WEBVTT 00:01.466 --> 00:03.266 align:left position:12.5% line:5% size:77.5% - Sarah Corso: Hello, everyone. 00:03.266 --> 00:06.600 align:left position:17.5% line:5% size:72.5% Welcome, and thank you for coming to tonight's Badger Talk, 00:06.600 --> 00:09.000 align:left position:12.5% line:5% size:77.5% brought to you by UW Connects. 00:09.000 --> 00:10.700 align:left position:22.5% line:5% size:67.5% My name is Sarah Corso, 00:10.700 --> 00:12.966 align:left position:27.5% line:5% size:62.5% and I'm a librarian and access services manager 00:12.966 --> 00:15.766 align:left position:25% line:5% size:65% here at the Oak Creek Public Library. 00:15.766 --> 00:17.900 align:left position:37.5% line:5% size:52.5% I'm pleased to introduce our guest, 00:17.900 --> 00:19.566 align:left position:27.5% line:5% size:62.5% Dr. Thomas Beatty, 00:19.566 --> 00:21.900 align:left position:27.5% line:71% size:62.5% assistant professor in the Astronomy Department 00:21.900 --> 00:24.300 align:left position:32.5% line:71% size:57.5% for the College of Letters & Science 00:24.300 --> 00:27.200 align:left position:30% line:71% size:60% at the University of Wisconsin-Madison. 00:27.200 --> 00:30.233 align:left position:15% line:71% size:75% The presentation he is giving this evening is called 00:30.233 --> 00:33.733 align:left position:17.5% line:71% size:72.5% "How Can We Find Other Life in the Universe?" 00:33.733 --> 00:36.166 align:left position:27.5% line:71% size:62.5% Dr. Beatty is from Riverside, Connecticut, 00:36.166 --> 00:39.033 align:left position:27.5% line:71% size:62.5% and grew up sailing off the coast of New England. 00:39.033 --> 00:41.900 align:left position:17.5% line:71% size:72.5% He has a bachelor's degree from Harvard University, 00:41.900 --> 00:44.966 align:left position:30% line:71% size:60% a master's degree in physics from MIT, 00:44.966 --> 00:49.333 align:left position:22.5% line:71% size:67.5% and a PhD in astronomy from Ohio State University. 00:49.333 --> 00:51.666 align:left position:20% line:71% size:70% Before moving to Madison, 00:51.666 --> 00:53.833 align:left position:40% line:71% size:50% he worked as an instrument scientist 00:53.833 --> 00:56.266 align:left position:30% line:71% size:60% on the James Webb Space Telescope, 00:56.266 --> 00:58.800 align:left position:25% line:71% size:65% where he helped build one of Webb's cameras 00:58.800 --> 01:02.566 align:left position:20% line:71% size:70% and helped to operate it once Webb reached space. 01:02.566 --> 01:05.533 align:left position:25% line:71% size:65% His research focuses on measuring the atmospheres 01:05.533 --> 01:09.133 align:left position:32.5% line:71% size:57.5% of exoplanets-- planets around other stars-- 01:09.133 --> 01:11.500 align:left position:35% line:71% size:55% to figure out what they are made out of 01:11.500 --> 01:15.100 align:left position:10% line:71% size:80% and what their climates are like to understand how planets form 01:15.100 --> 01:18.900 align:left position:22.5% line:71% size:67.5% and to search for life elsewhere in the universe. 01:18.900 --> 01:22.366 align:left position:22.5% line:71% size:67.5% He has also discovered nine new exoplanets, 01:22.366 --> 01:26.633 align:left position:15% line:71% size:75% none of which he got to name after himself, sadly. 01:26.633 --> 01:30.200 align:left position:25% line:71% size:65% Today, we are asking, "Are we alone in the universe?" 01:30.200 --> 01:34.100 align:left position:15% line:71% size:75% This question has been asked for over 2,000 years, 01:34.100 --> 01:37.333 align:left position:15% line:71% size:75% and now we possess the tools and techniques necessary 01:37.333 --> 01:39.233 align:left position:35% line:71% size:55% to answer it. 01:39.233 --> 01:42.200 align:left position:22.5% line:71% size:67.5% Dr. Beatty will discuss what we want to look for 01:42.200 --> 01:45.433 align:left position:30% line:71% size:60% on other planets to see if there is life, 01:45.433 --> 01:48.533 align:left position:17.5% line:71% size:72.5% as well as how this search has begun at UW 01:48.533 --> 01:51.400 align:left position:35% line:71% size:55% using current and future telescopes. 01:51.400 --> 01:54.000 align:left position:32.5% line:71% size:57.5% Please join me in welcoming Dr. Beatty. 01:54.000 --> 01:56.666 align:left position:25% line:5% size:65% [audience applauding] 02:00.066 --> 02:01.733 align:left position:27.5% line:5% size:62.5% - Thomas G. Beatty: Thank you very much. 02:01.733 --> 02:03.166 align:left position:25% line:83% size:65% That was a very nice introduction. 02:03.166 --> 02:04.500 align:left position:17.5% line:89% size:72.5% It's a pleasure to be here. 02:04.500 --> 02:06.733 align:left position:17.5% line:83% size:72.5% I actually, coincidentally, am in the universe. 02:06.733 --> 02:09.433 align:left position:25% line:83% size:65% And, really, how can we find life elsewhere, 02:09.433 --> 02:13.166 align:left position:25% line:83% size:65% and how are we trying to approach this problem 02:13.166 --> 02:16.466 align:left position:22.5% line:83% size:67.5% at UW and, in general, in the astronomical community 02:16.466 --> 02:19.300 align:left position:12.5% line:89% size:77.5% to try and solve this question? 