0:00:00.960,0:00:04.072
I'm here to tell you[br]about the real search for alien life.

0:00:04.675,0:00:07.906
Not little green humanoids[br]arriving in shiny UFOs,

0:00:07.930,0:00:09.654
although that would be nice.

0:00:09.678,0:00:12.955
But it's the search for planets[br]orbiting stars far away.

0:00:13.924,0:00:15.759
Every star in our sky is a sun.

0:00:15.783,0:00:17.164
And if our sun has planets --

0:00:17.188,0:00:19.685
Mercury, Venus, Earth, Mars, etc.,

0:00:19.709,0:00:22.145
surely those other stars[br]should have planets also,

0:00:22.169,0:00:23.431
and they do.

0:00:23.455,0:00:24.867
And in the last two decades,

0:00:24.891,0:00:27.788
astronomers have found[br]thousands of exoplanets.

0:00:28.502,0:00:31.313
Our night sky is literally[br]teeming with exoplanets.

0:00:31.337,0:00:32.889
We know, statistically speaking,

0:00:32.913,0:00:35.406
that every star has at least one planet.

0:00:35.984,0:00:37.961
And in the search for planets,

0:00:37.985,0:00:40.751
and in the future,[br]planets that might be like Earth,

0:00:40.775,0:00:42.144
we're able to help address

0:00:42.168,0:00:45.017
some of the most amazing[br]and mysterious questions

0:00:45.041,0:00:47.612
that have faced humankind for centuries.

0:00:47.636,0:00:48.882
Why are we here?

0:00:49.215,0:00:50.889
Why does our universe exist?

0:00:51.476,0:00:53.523
How did Earth form and evolve?

0:00:53.912,0:00:56.896
How and why did life originate[br]and populate our planet?

0:00:57.665,0:01:00.720
The second question[br]that we often think about is:

0:01:00.744,0:01:02.030
Are we alone?

0:01:02.911,0:01:04.299
Is there life out there?

0:01:05.109,0:01:06.601
Who is out there?

0:01:07.783,0:01:10.789
You know, this question has been around[br]for thousands of years,

0:01:10.813,0:01:13.230
since at least the time[br]of the Greek philosophers.

0:01:13.254,0:01:15.801
But I'm here to tell you[br]just how close we're getting

0:01:15.825,0:01:18.706
to finding out the answer[br]to this question.

0:01:18.730,0:01:22.945
It's the first time in human history[br]that this really is within reach for us.

0:01:23.294,0:01:26.273
Now when I think about the possibilities[br]for life out there,

0:01:26.297,0:01:30.384
I think of the fact that our sun[br]is but one of many stars.

0:01:30.825,0:01:32.703
This is a photograph of a real galaxy,

0:01:32.727,0:01:35.173
we think our Milky Way[br]looks like this galaxy.

0:01:35.197,0:01:36.836
It's a collection of bound stars.

0:01:36.860,0:01:41.247
But our Milky Way is one[br]of hundreds of billions of stars

0:01:41.271,0:01:45.595
and our galaxy is one of upwards[br]of hundreds of billions of galaxies.

0:01:46.707,0:01:49.474
Knowing that small planets[br]are very common,

0:01:49.498,0:01:50.772
you can just do the math.

0:01:51.424,0:01:55.425
And there are just so many stars[br]and so many planets out there,

0:01:55.449,0:01:58.139
that surely, there must be life[br]somewhere out there.

0:01:59.060,0:02:02.480
Well, the biologists get furious[br]with me for saying that,

0:02:02.504,0:02:05.948
because we have absolutely no evidence[br]for life beyond Earth, yet.

0:02:06.977,0:02:11.770
Well, if we were able to look[br]at our galaxy from the outside

0:02:11.794,0:02:14.002
and zoom in to where our sun is,

0:02:14.026,0:02:15.586
we see a real map of the stars.

0:02:16.046,0:02:19.069
And the highlighted stars[br]are those with known exoplanets.

0:02:19.745,0:02:21.934
This is really just[br]the tip of the iceberg.

0:02:22.642,0:02:26.284
Here, this animation is zooming in[br]onto our solar system.

