WEBVTT 00:00:00.960 --> 00:00:04.072 I'm here to tell you about the real search for alien life. 00:00:04.675 --> 00:00:07.906 Not little green humanoids arriving in shiny UFOs, 00:00:07.930 --> 00:00:09.654 although that would be nice. 00:00:09.678 --> 00:00:12.955 But it's the search for planets orbiting stars far away. NOTE Paragraph 00:00:13.924 --> 00:00:15.759 Every star in our sky is a sun. 00:00:15.783 --> 00:00:17.164 And if our sun has planets -- 00:00:17.188 --> 00:00:19.685 Mercury, Venus, Earth, Mars, etc., 00:00:19.709 --> 00:00:22.145 surely those other stars should have planets also, 00:00:22.169 --> 00:00:23.431 and they do. 00:00:23.455 --> 00:00:24.867 And in the last two decades, 00:00:24.891 --> 00:00:27.788 astronomers have found thousands of exoplanets. NOTE Paragraph 00:00:28.502 --> 00:00:31.313 Our night sky is literally teeming with exoplanets. 00:00:31.337 --> 00:00:32.889 We know, statistically speaking, 00:00:32.913 --> 00:00:35.406 that every star has at least one planet. 00:00:35.984 --> 00:00:37.961 And in the search for planets, 00:00:37.985 --> 00:00:40.751 and in the future, planets that might be like Earth, 00:00:40.775 --> 00:00:42.144 we're able to help address 00:00:42.168 --> 00:00:45.017 some of the most amazing and mysterious questions 00:00:45.041 --> 00:00:47.612 that have faced humankind for centuries. 00:00:47.636 --> 00:00:48.882 Why are we here? 00:00:49.215 --> 00:00:50.889 Why does our universe exist? 00:00:51.476 --> 00:00:53.523 How did Earth form and evolve? 00:00:53.912 --> 00:00:56.896 How and why did life originate and populate our planet? 00:00:57.665 --> 00:01:00.720 The second question that we often think about is: 00:01:00.744 --> 00:01:02.030 Are we alone? 00:01:02.911 --> 00:01:04.299 Is there life out there? 00:01:05.109 --> 00:01:06.601 Who is out there? 00:01:07.783 --> 00:01:10.789 You know, this question has been around for thousands of years, 00:01:10.813 --> 00:01:13.230 since at least the time of the Greek philosophers. 00:01:13.254 --> 00:01:15.801 But I'm here to tell you just how close we're getting 00:01:15.825 --> 00:01:18.706 to finding out the answer to this question. 00:01:18.730 --> 00:01:22.945 It's the first time in human history that this really is within reach for us. NOTE Paragraph 00:01:23.294 --> 00:01:26.273 Now when I think about the possibilities for life out there, 00:01:26.297 --> 00:01:30.384 I think of the fact that our sun is but one of many stars. 00:01:30.825 --> 00:01:32.703 This is a photograph of a real galaxy, 00:01:32.727 --> 00:01:35.173 we think our Milky Way looks like this galaxy. 00:01:35.197 --> 00:01:36.836 It's a collection of bound stars. 00:01:36.860 --> 00:01:41.247 But our [sun] is one of hundreds of billions of stars 00:01:41.271 --> 00:01:45.595 and our galaxy is one of upwards of hundreds of billions of galaxies. 00:01:46.707 --> 00:01:49.474 Knowing that small planets are very common, 00:01:49.498 --> 00:01:50.772 you can just do the math. 00:01:51.424 --> 00:01:55.425 And there are just so many stars and so many planets out there, 00:01:55.449 --> 00:01:58.139 that surely, there must be life somewhere out there. 