[Script Info]
Title: 
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:01.33,0:00:04.79,Default,,0000,0000,0000,,So I'm pretty sure that I'm not\Nthe only one in this room
Dialogue: 0,0:00:04.81,0:00:09.52,Default,,0000,0000,0000,,who at some point have found myself,\Nyou know, looking up towards the stars,
Dialogue: 0,0:00:09.55,0:00:12.18,Default,,0000,0000,0000,,and wondered, you know, "Are we it,
Dialogue: 0,0:00:12.20,0:00:16.00,Default,,0000,0000,0000,,or are there other living planets\Nout there such as our own?"
Dialogue: 0,0:00:17.01,0:00:20.52,Default,,0000,0000,0000,,I guess it is possible\Nthat I'm then the only person
Dialogue: 0,0:00:20.54,0:00:22.82,Default,,0000,0000,0000,,who has obsessed enough\Nabout that question
Dialogue: 0,0:00:22.84,0:00:24.46,Default,,0000,0000,0000,,to make it my career.
Dialogue: 0,0:00:24.48,0:00:26.48,Default,,0000,0000,0000,,But moving on.
Dialogue: 0,0:00:26.51,0:00:29.62,Default,,0000,0000,0000,,How do we get to this question?
Dialogue: 0,0:00:29.64,0:00:32.01,Default,,0000,0000,0000,,Well, I would argue the first thing to do
Dialogue: 0,0:00:32.03,0:00:37.45,Default,,0000,0000,0000,,is to turn our eyes back down from the sky\Nto our own planet, the Earth.
Dialogue: 0,0:00:38.17,0:00:42.38,Default,,0000,0000,0000,,And think about just how lucky\Ndid the Earth have to be
Dialogue: 0,0:00:42.40,0:00:44.63,Default,,0000,0000,0000,,to be the living planet it is.
Dialogue: 0,0:00:44.65,0:00:46.90,Default,,0000,0000,0000,,Well, it had to be\Nat least somewhat lucky.
Dialogue: 0,0:00:46.92,0:00:49.43,Default,,0000,0000,0000,,Had we been sitting closer to the Sun
Dialogue: 0,0:00:49.45,0:00:51.46,Default,,0000,0000,0000,,or a bit further away,
Dialogue: 0,0:00:51.48,0:00:55.100,Default,,0000,0000,0000,,any water that we have had\Nwould have boiled off or frozen over.
Dialogue: 0,0:00:56.02,0:01:00.08,Default,,0000,0000,0000,,And I mean, it's not a given\Nthat a planet has water on it.
Dialogue: 0,0:01:00.11,0:01:03.72,Default,,0000,0000,0000,,So had we been a dry planet,
Dialogue: 0,0:01:03.75,0:01:06.08,Default,,0000,0000,0000,,there would not have been\Na lot of life on it.
Dialogue: 0,0:01:06.11,0:01:09.66,Default,,0000,0000,0000,,And even if we had had all the water\Nthat we have today,
Dialogue: 0,0:01:09.69,0:01:11.93,Default,,0000,0000,0000,,if that water had not been accompanied
Dialogue: 0,0:01:11.96,0:01:15.07,Default,,0000,0000,0000,,by the right kind of chemicals\Nto get life going,
Dialogue: 0,0:01:15.09,0:01:18.01,Default,,0000,0000,0000,,we would have a wet planet,\Nbut just as dead.
Dialogue: 0,0:01:18.32,0:01:20.58,Default,,0000,0000,0000,,So it's so many things that can go wrong,
Dialogue: 0,0:01:20.60,0:01:23.52,Default,,0000,0000,0000,,what are the chances that they go right?
Dialogue: 0,0:01:23.55,0:01:25.98,Default,,0000,0000,0000,,What are the chances that the planet forms
Dialogue: 0,0:01:26.01,0:01:28.66,Default,,0000,0000,0000,,with at least the basic ingredients needed
Dialogue: 0,0:01:28.68,0:01:31.28,Default,,0000,0000,0000,,to have an origins of life happening?
Dialogue: 0,0:01:32.52,0:01:35.17,Default,,0000,0000,0000,,Well, let's explore that together.
Dialogue: 0,0:01:35.19,0:01:37.24,Default,,0000,0000,0000,,So if you're going to have\Na living planet,
Dialogue: 0,0:01:37.26,0:01:40.67,Default,,0000,0000,0000,,the first thing you're going to need
Dialogue: 0,0:01:40.69,0:01:42.48,Default,,0000,0000,0000,,is a planet.
