WEBVTT 00:00:01.072 --> 00:00:04.897 I'm here to tell you about the real search for alien life. 00:00:04.897 --> 00:00:07.930 Not little green humanoids arriving in shiny UFOs, 00:00:07.930 --> 00:00:09.678 although that would be nice. 00:00:09.678 --> 00:00:11.488 But it's the search for planets 00:00:11.488 --> 00:00:14.056 orbiting stars far away. 00:00:14.056 --> 00:00:15.783 Every star in our sky is a sun. 00:00:15.783 --> 00:00:17.161 And if our sun has planets -- 00:00:17.161 --> 00:00:18.798 Mercury, Venus, Earth, Mars, etc. 00:00:18.798 --> 00:00:21.434 Surely those other stars should have planets also 00:00:21.434 --> 00:00:23.293 -- and they do. 00:00:23.293 --> 00:00:24.701 And in the last two decades, 00:00:24.701 --> 00:00:28.713 astronomers have found thousands of exoplanets. 00:00:28.713 --> 00:00:31.337 Our night sky is literally teeming with exoplanets. 00:00:31.337 --> 00:00:32.913 We know, statistically speaking, 00:00:32.913 --> 00:00:36.152 that every star has at least one planet. 00:00:36.152 --> 00:00:37.985 And in the search for planets, 00:00:37.985 --> 00:00:40.775 and in the future, planets that might be like earth, 00:00:40.775 --> 00:00:42.168 we're able to help address 00:00:42.168 --> 00:00:44.872 some of the most amazing and mysterious questions 00:00:44.872 --> 00:00:47.987 that have faced humankind for centuries. 00:00:47.987 --> 00:00:49.390 Why are we here? 00:00:49.390 --> 00:00:51.607 Why does our universe exist? 00:00:51.607 --> 00:00:54.073 How did earth form and evolve? 00:00:54.073 --> 00:00:57.880 How and why did life originate and populate our planet? 00:00:57.880 --> 00:01:00.555 The second question that we often think about is: 00:01:00.555 --> 00:01:03.039 Are we alone? 00:01:03.039 --> 00:01:05.317 Is there life out there? 00:01:05.317 --> 00:01:07.300 Who is out there? 00:01:07.300 --> 00:01:09.190 You know, this question has been around 00:01:09.190 --> 00:01:10.413 for thousands of years, 00:01:10.413 --> 00:01:12.942 since at least the time of the Greek philosophers. 00:01:12.942 --> 00:01:15.550 But, I'm here to tell you just how close we're getting 00:01:15.550 --> 00:01:18.447 to finding out the answer to this question. 00:01:18.447 --> 00:01:20.264 It's the first time in human history 00:01:20.264 --> 00:01:22.969 that this really is within reach for us. 00:01:22.969 --> 00:01:24.975 Now when I think about the possibilities 00:01:24.975 --> 00:01:26.297 for life out there, 00:01:26.297 --> 00:01:28.550 I think of the fact that our sun 00:01:28.550 --> 00:01:30.825 is but one of many stars. 00:01:30.825 --> 00:01:32.727 This is a photograph of a real galaxy, 00:01:32.727 --> 00:01:35.197 we think our milky way looks like this galaxy. 00:01:35.197 --> 00:01:37.031 It's a collection of bound stars. 00:01:37.031 --> 00:01:41.271 But our milky way is one of hundreds of billions of stars 00:01:41.271 --> 00:01:45.619 and our galaxy is one of upwards of hundreds of billions of galaxies. 00:01:45.619 --> 00:01:49.498 Knowing that small planets are very common, 00:01:49.498 --> 00:01:52.035 you can just do the math. 00:01:52.035 --> 00:01:55.449 And there are just so many stars and so many planets out there, 00:01:55.449 --> 00:01:58.777 that surely, there must be life somewhere out there. 00:01:58.777 --> 00:02:02.742 Well, the biologists get furious with me for saying that, 00:02:02.742 --> 00:02:05.082 because we have absolutely no evidence. 