00:01:59.060 --> 00:02:02.480 Well, the biologists get furious with me for saying that, 00:02:02.504 --> 00:02:05.948 because we have absolutely no evidence for life beyond Earth yet. NOTE Paragraph 00:02:06.977 --> 00:02:11.770 Well, if we were able to look at our galaxy from the outside 00:02:11.794 --> 00:02:14.002 and zoom in to where our sun is, 00:02:14.026 --> 00:02:15.586 we see a real map of the stars. 00:02:16.046 --> 00:02:19.069 And the highlighted stars are those with known exoplanets. 00:02:19.745 --> 00:02:21.934 This is really just the tip of the iceberg. 00:02:22.642 --> 00:02:26.284 Here, this animation is zooming in onto our solar system. 00:02:26.872 --> 00:02:28.357 And you'll see here the planets 00:02:28.381 --> 00:02:31.214 as well as some spacecraft that are also orbiting our sun. 00:02:32.968 --> 00:02:36.332 Now if we can imagine going to the West Coast of North America, 00:02:36.356 --> 00:02:38.482 and looking out at the night sky, 00:02:38.506 --> 00:02:40.784 here's what we'd see on a spring night. 00:02:40.808 --> 00:02:42.818 And you can see the constellations overlaid 00:02:42.842 --> 00:02:45.111 and again, so many stars with planets. 00:02:45.135 --> 00:02:49.329 There's a special patch of the sky where we have thousands of planets. NOTE Paragraph 00:02:49.353 --> 00:02:53.043 This is where the Kepler Space Telescope focused for many years. 00:02:53.576 --> 00:02:58.250 Let's zoom in and look at one of the favorite exoplanets. 00:02:58.863 --> 00:03:02.124 This star is called Kepler-186f. 00:03:02.529 --> 00:03:04.727 It's a system of about five planets. 00:03:04.751 --> 00:03:08.576 And by the way, most of these exoplanets, we don't know too much about. 00:03:08.600 --> 00:03:11.583 We know their size, and their orbit and things like that. 00:03:11.607 --> 00:03:15.569 But there's a very special planet here called Kepler-186f. 00:03:15.593 --> 00:03:19.697 This planet is in a zone that is not too far from the star, 00:03:19.721 --> 00:03:22.980 so that the temperature may be just right for life. 00:03:23.004 --> 00:03:26.035 Here, the artist's conception is just zooming in 00:03:26.059 --> 00:03:28.329 and showing you what that planet might be like. NOTE Paragraph 00:03:31.074 --> 00:03:36.676 So, many people have this romantic notion of astronomers 00:03:36.700 --> 00:03:40.256 going to the telescope on a lonely mountaintop 00:03:40.280 --> 00:03:43.829 and looking at the spectacular night sky through a big telescope. 00:03:43.853 --> 00:03:47.225 But actually, we just work on our computers like everyone else, 00:03:47.249 --> 00:03:51.074 and we get our data by email or downloading from a database. 00:03:51.098 --> 00:03:53.621 So instead of coming here to tell you 00:03:53.645 --> 00:03:56.776 about the somewhat tedious nature of the data and data analysis 00:03:56.800 --> 00:03:58.866 and the complex computer models we make, 00:03:58.890 --> 00:04:01.088 I have a different way to try to explain to you 00:04:01.112 --> 00:04:03.757 some of the things that we're thinking about exoplanets. NOTE Paragraph 00:04:03.781 --> 00:04:04.947 Here's a travel poster: 00:04:04.971 --> 00:04:07.291 "Kepler-186f: 00:04:07.315 --> 00:04:10.029 Where the grass is always redder on the other side." 00:04:10.053 --> 00:04:13.783 That's because Kepler-186f orbits a red star, 00:04:13.807 --> 00:04:16.499 and we're just speculating that perhaps the plants there, 00:04:16.523 --> 00:04:19.141 if there is vegetation that does photosynthesis, 00:04:19.165 --> 00:04:21.108 it has different pigments and looks red. 00:04:22.137 --> 00:04:26.495 "Enjoy the gravity on HD 40307g, 00:04:26.519 --> 00:04:27.978 a Super-Earth." 