02:19.300 --> 02:22.200 align:left position:27.5% line:83% size:62.5% And I like to begin talks like this 02:22.200 --> 02:24.433 align:left position:17.5% line:83% size:72.5% with just sort of a picture of the night sky 02:24.433 --> 02:27.700 align:left position:17.5% line:83% size:72.5% and the thought, the idea, that in many ways, 02:27.700 --> 02:31.133 align:left position:12.5% line:83% size:77.5% astronomy is sort of, you know, the second-oldest profession 02:31.133 --> 02:33.133 align:left position:32.5% line:83% size:57.5% in the world-- being an astronomer, right? 02:33.133 --> 02:35.433 align:left position:10% line:83% size:80% It's probably the oldest science that we have 02:35.433 --> 02:38.433 align:left position:32.5% line:83% size:57.5% in the sense of you could imagine people, 02:38.433 --> 02:41.666 align:left position:15% line:83% size:75% very early people in Africa, just looking up at the night sky 02:41.666 --> 02:44.033 align:left position:35% line:83% size:55% and wondering what is going on up there, 02:44.033 --> 02:45.800 align:left position:12.5% line:89% size:77.5% what's going on with the stars, 02:45.800 --> 02:49.033 align:left position:20% line:83% size:70% and that, fundamentally, is what my job is. 02:49.033 --> 02:50.633 align:left position:20% line:83% size:70% What we do as astronomers today is, 02:50.633 --> 02:52.333 align:left position:22.5% line:83% size:67.5% we're still looking up at the night sky, 02:52.333 --> 02:54.066 align:left position:32.5% line:83% size:57.5% and we're still trying to figure out 02:54.066 --> 02:56.833 align:left position:12.5% line:89% size:77.5% what's going on with the stars. 02:56.833 --> 02:59.833 align:left position:27.5% line:83% size:62.5% And, in particular, I work on exoplanets, 02:59.833 --> 03:01.566 align:left position:25% line:83% size:65% so I look for planets around other stars, 03:01.566 --> 03:03.600 align:left position:17.5% line:83% size:72.5% and we're trying to measure these planets around other stars 03:03.600 --> 03:06.400 align:left position:20% line:71% size:70% and figure out if there's planets like the Earth 03:06.400 --> 03:08.266 align:left position:20% line:71% size:70% elsewhere in the galaxy. 03:08.266 --> 03:11.900 align:left position:15% line:71% size:75% That question, the idea that there might be another planet 03:11.900 --> 03:14.900 align:left position:32.5% line:71% size:57.5% like the Earth somewhere up there, 03:14.900 --> 03:17.366 align:left position:37.5% line:71% size:52.5% probably-- it's a little bit fuzzy-- 03:17.366 --> 03:19.866 align:left position:20% line:71% size:70% was probably first posed by the ancient Greeks 03:19.866 --> 03:22.466 align:left position:22.5% line:71% size:67.5% about 2,500 years ago, probably the first person 03:22.466 --> 03:24.500 align:left position:35% line:71% size:55% to, at least, write that question down. 03:24.500 --> 03:27.900 align:left position:35% line:71% size:55% Maybe people thought of it before that. 03:27.900 --> 03:32.566 align:left position:12.5% line:71% size:77.5% So we're really thinking today very concretely 03:32.566 --> 03:34.233 align:left position:32.5% line:71% size:57.5% about how do we answer this question: 03:34.233 --> 03:35.633 align:left position:10% line:71% size:80% Is there a planet like the Earth 03:35.633 --> 03:37.100 align:left position:32.5% line:71% size:57.5% somewhere else in the universe? 03:37.100 --> 03:39.100 align:left position:12.5% line:71% size:77.5% And it's a question that people have been wondering about 03:39.100 --> 03:42.100 align:left position:22.5% line:71% size:67.5% for over two millennia, 03:42.100 --> 03:44.266 align:left position:25% line:71% size:65% and we're very close to actually answering it, 03:44.266 --> 03:45.700 align:left position:25% line:71% size:65% and that's the topic 03:45.700 --> 03:48.533 align:left position:20% line:71% size:70% of what I'd like to talk to you about tonight. 03:48.533 --> 03:50.666 align:left position:20% line:71% size:70%   So I wanna begin by just talking 03:50.666 --> 03:53.200 align:left position:17.5% line:83% size:72.5% about what is an exoplanet, right? 03:53.200 --> 03:55.600 align:left position:20% line:83% size:70% What does that mean when I talk about an exoplanet? 03:55.600 --> 03:57.433 align:left position:32.5% line:89% size:57.5% What are those? 03:58.533 --> 04:01.100 align:left position:22.5% line:89% size:67.5% So in the solar system, 04:01.100 --> 04:03.400 align:left position:27.5% line:83% size:62.5% we have our planets in our solar system. 04:03.400 --> 04:05.633 align:left position:22.5% line:83% size:67.5% We have all the planets that go around the Sun, 04:05.633 --> 04:07.300 align:left position:32.5% line:83% size:57.5% so the planets go around the Sun, 04:07.300 --> 04:08.800 align:left position:27.5% line:89% size:62.5% those are planets, 04:08.800 --> 04:12.133 align:left position:30% line:83% size:60% and an exoplanet is simply a planet 04:12.133 --> 04:15.100 align:left position:27.5% line:83% size:62.5% that orbits a star other than the Sun. 04:15.100 --> 04:16.266 align:left position:25% line:89% size:65% So just like the Sun 04:16.266 --> 04:18.000 align:left position:27.5% line:83% size:62.5% has a solar system of planets around it, 04:18.000 --> 04:21.033 align:left position:20% line:83% size:70% there are other exoplanet systems around other stars 04:21.033 --> 04:23.933 align:left position:22.5% line:83% size:67.5% elsewhere in our galaxy that we know of. 04:25.700 --> 04:30.066 align:left position:27.5% line:89% size:62.5% In galactic terms, 04:30.066 --> 04:32.566 align:left position:27.5% line:83% size:62.5% most of the planets that we are looking at 04:32.566 --> 04:36.100 align:left position:12.5% line:83% size:77.5% are very close by in the terms of the universe, right? 