00:02:05.082 --> 00:02:07.231 for life beyond earth, yet. 00:02:07.231 --> 00:02:10.815 Well, if we were able to look at our galaxy from the outside 00:02:10.815 --> 00:02:14.026 and zoom in to where our sun is, 00:02:14.026 --> 00:02:16.196 we see a real map of the stars. 00:02:16.196 --> 00:02:19.004 And the highlighted stars are those with known exoplanets. 00:02:19.004 --> 00:02:22.860 This is really just the tip of the iceberg. 00:02:22.860 --> 00:02:26.801 Here, this animation is zooming in onto our solar system. 00:02:26.801 --> 00:02:28.381 And you'll see here the planets 00:02:28.381 --> 00:02:31.583 as well as some spacecraft that are also orbiting our sun. 00:02:31.583 --> 00:02:35.553 Now if we can imagine going to the west coast of North America, 00:02:35.553 --> 00:02:38.723 and looking out at the night sky, 00:02:38.723 --> 00:02:40.808 here's what we'd see on a spring night. 00:02:40.808 --> 00:02:42.842 And you can see the constellations overlaid 00:02:42.842 --> 00:02:45.313 and again, so many stars with planets. 00:02:45.313 --> 00:02:47.375 There's a special patch of the sky 00:02:47.375 --> 00:02:49.353 where we have thousands of planets. 00:02:49.353 --> 00:02:53.841 This is where the Kepler Space Telescope focused for many years. 00:02:53.841 --> 00:02:58.743 Let's zoom in and look at one of the favorite exoplanets. 00:02:58.743 --> 00:03:02.856 This star is called Kepler-186f. 00:03:02.856 --> 00:03:04.603 It's a system of about five planets. 00:03:04.603 --> 00:03:06.585 And by the way, most of these exoplanets, 00:03:06.585 --> 00:03:08.802 we don't know too much about. 00:03:08.802 --> 00:03:11.760 We know their size, and their orbit and things like that. 00:03:11.760 --> 00:03:15.796 But there's a very special planet here called Kepler-186f, 00:03:15.796 --> 00:03:19.721 this planet is in a zone that is not too far from the star, 00:03:19.721 --> 00:03:23.282 so that the temperature may be just right for life. 00:03:23.282 --> 00:03:25.587 Here, the artist conniption is just zooming in 00:03:25.587 --> 00:03:28.936 and showing you what that planet might be like. 00:03:31.186 --> 00:03:36.949 So, many people have this romantic notion of astronomers 00:03:36.949 --> 00:03:40.280 going to the telescope on a lonely mountaintop 00:03:40.280 --> 00:03:42.407 and looking at the spectacular night sky 00:03:42.407 --> 00:03:44.089 through a big telescope. 00:03:44.089 --> 00:03:47.465 But actually, we just work on our computers like everyone else 00:03:47.465 --> 00:03:50.906 and we get our data by email or by loading from a database. 00:03:50.906 --> 00:03:53.048 So instead of coming here to tell you about 00:03:53.048 --> 00:03:56.800 the somewhat tedious nature of the data and data analysis 00:03:56.800 --> 00:03:58.890 and the complex computer models we make, 00:03:58.890 --> 00:04:01.258 I have a different way to try to explain to you 00:04:01.258 --> 00:04:03.178 some of the things that we're thinking about exoplanets. 00:04:03.178 --> 00:04:04.909 Here's a travel poster: 00:04:04.909 --> 00:04:07.315 "Kepler-186f, 00:04:07.315 --> 00:04:10.234 Where the grass is always redder on the other side." 00:04:10.234 --> 00:04:13.001 That's because Kepler-186f orbits a red star, 00:04:13.001 --> 00:04:16.323 and we're just speculating that perhaps the plants there, 00:04:16.323 --> 00:04:19.165 if there is vegetation that does photosynthesis, 00:04:19.165 --> 00:04:22.296 it has different pigments and looks red. 00:04:22.296 --> 00:04:26.519 "Enjoy the gravity on HD 40307g, " 00:04:26.519 --> 00:04:28.189 a super-earth. 