Dialogue: 0,0:01:42.51,0:01:43.51,Default,,0000,0000,0000,,(Laughter)
Dialogue: 0,0:01:43.53,0:01:45.66,Default,,0000,0000,0000,,But not any planet will do.
Dialogue: 0,0:01:45.68,0:01:49.46,Default,,0000,0000,0000,,You're probably going to need\Na rather specific and earthlike planet.
Dialogue: 0,0:01:49.48,0:01:50.97,Default,,0000,0000,0000,,A planet that is rocky,
Dialogue: 0,0:01:50.100,0:01:53.11,Default,,0000,0000,0000,,so you can have both oceans and land,
Dialogue: 0,0:01:53.13,0:01:57.36,Default,,0000,0000,0000,,and it's sitting neither too close\Nnor too far away from its star,
Dialogue: 0,0:01:57.39,0:01:59.84,Default,,0000,0000,0000,,but at the just-right temperature.
Dialogue: 0,0:01:59.86,0:02:03.16,Default,,0000,0000,0000,,And it's just right\Nfor liquid water, that is.
Dialogue: 0,0:02:03.18,0:02:06.28,Default,,0000,0000,0000,,So how many of these planets\Ndo we have in our galaxy?
Dialogue: 0,0:02:06.80,0:02:10.27,Default,,0000,0000,0000,,Well, one of the great discoveries\Nof the past decades
Dialogue: 0,0:02:10.29,0:02:12.77,Default,,0000,0000,0000,,is that planets are incredibly common.
Dialogue: 0,0:02:13.21,0:02:16.21,Default,,0000,0000,0000,,Almost every star\Nhas a planet around them.
Dialogue: 0,0:02:16.24,0:02:17.65,Default,,0000,0000,0000,,Some have many.
Dialogue: 0,0:02:17.67,0:02:20.56,Default,,0000,0000,0000,,And among these planets,
Dialogue: 0,0:02:20.59,0:02:24.43,Default,,0000,0000,0000,,on the order of a few percent\Nare earthlike enough
Dialogue: 0,0:02:24.45,0:02:28.01,Default,,0000,0000,0000,,that we would consider them\Npotentially living planets.
Dialogue: 0,0:02:28.03,0:02:31.66,Default,,0000,0000,0000,,So having the right kind of planet\Nis actually not that difficult
Dialogue: 0,0:02:31.69,0:02:35.93,Default,,0000,0000,0000,,when we consider that there's\Nabout 100 billion stars in our galaxy.
Dialogue: 0,0:02:35.95,0:02:40.05,Default,,0000,0000,0000,,So that gives you about a billion\Npotential living planets.
Dialogue: 0,0:02:40.43,0:02:43.01,Default,,0000,0000,0000,,But it's not enough to just be\Nat the right temperature
Dialogue: 0,0:02:43.04,0:02:44.85,Default,,0000,0000,0000,,or have the right overall composition.
Dialogue: 0,0:02:44.87,0:02:47.14,Default,,0000,0000,0000,,You also need the right chemicals.
Dialogue: 0,0:02:47.55,0:02:51.77,Default,,0000,0000,0000,,And what the second and important\Ningredient to make a living planet is --
Dialogue: 0,0:02:51.79,0:02:54.72,Default,,0000,0000,0000,,I think it's pretty intuitive --
Dialogue: 0,0:02:54.74,0:02:56.33,Default,,0000,0000,0000,,it's water.
Dialogue: 0,0:02:56.36,0:03:01.50,Default,,0000,0000,0000,,After all, we did define our planet\Nas being potentially living
Dialogue: 0,0:03:01.52,0:03:04.20,Default,,0000,0000,0000,,if it had the right temperature\Nto keep water liquid.
Dialogue: 0,0:03:04.84,0:03:08.41,Default,,0000,0000,0000,,And I mean, here on Earth,\Nlife is water-based.
Dialogue: 0,0:03:08.71,0:03:10.00,Default,,0000,0000,0000,,But more generally,
Dialogue: 0,0:03:10.03,0:03:14.28,Default,,0000,0000,0000,,water is just really good\Nas a meeting place for chemicals.
Dialogue: 0,0:03:14.31,0:03:16.31,Default,,0000,0000,0000,,It is a very special liquid.
Dialogue: 0,0:03:16.33,0:03:19.91,Default,,0000,0000,0000,,So this is our second basic ingredient.
Dialogue: 0,0:03:20.28,0:03:22.21,Default,,0000,0000,0000,,Now the third ingredient, I think,
Dialogue: 0,0:03:22.23,0:03:24.85,Default,,0000,0000,0000,,is probably a little bit more surprising.