0:02:26.872,0:02:28.357
And you'll see here the planets

0:02:28.381,0:02:31.214
as well as some spacecraft[br]that are also orbiting our sun.

0:02:32.968,0:02:36.332
Now if we can imagine going[br]to the west coast of North America,

0:02:36.356,0:02:38.482
and looking out at the night sky,

0:02:38.506,0:02:40.784
here's what we'd see on a spring night.

0:02:40.808,0:02:42.818
And you can see[br]the constellations overlaid

0:02:42.842,0:02:45.111
and again, so many stars with planets.

0:02:45.135,0:02:49.329
There's a special patch of the sky[br]where we have thousands of planets.

0:02:49.353,0:02:53.043
This is where the Kepler Space Telescope[br]focused for many years.

0:02:53.576,0:02:58.250
Let's zoom in and look[br]at one of the favorite exoplanets.

0:02:58.863,0:03:02.124
This star is called Kepler-186f.

0:03:02.529,0:03:04.727
It's a system of about five planets.

0:03:04.751,0:03:08.576
And by the way, most of these exoplanets,[br]we don't know too much about.

0:03:08.600,0:03:11.583
We know their size, and their orbit[br]and things like that.

0:03:11.607,0:03:15.569
But there's a very special planet[br]here called Kepler-186f.

0:03:15.593,0:03:19.697
This planet is in a zone[br]that is not too far from the star,

0:03:19.721,0:03:22.980
so that the temperature[br]may be just right for life.

0:03:23.004,0:03:26.035
Here, the artist's conception[br]is just zooming in

0:03:26.059,0:03:28.329
and showing you what that planet[br]might be like.

0:03:31.074,0:03:36.676
So, many people have this[br]romantic notion of astronomers

0:03:36.700,0:03:40.256
going to the telescope[br]on a lonely mountaintop

0:03:40.280,0:03:43.829
and looking at the spectacular night sky[br]through a big telescope.

0:03:43.853,0:03:47.225
But actually, we just work[br]on our computers like everyone else,

0:03:47.249,0:03:51.074
and we get our data by email[br]or downloading from a database.

0:03:51.098,0:03:53.621
So instead of coming here to tell you

0:03:53.645,0:03:56.776
about the somewhat tedious nature[br]of the data and data analysis

0:03:56.800,0:03:58.866
and the complex computer models we make,

0:03:58.890,0:04:01.088
I have a different way[br]to try to explain to you

0:04:01.112,0:04:03.757
some of the things[br]that we're thinking about exoplanets.

0:04:03.781,0:04:04.947
Here's a travel poster:

0:04:04.971,0:04:07.291
"Kepler-186f:

0:04:07.315,0:04:10.029
Where the grass is always redder[br]on the other side."

0:04:10.053,0:04:13.783
That's because Kepler-186f[br]orbits a red star,

0:04:13.807,0:04:16.499
and we're just speculating[br]that perhaps the plants there,

0:04:16.523,0:04:19.141
if there is vegetation[br]that does photosynthesis,

0:04:19.165,0:04:21.108
it has different pigments and looks red.

0:04:22.137,0:04:26.495
"Enjoy the gravity on HD 40307g,

0:04:26.519,0:04:27.978
a Super-Earth."

0:04:28.002,0:04:30.159
This planet is more massive than Earth

0:04:30.183,0:04:31.905
and has a higher surface gravity.

0:04:32.333,0:04:35.230
"Relax on Kepler-16b,

0:04:35.254,0:04:37.150
where your shadow always has company."

0:04:37.174,0:04:39.134
(Laughter)

0:04:39.158,0:04:43.340
We know of a dozen planets[br]that orbit two stars,

0:04:43.364,0:04:45.483
and there's likely many more out there.

0:04:45.507,0:04:47.468
If we could visit one of those planets,

0:04:47.492,0:04:49.379
you literally would see two sunsets

0:04:49.403,0:04:50.658
and have two shadows.

0:04:51.484,0:04:53.901
So actually, science fiction[br]got some things right.

0:04:53.925,0:04:55.134
Tatooine from Star Wars.

0:04:56.047,0:04:58.342
And I have a couple of other[br]favorite exoplanets

0:04:58.366,0:04:59.563
to tell you about.