00:04:28.189 --> 00:04:30.183 This planet is more massive than earth 00:04:30.183 --> 00:04:32.496 and has a higher surface gravity. 00:04:32.496 --> 00:04:35.419 "Relax on Kepler-16b, 00:04:35.419 --> 00:04:38.173 where your shadow always has company." 00:04:38.173 --> 00:04:43.544 We know of a dozen planets that orbit two stars, 00:04:43.544 --> 00:04:45.507 and there's likely many more out there. 00:04:45.507 --> 00:04:47.689 If we could visit one of those planets, 00:04:47.689 --> 00:04:49.599 you literally would see two sunsets 00:04:49.599 --> 00:04:51.436 and have two shadows. 00:04:51.436 --> 00:04:53.970 So actually, science fiction got some things right, 00:04:53.970 --> 00:04:55.765 Tatooine from Star Wars. 00:04:55.765 --> 00:04:58.142 And I have a couple of other favorite exoplanets 00:04:58.142 --> 00:04:59.771 to tell you about. 00:04:59.771 --> 00:05:01.392 This one is Kepler-10b, 00:05:01.392 --> 00:05:03.797 it's a hot, hot planet. 00:05:03.797 --> 00:05:06.601 It orbits over 50 times closer to its star 00:05:06.601 --> 00:05:08.964 than the earth does to our sun. 00:05:08.964 --> 00:05:10.396 And actually, it's so hot 00:05:10.396 --> 00:05:12.283 we can't visit any of these planets, 00:05:12.283 --> 00:05:13.046 but if we could, 00:05:13.046 --> 00:05:15.051 we would melt long before we got there. 00:05:15.051 --> 00:05:17.404 We think the surface is hot enough to melt rock 00:05:17.404 --> 00:05:19.672 and has liquid lava lakes. 00:05:19.672 --> 00:05:21.315 We use 1214b, 00:05:21.315 --> 00:05:22.008 this planet, 00:05:22.008 --> 00:05:23.111 we know the mass and the size 00:05:23.111 --> 00:05:24.800 and it has a fairly low density, 00:05:24.800 --> 00:05:25.970 it's somewhat warm. 00:05:25.970 --> 00:05:28.205 We actually don't know really anything about this planet. 00:05:28.205 --> 00:05:31.290 One possibility is that it's a water world, 00:05:31.290 --> 00:05:34.529 like a scaled-up version of one of Jupiter's icy moons 00:05:34.529 --> 00:05:37.551 that might be 50 percent water by mass. 00:05:37.551 --> 00:05:40.313 In this case, it would have a thick steam atmosphere 00:05:40.313 --> 00:05:42.514 overlaying an ocean, 00:05:42.514 --> 00:05:43.727 not of liquid water, 00:05:43.727 --> 00:05:45.947 but of an exotic form of water, 00:05:45.947 --> 00:05:46.756 a superfluid -- 00:05:46.756 --> 00:05:48.990 not quite a gas, not quite a liquid. 00:05:48.990 --> 00:05:50.294 Under that wouldn't be rock, 00:05:50.294 --> 00:05:54.713 but a form of high pressure ice, like (word) 00:05:54.713 --> 00:05:56.956 So out of all these planets out there, 00:05:56.956 --> 00:06:00.275 and the variety is just simply astonishing, 00:06:00.275 --> 00:06:02.118 we mostly want to find the planets 00:06:02.118 --> 00:06:05.184 that are Goldie Locks planets, we call them, 00:06:05.184 --> 00:06:07.125 not too big, not too small 00:06:07.125 --> 00:06:08.996 not too hot, not too cold -- 00:06:08.996 --> 00:06:10.859 just right for life. 00:06:10.859 --> 00:06:12.500 But to do that, we'd have to be able to look 00:06:12.500 --> 00:06:14.269 at the planet's atmosphere 00:06:14.269 --> 00:06:16.058 because the atmosphere acts like a blanket 00:06:16.058 --> 00:06:16.978 trapping heat -- 00:06:16.978 --> 00:06:18.338 the greenhouse effect. 