04:36.100 --> 04:39.833 align:left position:12.5% line:83% size:77.5% All the planets that we know of are within the Milky Way galaxy. 04:39.833 --> 04:44.466 align:left position:17.5% line:83% size:72.5% This is a nice map produced by Professor Bob Benjamin, 04:44.466 --> 04:46.633 align:left position:27.5% line:89% size:62.5% who's at UW, right, 04:46.633 --> 04:48.100 align:left position:35% line:83% size:55% showing what the Milky Way looks like, 04:48.100 --> 04:50.100 align:left position:22.5% line:83% size:67.5% so all the planets that we're thinking about looking at 04:50.100 --> 04:53.833 align:left position:32.5% line:83% size:57.5% and know about are within the Milky Way galaxy, 04:53.833 --> 04:56.333 align:left position:25% line:83% size:65% and they're actually very close to the sun, 04:56.333 --> 04:58.100 align:left position:15% line:83% size:75% within the Milky Way galaxy, right? 04:58.100 --> 05:01.100 align:left position:27.5% line:83% size:62.5% This red circle is about the limit of detection, 05:01.100 --> 05:04.233 align:left position:12.5% line:83% size:77.5% so where we've seen exoplanets, how far out we've seen them. 05:04.233 --> 05:06.833 align:left position:27.5% line:83% size:62.5% If I zoom back out on the entire galaxy, 05:06.833 --> 05:09.933 align:left position:12.5% line:83% size:77.5% you can see we've actually been probing a very small segment 05:09.933 --> 05:12.733 align:left position:20% line:83% size:70% just of our local corner of the universe, right? 05:12.733 --> 05:14.433 align:left position:32.5% line:83% size:57.5% We now know of a lot of exoplanets, 05:14.433 --> 05:16.433 align:left position:32.5% line:83% size:57.5% but all of them are very close by 05:16.433 --> 05:18.300 align:left position:20% line:89% size:70% on an astronomical scale. 05:18.300 --> 05:19.500 align:left position:12.5% line:89% size:77.5% They're all within our galaxy, 05:19.500 --> 05:21.333 align:left position:25% line:83% size:65% and they're all close within our galaxy. 05:22.866 --> 05:26.266 align:left position:35% line:5% size:55% All together, over the last 25 years-- 05:26.266 --> 05:27.933 align:left position:35% line:5% size:55% 30 years now, 05:27.933 --> 05:31.300 align:left position:25% line:5% size:65% we've now discovered over 5,000 exoplanets. 05:31.300 --> 05:36.366 align:left position:22.5% line:5% size:67.5% I think the count as of this morning was 5,761, right? 05:36.366 --> 05:40.266 align:left position:32.5% line:5% size:57.5% And if you look at this graph, right, 05:40.266 --> 05:42.933 align:left position:15% line:5% size:75% you can see there's actually a lot of sort of features here 05:42.933 --> 05:44.500 align:left position:32.5% line:5% size:57.5% you could think about teasing out. 05:44.500 --> 05:47.666 align:left position:15% line:5% size:75% So I've marked on this slide, 05:47.666 --> 05:49.466 align:left position:35% line:5% size:55% the capital J is where Jupiter is, 05:49.466 --> 05:52.133 align:left position:30% line:5% size:60% and the capital E is where the Earth is, 05:52.133 --> 05:53.733 align:left position:22.5% line:5% size:67.5% and you can see we have 05:53.733 --> 05:55.766 align:left position:20% line:5% size:70% a whole bunch of planets that are like Jupiter, 05:55.766 --> 05:57.966 align:left position:25% line:5% size:65% we have a whole bunch of planets that are like Earth, 05:57.966 --> 05:59.566 align:left position:17.5% line:5% size:72.5% and a whole bunch of things in between, 05:59.566 --> 06:01.833 align:left position:10% line:5% size:80% and, in particular, we also have a whole bunch of planets 06:01.833 --> 06:04.500 align:left position:15% line:5% size:75% that don't even really exist in our solar system, right? 06:04.500 --> 06:07.066 align:left position:17.5% line:5% size:72.5% A lot of the ways that even we astronomers conceptualize 06:07.066 --> 06:09.633 align:left position:15% line:5% size:75% what these planets look like is by thinking about 06:09.633 --> 06:12.800 align:left position:12.5% line:5% size:77.5% how do they compare to a planet in the solar system. 06:12.800 --> 06:14.566 align:left position:12.5% line:89% size:77.5% Are they, like, a hot Jupiter? 06:14.566 --> 06:16.566 align:left position:22.5% line:89% size:67.5% Are they a super-Earth? 06:16.566 --> 06:17.966 align:left position:22.5% line:89% size:67.5% Are they a warm Saturn? 06:17.966 --> 06:19.133 align:left position:22.5% line:89% size:67.5% We use words like that, 06:19.133 --> 06:21.633 align:left position:17.5% line:83% size:72.5% but there is a whole class of planets, 06:21.633 --> 06:23.333 align:left position:30% line:83% size:60% like super-Earths or sub-Neptunes, 06:23.333 --> 06:25.333 align:left position:20% line:83% size:70% that don't actually exist in the solar system. 06:25.333 --> 06:27.533 align:left position:27.5% line:71% size:62.5% And so, by finding all these new planets, 06:27.533 --> 06:30.266 align:left position:20% line:71% size:70% we're actually uncovering new processes 06:30.266 --> 06:32.433 align:left position:37.5% line:71% size:52.5% and physics that we didn't know about 06:32.433 --> 06:35.266 align:left position:32.5% line:71% size:57.5% before we knew that these planets existed. 