Dialogue: 0,0:03:24.87,0:03:27.66,Default,,0000,0000,0000,,I mean, we are going to need\Nsome organics in there,
Dialogue: 0,0:03:27.68,0:03:29.81,Default,,0000,0000,0000,,since we are thinking about organic life.
Dialogue: 0,0:03:30.19,0:03:31.90,Default,,0000,0000,0000,,But the organic molecule
Dialogue: 0,0:03:31.93,0:03:35.70,Default,,0000,0000,0000,,that seems to be at the center\Nof the chemical networks
Dialogue: 0,0:03:35.73,0:03:40.16,Default,,0000,0000,0000,,that can produce biomolecules\Nis hydrogen cyanide.
Dialogue: 0,0:03:40.48,0:03:43.81,Default,,0000,0000,0000,,So for those of you who know\Nwhat this molecule is like,
Dialogue: 0,0:03:43.84,0:03:47.22,Default,,0000,0000,0000,,you know it's something\Nthat it's a good idea to stay away from.
Dialogue: 0,0:03:47.78,0:03:48.93,Default,,0000,0000,0000,,But it turns out
Dialogue: 0,0:03:48.95,0:03:52.12,Default,,0000,0000,0000,,that what's really, really bad\Nfor advanced life forms,
Dialogue: 0,0:03:52.14,0:03:53.80,Default,,0000,0000,0000,,such as yourselves,
Dialogue: 0,0:03:53.82,0:03:57.31,Default,,0000,0000,0000,,is really, really good\Nto get the chemistry started,
Dialogue: 0,0:03:57.33,0:04:00.62,Default,,0000,0000,0000,,the right kind of chemistry\Nthat can lead to origins of life.
Dialogue: 0,0:04:01.18,0:04:03.98,Default,,0000,0000,0000,,So now we have our three\Ningredients that we need,
Dialogue: 0,0:04:04.01,0:04:06.01,Default,,0000,0000,0000,,you know, the temperate planet,
Dialogue: 0,0:04:06.03,0:04:08.58,Default,,0000,0000,0000,,water and hydrogen cyanide.
Dialogue: 0,0:04:08.60,0:04:11.37,Default,,0000,0000,0000,,So how often do these three come together?
Dialogue: 0,0:04:11.40,0:04:14.04,Default,,0000,0000,0000,,How many temperate planets\Nare there out there
Dialogue: 0,0:04:14.07,0:04:16.54,Default,,0000,0000,0000,,that have water and hydrogen cyanide?
Dialogue: 0,0:04:17.03,0:04:18.69,Default,,0000,0000,0000,,Well, in an ideal world,
Dialogue: 0,0:04:18.71,0:04:24.69,Default,,0000,0000,0000,,we would now turn one of our telescopes\Ntowards one of these temperate planets
Dialogue: 0,0:04:24.71,0:04:26.28,Default,,0000,0000,0000,,and check for ourselves.
Dialogue: 0,0:04:26.30,0:04:29.93,Default,,0000,0000,0000,,Just, "Do these planets have water\Nand cyanides on them?"
Dialogue: 0,0:04:30.53,0:04:36.66,Default,,0000,0000,0000,,Unfortunately, we don't yet\Nhave large enough telescopes to do this.
Dialogue: 0,0:04:36.69,0:04:40.57,Default,,0000,0000,0000,,We can detect molecules\Nin the atmospheres of some planets.
Dialogue: 0,0:04:40.59,0:04:42.20,Default,,0000,0000,0000,,But these are large planets
Dialogue: 0,0:04:42.22,0:04:44.68,Default,,0000,0000,0000,,sitting often pretty close to their star,
Dialogue: 0,0:04:44.70,0:04:47.49,Default,,0000,0000,0000,,nothing like these, you know,\Njust-right planets
Dialogue: 0,0:04:47.51,0:04:48.98,Default,,0000,0000,0000,,that we're talking about here,
Dialogue: 0,0:04:49.00,0:04:51.20,Default,,0000,0000,0000,,which are much smaller and further away.
Dialogue: 0,0:04:51.53,0:04:53.70,Default,,0000,0000,0000,,So we have to come up with another way.
Dialogue: 0,0:04:53.73,0:04:58.66,Default,,0000,0000,0000,,And the other way that we have\Nconceived of and then followed
Dialogue: 0,0:04:58.69,0:05:01.30,Default,,0000,0000,0000,,is to instead of looking\Nfor these molecules
Dialogue: 0,0:05:01.33,0:05:03.52,Default,,0000,0000,0000,,in the planets when they exist,
Dialogue: 0,0:05:03.54,0:05:07.28,Default,,0000,0000,0000,,is to look for them in the material\Nthat's forming new planets.
