中心像素上。 我们距离这颗彗星 只有20、30、40千米。
So what's important to remember? Comets contain the original material from which our solar system was formed, so they're ideal to study the components that were present at the time when Earth, and life, started. Comets are also suspected of having brought the elements which may have bootstrapped life. In 1983, ESA set up its long-term Horizon 2000 program, which contained one cornerstone, which would be a mission to a comet. In parallel, a small mission to a comet, what you see here, Giotto, was launched, and in 1986, flew by the comet of Halley with an armada of other spacecraft. From the results of that mission, it became immediately clear that comets were ideal bodies to study to understand our solar system. And thus, the Rosetta mission was approved in 1993, and originally it was supposed to be launched in 2003, but a problem arose with an Ariane rocket. However, our P.R. department, in its enthusiasm, had already made 1,000 Delft Blue plates with the name of the wrong comets. So I've never had to buy any china since. That's the positive part. (Laughter)
那么需要记住哪些关键点呢? 彗星中含有来自太阳系 形成时的原始物质, 因此它们是用来研究 地球和生命起源时 所出现的成份的理想对象。 彗星还很可能 带来了那些引发了生命起源的元素。 1983年,欧洲航天局开始了 长期的地平线2000计划, 它包含了一个基础项目, 可能是一个造访彗星的任务。 同时,一个小的造访彗星的任务, 就是你们在这里看到的乔托号,启动了, 1986年,它与其它航天器组成的 舰队飞经了哈雷彗星。 那次任务的结果清晰地表明, 彗星是用来研究太阳系的理想天体。 因此,1993年,罗塞塔任务被批准, 最初它被设定在2003年发射, 但是后来由于阿里亚娜火箭 出现问题而被取消。 然而,我们的公关部门,充满热情, 他们已经制作了1000个 代尔夫特蓝色瓷盘, 并印上了那些错误的彗星名字。 因此从那以后我没有买过任何的瓷器。 这是积极的一面。 (笑声)
Once the whole problem was solved, we left Earth in 2004 to the newly selected comet, Churyumov-Gerasimenko. This comet had to be specially selected because A, you have to be able to get to it, and B, it shouldn't have been in the solar system too long. This particular comet has been in the solar system since 1959. That's the first time when it was deflected by Jupiter, and it got close enough to the sun to start changing. So it's a very fresh comet.
在所有的问题被解决之后, 罗塞塔在2004年离开了地球, 飞向重新被选定的彗星, 丘留莫夫·格拉西缅科彗星。 这颗彗星是被特别选中的, 因为首先,你得能够到达它, 其次,它没有在太阳系待太长时间。 这颗特别的彗星在1959年进入太阳系。 那是它被木星偏转后第一次来到太阳系, 并且它跟太阳的距离近到 足够让它发生变化。 所以这是一颗非常新的彗星。
Rosetta made a few historic firsts. It's the first satellite to orbit a comet, and to escort it throughout its whole tour through the solar system -- closest approach to the sun, as we will see in August, and then away again to the exterior. It's the first ever landing on a comet. We actually orbit the comet using something which is not normally done with spacecraft. Normally, you look at the sky and you know where you point and where you are. In this case, that's not enough. We navigated by looking at landmarks on the comet. We recognized features -- boulders, craters -- and that's how we know where we are respective to the comet.
罗塞塔取得了很多历史性的突破。 它是首个进入彗星轨道的人造卫星, 并且伴随彗星走过了 它的整个太阳系之旅—— 到达了距离最短的近日点, 这个我们将会在8份看到, 然后重新离开太阳系。 这是第一次有航天器在彗星上着陆。 我们实际上在罗塞塔号上 使用了一些通常不会在其他航天器上 使用的彗星轨道环绕技术。 通常,你们看看天空, 就会知道方位和坐标。 但是在这个案例中,那还不够。 我们通过观察彗星上的地标来导航。 我们辨别那些特征——卵石、环形山—— 然后我们就知道我们处在彗星上 哪个对应的区域。
And, of course, it's the first satellite to go beyond the orbit of Jupiter on solar cells. Now, this sounds more heroic than it actually is, because the technology to use radio isotope thermal generators wasn't available in Europe at that time, so there was no choice. But these solar arrays are big. This is one wing, and these are not specially selected small people. They're just like you and me. (Laughter) We have two of these wings, 65 square meters. Now later on, of course, when we got to the comet, you find out that 65 square meters of sail close to a body which is outgassing is not always a very handy choice.