0:04:59.587,0:05:01.119
This one is Kepler-10b,

0:05:01.143,0:05:03.126
it's a hot, hot planet.

0:05:03.642,0:05:06.577
It orbits over 50 times closer to its star

0:05:06.601,0:05:08.768
than the Earth does to our sun.

0:05:08.792,0:05:10.372
And actually, it's so hot,

0:05:10.396,0:05:13.029
we can't visit any[br]of these planets, but if we could,

0:05:13.053,0:05:15.027
we would melt long before we got there.

0:05:15.051,0:05:17.380
We think the surface[br]is hot enough to melt rock

0:05:17.404,0:05:18.830
and has liquid lava lakes.

0:05:19.457,0:05:21.041
Gliese 1214b.

0:05:21.065,0:05:23.164
This planet, we know the mass and the size

0:05:23.188,0:05:24.776
and it has a fairly low density.

0:05:24.800,0:05:25.998
It's somewhat warm.

0:05:26.053,0:05:28.737
We actually don't know[br]really anything about this planet,

0:05:28.761,0:05:31.266
but one possibility[br]is that it's a water world,

0:05:31.290,0:05:34.797
like a scaled-up version[br]of one of Jupiter's icy moons

0:05:34.821,0:05:37.304
that might be 50 percent water by mass.

0:05:37.328,0:05:40.289
And in this case, it would have[br]a thick steam atmosphere

0:05:40.313,0:05:42.169
overlaying an ocean,

0:05:42.193,0:05:43.703
not of liquid water,

0:05:43.727,0:05:46.732
but of an exotic form[br]of water, a superfluid --

0:05:46.756,0:05:48.746
not quite a gas, not quite a liquid.

0:05:48.770,0:05:50.370
And under that wouldn't be rock,

0:05:50.394,0:05:51.990
but a form of high-pressure ice,

0:05:52.014,0:05:53.290
like ice IX.

0:05:54.593,0:05:56.768
So out of all these planets out there,

0:05:56.792,0:06:00.006
and the variety[br]is just simply astonishing,

0:06:00.030,0:06:05.160
we mostly want to find the planets[br]that are Goldilocks planets, we call them.

0:06:05.184,0:06:07.101
Not too big, not too small,

0:06:07.125,0:06:08.972
not too hot, not too cold --

0:06:08.996,0:06:10.345
but just right for life.

0:06:10.658,0:06:12.776
But to do that,[br]we'd have to be able to look

0:06:12.800,0:06:14.134
at the planet's atmosphere,

0:06:14.158,0:06:16.954
because the atmosphere[br]acts like a blanket trapping heat --

0:06:16.978,0:06:18.314
the greenhouse effect.

0:06:18.338,0:06:21.158
We have to be able to asses[br]the greenhouse gases

0:06:21.182,0:06:22.332
on other planets.

0:06:23.169,0:06:25.288
Well, science fiction[br]got some things wrong.

0:06:25.796,0:06:27.186
The Star Trek Enterprise

0:06:27.210,0:06:30.837
had to travel vast distances[br]at incredible speeds

0:06:30.861,0:06:32.590
to orbit other planets

0:06:32.614,0:06:36.590
so that First Officer Spock[br]could analyze the atmosphere

0:06:36.614,0:06:38.575
to see if the planet was habitable

0:06:38.599,0:06:40.272
or if there were lifeforms there.

0:06:40.745,0:06:43.235
Well, we don't need[br]to travel at warp speeds

0:06:43.259,0:06:45.388
to see other planet atmospheres,

0:06:45.412,0:06:48.196
although I don't want to dissuade[br]any budding engineers

0:06:48.220,0:06:50.143
from figuring out how to do that.

0:06:50.167,0:06:52.459
We actually can and do study[br]planet atmospheres

0:06:52.483,0:06:54.096
from here, from Earth orbit.

0:06:54.120,0:06:57.297
This is a picture, a photograph[br]of the Hubble Space Telescope

0:06:57.321,0:07:00.071
taken by the shuttle Atlantis[br]as it was departing

0:07:00.095,0:07:02.334
after the last[br]human space flight to Hubble.