Dialogue: 0,0:05:07.31,0:05:11.75,Default,,0000,0000,0000,,So planets form in discs\Nof dust and gas around young stars.
Dialogue: 0,0:05:11.78,0:05:15.90,Default,,0000,0000,0000,,And these discs get their material\Nfrom the interstellar medium.
Dialogue: 0,0:05:15.92,0:05:18.63,Default,,0000,0000,0000,,Turns out that the empty space\Nyou see between stars
Dialogue: 0,0:05:18.66,0:05:22.39,Default,,0000,0000,0000,,when you are looking up towards them,\Nasking existential questions,
Dialogue: 0,0:05:22.42,0:05:24.59,Default,,0000,0000,0000,,is not as empty as it seems,
Dialogue: 0,0:05:24.61,0:05:26.57,Default,,0000,0000,0000,,but actually full of gas and dust,
Dialogue: 0,0:05:26.60,0:05:28.84,Default,,0000,0000,0000,,which can, you know,\Ncome together in clouds,
Dialogue: 0,0:05:28.87,0:05:32.22,Default,,0000,0000,0000,,then collapses to form these discs,\Nstars and planets.
Dialogue: 0,0:05:32.97,0:05:37.54,Default,,0000,0000,0000,,And one of the things we always see\Nwhen we do look at these clouds
Dialogue: 0,0:05:37.56,0:05:38.97,Default,,0000,0000,0000,,is water.
Dialogue: 0,0:05:38.99,0:05:41.66,Default,,0000,0000,0000,,You know, I think we have a tendency\Nto think about water
Dialogue: 0,0:05:41.69,0:05:44.29,Default,,0000,0000,0000,,as something that's,\Nyou know, special to us.
Dialogue: 0,0:05:44.85,0:05:48.66,Default,,0000,0000,0000,,Water is one of the most abundant\Nmolecules in the universe,
Dialogue: 0,0:05:48.68,0:05:50.41,Default,,0000,0000,0000,,including in these clouds,
Dialogue: 0,0:05:50.43,0:05:52.90,Default,,0000,0000,0000,,these star- and planet-forming clouds.
Dialogue: 0,0:05:53.66,0:05:54.82,Default,,0000,0000,0000,,And not only that --
Dialogue: 0,0:05:54.84,0:05:56.82,Default,,0000,0000,0000,,water is also a pretty robust molecule:
Dialogue: 0,0:05:56.84,0:05:59.24,Default,,0000,0000,0000,,it's actually not that easy to destroy.
Dialogue: 0,0:05:59.26,0:06:02.34,Default,,0000,0000,0000,,So a lot of this water\Nthat is in interstellar medium
Dialogue: 0,0:06:02.36,0:06:07.95,Default,,0000,0000,0000,,will survive the rather dangerous,\Ncollapsed journey from clouds
Dialogue: 0,0:06:07.97,0:06:10.16,Default,,0000,0000,0000,,to disc, to planet.
Dialogue: 0,0:06:10.97,0:06:13.05,Default,,0000,0000,0000,,So water is alright.
Dialogue: 0,0:06:13.07,0:06:15.93,Default,,0000,0000,0000,,That second ingredient\Nis not going to be a problem.
Dialogue: 0,0:06:15.95,0:06:20.17,Default,,0000,0000,0000,,Most planets are going to form\Nwith some access to water.
Dialogue: 0,0:06:21.12,0:06:23.46,Default,,0000,0000,0000,,So what about hydrogen cyanide?
Dialogue: 0,0:06:23.48,0:06:27.99,Default,,0000,0000,0000,,Well, we also see cyanides\Nand other similar organic molecules
Dialogue: 0,0:06:28.01,0:06:30.60,Default,,0000,0000,0000,,in these interstellar clouds.
Dialogue: 0,0:06:30.62,0:06:35.91,Default,,0000,0000,0000,,But here, we're less certain\Nabout the molecules surviving,
Dialogue: 0,0:06:35.93,0:06:37.94,Default,,0000,0000,0000,,going from the cloud to the disc.
Dialogue: 0,0:06:37.97,0:06:40.63,Default,,0000,0000,0000,,They're just a bit more delicate,\Na bit more fragile.
Dialogue: 0,0:06:40.66,0:06:43.99,Default,,0000,0000,0000,,So if we're going to know\Nthat this hydrogen cyanide
Dialogue: 0,0:06:44.02,0:06:47.22,Default,,0000,0000,0000,,is sitting in the vicinity\Nof new planets forming,
Dialogue: 0,0:06:47.25,0:06:49.54,Default,,0000,0000,0000,,we'd really need to see it\Nin the disc itself,
Dialogue: 0,0:06:49.56,0:06:51.79,Default,,0000,0000,0000,,in these planet-forming discs.