06:35.266 --> 06:39.800 align:left position:22.5% line:71% size:67.5% And this has been a lot of the work of the last 30 years 06:39.800 --> 06:42.366 align:left position:32.5% line:71% size:57.5% in this field, is finding new planets, 06:42.366 --> 06:44.266 align:left position:27.5% line:71% size:62.5% getting this number to go from one-- 06:44.266 --> 06:46.533 align:left position:35% line:71% size:55% the first one was discovered in 1995-- 06:46.533 --> 06:50.633 align:left position:32.5% line:71% size:57.5% getting it from 1 to 5,761, right? 06:50.633 --> 06:53.600 align:left position:17.5% line:71% size:72.5% That's taken a lot of work, and it's taken over two decades 06:53.600 --> 06:57.600 align:left position:15% line:71% size:75% of people finding new planets around other stars. 06:58.800 --> 07:02.366 align:left position:15% line:71% size:75% Most of these are discovered indirectly, right? 07:02.366 --> 07:05.566 align:left position:22.5% line:71% size:67.5% We actually-- of those over 5,000 exoplanets, 07:05.566 --> 07:09.966 align:left position:10% line:71% size:80% we only have direct images where we can see them in a photograph 07:09.966 --> 07:14.433 align:left position:12.5% line:71% size:77.5% or an image for only a handful, probably about a dozen. 07:14.433 --> 07:17.300 align:left position:10% line:5% size:80% Most of these, we never actually see the planet directly. 07:17.300 --> 07:19.900 align:left position:20% line:5% size:70% Instead, what we see is, we see the planet's effect 07:19.900 --> 07:22.566 align:left position:37.5% line:5% size:52.5% on the star that it's orbiting, right? 07:22.566 --> 07:26.933 align:left position:12.5% line:5% size:77.5% So one way, on the left there, one way that we see the planet 07:26.933 --> 07:29.833 align:left position:17.5% line:5% size:72.5% affecting its star is that we can look at the star, 07:29.833 --> 07:32.666 align:left position:17.5% line:5% size:72.5% we can measure the velocity of the star, 07:32.666 --> 07:35.566 align:left position:17.5% line:5% size:72.5% and we see the star moving back and forth a little bit 07:35.566 --> 07:39.233 align:left position:12.5% line:5% size:77.5% because the planet as it orbits the star is tugging on the star, 07:39.233 --> 07:42.200 align:left position:27.5% line:5% size:62.5% and the star itself is moving just a little bit 07:42.200 --> 07:44.233 align:left position:12.5% line:5% size:77.5% as the planet orbits around it, 07:44.233 --> 07:46.433 align:left position:30% line:5% size:60% and so we can see that motion of the star 07:46.433 --> 07:48.700 align:left position:17.5% line:5% size:72.5% with our telescopes, right, so we see the star moving, 07:48.700 --> 07:51.100 align:left position:12.5% line:5% size:77.5% and we know it must be a planet based on that motion. 07:51.100 --> 07:53.400 align:left position:25% line:5% size:65% We never actually see the planet itself. 07:53.400 --> 07:56.233 align:left position:10% line:5% size:80% Another way we discover planets, that's on the right, 07:56.233 --> 08:00.033 align:left position:15% line:5% size:75% is, we look, and as a planet goes in front of a star, 08:00.033 --> 08:02.033 align:left position:30% line:5% size:60% it will block out part of that star, 08:02.033 --> 08:03.833 align:left position:17.5% line:5% size:72.5% and the light from the star will go down. 08:03.833 --> 08:06.533 align:left position:30% line:5% size:60% So Jupiter going in front of the Sun 08:06.533 --> 08:08.800 align:left position:15% line:5% size:75% would make the Sun get dimmer 08:08.800 --> 08:11.666 align:left position:37.5% line:5% size:52.5% by about 1% for a couple of hours, 08:11.666 --> 08:13.833 align:left position:30% line:5% size:60% and then it would go back up again, right? 08:13.833 --> 08:15.566 align:left position:20% line:71% size:70% And we can detect planets that way. 08:15.566 --> 08:18.300 align:left position:20% line:71% size:70% Actually, that technique has gotten-- 08:18.300 --> 08:20.500 align:left position:17.5% line:71% size:72.5% We're all sufficiently good at doing that 08:20.500 --> 08:25.233 align:left position:12.5% line:71% size:77.5% that I'm actually with a couple of students looking, 08:25.233 --> 08:28.066 align:left position:12.5% line:71% size:77.5% trying to detect a new planet-- or confirm a new planet 08:28.066 --> 08:29.633 align:left position:35% line:71% size:55% from the roof of the Astronomy Department 08:29.633 --> 08:33.566 align:left position:27.5% line:71% size:62.5% in downtown Madison sometime next week. 08:33.566 --> 08:36.033 align:left position:17.5% line:71% size:72.5% So that sort of measurement for a Jupiter 08:36.033 --> 08:38.533 align:left position:17.5% line:71% size:72.5% in front of a Sun-like star has gotten relatively easy 08:38.533 --> 08:40.433 align:left position:22.5% line:71% size:67.5% with modern technology. 08:40.433 --> 08:42.633 align:left position:22.5% line:71% size:67.5% Planets like the Earth is a lot harder, right? 08:42.633 --> 08:46.333 align:left position:20% line:71% size:70% The Earth is 10,000 times less of a signal 08:46.333 --> 08:48.500 align:left position:12.5% line:71% size:77.5% that we have to measure, right, 08:48.500 --> 08:53.266 align:left position:27.5% line:71% size:62.5% but the real point to just take away from this is, 08:53.266 --> 08:55.066 align:left position:25% line:71% size:65% we have a lot of ways to detect planets. 