0:07:02.358,0:07:04.244
They installed a new camera, actually,

0:07:04.268,0:07:06.413
that we use for exoplanet atmospheres.

0:07:06.437,0:07:11.342
And so far, we've been able to study[br]dozens of exoplanet atmospheres,

0:07:11.366,0:07:13.490
about six of them in great detail.

0:07:13.514,0:07:15.686
But those are not[br]small planets like Earth.

0:07:15.710,0:07:18.104
They're big, hot planets[br]that are easy to see.

0:07:18.128,0:07:19.366
We're not ready,

0:07:19.390,0:07:23.765
we don't have the right technology yet[br]to study small exoplanets.

0:07:24.106,0:07:25.264
But nevertheless,

0:07:25.288,0:07:29.185
I wanted to try to explain to you[br]how we study exoplanet atmospheres.

0:07:29.652,0:07:31.874
I want you to imagine,[br]for a moment, a rainbow.

0:07:32.532,0:07:35.278
And if we could look[br]at this rainbow closely,

0:07:35.302,0:07:37.969
we would see that some[br]dark lines are missing.

0:07:39.127,0:07:40.548
And here's our sun,

0:07:40.572,0:07:42.339
the white light of our sun split up,

0:07:42.363,0:07:44.649
not by raindrops, but by a spectrograph.

0:07:44.673,0:07:47.124
And you can see[br]all these dark, vertical lines.

0:07:47.148,0:07:48.702
Some are narrow, some are wide,

0:07:48.726,0:07:50.407
some are shaded at the edges.

0:07:50.431,0:07:54.035
And this is how astronomers[br]have studied objects in the heavens,

0:07:54.059,0:07:55.554
literally, for over a century.

0:07:55.578,0:07:58.004
So here, each different atom and molecule

0:07:58.028,0:07:59.553
has a special set of lines,

0:07:59.577,0:08:01.133
a fingerprint, if you will.

0:08:01.157,0:08:03.894
And that's how we study[br]exoplanet atmospheres.

0:08:03.918,0:08:06.278
And I'll just never forget[br]when I started working

0:08:06.302,0:08:08.158
on exoplanet atmospheres 20 years ago,

0:08:08.182,0:08:09.367
how many people told me,

0:08:09.391,0:08:10.600
"This will never happen,

0:08:10.624,0:08:13.414
we'll never be able to study them.[br]Why are you bothering?"

0:08:13.438,0:08:17.112
And that's why I'm pleased to tell you[br]about all the atmospheres studied now,

0:08:17.136,0:08:18.985
and this is really a field of its own.

0:08:19.009,0:08:21.531
So when it comes to[br]other planets, other earths,

0:08:21.555,0:08:23.632
in the future when we can observe them,

0:08:23.656,0:08:25.715
what kind of gases would be looking for?

0:08:26.144,0:08:29.319
Well, you know, our own Earth[br]has oxygen in the atmosphere

0:08:29.343,0:08:30.802
to 20 percent by volume.

0:08:31.445,0:08:32.714
That's a lot of oxygen.

0:08:33.457,0:08:36.202
But without plants[br]and photosynthetic life,

0:08:36.226,0:08:37.636
there would be no oxygen,

0:08:37.660,0:08:39.501
virtually no oxygen in our atmosphere.

0:08:40.116,0:08:42.039
So oxygen is here because of life.

0:08:42.063,0:08:46.170
And our goal then is to look for gases[br]in other planet atmospheres,

0:08:46.194,0:08:48.231
gases that don't belong,

0:08:48.255,0:08:50.638
that we might be able[br]to attribute to life.

0:08:50.662,0:08:52.743
But which molecules should we search for?

0:08:52.767,0:08:55.430
I actually told you[br]how diverse exoplanets are.

0:08:55.454,0:08:57.451
We expect that to continue in the future

0:08:57.475,0:08:58.776
when we find other earths.

0:08:58.800,0:09:01.372
And that's one of the main things[br]I'm working on now,

0:09:01.396,0:09:02.689
I have a theory about this.