00:04:28.002 --> 00:04:30.159 This planet is more massive than Earth 00:04:30.183 --> 00:04:31.905 and has a higher surface gravity. 00:04:32.333 --> 00:04:35.230 "Relax on Kepler-16b, 00:04:35.254 --> 00:04:37.150 where your shadow always has company." 00:04:37.174 --> 00:04:39.134 (Laughter) 00:04:39.158 --> 00:04:43.340 We know of a dozen planets that orbit two stars, 00:04:43.364 --> 00:04:45.483 and there's likely many more out there. 00:04:45.507 --> 00:04:47.468 If we could visit one of those planets, 00:04:47.492 --> 00:04:49.379 you literally would see two sunsets 00:04:49.403 --> 00:04:50.658 and have two shadows. 00:04:51.484 --> 00:04:53.901 So actually, science fiction got some things right. 00:04:53.925 --> 00:04:55.134 Tatooine from Star Wars. 00:04:56.047 --> 00:04:58.342 And I have a couple of other favorite exoplanets 00:04:58.366 --> 00:04:59.563 to tell you about. 00:04:59.587 --> 00:05:01.119 This one is Kepler-10b, 00:05:01.143 --> 00:05:03.126 it's a hot, hot planet. 00:05:03.642 --> 00:05:06.577 It orbits over 50 times closer to its star 00:05:06.601 --> 00:05:08.768 than our Earth does to our sun. 00:05:08.792 --> 00:05:10.372 And actually, it's so hot, 00:05:10.396 --> 00:05:13.029 we can't visit any of these planets, but if we could, 00:05:13.053 --> 00:05:15.027 we would melt long before we got there. 00:05:15.051 --> 00:05:17.380 We think the surface is hot enough to melt rock 00:05:17.404 --> 00:05:18.830 and has liquid lava lakes. NOTE Paragraph 00:05:19.457 --> 00:05:21.041 Gliese 1214b. 00:05:21.065 --> 00:05:23.164 This planet, we know the mass and the size 00:05:23.188 --> 00:05:24.776 and it has a fairly low density. 00:05:24.800 --> 00:05:25.998 It's somewhat warm. 00:05:26.053 --> 00:05:28.737 We actually don't know really anything about this planet, 00:05:28.761 --> 00:05:31.266 but one possibility is that it's a water world, 00:05:31.290 --> 00:05:34.797 like a scaled-up version of one of Jupiter's icy moons 00:05:34.821 --> 00:05:37.304 that might be 50 percent water by mass. 00:05:37.328 --> 00:05:40.289 And in this case, it would have a thick steam atmosphere 00:05:40.313 --> 00:05:42.169 overlaying an ocean, 00:05:42.193 --> 00:05:43.703 not of liquid water, 00:05:43.727 --> 00:05:46.732 but of an exotic form of water, a superfluid -- 00:05:46.756 --> 00:05:48.746 not quite a gas, not quite a liquid. 00:05:48.770 --> 00:05:50.370 And under that wouldn't be rock, 00:05:50.394 --> 00:05:51.990 but a form of high-pressure ice, 00:05:52.014 --> 00:05:53.290 like ice IX. NOTE Paragraph 00:05:54.593 --> 00:05:56.768 So out of all these planets out there, 00:05:56.792 --> 00:06:00.006 and the variety is just simply astonishing, 00:06:00.030 --> 00:06:05.160 we mostly want to find the planets that are Goldilocks planets, we call them. 00:06:05.184 --> 00:06:07.101 Not too big, not too small, 00:06:07.125 --> 00:06:08.972 not too hot, not too cold -- 00:06:08.996 --> 00:06:10.345 but just right for life. 00:06:10.658 --> 00:06:12.776 But to do that, we'd have to be able to look 00:06:12.800 --> 00:06:14.134 at the planet's atmosphere, 00:06:14.158 --> 00:06:16.954 because the atmosphere acts like a blanket trapping heat -- 00:06:16.978 --> 00:06:18.314 the greenhouse effect. 