00:06:18.338 --> 00:06:21.182 We have to be able to asses the greenhouse gasses 00:06:21.182 --> 00:06:23.368 on other planets. 00:06:23.368 --> 00:06:25.796 Well, science fiction got some things wrong. 00:06:25.796 --> 00:06:29.330 The Star Trek Enterprise had to travel vast distances 00:06:29.330 --> 00:06:31.003 at incredible speeds to orbit other planets 00:06:31.003 --> 00:06:32.637 so that First officer Spok could further analyze 00:06:32.637 --> 00:06:37.615 the atmosphere and see if the planet 00:06:37.615 --> 00:06:40.999 was habitable or if there were lifeforms there. 00:06:40.999 --> 00:06:43.259 Well, we don't need to travel at warp speeds 00:06:43.259 --> 00:06:45.632 to see other planets' atmospheres, 00:06:45.632 --> 00:06:47.980 although I don't want to dissuade any budding engineers 00:06:47.980 --> 00:06:50.167 from figuring out how to do that. 00:06:50.167 --> 00:06:52.483 We actually can and do study planet atmospheres 00:06:52.483 --> 00:06:54.120 from here, from earth orbit. 00:06:54.120 --> 00:06:55.347 This is a picture, a photograph 00:06:55.347 --> 00:06:57.321 of the Hubble Space Telescope 00:06:57.321 --> 00:07:00.095 taken by the shuttle Atlantis as it was departing 00:07:00.095 --> 00:07:02.653 after the last human space flight to Hubble. 00:07:02.653 --> 00:07:03.926 They installed a new camera, actually, 00:07:03.926 --> 00:07:06.640 that we use for exoplanet atmospheres. 00:07:06.640 --> 00:07:11.366 And so far, we've been able to study dozens of exoplanet atmospheres, 00:07:11.366 --> 00:07:13.684 about six of them in great detail. 00:07:13.684 --> 00:07:15.710 But those are not small planets like earth. 00:07:15.710 --> 00:07:17.438 They're big, hot planets 00:07:17.438 --> 00:07:18.428 that are easy to see. 00:07:18.428 --> 00:07:19.190 We're not ready, 00:07:19.190 --> 00:07:21.068 we don't have the right technology yet 00:07:21.068 --> 00:07:24.359 to study small exoplanets. 00:07:24.359 --> 00:07:25.160 But nevertheless, 00:07:25.160 --> 00:07:26.916 I wanted to try to explain to you 00:07:26.916 --> 00:07:29.874 how we study exoplanet atmospheres. 00:07:29.874 --> 00:07:32.748 I want you to image, for a moment, a rainbow. 00:07:32.748 --> 00:07:35.515 And if we could look at this rainbow closely, 00:07:35.515 --> 00:07:39.287 we would see that some dark lines are missing. 00:07:39.287 --> 00:07:40.572 And here's our sun, 00:07:40.572 --> 00:07:42.003 the white light of our sun split up, 00:07:42.003 --> 00:07:44.953 not by raindrops, but by a spectrograph. 00:07:44.953 --> 00:07:47.148 And you can see all these dark, vertical lines. 00:07:47.148 --> 00:07:48.726 Some are narrow, some are wide, 00:07:48.726 --> 00:07:50.883 some are shaded at the edges. 00:07:50.883 --> 00:07:54.059 And this is how astronomers have studied objects in the heavens 00:07:54.059 --> 00:07:55.812 literally, for over a century. 00:07:55.812 --> 00:07:58.888 So here, each different atom and molecule 00:07:58.888 --> 00:07:59.577 has a special set of lines, 00:07:59.577 --> 00:08:01.157 a fingerprint, if you will. 00:08:01.157 --> 00:08:04.064 And that's how we study exoplanet atmospheres. 