Dialogue: 0,0:06:51.82,0:06:54.26,Default,,0000,0000,0000,,So about a decade ago,
Dialogue: 0,0:06:54.28,0:06:59.52,Default,,0000,0000,0000,,I started a program\Nto look for this hydrogen cyanide
Dialogue: 0,0:06:59.55,0:07:02.72,Default,,0000,0000,0000,,and other molecules\Nin these planet-forming discs.
Dialogue: 0,0:07:02.75,0:07:05.98,Default,,0000,0000,0000,,And this is what we found.
Dialogue: 0,0:07:06.01,0:07:08.93,Default,,0000,0000,0000,,So good news, in these six images,
Dialogue: 0,0:07:08.95,0:07:15.07,Default,,0000,0000,0000,,those bright pixels represent emissions\Noriginating from hydrogen cyanide
Dialogue: 0,0:07:15.09,0:07:18.58,Default,,0000,0000,0000,,in planet-forming discs\Nhundreds of light-years away
Dialogue: 0,0:07:18.60,0:07:20.62,Default,,0000,0000,0000,,that have made it to our telescope,
Dialogue: 0,0:07:20.65,0:07:21.93,Default,,0000,0000,0000,,onto the detector,
Dialogue: 0,0:07:21.95,0:07:24.68,Default,,0000,0000,0000,,allowing us to see it like this.
Dialogue: 0,0:07:25.23,0:07:26.51,Default,,0000,0000,0000,,So the very good news
Dialogue: 0,0:07:26.53,0:07:30.60,Default,,0000,0000,0000,,is that these discs do indeed have\Nhydrogen cyanide in them.
Dialogue: 0,0:07:30.62,0:07:34.02,Default,,0000,0000,0000,,That last, more elusive ingredient.
Dialogue: 0,0:07:35.16,0:07:40.22,Default,,0000,0000,0000,,Now the bad news is that we don't know\Nwhere in the disc it is.
Dialogue: 0,0:07:40.81,0:07:42.21,Default,,0000,0000,0000,,If we look at these,
Dialogue: 0,0:07:42.23,0:07:44.53,Default,,0000,0000,0000,,I mean, no one can say\Nthey are beautiful images,
Dialogue: 0,0:07:44.55,0:07:47.32,Default,,0000,0000,0000,,even at the time when we got them.
Dialogue: 0,0:07:47.34,0:07:50.76,Default,,0000,0000,0000,,You see the pixel size is pretty big
Dialogue: 0,0:07:50.78,0:07:53.91,Default,,0000,0000,0000,,and it's actually bigger\Nthan these discs themselves.
Dialogue: 0,0:07:53.94,0:07:55.39,Default,,0000,0000,0000,,So each pixel here
Dialogue: 0,0:07:55.42,0:07:58.90,Default,,0000,0000,0000,,represents something that's much bigger\Nthan our solar system.
Dialogue: 0,0:07:59.34,0:08:01.28,Default,,0000,0000,0000,,And that means
Dialogue: 0,0:08:01.30,0:08:05.41,Default,,0000,0000,0000,,that we don't know where in the disc\Nthe hydrogen cyanide is coming from.
Dialogue: 0,0:08:05.77,0:08:06.100,Default,,0000,0000,0000,,And that's a problem,
Dialogue: 0,0:08:07.02,0:08:08.57,Default,,0000,0000,0000,,because these temperate planets,
Dialogue: 0,0:08:08.60,0:08:11.55,Default,,0000,0000,0000,,they can't access\Nhydrogen cyanide just anywhere,
Dialogue: 0,0:08:11.58,0:08:14.95,Default,,0000,0000,0000,,but it must be fairly close\Nto where they assemble
Dialogue: 0,0:08:14.98,0:08:16.87,Default,,0000,0000,0000,,for them to have access to it.
Dialogue: 0,0:08:16.89,0:08:22.03,Default,,0000,0000,0000,,So to bring this home,\Nlet's think about an analogous example,
Dialogue: 0,0:08:22.06,0:08:25.28,Default,,0000,0000,0000,,that is, of cypress growing\Nin the United States.
Dialogue: 0,0:08:25.66,0:08:27.37,Default,,0000,0000,0000,,So let's say, hypothetically,
Dialogue: 0,0:08:27.40,0:08:29.17,Default,,0000,0000,0000,,that you've returned from Europe
Dialogue: 0,0:08:29.19,0:08:31.93,Default,,0000,0000,0000,,where you have seen\Nbeautiful Italian cypresses,
Dialogue: 0,0:08:31.96,0:08:34.37,Default,,0000,0000,0000,,and you want to understand, you know,
Dialogue: 0,0:08:34.40,0:08:37.01,Default,,0000,0000,0000,,does it make sense to import them\Nto the United States.