0:09:02.713,0:09:05.001
It reminds me that nearly every day,

0:09:05.025,0:09:07.677
I receive an email or emails

0:09:07.701,0:09:11.328
from someone with a crazy theory[br]about physics of gravity

0:09:11.352,0:09:13.184
or cosmology or some such.

0:09:13.208,0:09:16.541
So, please don't email me[br]one of your crazy theories.

0:09:16.565,0:09:17.779
(Laughter)

0:09:17.803,0:09:19.981
Well, I had my own crazy theory.

0:09:20.005,0:09:21.989
But, who does the MIT professor go to?

0:09:22.703,0:09:26.914
Well, I emailed a Nobel Laureate[br]in physiology and medicine

0:09:26.938,0:09:28.911
and he said, "Sure, come and talk to me."

0:09:28.935,0:09:30.934
So I brought my two biochemistry friends

0:09:30.958,0:09:33.310
and we went to talk to him[br]about our crazy theory.

0:09:33.334,0:09:36.775
And that theory was that life[br]produces all small molecules,

0:09:36.799,0:09:38.473
so many molecules.

0:09:38.497,0:09:41.392
Like, everything I could think of,[br]but not being a chemist.

0:09:41.416,0:09:42.599
Think about it:

0:09:42.623,0:09:44.653
carbon dioxide, carbon monoxide,

0:09:44.677,0:09:46.536
molecular hydrogen, molecular nitrogen,

0:09:46.560,0:09:47.926
methane, methyl chloride --

0:09:47.950,0:09:49.111
so many gases.

0:09:49.135,0:09:51.070
They also exist for other reasons,

0:09:51.094,0:09:52.946
but just life even produces ozone.

0:09:52.970,0:09:54.728
So we go to talk to him about this,

0:09:54.752,0:09:56.894
and immediately, he shot down the theory.

0:09:57.226,0:09:59.493
He found an example that didn't exist.

0:09:59.948,0:10:01.729
So, we went back to the drawing board

0:10:01.753,0:10:05.181
and we think we have found something[br]very interesting in another field.

0:10:05.205,0:10:06.625
But back to exoplanets,

0:10:06.649,0:10:09.928
the point is that life produces[br]so many different types of gases,

0:10:09.952,0:10:12.164
literally thousands of gases.

0:10:12.188,0:10:14.855
And so what we're doing now[br]is just trying to figure out

0:10:14.879,0:10:16.468
on which types of exoplanets,

0:10:16.492,0:10:19.712
which gases could be attributed to life.

0:10:22.182,0:10:24.230
And so when it comes time[br]when we find gases

0:10:24.254,0:10:25.605
in exoplanet atmospheres

0:10:25.629,0:10:27.725
that we won't know[br]if they're being produced

0:10:27.749,0:10:30.779
by intelligent aliens or by trees,

0:10:30.803,0:10:32.013
or a swamp,

0:10:32.037,0:10:34.898
or even just by simple,[br]single-celled microbial life.

0:10:35.541,0:10:37.091
So working on the models

0:10:37.115,0:10:38.766
and thinking about biochemistry,

0:10:38.790,0:10:39.987
it's all well and good.

0:10:40.011,0:10:42.896
But a really big challenge[br]ahead of us is how.

0:10:42.920,0:10:45.082
How are we going to find these planets?

0:10:45.106,0:10:47.170
They're actually many ways[br]to find planets,

0:10:47.194,0:10:48.829
several different ways.

0:10:48.853,0:10:52.712
But the one that I'm most focused on[br]is how can we open a gateway

0:10:52.736,0:10:53.973
so that in the future,

0:10:53.997,0:10:55.846
we can find hundreds of earths.

0:10:55.870,0:10:58.203
We have a real shot[br]at finding signs of life.

0:10:58.227,0:11:01.353
And actually, I just finished[br]leading a two-year project

0:11:01.377,0:11:03.465
in this very special phase

0:11:03.489,0:11:06.143
of a concept we call the starshade.

0:11:06.167,0:11:09.120
And the starshade[br]is a very specially shaped screen

0:11:09.144,0:11:11.011
and the goal is to fly that starshade

0:11:11.035,0:11:14.129
so it blocks out the light of a star

0:11:14.153,0:11:17.092
so that a telescope[br]can see the planets directly.