00:06:18.338 --> 00:06:21.158 We have to be able to assess the greenhouse gases 00:06:21.182 --> 00:06:22.332 on other planets. 00:06:23.169 --> 00:06:25.288 Well, science fiction got some things wrong. 00:06:25.796 --> 00:06:27.186 The Star Trek Enterprise 00:06:27.210 --> 00:06:30.837 had to travel vast distances at incredible speeds 00:06:30.861 --> 00:06:32.590 to orbit other planets 00:06:32.614 --> 00:06:36.590 so that First Officer Spock could analyze the atmosphere 00:06:36.614 --> 00:06:38.575 to see if the planet was habitable 00:06:38.599 --> 00:06:40.272 or if there were lifeforms there. NOTE Paragraph 00:06:40.745 --> 00:06:43.235 Well, we don't need to travel at warp speeds 00:06:43.259 --> 00:06:45.388 to see other planet atmospheres, 00:06:45.412 --> 00:06:48.196 although I don't want to dissuade any budding engineers 00:06:48.220 --> 00:06:50.143 from figuring out how to do that. 00:06:50.167 --> 00:06:52.459 We actually can and do study planet atmospheres 00:06:52.483 --> 00:06:54.096 from here, from Earth orbit. 00:06:54.120 --> 00:06:57.297 This is a picture, a photograph of the Hubble Space Telescope 00:06:57.321 --> 00:07:00.071 taken by the shuttle Atlantis as it was departing 00:07:00.095 --> 00:07:02.334 after the last human space flight to Hubble. 00:07:02.358 --> 00:07:04.244 They installed a new camera, actually, 00:07:04.268 --> 00:07:06.413 that we use for exoplanet atmospheres. 00:07:06.437 --> 00:07:11.342 And so far, we've been able to study dozens of exoplanet atmospheres, 00:07:11.366 --> 00:07:13.490 about six of them in great detail. 00:07:13.514 --> 00:07:15.686 But those are not small planets like Earth. 00:07:15.710 --> 00:07:18.104 They're big, hot planets that are easy to see. 00:07:18.128 --> 00:07:19.366 We're not ready, 00:07:19.390 --> 00:07:23.765 we don't have the right technology yet to study small exoplanets. 00:07:24.106 --> 00:07:25.264 But nevertheless, 00:07:25.288 --> 00:07:29.185 I wanted to try to explain to you how we study exoplanet atmospheres. NOTE Paragraph 00:07:29.652 --> 00:07:31.874 I want you to imagine, for a moment, a rainbow. 00:07:32.532 --> 00:07:35.278 And if we could look at this rainbow closely, 00:07:35.302 --> 00:07:37.969 we would see that some dark lines are missing. 00:07:39.127 --> 00:07:40.548 And here's our sun, 00:07:40.572 --> 00:07:42.339 the white light of our sun split up, 00:07:42.363 --> 00:07:44.649 not by raindrops, but by a spectrograph. 00:07:44.673 --> 00:07:47.124 And you can see all these dark, vertical lines. 00:07:47.148 --> 00:07:48.982 Some are very narrow, some are wide, 00:07:48.982 --> 00:07:50.407 some are shaded at the edges. 00:07:50.431 --> 00:07:54.035 And this is actually how astronomers have studied objects in the heavens, 00:07:54.059 --> 00:07:55.554 literally, for over a century. 00:07:55.578 --> 00:07:58.004 So here, each different atom and molecule 00:07:58.028 --> 00:07:59.553 has a special set of lines, 00:07:59.577 --> 00:08:01.133 a fingerprint, if you will. 00:08:01.157 --> 00:08:03.894 And that's how we study exoplanet atmospheres. 00:08:03.918 --> 00:08:06.278 And I'll just never forget when I started working 00:08:06.302 --> 00:08:08.158 on exoplanet atmospheres 20 years ago, 00:08:08.182 --> 00:08:09.367 how many people told me, 00:08:09.391 --> 00:08:10.600 "This will never happen. 