Dialogue: 0,0:08:37.04,0:08:38.67,Default,,0000,0000,0000,,Could you grow them here?
Dialogue: 0,0:08:38.70,0:08:40.76,Default,,0000,0000,0000,,So you talk to the cypress experts,
Dialogue: 0,0:08:40.78,0:08:42.45,Default,,0000,0000,0000,,they tell you that there is indeed
Dialogue: 0,0:08:42.47,0:08:46.41,Default,,0000,0000,0000,,a band of not-too-hot, not-too-cold\Nacross the United States
Dialogue: 0,0:08:46.43,0:08:47.97,Default,,0000,0000,0000,,where you could grow them.
Dialogue: 0,0:08:47.100,0:08:51.90,Default,,0000,0000,0000,,And if you have a nice,\Nhigh-resolution map or image like this,
Dialogue: 0,0:08:51.92,0:08:54.74,Default,,0000,0000,0000,,it's quite easy to see\Nthat this cypress strip
Dialogue: 0,0:08:54.77,0:08:58.23,Default,,0000,0000,0000,,overlaps with a lot of green\Nfertile land pixels.
Dialogue: 0,0:08:58.75,0:09:01.72,Default,,0000,0000,0000,,Even if I start degrading\Nthis map quite a bit,
Dialogue: 0,0:09:01.74,0:09:04.05,Default,,0000,0000,0000,,making it lower and lower resolution,
Dialogue: 0,0:09:04.08,0:09:05.41,Default,,0000,0000,0000,,it's still possible to tell
Dialogue: 0,0:09:05.43,0:09:09.03,Default,,0000,0000,0000,,that there's going to be some fertile land\Noverlapping with this strip.
Dialogue: 0,0:09:09.47,0:09:14.50,Default,,0000,0000,0000,,But what about if the whole United States
Dialogue: 0,0:09:14.52,0:09:17.73,Default,,0000,0000,0000,,is incorporated into a single pixel?
Dialogue: 0,0:09:17.75,0:09:19.77,Default,,0000,0000,0000,,If the resolution is that low.
Dialogue: 0,0:09:19.79,0:09:21.08,Default,,0000,0000,0000,,What do you do now,
Dialogue: 0,0:09:21.11,0:09:26.23,Default,,0000,0000,0000,,how do you now tell whether you can grow\Ncypresses in the United States?
Dialogue: 0,0:09:26.54,0:09:28.47,Default,,0000,0000,0000,,Well the answer is you can't.
Dialogue: 0,0:09:28.49,0:09:30.88,Default,,0000,0000,0000,,I mean, there's definitely\Nsome fertile land there,
Dialogue: 0,0:09:30.90,0:09:33.66,Default,,0000,0000,0000,,or you wouldn't have\Nthat green tint to the pixel,
Dialogue: 0,0:09:33.68,0:09:35.65,Default,,0000,0000,0000,,but there's just no way of telling
Dialogue: 0,0:09:35.67,0:09:38.87,Default,,0000,0000,0000,,whether any of that green\Nis in the right place.
Dialogue: 0,0:09:38.90,0:09:41.66,Default,,0000,0000,0000,,And that is exactly the problem\Nwe were facing
Dialogue: 0,0:09:41.69,0:09:44.88,Default,,0000,0000,0000,,with our single-pixel\Nimages of these discs
Dialogue: 0,0:09:44.90,0:09:46.50,Default,,0000,0000,0000,,with hydrogen cyanide.
Dialogue: 0,0:09:46.52,0:09:48.70,Default,,0000,0000,0000,,So what we need is something analogous,
Dialogue: 0,0:09:48.72,0:09:51.79,Default,,0000,0000,0000,,at least those low-resolution maps\Nthat I just showed you,
Dialogue: 0,0:09:51.82,0:09:56.66,Default,,0000,0000,0000,,to be able to tell whether there's overlap\Nbetween where the hydrogen cyanide is
Dialogue: 0,0:09:56.69,0:09:59.65,Default,,0000,0000,0000,,and where these planets\Ncan access it as they are forming.