0:11:17.116,0:11:19.509
Here, you can see myself[br]and two team members

0:11:19.533,0:11:21.722
holding up one small part[br]of the starshade.

0:11:21.746,0:11:23.326
It's shaped like a giant flower,

0:11:23.350,0:11:25.833
and this is one of the prototype petals.

0:11:26.907,0:11:31.368
The concept is that a starshade[br]and telescope could launch together,

0:11:31.392,0:11:33.986
with the petals unfurling[br]from the stowed position.

0:11:34.896,0:11:36.952
The central truss would expand,

0:11:36.976,0:11:40.068
with the petals snapping into place.

0:11:40.092,0:11:42.322
Now, this has to be made very precisely,

0:11:42.346,0:11:43.934
literally, the petals to microns

0:11:43.958,0:11:46.673
and they have to deploy to millimeters.

0:11:46.697,0:11:48.752
And this whole structure would have to fly

0:11:48.776,0:11:52.135
tens of thousands of kilometers[br]away from the telescope.

0:11:52.159,0:11:54.301
It's about tens of meters in diameter.

0:11:54.785,0:11:59.738
And the goal is to block out[br]the starlight to incredible precision

0:11:59.762,0:12:02.500
so that we'd be able to see[br]the planets directly.

0:12:03.333,0:12:05.562
And it has to be a very special shape,

0:12:05.586,0:12:07.475
because of the physics of defraction.

0:12:07.499,0:12:09.718
Now this is a real project[br]that we worked on,

0:12:09.742,0:12:12.210
literally, you would not believe how hard.

0:12:12.234,0:12:14.896
Just so you believe[br]it's not just in movie format,

0:12:14.920,0:12:16.556
here's a real photograph

0:12:16.580,0:12:21.571
of a second-generation[br]starshade deployment test bed in the lab.

0:12:21.595,0:12:23.674
And in this case,[br]I just wanted you to know

0:12:23.698,0:12:26.188
that that central truss[br]has heritage left over

0:12:26.212,0:12:28.126
from large radio deployables in space.

0:12:29.372,0:12:31.028
So after all of that hard work

0:12:31.052,0:12:34.845
where we try to think of all the crazy[br]gases that might be out there,

0:12:34.869,0:12:37.797
and we build the very[br]complicated space telescopes

0:12:37.821,0:12:39.048
that might be out there,

0:12:39.072,0:12:40.368
what are we going to find?

0:12:40.725,0:12:42.483
Well, in the best case,

0:12:42.507,0:12:45.304
we will find an image[br]of another exo-Earth.

0:12:46.328,0:12:48.587
Here is Earth as a pale blue dot.

0:12:48.611,0:12:51.170
And this is actually[br]a real photograph of Earth

0:12:51.194,0:12:53.064
taken by the Voyager 1 spacecraft,

0:12:53.088,0:12:54.706
four billion miles away.

0:12:55.159,0:12:58.397
And that red light is just scattered light[br]in the camera optics.

0:12:59.315,0:13:01.711
But what's so awesome to consider

0:13:01.735,0:13:04.784
is that if there are intelligent aliens

0:13:04.808,0:13:08.762
orbiting on a planet[br]around a star near to us

0:13:08.786,0:13:10.831
and they build complicated[br]space telescopes

0:13:10.855,0:13:12.782
of the kind that we're trying to build,

0:13:12.806,0:13:15.306
all they'll see is this pale blue dot,

0:13:15.330,0:13:16.615
a pinprick of light.

0:13:17.456,0:13:20.522
And so sometimes, when I pause to think

0:13:20.546,0:13:24.799
about my professional struggle[br]and huge ambition,

0:13:24.823,0:13:26.816
it's hard to think about that

0:13:26.840,0:13:29.259
in contrast to the vastness[br]of the universe.

0:13:30.120,0:13:34.246
But nonetheless, I am devoting[br]the rest of my life

0:13:34.270,0:13:35.620
to finding another Earth.

0:13:36.296,0:13:38.511
And I can guarantee

0:13:38.535,0:13:40.918
that in the next generation[br]of space telescopes,

0:13:40.942,0:13:42.482
and the second generation,

0:13:42.506,0:13:47.912
we will have the capability[br]to find and identity other earths.