当然,这也是第一次 使用太阳能电池飞跃 木星轨道的航天器。 这听起来比事实更称得上是壮举, 因为那时放射性同位素热电机的技术 在欧洲尚未得到应用,所以当时别无选择。 但是这些太阳能电池板很大。 这是它的一个侧翼, 下面这些可不是特意挑选的矮小的人。 他们是跟你我一样的正常人。 (笑声) 我们有两个这样的侧翼,65平米。 随后,当然,当我们飞向这颗彗星时, 你们会发现扬着一个65平米的帆 向一个正在排气的天体靠近, 并不总是一个便捷的选择。
Now, how did we get to the comet? Because we had to go there for the Rosetta scientific objectives very far away -- four times the distance of the Earth to the sun -- and also at a much higher velocity than we could achieve with fuel, because we'd have to take six times as much fuel as the whole spacecraft weighed. So what do you do? You use gravitational flybys, slingshots, where you pass by a planet at very low altitude, a few thousand kilometers, and then you get the velocity of that planet around the sun for free. We did that a few times. We did Earth, we did Mars, we did twice Earth again, and we also flew by two asteroids, Lutetia and Steins. Then in 2011, we got so far from the sun that if the spacecraft got into trouble, we couldn't actually save the spacecraft anymore, so we went into hibernation. Everything was switched off except for one clock. Here you see in white the trajectory, and the way this works. You see that from the circle where we started, the white line, actually you get more and more and more elliptical, and then finally we approached the comet in May 2014, and we had to start doing the rendezvous maneuvers.
我们是怎么到达这颗彗星的呢? 因为我们得去一个十分遥远的地方 去完成罗塞塔号的 科学目标—— 是地球到太阳距离的4倍—— 而且以一个我们用普通燃料 无法达到的速度。 因为我们得携带六倍于 航天器本身重量的燃料。 那要怎么做呢? 在一个非常低的高度,大概几千公里, 经过一个行星时, 利用引力的拉扯效应和 弹力作用, 你就会直接获得跟那颗行星同样的 绕日运行速度。 我们尝试过很多次。 在地球上,火星上 , 然后又在地球上试过两次, 我们还飞掠了两颗小行星, 鲁特西亚和斯坦斯。 到了2011年,我们已经距离太阳太远了, 如果这个航天器遇到问题, 我们根本没办法挽救它了, 所以我们进入了冬眠状态。 除了一个计时器,所有的仪器都关掉了。 这里你们看到白色的是它的轨道, 以及运动轨迹。 可以看到从一开始的这个圆, 这条白线, 我们可以得到越来越多的椭圆, 最终我们在2014年5月靠近了这颗彗星, 然后我们得开始做会合减速。
On the way there, we flew by Earth and we took a few pictures to test our cameras. This is the moon rising over Earth, and this is what we now call a selfie, which at that time, by the way, that word didn't exist. (Laughter) It's at Mars. It was taken by the CIVA camera. That's one of the cameras on the lander, and it just looks under the solar arrays, and you see the planet Mars and the solar array in the distance.
在途中,我们飞经地球并拍了一些照片 以测试我们的相机。 这是月球在地球另一侧升起, 这是我们现在所称的自拍, 顺便说一下,那个时候“自拍” 这个词还不存在。(笑声) 这是在火星上, 由彗星红外与可见光分析仪 相机拍摄的。 那是着陆器上的一台相机, 它看起来处在太阳能电池板的下方, 你们能看到火星和太阳能电池板 出现在远处。
Now, when we got out of hibernation in January 2014, we started arriving at a distance of two million kilometers from the comet in May. However, the velocity the spacecraft had was much too fast. We were going 2,800 kilometers an hour faster than the comet, so we had to brake. We had to do eight maneuvers, and you see here, some of them were really big. We had to brake the first one by a few hundred kilometers per hour, and actually, the duration of that was seven hours, and it used 218 kilos of fuel, and those were seven nerve-wracking hours, because in 2007, there was a leak in the system of the propulsion of Rosetta, and we had to close off a branch, so the system was actually operating at a pressure which it was never designed or qualified for.