Dialogue: 0,0:10:00.24,0:10:03.44,Default,,0000,0000,0000,,So coming to the rescue, a few years ago,
Dialogue: 0,0:10:03.46,0:10:07.45,Default,,0000,0000,0000,,is this new, amazing,\Nbeautiful telescope ALMA,
Dialogue: 0,0:10:07.47,0:10:10.33,Default,,0000,0000,0000,,the Atacama Large Millimeter\Nand submillimeter Array
Dialogue: 0,0:10:10.35,0:10:11.55,Default,,0000,0000,0000,,in northern Chile.
Dialogue: 0,0:10:11.90,0:10:15.66,Default,,0000,0000,0000,,So, ALMA is amazing\Nin many different ways,
Dialogue: 0,0:10:15.69,0:10:18.17,Default,,0000,0000,0000,,but the one that I'm going to focus on
Dialogue: 0,0:10:18.20,0:10:22.12,Default,,0000,0000,0000,,is that, as you can see,\NI call this one telescope,
Dialogue: 0,0:10:22.14,0:10:25.48,Default,,0000,0000,0000,,but you can there are actually\Nmany dishes in this image.
Dialogue: 0,0:10:25.50,0:10:30.13,Default,,0000,0000,0000,,And this is a telescope\Nthat consists of 66 individual dishes
Dialogue: 0,0:10:30.15,0:10:31.75,Default,,0000,0000,0000,,that all work in unison.
Dialogue: 0,0:10:32.48,0:10:35.05,Default,,0000,0000,0000,,And that means that you have a telescope
Dialogue: 0,0:10:35.07,0:10:39.94,Default,,0000,0000,0000,,that is the size of the largest distance\Nthat you can put these dishes
Dialogue: 0,0:10:39.96,0:10:41.28,Default,,0000,0000,0000,,away from one another.
Dialogue: 0,0:10:41.30,0:10:44.40,Default,,0000,0000,0000,,Which in ALMA's case are a few miles.
Dialogue: 0,0:10:44.43,0:10:47.90,Default,,0000,0000,0000,,So you have a more\Nthan mile-sized telescope.
Dialogue: 0,0:10:48.27,0:10:50.14,Default,,0000,0000,0000,,And when you have such a big telescope,
Dialogue: 0,0:10:50.16,0:10:52.66,Default,,0000,0000,0000,,you can zoom in on really small things,
Dialogue: 0,0:10:52.69,0:10:57.56,Default,,0000,0000,0000,,including making maps of hydrogen cyanide\Nin these planet-forming discs.
Dialogue: 0,0:10:57.58,0:11:00.41,Default,,0000,0000,0000,,So when ALMA came online a few years ago,
Dialogue: 0,0:11:00.43,0:11:04.51,Default,,0000,0000,0000,,that was one of the first things\Nthat I proposed that we use it for.
Dialogue: 0,0:11:05.09,0:11:09.02,Default,,0000,0000,0000,,And what does a map of hydrogen cyanide\Nlook like in a disc?
Dialogue: 0,0:11:09.05,0:11:11.56,Default,,0000,0000,0000,,Is the hydrogen cyanide\Nat the right place?
Dialogue: 0,0:11:11.58,0:11:13.70,Default,,0000,0000,0000,,And the answer is that it is.
Dialogue: 0,0:11:13.72,0:11:15.73,Default,,0000,0000,0000,,So this is the map.
Dialogue: 0,0:11:15.75,0:11:19.69,Default,,0000,0000,0000,,You see the hydrogen cyanide emission\Nbeing spread out across the disc.
Dialogue: 0,0:11:19.72,0:11:21.57,Default,,0000,0000,0000,,First of all, it's almost everywhere,
Dialogue: 0,0:11:21.59,0:11:23.16,Default,,0000,0000,0000,,which is very good news.
Dialogue: 0,0:11:23.18,0:11:26.36,Default,,0000,0000,0000,,But you have a lot\Nof extra bright emission
Dialogue: 0,0:11:26.39,0:11:29.59,Default,,0000,0000,0000,,coming from close to the star\Ntowards the center of the disc.
Dialogue: 0,0:11:29.96,0:11:33.12,Default,,0000,0000,0000,,And this is exactly\Nwhere we want to see it.
Dialogue: 0,0:11:33.15,0:11:35.79,Default,,0000,0000,0000,,This is close to where\Nthese planets are forming.
Dialogue: 0,0:11:35.82,0:11:39.60,Default,,0000,0000,0000,,And this is not what we see\Njust towards one disc --
Dialogue: 0,0:11:39.62,0:11:41.98,Default,,0000,0000,0000,,here are three more examples.