00:08:04.064 --> 00:08:05.902 And, I'll just never forget when I started working 00:08:05.902 --> 00:08:08.437 on exoplanet atmospheres 20 years ago, 00:08:08.437 --> 00:08:09.553 how many people told me, 00:08:09.553 --> 00:08:11.691 "This will never happen, 00:08:11.691 --> 00:08:13.087 we'll never be able to study them. 00:08:13.087 --> 00:08:14.268 Why are you bothering?" 00:08:14.268 --> 00:08:15.354 And that's why I'm pleased to tell you about 00:08:15.354 --> 00:08:16.232 all the atmospheres studied now, 00:08:16.232 --> 00:08:18.723 and this is really a whole field of its own. 00:08:18.723 --> 00:08:21.555 So when it comes to other planets, other earths, 00:08:21.555 --> 00:08:23.656 in the future when we can observe them, 00:08:23.656 --> 00:08:26.373 what kind of gasses would be looking for? 00:08:26.373 --> 00:08:29.343 Well, you know, our own earth has oxygen in the atmosphere 00:08:29.343 --> 00:08:31.689 to 20 percent by volume. 00:08:31.689 --> 00:08:33.457 That's a lot of oxygen. 00:08:33.457 --> 00:08:35.811 But without plants and photosynthetic life, 00:08:35.811 --> 00:08:37.660 there would be no oxygen, virtually no oxygen 00:08:37.660 --> 00:08:40.299 in our atmosphere. 00:08:40.299 --> 00:08:42.063 So oxygen is here because of life 00:08:42.063 --> 00:08:44.102 and our goal then is to look for gasses 00:08:44.102 --> 00:08:46.194 in other planet atmospheres, 00:08:46.194 --> 00:08:48.255 gasses that don't belong, 00:08:48.255 --> 00:08:50.882 that we might be able to attribute to life. 00:08:50.882 --> 00:08:52.767 But which molecules should we search for? 00:08:52.767 --> 00:08:55.454 I actually told you how diverse exoplanets are, 00:08:55.454 --> 00:08:57.375 we expect that to continue in the future 00:08:57.375 --> 00:08:58.888 when we find other earths. 00:08:58.888 --> 00:09:00.619 And that's one of the main things I'm working on now, 00:09:00.619 --> 00:09:02.892 I have a theory about this. 00:09:02.892 --> 00:09:05.237 It reminds me that nearly everyday, 00:09:05.237 --> 00:09:06.492 I receive an email -- 00:09:06.492 --> 00:09:07.424 email or emails-- 00:09:07.424 --> 00:09:11.745 from someone with a crazy theory about physics, gravity 00:09:11.745 --> 00:09:13.424 or cosmology or some such. 00:09:13.424 --> 00:09:18.023 Please don't email me one of your crazy theories. 00:09:18.023 --> 00:09:20.209 Well, I have my own crazy theory. 00:09:20.209 --> 00:09:23.077 But, who does the MIT professor go to? 00:09:23.077 --> 00:09:26.938 Well I emailed a Nobel Laureate in physiology and medicine 00:09:26.938 --> 00:09:28.975 and he said, "Sure, come and talk to me." 00:09:28.975 --> 00:09:30.598 So I brought my two biochemistry frirnds 00:09:30.598 --> 00:09:32.864 and we went to talk to him about our crazy theory. 00:09:32.864 --> 00:09:36.799 And that theory was that life produces all small molecules, 00:09:36.799 --> 00:09:38.857 so many molecules. 00:09:38.857 --> 00:09:40.307 Like, everything I could think of, 00:09:40.307 --> 00:09:41.306 but not being a chemist. 00:09:41.306 --> 00:09:42.153 Think about it: 00:09:42.153 --> 00:09:44.677 carbon dioxide, carbon monoxide, 00:09:44.677 --> 00:09:46.835 molecular hydrogen, molecular nitrogen, 00:09:46.835 --> 00:09:47.723 methane, methal choloride (?) -- 00:09:47.723 --> 00:09:48.822 so many gasses, 00:09:48.822 --> 00:09:51.094 they also exist for other reasons, 00:09:51.094 --> 00:09:53.117 but just life even produces ozone. 00:09:53.117 --> 00:09:54.427 So we go to talk to him about this, 00:09:54.427 --> 00:09:56.918 and immediately, he shot down the theory. 