0:13:47.936,0:13:50.610
And the capability[br]to split up the starlight

0:13:50.634,0:13:52.187
so that we can look for gases

0:13:52.211,0:13:55.697
and assess the greenhouse gases[br]in the atmosphere,

0:13:55.721,0:13:57.319
estimate the surface temperature,

0:13:57.343,0:13:59.101
and look for signs of life.

0:13:59.736,0:14:01.157
But there's more.

0:14:01.181,0:14:04.545
In this case of searching[br]for other planets like Earth,

0:14:04.569,0:14:07.164
we are making a new kind of map

0:14:07.188,0:14:10.448
of the nearby stars[br]and of the planets orbiting them,

0:14:10.472,0:14:14.243
including stars that actually might be[br]inhabitable by humans.

0:14:14.915,0:14:17.296
And so I envision that our descendants,

0:14:17.320,0:14:19.125
hundreds of years from now,

0:14:19.149,0:14:22.176
will embark on an interstellar[br]journey to other worlds.

0:14:23.059,0:14:25.971
And they will look back at all of us

0:14:25.995,0:14:29.003
as the generation who first found[br]the Earth-like worlds.

0:14:29.822,0:14:30.973
Thank you.

0:14:30.997,0:14:37.508
(Applause)

0:14:37.532,0:14:39.632
June Cohen: And I give you,[br]for a question,

0:14:39.656,0:14:41.384
Rosetta Mission manager Fred Jansen.

0:14:41.817,0:14:43.848
Fred Jansen: You mentioned halfway through

0:14:43.872,0:14:47.659
that the technology[br]to actually look at the spectrum

0:14:47.683,0:14:50.312
of an exoplanet like Earth[br]is not there yet.

0:14:50.336,0:14:52.223
When do you expect this will be there,

0:14:52.247,0:14:53.515
and what's needed?

0:14:53.539,0:14:58.154
Actually, what we expect is what we call[br]our next-generation Hubble telescope.

0:14:58.531,0:15:00.872
And this is called the James Webb[br]Space Telescope,

0:15:00.896,0:15:02.599
and that will launch in 2018,

0:15:02.623,0:15:04.445
and that's what we're going to do,

0:15:04.469,0:15:06.733
we're going to look[br]at a special kind of planet

0:15:06.757,0:15:08.213
called transient exoplanets,

0:15:08.237,0:15:11.338
and that will be our first shot[br]at studying small planets

0:15:11.362,0:15:14.660
for gases that might indicate[br]the planet is habitable.

0:15:15.477,0:15:18.286
JC: I'm going to ask you[br]one follow-up question, too, Sara,

0:15:18.310,0:15:19.516
as the generalist.

0:15:19.540,0:15:22.633
So I am really struck[br]by the notion in your career

0:15:22.657,0:15:24.056
of the opposition you faced,

0:15:24.080,0:15:26.224
that when you began thinking[br]about exoplanets,

0:15:26.248,0:15:28.914
there was extreme skepticism[br]in the scientific community

0:15:28.938,0:15:30.089
that they existed,

0:15:30.113,0:15:31.382
and you proved them wrong.

0:15:31.406,0:15:33.119
What did it take to take that on?

0:15:33.143,0:15:35.213
SS: Well, the thing is that as scientists,

0:15:35.237,0:15:37.195
we're supposed to be skeptical,

0:15:37.219,0:15:40.267
because our job to make sure[br]that what the other person is saying

0:15:40.291,0:15:41.630
actually makes sense or not.

0:15:41.654,0:15:44.211
But being a scientist,

0:15:44.235,0:15:46.655
I think you've seen it from this session,

0:15:46.679,0:15:48.361
it's like being an explorer.

0:15:48.385,0:15:50.374
You have this immense curiosity,

0:15:50.398,0:15:51.697
this stubbornness,

0:15:51.721,0:15:54.103
this sort of resolute will[br]that you will go forward

0:15:54.127,0:15:56.158
no matter what other people say.

0:15:56.182,0:15:57.858
JC: I love that. Thank you, Sara.

0:15:57.882,0:16:00.877
(Applause)