08:55.066 --> 08:56.866 align:left position:27.5% line:71% size:62.5% We've found a lot, and we know a lot 08:56.866 --> 08:59.666 align:left position:22.5% line:71% size:67.5% from just their masses and their radii and their sizes 08:59.666 --> 09:02.033 align:left position:27.5% line:71% size:62.5% and where they are relative to their stars, 09:02.033 --> 09:05.033 align:left position:17.5% line:71% size:72.5% but we still never actually see the planet directly, right? 09:05.033 --> 09:06.833 align:left position:20% line:71% size:70% We just see what it does to the star. 09:06.833 --> 09:09.666 align:left position:35% line:71% size:55% We don't have a lot of information 09:09.666 --> 09:12.666 align:left position:22.5% line:71% size:67.5% about what is happening on the planet itself. 09:12.666 --> 09:16.100 align:left position:22.5% line:71% size:67.5%   And so if we're thinking about detecting life on an exoplanet, 09:16.100 --> 09:19.433 align:left position:12.5% line:83% size:77.5% figuring out if it's habitable, if it's like the Earth, right, 09:19.433 --> 09:21.900 align:left position:22.5% line:83% size:67.5% what we will start with is something like this. 09:21.900 --> 09:24.600 align:left position:10% line:89% size:80% This is a simulated light curve, 09:24.600 --> 09:26.600 align:left position:32.5% line:83% size:57.5% so measurements of the brightness of a star, 09:26.600 --> 09:28.933 align:left position:17.5% line:83% size:72.5% as a planet like the Earth goes in front of it. 09:28.933 --> 09:30.533 align:left position:25% line:83% size:65% So if we were looking at the Sun 09:30.533 --> 09:32.133 align:left position:35% line:83% size:55% and the Earth passed in front of it, 09:32.133 --> 09:33.333 align:left position:17.5% line:89% size:72.5% this is what we would see. 09:33.333 --> 09:34.733 align:left position:20% line:89% size:70% It's a very small signal. 09:34.733 --> 09:36.600 align:left position:22.5% line:83% size:67.5% We'd have to measure it from space. 09:36.600 --> 09:39.000 align:left position:22.5% line:83% size:67.5% And what we learn if we were looking at the Sun is, 09:39.000 --> 09:40.600 align:left position:27.5% line:83% size:62.5% we could, you know, learn that the planet 09:40.600 --> 09:42.000 align:left position:10% line:89% size:80% was about the size of the Earth. 09:42.000 --> 09:43.233 align:left position:20% line:89% size:70% We maybe could get a mass 09:43.233 --> 09:44.833 align:left position:20% line:83% size:70% by looking at the motion of the Sun, 09:44.833 --> 09:47.433 align:left position:17.5% line:83% size:72.5% so we knew it was the mass and the radius of the Earth, 09:47.433 --> 09:50.033 align:left position:12.5% line:89% size:77.5% and we know how far away it is 09:50.033 --> 09:52.966 align:left position:12.5% line:83% size:77.5% using things like Kepler's laws and the orbital period. 09:52.966 --> 09:54.566 align:left position:17.5% line:89% size:72.5% But the important thing is, 09:54.566 --> 09:56.800 align:left position:25% line:83% size:65% if we were doing this on the solar system, 09:56.800 --> 09:58.666 align:left position:25% line:83% size:65% we wouldn't just get one planet like the Earth. 09:58.666 --> 10:00.666 align:left position:25% line:89% size:65% We'd get two, right? 10:00.666 --> 10:02.266 align:left position:27.5% line:83% size:62.5% If we were looking at the solar system 10:02.266 --> 10:05.466 align:left position:15% line:89% size:75% with our current technology, 10:05.466 --> 10:08.100 align:left position:15% line:83% size:75% we would say the solar system has two habitable planets 10:08.100 --> 10:10.500 align:left position:20% line:83% size:70% because we have the Earth and we also have Venus, 10:10.500 --> 10:13.333 align:left position:15% line:83% size:75% and Venus is nearly the same mass and radius as the Earth, 10:13.333 --> 10:17.233 align:left position:17.5% line:83% size:72.5% and it's closer to the Sun, but it's not that much closer, 10:17.233 --> 10:19.600 align:left position:22.5% line:83% size:67.5% and the theory we have about habitability 10:19.600 --> 10:22.533 align:left position:32.5% line:83% size:57.5% says that Venus probably should be habitable. 10:22.533 --> 10:24.133 align:left position:12.5% line:83% size:77.5% There's a lot of other factors, of course, 10:24.133 --> 10:25.766 align:left position:25% line:83% size:65% that have made Venus not habitable, 10:25.766 --> 10:28.033 align:left position:27.5% line:83% size:62.5% but we don't fully understand them yet, right? 10:28.033 --> 10:29.966 align:left position:27.5% line:83% size:62.5% So one of the tasks that we have, 10:29.966 --> 10:33.133 align:left position:22.5% line:83% size:67.5% and this is what I do, is trying to figure out, right, 10:33.133 --> 10:37.200 align:left position:12.5% line:83% size:77.5% if we have a planet like this, how do we determine 10:37.200 --> 10:40.866 align:left position:20% line:5% size:70% if it's like the Earth-- that is, a nice beach vacation-- 10:40.866 --> 10:45.500 align:left position:12.5% line:5% size:77.5% or if it's like Venus and it's gonna melt your spacecraft 10:45.500 --> 10:47.966 align:left position:37.5% line:5% size:52.5% 30 minutes after you land, right? 