00:08:10.624 --> 00:08:13.414 We'll never be able to study them. Why are you bothering?" 00:08:13.438 --> 00:08:17.112 And that's why I'm pleased to tell you about all the atmospheres studied now, 00:08:17.136 --> 00:08:18.985 and this is really a field of its own. 00:08:19.009 --> 00:08:21.531 So when it comes to other planets, other Earths, 00:08:21.555 --> 00:08:23.632 in the future when we can observe them, 00:08:23.656 --> 00:08:25.715 what kind of gases would we be looking for? 00:08:26.144 --> 00:08:29.319 Well, you know, our own Earth has oxygen in the atmosphere 00:08:29.343 --> 00:08:30.802 to 20 percent by volume. 00:08:31.445 --> 00:08:32.714 That's a lot of oxygen. 00:08:33.457 --> 00:08:36.202 But without plants and photosynthetic life, 00:08:36.226 --> 00:08:37.636 there would be no oxygen, 00:08:37.660 --> 00:08:39.501 virtually no oxygen in our atmosphere. 00:08:40.116 --> 00:08:42.039 So oxygen is here because of life. 00:08:42.063 --> 00:08:46.170 And our goal then is to look for gases in other planet atmospheres, 00:08:46.194 --> 00:08:48.231 gases that don't belong, 00:08:48.255 --> 00:08:50.638 that we might be able to attribute to life. 00:08:50.662 --> 00:08:52.743 But which molecules should we search for? 00:08:52.767 --> 00:08:55.430 I actually told you how diverse exoplanets are. 00:08:55.454 --> 00:08:57.451 We expect that to continue in the future 00:08:57.475 --> 00:08:58.776 when we find other Earths. NOTE Paragraph 00:08:58.800 --> 00:09:01.372 And that's one of the main things I'm working on now, 00:09:01.396 --> 00:09:02.689 I have a theory about this. 00:09:02.713 --> 00:09:05.001 It reminds me that nearly every day, 00:09:05.025 --> 00:09:07.677 I receive an email or emails 00:09:07.701 --> 00:09:11.328 from someone with a crazy theory about physics of gravity 00:09:11.352 --> 00:09:13.184 or cosmology or some such. 00:09:13.208 --> 00:09:16.541 So, please don't email me one of your crazy theories. 00:09:16.565 --> 00:09:17.779 (Laughter) 00:09:17.803 --> 00:09:19.981 Well, I had my own crazy theory. 00:09:20.005 --> 00:09:21.989 But, who does the MIT professor go to? 00:09:22.703 --> 00:09:26.914 Well, I emailed a Nobel Laureate in Physiology or Medicine 00:09:26.938 --> 00:09:28.911 and he said, "Sure, come and talk to me." 00:09:28.935 --> 00:09:30.934 So I brought my two biochemistry friends 00:09:30.958 --> 00:09:33.310 and we went to talk to him about our crazy theory. 00:09:33.334 --> 00:09:36.775 And that theory was that life produces all small molecules, 00:09:36.799 --> 00:09:38.473 so many molecules. 00:09:38.497 --> 00:09:41.392 Like, everything I could think of, but not being a chemist. 00:09:41.416 --> 00:09:42.599 Think about it: 00:09:42.623 --> 00:09:44.653 carbon dioxide, carbon monoxide, 00:09:44.677 --> 00:09:46.536 molecular hydrogen, molecular nitrogen, 00:09:46.560 --> 00:09:47.926 methane, methyl chloride -- 00:09:47.950 --> 00:09:49.111 so many gases. 00:09:49.135 --> 00:09:51.070 They also exist for other reasons, 00:09:51.094 --> 00:09:52.946 but just life even produces ozone. 00:09:52.970 --> 00:09:54.728 So we go to talk to him about this, 00:09:54.752 --> 00:09:56.894 and immediately, he shot down the theory. 00:09:57.226 --> 00:09:59.493 He found an example that didn't exist. 