当我们在2014年1月从冬眠中被唤醒后, 我们开始前进,并在5月份 到达了距离这个彗星 200万公里的地方。 然而,这个航天器的速度太快了。 我们的时速要比这颗彗星快2800公里, 因此我们需要刹一刹车。 我们得做8次减速, 可以看到, 其中的一些减速幅度真的很大。 我们的第一次减速需要 将速度每小时降低数百公里, 事实上这个过程花了7个小时, 消耗了218公斤的燃料, 这也是令人心惊胆战的7小时, 因为在2007年, 罗塞塔号的推进系统出现了一处泄漏, 我们不得不关掉了一个分路, 因此推进系统是在超出设计能力的 压力下运行的。
Then we got in the vicinity of the comet, and these were the first pictures we saw. The true comet rotation period is 12 and a half hours, so this is accelerated, but you will understand that our flight dynamics engineers thought, this is not going to be an easy thing to land on. We had hoped for some kind of spud-like thing where you could easily land. But we had one hope: maybe it was smooth. No. That didn't work either. (Laughter)
然后我们到达了这颗彗星的附近, 这是我们看到的第一批照片。 这颗彗星真实的自转周期是12.5个小时, 所以这是加速播放的, 但是你们肯定能够理解我们的 飞行动力学工程师的想法, 这不是一个容易登陆的东西。 我们曾经幻想过它是某种 形状像土豆一样的 容易登陆的东西。 但我们扔抱着一线希望: 也许它比较平坦。 不,它的表面还很粗糙。(笑声)
So at that point in time, it was clearly unavoidable: we had to map this body in all the detail you could get, because we had to find an area which is 500 meters in diameter and flat. Why 500 meters? That's the error we have on landing the probe. So we went through this process, and we mapped the comet. We used a technique called photoclinometry. You use shadows thrown by the sun. What you see here is a rock sitting on the surface of the comet, and the sun shines from above. From the shadow, we, with our brain, can immediately determine roughly what the shape of that rock is. You can program that in a computer, you then cover the whole comet, and you can map the comet. For that, we flew special trajectories starting in August. First, a triangle of 100 kilometers on a side at 100 kilometers' distance, and we repeated the whole thing at 50 kilometers. At that time, we had seen the comet at all kinds of angles, and we could use this technique to map the whole thing.
因此,当时我们迫不得已 做出了如下选择: 我们得利用收集到的所有细节 去绘制这个天体的地图, 因为我们得找到一块直径500米的平地。 为什么是500米? 这是我们让探测器着陆时的误差。 于是我们立即采取行动 并绘制出了彗星表面的地图。 我们采用了一种叫做 照相测斜术的技术。 利用太阳拋下的阴影。 你们现在看到的是一块 位于彗星表面的岩石, 而阳光从上面照下来。 透过阴影,我们用大脑, 可以立刻大致判断出这块岩石的形状。 你可以编一套那样的程序, 然后覆盖整颗彗星, 就可以绘制出它表面的形貌图了。 为此,我们从8月份开始沿着 一种特殊的轨迹飞行。 首先,在100公里外的地方沿着一个 边长为100公里的三角形飞行, 然后将三角形的边长改为50公里, 再重复整个过程。 那时候,我们已经通过所有的角度 观察过这颗彗星了, 我们也可以利用这一技术绘制出 整个彗星的表面形貌。
Now, this led to a selection of landing sites. This whole process we had to do, to go from the mapping of the comet to actually finding the final landing site, was 60 days. We didn't have more. To give you an idea, the average Mars mission takes hundreds of scientists for years to meet about where shall we go? We had 60 days, and that was it.