00:09:56.918 --> 00:09:59.517 He found an example that didn't exist. 00:09:59.517 --> 00:10:01.453 So, we went back to the drawing board 00:10:01.453 --> 00:10:04.093 and we actually think we have found something 00:10:04.093 --> 00:10:05.337 very interesting in another field. 00:10:05.337 --> 00:10:06.649 But back to exoplanets, 00:10:06.649 --> 00:10:09.952 the point is that life produces so many different types of gases, 00:10:09.952 --> 00:10:12.398 literally thousands of gasses. 00:10:12.398 --> 00:10:13.462 And so what we're doing now is just trying to figure out 00:10:13.462 --> 00:10:16.492 on which types of exoplanets, 00:10:16.492 --> 00:10:22.432 which gasses could be attributed to life. 00:10:22.432 --> 00:10:24.584 And so when it comes time 00:10:24.584 --> 00:10:25.629 that we find gasses on exoplanet atmospheres, 00:10:25.629 --> 00:10:28.417 that we won't know if they're being produced 00:10:28.417 --> 00:10:30.977 by intelligent aliens or by trees, 00:10:30.977 --> 00:10:31.227 or earth(?) swamp, 00:10:31.227 --> 00:10:35.757 or even just by simple, single celled microbial life. 00:10:35.757 --> 00:10:36.992 And so working on the models 00:10:36.992 --> 00:10:38.790 and thinking about biochemistry 00:10:38.790 --> 00:10:40.011 it's all well and good. 00:10:40.011 --> 00:10:42.111 But a really big challenge ahead of us 00:10:42.111 --> 00:10:42.920 is how. 00:10:42.920 --> 00:10:45.294 How are we going to find these planets? 00:10:45.294 --> 00:10:45.544 They're actually many ways to find planets, 00:10:46.973 --> 00:10:48.853 several different ways. 00:10:48.853 --> 00:10:50.676 But the one that I'm most focused on 00:10:50.676 --> 00:10:53.106 is how can we open a gateway 00:10:53.106 --> 00:10:53.997 so that in the future, 00:10:53.997 --> 00:10:56.094 we can find hundreds of earths. 00:10:56.094 --> 00:10:58.447 We have a real shot at finding signs of life. 00:10:58.447 --> 00:11:01.508 And actually, I just finished leading a two-year project 00:11:01.508 --> 00:11:04.391 in this very special phase of a concept 00:11:04.391 --> 00:11:06.167 we call the star shade. 00:11:06.167 --> 00:11:09.144 And the star shade is very specially shaped screen 00:11:09.144 --> 00:11:11.035 and the goal is to fly that star shade 00:11:11.035 --> 00:11:14.153 so it blocks out the light of a star 00:11:14.153 --> 00:11:17.116 so that a telescope can see the planets directly. 00:11:17.116 --> 00:11:19.533 Here, you can see myself and two team members 00:11:19.533 --> 00:11:21.994 holding up one small part of the star shade. 00:11:21.994 --> 00:11:23.350 It's shaped like a giant flower, 00:11:23.350 --> 00:11:27.160 and this is one of the prototype petals. 00:11:27.160 --> 00:11:31.598 The concept is that a star shade and telescope launch together, 00:11:31.598 --> 00:11:35.150 with the petals unfurling from the stowed position. 00:11:35.150 --> 00:11:37.222 The central trust would expand, 00:11:37.222 --> 00:11:40.092 with the petals snapping into place. 00:11:40.092 --> 00:11:42.586 Now, this has to be made very precisely, 00:11:42.586 --> 00:11:43.958 literally, the petals to microns 00:11:43.958 --> 00:11:46.847 and they have to deploy to millimeters. 00:11:46.847 --> 00:11:48.816 And this hole structure would have to fly 00:11:48.816 --> 00:11:51.222 tens of thousands of kilometers away from the telescope, 00:11:51.222 --> 00:11:52.390 it's about tens of meters in diameter. 