00:09:59.948 --> 00:10:01.729 So, we went back to the drawing board 00:10:01.753 --> 00:10:05.181 and we think we have found something very interesting in another field. NOTE Paragraph 00:10:05.205 --> 00:10:06.625 But back to exoplanets, 00:10:06.649 --> 00:10:09.928 the point is that life produces so many different types of gases, 00:10:09.952 --> 00:10:12.164 literally thousands of gases. 00:10:12.188 --> 00:10:14.855 And so what we're doing now is just trying to figure out 00:10:14.879 --> 00:10:16.468 on which types of exoplanets, 00:10:16.492 --> 00:10:19.712 which gases could be attributed to life. 00:10:22.182 --> 00:10:24.230 And so when it comes time when we find gases 00:10:24.254 --> 00:10:25.605 in exoplanet atmospheres 00:10:25.629 --> 00:10:27.725 that we won't know if they're being produced 00:10:27.749 --> 00:10:30.779 by intelligent aliens or by trees, 00:10:30.803 --> 00:10:32.013 or a swamp, 00:10:32.037 --> 00:10:34.898 or even just by simple, single-celled microbial life. NOTE Paragraph 00:10:35.541 --> 00:10:37.091 So working on the models 00:10:37.115 --> 00:10:38.766 and thinking about biochemistry, 00:10:38.790 --> 00:10:39.987 it's all well and good. 00:10:40.011 --> 00:10:42.896 But a really big challenge ahead of us is: how? 00:10:42.920 --> 00:10:45.082 How are we going to find these planets? 00:10:45.106 --> 00:10:47.310 There are actually many ways to find planets, 00:10:47.310 --> 00:10:48.829 several different ways. 00:10:48.853 --> 00:10:52.712 But the one that I'm most focused on is how can we open a gateway 00:10:52.736 --> 00:10:53.973 so that in the future, 00:10:53.997 --> 00:10:55.846 we can find hundreds of Earths. 00:10:55.870 --> 00:10:58.203 We have a real shot at finding signs of life. 00:10:58.227 --> 00:11:01.353 And actually, I just finished leading a two-year project 00:11:01.377 --> 00:11:03.465 in this very special phase 00:11:03.489 --> 00:11:06.143 of a concept we call the starshade. 00:11:06.167 --> 00:11:09.120 And the starshade is a very specially shaped screen 00:11:09.144 --> 00:11:11.011 and the goal is to fly that starshade 00:11:11.035 --> 00:11:14.129 so it blocks out the light of a star 00:11:14.153 --> 00:11:17.092 so that the telescope can see the planets directly. 00:11:17.116 --> 00:11:19.509 Here, you can see myself and two team members 00:11:19.533 --> 00:11:21.722 holding up one small part of the starshade. 00:11:21.746 --> 00:11:23.326 It's shaped like a giant flower, 00:11:23.350 --> 00:11:25.833 and this is one of the prototype petals. 00:11:26.907 --> 00:11:31.368 The concept is that a starshade and telescope could launch together, 00:11:31.392 --> 00:11:33.986 with the petals unfurling from the stowed position. 00:11:34.896 --> 00:11:36.952 The central truss would expand, 00:11:36.976 --> 00:11:40.068 with the petals snapping into place. 00:11:40.092 --> 00:11:42.322 Now, this has to be made very precisely, 00:11:42.346 --> 00:11:43.934 literally, the petals to microns 00:11:43.958 --> 00:11:46.673 and they have to deploy to millimeters. 00:11:46.697 --> 00:11:48.752 And this whole structure would have to fly 00:11:48.776 --> 00:11:52.135 tens of thousands of kilometers away from the telescope. 00:11:52.159 --> 00:11:54.301 It's about tens of meters in diameter. 00:11:54.785 --> 00:11:59.738 And the goal is to block out the starlight to incredible precision 00:11:59.762 --> 00:12:02.500 so that we'd be able to see the planets directly. 