现在,到了选择登陆地点的时候了。 我们要做的就是在60天内, 通过绘制这颗彗星的形貌图, 来找到一个最终的登陆地点。 我们没有更多的时间。 对比一下,平均来说,火星上的任务 需要成百上千的科学家花数年的时间 去找到一个登陆地点。 但我们只有60天,就那么多了。
We finally selected the final landing site and the commands were prepared for Rosetta to launch Philae. The way this works is that Rosetta has to be at the right point in space, and aiming towards the comet, because the lander is passive. The lander is then pushed out and moves towards the comet. Rosetta had to turn around to get its cameras to actually look at Philae while it was departing and to be able to communicate with it.
我们最终选定了一个登陆点, 并且让罗塞塔号发送菲莱号的 指令也准备好了。 不过前提条件是罗塞塔号 得处在空中的正确位置, 并且瞄准这颗彗星,因为着陆器是被动的。 它需要被推出并飞向彗星。 罗塞塔号得转过身, 以便使它的相机在 菲莱飞离的过程中能对着它, 并且能与它进行交流。
Now, the landing duration of the whole trajectory was seven hours. Now do a simple calculation: if the velocity of Rosetta is off by one centimeter per second, seven hours is 25,000 seconds. That means 252 meters wrong on the comet. So we had to know the velocity of Rosetta much better than one centimeter per second, and its location in space better than 100 meters at 500 million kilometers from Earth. That's no mean feat.
整个着陆过程花了7个小时。 简单的计算一下: 如果罗塞塔号的速度误差是1厘米每秒, 7个小时就是25000秒, 那就意味着着陆器 登陆彗星时的误差是252米。 因此我们得将罗塞塔的速度误差 精确到小于1厘米每秒, 而它在太空中远离地球5亿公里的位置, 误差要精确到100米以内。 那不是一件易事。
Let me quickly take you through some of the science and the instruments. I won't bore you with all the details of all the instruments, but it's got everything. We can sniff gas, we can measure dust particles, the shape of them, the composition, there are magnetometers, everything. This is one of the results from an instrument which measures gas density at the position of Rosetta, so it's gas which has left the comet. The bottom graph is September of last year. There is a long-term variation, which in itself is not surprising, but you see the sharp peaks. This is a comet day. You can see the effect of the sun on the evaporation of gas and the fact that the comet is rotating. So there is one spot, apparently, where there is a lot of stuff coming from, it gets heated in the Sun, and then cools down on the back side. And we can see the density variations of this.
让我快速的介绍一下 其中的一些科学理论和仪器。 我不会介绍所有仪器的细节, 以免你们听得一头雾水, 但想帮助你们了解一些概念。 我们可以检测气体,测量粉尘, 测它们的形状和成分, 这里有磁力仪等等我们需要的一切。 这是一部仪器所测到的 罗塞塔号所处位置的 气体密度的结果, 这是从彗星上释放出来的气体。 下面的图是去年9月份的。 这是一个长期的变化, 对于它本身来说可能不算什么, 但是看看那些尖峰。 这就是彗星上的一天。 你们可以看到太阳对于气体蒸发的影响, 以及彗星是旋转的这一事实。 这里有一个点,很明显地, 很多东西都出自那里, 它被太阳加热,然后在背面冷却。 我们可以看看这里的密度差异。
These are the gases and the organic compounds that we already have measured. You will see it's an impressive list, and there is much, much, much more to come, because there are more measurements. Actually, there is a conference going on in Houston at the moment where many of these results are presented.
这些是我们已经测量到的 气体和有机化合物。 看得出这是一份令人印象深刻的列表, 并且还会有更多更多的东西出现在上面, 因为我们还进行了更多的测量。 事实上,这会儿正有一个 在休斯顿举行的会议, 这些数据会在会上被展示出来。
Also, we measured dust particles. Now, for you, this will not look very impressive, but the scientists were thrilled when they saw this. Two dust particles: the right one they call Boris, and they shot it with tantalum in order to be able to analyze it. Now, we found sodium and magnesium. What this tells you is this is the concentration of these two materials at the time the solar system was formed, so we learned things about which materials were there when the planet was made.