00:11:52.390 --> 00:11:54.983 And the goal is to block out the starlight to incredible percussion 00:11:54.983 --> 00:12:00.076 so that we'd be able to see the planets directly. 00:12:00.076 --> 00:12:04.954 It has to be a very special shape 00:12:04.954 --> 00:12:07.885 because of the physics of defraction. 00:12:07.885 --> 00:12:09.742 Now this is a really project that we worked on, 00:12:09.742 --> 00:12:12.564 literally, you would not believe how hard. 00:12:12.564 --> 00:12:14.920 Just so you believe that it's not just in movie format, 00:12:14.920 --> 00:12:18.186 here's a real photograph of a second generation 00:12:18.186 --> 00:12:21.890 star shade deployment test bed in the lab. 00:12:21.890 --> 00:12:22.654 And in this case, 00:12:22.654 --> 00:12:23.498 I just want you to know, 00:12:23.498 --> 00:12:25.793 that that central trust has heritage left over 00:12:25.793 --> 00:12:29.789 from large radio deployables in space. 00:12:29.789 --> 00:12:31.052 So after all of that hard work 00:12:31.052 --> 00:12:33.555 where we try to think of all the crazy gasses 00:12:33.555 --> 00:12:35.575 that might be out there, 00:12:35.575 --> 00:12:38.009 we build the very complicated space telescopes, 00:12:38.009 --> 00:12:41.039 what are we going to find? 00:12:41.039 --> 00:12:42.507 Well, in the best case, 00:12:42.507 --> 00:12:46.554 we will find an image of another eco-earth. 00:12:46.554 --> 00:12:48.611 Here's earth as a pale blue dot. 00:12:48.611 --> 00:12:51.194 This is actually a real photograph of earth 00:12:51.194 --> 00:12:53.321 taken by the Voyager I spacecraft, 00:12:53.321 --> 00:12:55.606 four billion miles away. 00:12:55.606 --> 00:12:59.425 And that red light is just scattered light in the camera optics. 00:12:59.425 --> 00:13:02.516 But what's so awesome to consider is that 00:13:02.516 --> 00:13:07.206 if there are intelligent aliens orbiting on a planet 00:13:07.206 --> 00:13:08.786 around a star near to us 00:13:08.786 --> 00:13:10.855 and they build complicated space telescopes 00:13:10.855 --> 00:13:12.911 of a kind we're trying to build, 00:13:12.911 --> 00:13:15.589 all they'll see is this pale blue dot, 00:13:15.589 --> 00:13:17.727 a pinprick of light. 00:13:17.727 --> 00:13:20.869 And so sometimes when I pause to think about 00:13:20.869 --> 00:13:24.733 my professional struggle and huge ambition, 00:13:24.733 --> 00:13:27.601 it's hard to think about that in contrast 00:13:27.601 --> 00:13:30.351 to the vastness of the universe. 00:13:30.351 --> 00:13:33.912 But nonetheless, I am devoting the rest of my life 00:13:33.912 --> 00:13:36.439 to finding another earth. 00:13:36.439 --> 00:13:39.868 And I can guarantee that in the next generation 00:13:39.868 --> 00:13:40.942 of space telescopes, 00:13:40.942 --> 00:13:42.506 and the second generation, 00:13:42.506 --> 00:13:46.885 we will have the capability to find and identity other earths. 00:13:46.885 --> 00:13:48.119 And the capability to split up the starlight 00:13:48.119 --> 00:13:52.211 so that we can look for gasses 00:13:52.211 --> 00:13:55.981 and assess the greenhouse gasses in the atmosphere, 00:13:55.981 --> 00:13:57.343 estimate the surface temperature, 00:13:57.343 --> 00:14:00.009 and look for signs of life. 00:14:00.009 --> 00:14:01.406 But there's more, 00:14:01.406 --> 00:14:03.742 in this case of searching for other planets like earth, 00:14:03.742 --> 00:14:07.413 we are making a new kind of map 00:14:07.413 --> 00:14:10.472 of the nearby stars and of the planets orbiting them, 00:14:10.472 --> 00:14:12.794 including stars that actually might be 00:14:12.794 --> 00:14:15.225 inhabitable by humans. 