00:12:03.333 --> 00:12:05.562 And it has to be a very special shape, 00:12:05.586 --> 00:12:07.475 because of the physics of defraction. 00:12:07.499 --> 00:12:09.718 Now this is a real project that we worked on, 00:12:09.742 --> 00:12:12.210 literally, you would not believe how hard. 00:12:12.234 --> 00:12:14.896 Just so you believe it's not just in movie format, 00:12:14.920 --> 00:12:16.556 here's a real photograph 00:12:16.580 --> 00:12:21.571 of a second-generation starshade deployment test bed in the lab. 00:12:21.595 --> 00:12:23.674 And in this case, I just wanted you to know 00:12:23.698 --> 00:12:26.188 that that central truss has heritage left over 00:12:26.212 --> 00:12:28.126 from large radio deployables in space. NOTE Paragraph 00:12:29.372 --> 00:12:31.028 So after all of that hard work 00:12:31.052 --> 00:12:34.845 where we try to think of all the crazy gases that might be out there, 00:12:34.869 --> 00:12:37.797 and we build the very complicated space telescopes 00:12:37.821 --> 00:12:39.048 that might be out there, 00:12:39.072 --> 00:12:40.368 what are we going to find? 00:12:40.725 --> 00:12:42.483 Well, in the best case, 00:12:42.507 --> 00:12:45.304 we will find an image of another exo-Earth. 00:12:46.328 --> 00:12:48.587 Here is Earth as a pale blue dot. 00:12:48.611 --> 00:12:51.170 And this is actually a real photograph of Earth 00:12:51.194 --> 00:12:53.064 taken by the Voyager 1 spacecraft, 00:12:53.088 --> 00:12:54.706 four billion miles away. 00:12:55.159 --> 00:12:58.397 And that red light is just scattered light in the camera optics. NOTE Paragraph 00:12:59.315 --> 00:13:01.711 But what's so awesome to consider 00:13:01.735 --> 00:13:04.784 is that if there are intelligent aliens 00:13:04.808 --> 00:13:08.762 orbiting on a planet around a star near to us 00:13:08.786 --> 00:13:10.831 and they build complicated space telescopes 00:13:10.855 --> 00:13:12.782 of the kind that we're trying to build, 00:13:12.806 --> 00:13:15.306 all they'll see is this pale blue dot, 00:13:15.330 --> 00:13:16.615 a pinprick of light. 00:13:17.456 --> 00:13:20.522 And so sometimes, when I pause to think 00:13:20.546 --> 00:13:24.799 about my professional struggle and huge ambition, 00:13:24.823 --> 00:13:26.816 it's hard to think about that 00:13:26.840 --> 00:13:29.259 in contrast to the vastness of the universe. 00:13:30.120 --> 00:13:34.246 But nonetheless, I am devoting the rest of my life 00:13:34.270 --> 00:13:35.620 to finding another Earth. NOTE Paragraph 00:13:36.296 --> 00:13:38.511 And I can guarantee NOTE Paragraph 00:13:38.535 --> 00:13:40.918 that in the next generation of space telescopes, 00:13:40.942 --> 00:13:42.482 in the second generation, 00:13:42.506 --> 00:13:47.912 we will have the capability to find and identity other Earths. 00:13:47.936 --> 00:13:50.610 And the capability to split up the starlight 00:13:50.634 --> 00:13:52.187 so that we can look for gases 00:13:52.211 --> 00:13:55.697 and assess the greenhouse gases in the atmosphere, 00:13:55.721 --> 00:13:57.319 estimate the surface temperature, 00:13:57.343 --> 00:13:59.101 and look for signs of life. NOTE Paragraph 00:13:59.736 --> 00:14:01.157 But there's more. 00:14:01.181 --> 00:14:04.545 In this case of searching for other planets like Earth, 00:14:04.569 --> 00:14:07.164 we are making a new kind of map 00:14:07.188 --> 00:14:10.448 of the nearby stars and of the planets orbiting them, 00:14:10.472 --> 00:14:14.243 including [planets] that actually might be inhabitable by humans. NOTE Paragraph 00:14:14.915 --> 00:14:17.296 And so I envision that our descendants, 00:14:17.320 --> 00:14:19.125 hundreds of years from now, 00:14:19.149 --> 00:14:22.176 will embark on an interstellar journey to other worlds. 