我们还测量了尘粒。 对于你们来说,这可能没什么太大的意义, 但是当科学家们 看到这个的时候都非常激动。 两颗尘粒: 右边的他们叫它鲍里斯, 他们用钽去射击它, 以便能够分析它。 我们发现了钠和镁。 而这也说明了这就是当太阳系刚形成时 这两种物质的浓度, 因此我们知道了当行星形成时 存在着哪些物质。
Of course, one of the important elements is the imaging. This is one of the cameras of Rosetta, the OSIRIS camera, and this actually was the cover of Science magazine on January 23 of this year. Nobody had expected this body to look like this. Boulders, rocks -- if anything, it looks more like the Half Dome in Yosemite than anything else. We also saw things like this: dunes, and what look to be, on the righthand side, wind-blown shadows. Now we know these from Mars, but this comet doesn't have an atmosphere, so it's a bit difficult to create a wind-blown shadow. It may be local outgassing, stuff which goes up and comes back. We don't know, so there is a lot to investigate. Here, you see the same image twice. On the left-hand side, you see in the middle a pit. On the right-hand side, if you carefully look, there are three jets coming out of the bottom of that pit. So this is the activity of the comet. Apparently, at the bottom of these pits is where the active regions are, and where the material evaporates into space. There is a very intriguing crack in the neck of the comet. You see it on the right-hand side. It's a kilometer long, and it's two and a half meters wide. Some people suggest that actually, when we get close to the sun, the comet may split in two, and then we'll have to choose, which comet do we go for? The lander -- again, lots of instruments, mostly comparable except for the things which hammer in the ground and drill, etc. But much the same as Rosetta, and that is because you want to compare what you find in space with what you find on the comet. These are called ground truth measurements.
当然,最重要的因素之一就是成像。 这是罗塞塔号上的一个相机—— 奥西里斯相机——拍摄到的, 而这实际上是《科学》杂志 今年1月23日那一期的封面。 没有人想到它看起来会是这样的。 大卵石,岩石——相比于其它任何地方, 它看起来更像是约塞米蒂的半屏岩。 我们还看到了这样的东西: 沙丘,还有在右手边, 看起来像一些被风吹动的影子。 我们在火星上发现过这些, 但是这颗彗星没有大气层, 所以要制造一个被风吹动的 影子是有点困难的。 这可能是局部的出气, 有什么东西上升然后落下来。 我们还不清楚, 所以还要进行很多调查。 这里有两张同一地点的图像。 左手边这张,中间有一个坑。 右手边这张,如果你们仔细看, 有三股气流从那个坑的底部喷出。 所以这就是这颗彗星的活动。 显然,这些坑的底部就是活动区域, 也是物质蒸发到空中去的地方。 这颗彗星的脖子上 有一个非常有趣的裂缝。 就在右手边。 它有1公里长,2.5米宽。 有些人提出,事实上 当我们向太阳靠近的时候, 这颗彗星可能会一分为二, 然后我们不得不做出选择, 我们要去跟踪哪一半的彗星? 这个着陆器—— 一样的,携带了很多仪器, 除了一些打钻用的装置, 其他大部分跟航天器上的差不多。 与罗塞塔携带几乎一样的仪器是因为要把 太空中发现的物质跟这颗彗星上的做比较。 这被称为“地面实况调查”。
These are the landing descent images that were taken by the OSIRIS camera. You see the lander getting further and further away from Rosetta. On the top right, you see an image taken at 60 meters by the lander, 60 meters above the surface of the comet. The boulder there is some 10 meters. So this is one of the last images we took before we landed on the comet. Here, you see the whole sequence again, but from a different perspective, and you see three blown-ups from the bottom-left to the middle of the lander traveling over the surface of the comet. Then, at the top, there is a before and an after image of the landing. The only problem with the after image is, there is no lander. But if you carefully look at the right-hand side of this image, we saw the lander still there, but it had bounced. It had departed again.