10:47.966 --> 10:49.266 align:left position:22.5% line:89% size:67.5% This is actually true. 10:49.266 --> 10:51.266 align:left position:15% line:83% size:75% The only landers that we have that have ever reached 10:51.266 --> 10:54.333 align:left position:25% line:83% size:65% the surface of Venus are a couple of Soviet landers 10:54.333 --> 10:56.166 align:left position:20% line:89% size:70% that landed in the 1980s, 10:56.166 --> 10:57.700 align:left position:25% line:83% size:65% and they only lasted on the surface 10:57.700 --> 11:01.000 align:left position:25% line:83% size:65% for about 30 minutes before they got squished 11:01.000 --> 11:03.766 align:left position:27.5% line:83% size:62.5% by some combination of crushed by the pressure 11:03.766 --> 11:05.766 align:left position:35% line:83% size:55% and dissolved by the sulfuric acid 11:05.766 --> 11:08.633 align:left position:32.5% line:83% size:57.5% that's present in Venus's atmosphere. 11:08.633 --> 11:10.866 align:left position:35% line:83% size:55% And actually, a really fun story is, 11:10.866 --> 11:12.466 align:left position:22.5% line:83% size:67.5% we don't actually have a very good measurement. 11:12.466 --> 11:14.266 align:left position:22.5% line:83% size:67.5% This isn't that funny, this isn't that fun a-- 11:14.266 --> 11:15.466 align:left position:20% line:89% size:70% It's a fun story for us. 11:15.466 --> 11:18.600 align:left position:25% line:83% size:65% It's not a fun story for the scientists involved. 11:18.600 --> 11:20.333 align:left position:22.5% line:71% size:67.5% So we don't really have a good measurement 11:20.333 --> 11:22.266 align:left position:20% line:71% size:70% of the surface of Venus, 11:22.266 --> 11:25.466 align:left position:15% line:71% size:75% like, what the, like, dirt is in that picture, 11:25.466 --> 11:28.400 align:left position:25% line:71% size:65% because one of the-- 11:28.400 --> 11:30.633 align:left position:17.5% line:71% size:72.5% So the first Soviet lander that landed on Venus, 11:30.633 --> 11:33.400 align:left position:22.5% line:71% size:67.5% that had a camera, but the lens cap didn't come off, 11:33.400 --> 11:35.966 align:left position:10% line:71% size:80% so they didn't get any pictures, and so they said, 11:35.966 --> 11:38.500 align:left position:20% line:71% size:70% "Okay, for the next one, we're definitely making sure 11:38.500 --> 11:40.833 align:left position:15% line:71% size:75% the lens cap is coming off," right, and it did. 11:40.833 --> 11:42.533 align:left position:17.5% line:71% size:72.5% This is where this picture comes from, right, 11:42.533 --> 11:45.500 align:left position:20% line:71% size:70% so the lens cap comes off as it's drifting down, 11:45.500 --> 11:47.433 align:left position:12.5% line:71% size:77.5% and we get these nice pictures. 11:47.433 --> 11:49.233 align:left position:27.5% line:71% size:62.5% But one of the next experiments they had-- 11:49.233 --> 11:51.233 align:left position:15% line:71% size:75% and, remember, they only have about 30 minutes, and then 11:51.233 --> 11:54.733 align:left position:12.5% line:71% size:77.5% the whole thing is done because the spacecraft has melted. 11:54.733 --> 11:56.733 align:left position:22.5% line:71% size:67.5% One of the experiments they were gonna do was, 11:56.733 --> 11:59.666 align:left position:15% line:71% size:75% there was a spring-loaded arm inside the spacecraft 11:59.666 --> 12:01.933 align:left position:32.5% line:71% size:57.5% that was gonna, you know, a catch-release. 12:01.933 --> 12:04.866 align:left position:15% line:71% size:75% As the spring shoots the arm out, it goes into the dirt, 12:04.866 --> 12:07.266 align:left position:12.5% line:71% size:77.5% and then they retract it back, and they can get some dirt, 12:07.266 --> 12:10.966 align:left position:20% line:71% size:70% and they can analyze it, but it's a one-shot thing. 12:10.966 --> 12:13.166 align:left position:15% line:89% size:75% You can't retract the spring, 12:13.166 --> 12:15.066 align:left position:40% line:83% size:50% you know, once it's fired, right? 12:15.066 --> 12:17.033 align:left position:20% line:89% size:70% You fire it, you're done. 12:17.033 --> 12:19.200 align:left position:25% line:83% size:65% And so they're down, they're all ready, 12:19.200 --> 12:20.366 align:left position:15% line:89% size:75% they've released the spring. 12:20.366 --> 12:21.866 align:left position:27.5% line:83% size:62.5% The arm shoots out, and it shoots 12:21.866 --> 12:25.266 align:left position:10% line:89% size:80% directly into the lens cap that, 12:25.266 --> 12:27.966 align:left position:20% line:83% size:70% even though it popped off about 500 feet up in the air, 12:27.966 --> 12:30.100 align:left position:27.5% line:83% size:62.5% has landed directly next to the spacecraft 12:30.100 --> 12:33.333 align:left position:17.5% line:83% size:72.5% and directly where this arm was about to shoot out into, 12:33.333 --> 12:35.766 align:left position:27.5% line:83% size:62.5% and so that is why we don't actually have 12:35.766 --> 12:40.700 align:left position:27.5% line:83% size:62.5% a good measurement of what Venus's surface is like. 12:40.700 --> 12:43.000 align:left position:15% line:83% size:75% But okay, so we can't do that with exoplanets, right? 12:43.000 --> 12:44.166 align:left position:27.5% line:89% size:62.5% We can't go there. 