Dialogue: 0,0:11:42.01,0:11:44.09,Default,,0000,0000,0000,,You can see they all show\Nthe same thing --
Dialogue: 0,0:11:44.11,0:11:46.58,Default,,0000,0000,0000,,lots of bright hydrogen cyanide emission
Dialogue: 0,0:11:46.60,0:11:48.93,Default,,0000,0000,0000,,coming from close\Nto the center of the star.
Dialogue: 0,0:11:49.23,0:11:51.91,Default,,0000,0000,0000,,For full disclosure,\Nwe don't always see this.
Dialogue: 0,0:11:51.93,0:11:54.47,Default,,0000,0000,0000,,There are discs where we see the opposite,
Dialogue: 0,0:11:54.49,0:11:57.71,Default,,0000,0000,0000,,where there's actually a hole\Nin the emission towards the center.
Dialogue: 0,0:11:57.74,0:12:00.28,Default,,0000,0000,0000,,So this is the opposite\Nof what we want to see, right?
Dialogue: 0,0:12:00.30,0:12:02.46,Default,,0000,0000,0000,,This is not places where we could research
Dialogue: 0,0:12:02.48,0:12:06.49,Default,,0000,0000,0000,,if there is any hydrogen cyanide around\Nwhere these planets are forming.
Dialogue: 0,0:12:06.51,0:12:08.09,Default,,0000,0000,0000,,But in most cases,
Dialogue: 0,0:12:08.12,0:12:10.12,Default,,0000,0000,0000,,we just don't detect hydrogen cyanide,
Dialogue: 0,0:12:10.15,0:12:12.55,Default,,0000,0000,0000,,but we detect it in the right place.
Dialogue: 0,0:12:13.04,0:12:15.08,Default,,0000,0000,0000,,So what does all this mean?
Dialogue: 0,0:12:15.10,0:12:17.55,Default,,0000,0000,0000,,Well, I told you in the beginning
Dialogue: 0,0:12:17.57,0:12:20.96,Default,,0000,0000,0000,,that we have lots\Nof these temperate planets,
Dialogue: 0,0:12:20.98,0:12:22.89,Default,,0000,0000,0000,,maybe a billion or so of them,
Dialogue: 0,0:12:22.91,0:12:25.43,Default,,0000,0000,0000,,that could have life develop on them
Dialogue: 0,0:12:25.46,0:12:27.98,Default,,0000,0000,0000,,if they have the right ingredients.
Dialogue: 0,0:12:28.00,0:12:29.18,Default,,0000,0000,0000,,And I've also shown
Dialogue: 0,0:12:29.20,0:12:33.08,Default,,0000,0000,0000,,that we think a lot of the time,\Nthe right ingredients are there --
Dialogue: 0,0:12:33.10,0:12:35.28,Default,,0000,0000,0000,,we have water, we have hydrogen cyanide,
Dialogue: 0,0:12:35.30,0:12:37.51,Default,,0000,0000,0000,,there will be other\Norganic molecules as well
Dialogue: 0,0:12:37.53,0:12:39.20,Default,,0000,0000,0000,,coming with the cyanides.
Dialogue: 0,0:12:39.88,0:12:44.10,Default,,0000,0000,0000,,This means that planets\Nwith the most basic ingredients for life
Dialogue: 0,0:12:44.12,0:12:47.15,Default,,0000,0000,0000,,are likely to be incredibly\Ncommon in our galaxy.
Dialogue: 0,0:12:48.13,0:12:50.69,Default,,0000,0000,0000,,And if all it takes for life to develop
Dialogue: 0,0:12:50.71,0:12:54.01,Default,,0000,0000,0000,,is to have these basic\Ningredients available,
Dialogue: 0,0:12:54.04,0:12:56.90,Default,,0000,0000,0000,,there should be a lot\Nof living planets out there.
Dialogue: 0,0:12:57.40,0:12:59.34,Default,,0000,0000,0000,,But that is of course a big if.
Dialogue: 0,0:12:59.36,0:13:02.31,Default,,0000,0000,0000,,And I would say the challenge\Nof the next decades,
Dialogue: 0,0:13:02.34,0:13:04.82,Default,,0000,0000,0000,,for both astronomy and chemistry,
Dialogue: 0,0:13:04.84,0:13:07.58,Default,,0000,0000,0000,,is to figure out just how often
Dialogue: 0,0:13:07.61,0:13:10.36,Default,,0000,0000,0000,,we go from having\Na potentially living planet
Dialogue: 0,0:13:10.39,0:13:12.79,Default,,0000,0000,0000,,to having an actually living one.
Dialogue: 0,0:13:12.82,0:13:13.97,Default,,0000,0000,0000,,Thank you.
Dialogue: 0,0:13:13.99,0:13:18.82,Default,,0000,0000,0000,,(Applause)