00:14:23.059 --> 00:14:25.971 And they will look back at all of us 00:14:25.995 --> 00:14:29.003 as the generation who first found the Earth-like worlds. NOTE Paragraph 00:14:29.822 --> 00:14:30.973 Thank you. NOTE Paragraph 00:14:30.997 --> 00:14:37.508 (Applause) NOTE Paragraph 00:14:37.532 --> 00:14:39.632 June Cohen: And I give you, for a question, 00:14:39.656 --> 00:14:41.384 Rosetta Mission Manager Fred Jansen. NOTE Paragraph 00:14:41.817 --> 00:14:43.848 Fred Jansen: You mentioned halfway through 00:14:43.872 --> 00:14:47.659 that the technology to actually look at the spectrum 00:14:47.683 --> 00:14:50.312 of an exoplanet like Earth is not there yet. 00:14:50.336 --> 00:14:52.223 When do you expect this will be there, 00:14:52.247 --> 00:14:53.515 and what's needed? NOTE Paragraph 00:14:53.539 --> 00:14:58.154 Actually, what we expect is what we call our next-generation Hubble telescope. 00:14:58.531 --> 00:15:00.872 And this is called the James Webb Space Telescope, 00:15:00.896 --> 00:15:02.599 and that will launch in 2018, 00:15:02.623 --> 00:15:04.445 and that's what we're going to do, 00:15:04.469 --> 00:15:06.733 we're going to look at a special kind of planet 00:15:06.757 --> 00:15:08.213 called transient exoplanets, 00:15:08.237 --> 00:15:11.338 and that will be our first shot at studying small planets 00:15:11.362 --> 00:15:14.660 for gases that might indicate the planet is habitable. NOTE Paragraph 00:15:15.477 --> 00:15:18.286 JC: I'm going to ask you one follow-up question, too, Sara, 00:15:18.310 --> 00:15:19.516 as the generalist. 00:15:19.540 --> 00:15:22.633 So I am really struck by the notion in your career 00:15:22.657 --> 00:15:24.056 of the opposition you faced, 00:15:24.080 --> 00:15:26.224 that when you began thinking about exoplanets, 00:15:26.248 --> 00:15:28.914 there was extreme skepticism in the scientific community 00:15:28.938 --> 00:15:30.089 that they existed, 00:15:30.113 --> 00:15:31.382 and you proved them wrong. 00:15:31.406 --> 00:15:33.119 What did it take to take that on? NOTE Paragraph 00:15:33.143 --> 00:15:35.213 SS: Well, the thing is that as scientists, 00:15:35.237 --> 00:15:37.195 we're supposed to be skeptical, 00:15:37.219 --> 00:15:40.267 because our job to make sure that what the other person is saying 00:15:40.291 --> 00:15:41.630 actually makes sense or not. 00:15:41.654 --> 00:15:44.211 But being a scientist, 00:15:44.235 --> 00:15:46.655 I think you've seen it from this session, 00:15:46.679 --> 00:15:48.361 it's like being an explorer. 00:15:48.385 --> 00:15:50.374 You have this immense curiosity, 00:15:50.398 --> 00:15:51.697 this stubbornness, 00:15:51.721 --> 00:15:54.103 this sort of resolute will that you will go forward 00:15:54.127 --> 00:15:56.158 no matter what other people say. NOTE Paragraph 00:15:56.182 --> 00:15:57.858 JC: I love that. Thank you, Sara. NOTE Paragraph 00:15:57.882 --> 00:16:00.877 (Applause)