12:44.166 --> 12:46.900 align:left position:22.5% line:83% size:67.5% We can't try and dodge lens cap covers 12:46.900 --> 12:48.433 align:left position:32.5% line:83% size:57.5% to measure what these planets are like. 12:48.433 --> 12:51.200 align:left position:22.5% line:83% size:67.5% We can't even see them most of the time, right, 12:51.200 --> 12:53.066 align:left position:25% line:83% size:65% so we need to come up with other ways 12:53.066 --> 12:55.600 align:left position:32.5% line:83% size:57.5% of figuring out what they're like. 12:55.600 --> 12:57.800 align:left position:27.5% line:83% size:62.5% And so the main way in which we do this is, 12:57.800 --> 13:00.000 align:left position:15% line:83% size:75% we look at their atmospheres by watching 13:00.000 --> 13:02.366 align:left position:17.5% line:89% size:72.5% as transiting exoplanets-- 13:02.366 --> 13:05.466 align:left position:15% line:83% size:75% Those are the exoplanets that pass in front of their stars. 13:05.466 --> 13:07.466 align:left position:25% line:83% size:65% As they pass in front of their star, 13:07.466 --> 13:08.900 align:left position:27.5% line:89% size:62.5% some of that light, 13:08.900 --> 13:10.900 align:left position:15% line:83% size:75% some of that starlight that's getting blocked by the planet, 13:10.900 --> 13:12.500 align:left position:17.5% line:83% size:72.5% it isn't entirely blocked, right? 13:12.500 --> 13:13.933 align:left position:22.5% line:5% size:67.5% It filters through the outer edges 13:13.933 --> 13:15.866 align:left position:15% line:5% size:75% of the planetary atmosphere, 13:15.866 --> 13:19.400 align:left position:25% line:5% size:65% and that outer edges imprints on that starlight. 13:19.400 --> 13:21.133 align:left position:17.5% line:5% size:72.5% The starlight keeps coming to us on Earth 13:21.133 --> 13:23.600 align:left position:17.5% line:5% size:72.5% from the outer edges of the atmosphere imprint on it, 13:23.600 --> 13:24.800 align:left position:17.5% line:5% size:72.5% and that is what allows us 13:24.800 --> 13:27.100 align:left position:17.5% line:5% size:72.5% to measure the atmospheric composition 13:27.100 --> 13:28.266 align:left position:20% line:5% size:70% of these planets, right? 13:28.266 --> 13:29.466 align:left position:25% line:5% size:65% We never actually see the planet. 13:29.466 --> 13:31.633 align:left position:27.5% line:5% size:62.5% We just see it pass in front of the star, 13:31.633 --> 13:34.266 align:left position:27.5% line:5% size:62.5% but because of that little fringe of atmosphere, 13:34.266 --> 13:37.400 align:left position:12.5% line:5% size:77.5% we can measure what's going on in the exoplanet atmosphere. 13:37.400 --> 13:42.066 align:left position:22.5% line:5% size:67.5% And this was first done about just under 20 years ago 13:42.066 --> 13:48.066 align:left position:27.5% line:5% size:62.5% for a planet called HD 219--209458. 13:48.066 --> 13:52.500 align:left position:30% line:5% size:60% Most planet names are complete telephone numbers. 13:52.500 --> 13:53.900 align:left position:35% line:5% size:55% They're named after star catalog names. 13:53.900 --> 13:55.900 align:left position:22.5% line:5% size:67.5% Like I said, you never get to name an exoplanet 13:55.900 --> 13:57.200 align:left position:32.5% line:5% size:57.5% after yourself. 13:57.200 --> 14:00.633 align:left position:20% line:83% size:70% You get to name it after the star catalog that it's in. 14:00.633 --> 14:02.100 align:left position:12.5% line:89% size:77.5% But if you do this long enough, 14:02.100 --> 14:03.900 align:left position:27.5% line:83% size:62.5% you get to remember the telephone numbers, as well, 14:03.900 --> 14:06.566 align:left position:25% line:83% size:65% so it was first done on a planet called HD 209458, 14:06.566 --> 14:08.000 align:left position:32.5% line:83% size:57.5% it's well-known in the community, 14:08.000 --> 14:10.433 align:left position:25% line:83% size:65% and now we've done it for a whole bunch of exoplanets 14:10.433 --> 14:15.600 align:left position:15% line:83% size:75% using telescopes like Hubble and things from the ground. 14:15.600 --> 14:18.000 align:left position:15% line:83% size:75% But the really exciting thing is to do this 14:18.000 --> 14:19.733 align:left position:27.5% line:83% size:62.5% with the James Webb Space Telescope, 14:19.733 --> 14:21.733 align:left position:15% line:83% size:75% and this is the new telescope that was just launched 14:21.733 --> 14:25.433 align:left position:12.5% line:89% size:77.5% two years ago, and is really-- 14:25.433 --> 14:27.466 align:left position:25% line:83% size:65% You know, saying it's gonna usher in a new era 14:27.466 --> 14:30.033 align:left position:35% line:83% size:55% of, you know, exoplanet atmosphere studies 14:30.033 --> 14:32.133 align:left position:20% line:83% size:70% is probably understating what's about to happen 14:32.133 --> 14:34.333 align:left position:12.5% line:89% size:77.5% over the next couple of years. 14:34.333 --> 14:40.033 align:left position:20% line:83% size:70% So launch for James Webb was Christmas Day of 2020 14:40.033 --> 14:42.500 align:left position:27.5% line:89% size:62.5% from French Guiana. 14:42.500 --> 14:45.166 align:left position:30% line:83% size:60% As was mentioned in the introduction, 14:45.166 --> 14:47.566 align:left position:32.5% line:83% size:57.5% I worked on one of the Webb instrument teams, 14:47.566 --> 14:49.900 align:left position:32.5% line:83% size:57.5% one of the JWST instrument teams, 14:49.900 --> 14:52.766 align:left position:35% line:83% size:55% specifically on a camera called NIRCam. 