这些是奥西里斯相机拍摄的 着陆下降时的图像。 可以看到着陆器离罗塞塔号越来越远。 右上角,是着陆器在60米外拍的照片, 彗星表面60米以上。 那个大卵石直径大约10米。 这是我们在彗星上着陆之前 所拍的最后一张照片。 换个角度,再看一遍这整个过程, 大家可以看到从图中的 左下角到中间有三幅 着陆器飞过彗星表面时的放大照。 然后,在顶部有 着陆之前和之后的对比照。 唯一的问题就是在着陆后的照片中 没有出现着陆器。 但是你们仔细观察这张图像的右手边, 我们看到着陆器仍然在那, 但是它被反弹了。 又离开了彗星表面。
Now, on a bit of a comical note here is that originally Rosetta was designed to have a lander which would bounce. That was discarded because it was way too expensive. Now, we forgot, but the lander knew. (Laughter) During the first bounce, in the magnetometers, you see here the data from them, from the three axes, x, y and z. Halfway through, you see a red line. At that red line, there is a change. What happened, apparently, is during the first bounce, somewhere, we hit the edge of a crater with one of the legs of the lander, and the rotation velocity of the lander changed. So we've been rather lucky that we are where we are.
现在,有点滑稽的是, 本来在罗塞塔号的设计中, 它会携带一个能反弹的着陆器。 但是因为成本太高所以就放弃了。 我们已经忘记了这件事, 但是着陆器还记得。 (笑声) 第一次反弹期间,在磁力仪上, 你们可以看到来自X、Y、Z 三个坐标上的数据。 半途中,你们可以看到一条红线。 这条红线表示有变化产生。 发生了什么呢? 很显然是在第一次反弹期间, 着陆器的一条腿在某个地方 碰到了一个坑的边缘, 然后着陆器的旋转速度被改变了。 所以我们很幸运 是处在当时的位置。
This is one of the iconic images of Rosetta. It's a man-made object, a leg of the lander, standing on a comet. This, for me, is one of the very best images of space science I have ever seen.
这是罗塞塔号拍的标志性的图片之一。 那是一个人造物体,着陆器的一条腿, 站在一颗彗星上。 对我来说,这是我见过的 最棒的空间科学的照片之一。
(Applause)
(掌声)
One of the things we still have to do is to actually find the lander. The blue area here is where we know it must be. We haven't been able to find it yet, but the search is continuing, as are our efforts to start getting the lander to work again. We listen every day, and we hope that between now and somewhere in April, the lander will wake up again.
未来的任务之一就是要找到这个着陆器。 蓝色区域是我们知道的 它应该所处的位置。 我们还没能找到它,但是搜索仍在继续, 同时我们也在努力让着陆器重新工作。 我们每天都仔细监听, 希望从现在到4月份的某个时候, 这个着陆器会重新开始工作。
The findings of what we found on the comet: This thing would float in water. It's half the density of water. So it looks like a very big rock, but it's not. The activity increase we saw in June, July, August last year was a four-fold activity increase. By the time we will be at the sun, there will be 100 kilos a second leaving this comet: gas, dust, whatever. That's 100 million kilos a day.
我们在这颗彗星上的发现是: 这颗彗星可以在水上漂浮。 它的密度是水的一半。 因此它虽然看起来像一块大岩石, 但实际上不是。 去年6到8月间我们看到 它的活跃性提高了4倍。 当我们靠近太阳时, 每秒种将会有100公斤的物质 离开这颗彗星: 气体、灰尘等等。 1天的话就是1亿公斤。
Then, finally, the landing day. I will never forget -- absolute madness, 250 TV crews in Germany. The BBC was interviewing me, and another TV crew who was following me all day were filming me being interviewed, and it went on like that for the whole day. The Discovery Channel crew actually caught me when leaving the control room, and they asked the right question, and man, I got into tears, and I still feel this. For a month and a half, I couldn't think about landing day without crying, and I still have the emotion in me.
最终,到了着陆的那一天。 我将永生难忘——大家都疯狂了, 在德国有250名电视台工作人员争相报道。 在BBC采访我的同时, 另一家电视台全天都在 跟踪报道我的工作人员 也拍下了我的访问过程, 那种状况持续了一整天。 探索频道的工作人员 在我离开监控室时找到了我, 并且提出了正确的问题, 我当时激动得流下了眼泪, 而那种感觉依旧挥之不去。 此后的1个半月里, 每次想到着陆日我都会热泪盈眶, 并到现在那种情绪在我心中仍然存在。
With this image of the comet, I would like to leave you.
我想用这张这颗彗星的照片 来结束今天的演讲。
Thank you.
谢谢。
(Applause)
(掌声)