00:14:15.225 --> 00:14:17.670 And so I envision that our descendants, 00:14:17.670 --> 00:14:19.149 hundreds of years from now, 00:14:19.149 --> 00:14:21.513 will embark on an interstellar journey 00:14:21.513 --> 00:14:23.059 to other worlds. 00:14:23.059 --> 00:14:26.261 And they will look back at all of us 00:14:26.261 --> 00:14:29.894 as the generation who first found the earth-like worlds. 00:14:29.894 --> 00:14:30.785 Thank you. 00:14:30.785 --> 00:14:37.794 (Applause) 00:14:37.794 --> 00:14:38.970 June Cohen: And I give you, for a question, 00:14:38.970 --> 00:14:41.759 Rosetta Mission manager Fred Jansen. 00:14:41.759 --> 00:14:43.434 Fred Jansen: You mentioned halfway through 00:14:43.434 --> 00:14:47.683 that the technology to actually look at the spectrum 00:14:47.683 --> 00:14:50.736 of an exoplanet-like earth is not there yet. 00:14:50.736 --> 00:14:52.360 When do you expect this will be there 00:14:52.360 --> 00:14:53.865 and what's needed? 00:14:53.865 --> 00:14:55.620 Sara Seager: Well actually, what we expect is what 00:14:55.620 --> 00:14:58.748 we call our next-generation Hubble telescope. 00:14:58.748 --> 00:15:00.593 And this is called the James Webb Space Telescope, 00:15:00.593 --> 00:15:03.043 and that will launch in 2018 00:15:03.043 --> 00:15:04.459 and that's what we're going to do, 00:15:04.459 --> 00:15:06.097 we're going to look at a speicla kind of planet 00:15:06.097 --> 00:15:07.857 called transient exoplanets, 00:15:07.857 --> 00:15:09.642 and that will be our first shot 00:15:09.642 --> 00:15:11.423 at studying small plants for gasses that might indicate 00:15:11.423 --> 00:15:12.602 the planet is habitable. 00:15:12.602 --> 00:15:18.210 JC: I'm going to ask you one follow-up question, too, Sara, 00:15:18.210 --> 00:15:19.431 as the generalist. 00:15:19.431 --> 00:15:22.657 So I am really struck by the notion in your career 00:15:22.657 --> 00:15:24.216 of the opposition you faced, 00:15:24.216 --> 00:15:25.983 that when you began thinking about exoplanets, 00:15:25.983 --> 00:15:28.422 there was extreme skepticism in the scientific community 00:15:28.422 --> 00:15:29.226 that they existed, 00:15:29.226 --> 00:15:30.826 and you proved them wrong. 00:15:30.826 --> 00:15:33.143 What did it take to take that on? 00:15:33.143 --> 00:15:36.457 SS: Well, the thing is that as scientists, 00:15:36.457 --> 00:15:37.219 we're supposed to be skeptical. 00:15:37.219 --> 00:15:39.520 It's our job to make sure that what the other peson is saying 00:15:39.520 --> 00:15:41.164 makes sense or not. 00:15:41.164 --> 00:15:43.814 But being a scientist, 00:15:43.814 --> 00:15:46.518 I think you've seen it from this session, 00:15:46.518 --> 00:15:48.611 it's like being an explorer. 00:15:48.611 --> 00:15:50.398 You have this immense curiosity, 00:15:50.398 --> 00:15:51.721 this stubbornness, 00:15:51.721 --> 00:15:54.127 this sort of resolute will that you will go forward 00:15:54.127 --> 00:15:56.633 no matter what people say. 00:15:56.633 --> 00:15:57.764 JC: I love that. Thank you, Sara. 00:15:57.764 --> 00:16:02.039 (Applause)