14:52.766 --> 14:55.700 align:left position:12.5% line:83% size:77.5% That's one of the 4 instruments on the spacecraft, 14:55.700 --> 14:59.366 align:left position:15% line:83% size:75% and so all of us were online to watch the launch. 14:59.366 --> 15:02.433 align:left position:17.5% line:71% size:72.5% Actually, what happened is, I was at my in-laws in Chicago, 15:02.433 --> 15:03.633 align:left position:12.5% line:71% size:77.5% and I have two young children, 15:03.633 --> 15:07.400 align:left position:22.5% line:71% size:67.5% and so we did presents for about an hour, 15:07.400 --> 15:09.666 align:left position:15% line:71% size:75% and then launch was at 6:15, 15:09.666 --> 15:12.533 align:left position:17.5% line:71% size:72.5% so we woke up at 5:00 A.M., did presents for about an hour, 15:12.533 --> 15:16.666 align:left position:25% line:71% size:65% and then we all went and watched the launch for-- 15:16.666 --> 15:20.166 align:left position:22.5% line:71% size:67.5% you know, in the middle of Christmas morning. 15:20.166 --> 15:22.766 align:left position:25% line:71% size:65% And I will tell you, 15:22.766 --> 15:26.566 align:left position:30% line:71% size:60% my mother-in-law, who's very nice, 15:26.566 --> 15:28.900 align:left position:20% line:71% size:70% she's a wonderful woman, and you guys would love her, 15:28.900 --> 15:33.300 align:left position:22.5% line:71% size:67.5% but she also, you know, she thought, she understood 15:33.300 --> 15:36.666 align:left position:15% line:71% size:75% how important this was to me professionally, right? 15:36.666 --> 15:38.933 align:left position:22.5% line:71% size:67.5% Like, if this exploded on launch, 15:38.933 --> 15:42.033 align:left position:17.5% line:71% size:72.5% it was unclear I was gonna have a job the next day, right? 15:42.033 --> 15:44.166 align:left position:12.5% line:71% size:77.5% There was a lot riding on this, 15:44.166 --> 15:46.900 align:left position:35% line:71% size:55% but also her conception of this was, 15:46.900 --> 15:50.233 align:left position:15% line:71% size:75% if the rocket ignited and we were going, we were done, right? 15:50.233 --> 15:52.266 align:left position:20% line:89% size:70% And in reality, you know, 15:52.266 --> 15:54.766 align:left position:22.5% line:83% size:67.5% the rocket can blow up at any time, right? 15:54.766 --> 15:58.666 align:left position:10% line:83% size:80% And once you get off-- actually, the real sticking point 15:58.666 --> 16:01.566 align:left position:20% line:83% size:70% was as soon as JWST came off the top of the rocket, 16:01.566 --> 16:03.600 align:left position:20% line:83% size:70% it was on battery power, 16:03.600 --> 16:05.933 align:left position:22.5% line:83% size:67.5% and the batteries last for about 20 minutes, 16:05.933 --> 16:08.033 align:left position:22.5% line:83% size:67.5% and so it has to deploy a solar panel 16:08.033 --> 16:10.600 align:left position:10% line:83% size:80% and start generating electricity as soon as it can, 16:10.600 --> 16:12.233 align:left position:22.5% line:83% size:67.5% and if that solar panel didn't deploy, 16:12.233 --> 16:14.433 align:left position:27.5% line:83% size:62.5% you had 20 minutes to figure out what was going on, 16:14.433 --> 16:15.633 align:left position:12.5% line:89% size:77.5% and then you were done, right? 16:15.633 --> 16:17.166 align:left position:12.5% line:89% size:77.5% There was no way to recover it. 16:17.166 --> 16:19.800 align:left position:17.5% line:83% size:72.5% And one of the best things I ever saw in my life was, 16:19.800 --> 16:22.266 align:left position:27.5% line:83% size:62.5% there's video feed from the launch 16:22.266 --> 16:25.566 align:left position:15% line:83% size:75% of, you know, Webb detaching from the upper stage, 16:25.566 --> 16:27.666 align:left position:15% line:83% size:75% and you could immediately see the solar panel coming out, 16:27.666 --> 16:29.266 align:left position:32.5% line:83% size:57.5% and we were all on the internal comms, 16:29.266 --> 16:30.533 align:left position:35% line:83% size:55% and you could hear them reporting 16:30.533 --> 16:32.233 align:left position:22.5% line:83% size:67.5% that power was starting to be generated, 16:32.233 --> 16:34.133 align:left position:12.5% line:83% size:77.5% and everybody started cheering because we knew that, 16:34.133 --> 16:36.400 align:left position:40% line:83% size:50% you know, the first hurdle was overcome. 16:36.400 --> 16:38.066 align:left position:25% line:83% size:65% But my mother-in-law, who's a wonderful woman, 16:38.066 --> 16:40.966 align:left position:20% line:83% size:70% thought as we were, like, 30 seconds in and the rocket 16:40.966 --> 16:42.800 align:left position:17.5% line:83% size:72.5% was firing that, you know, everything was great, 16:42.800 --> 16:44.866 align:left position:17.5% line:83% size:72.5% and so we're 30 seconds in and the rocket's firing, 16:44.866 --> 16:46.266 align:left position:27.5% line:83% size:62.5% and she comes over, and she's like, 16:46.266 --> 16:47.433 align:left position:25% line:89% size:65% "Thomas, you did it. 16:47.433 --> 16:50.333 align:left position:20% line:83% size:70% Like, it's all happening, congratulations," 16:50.333 --> 16:52.666 align:left position:25% line:83% size:65% and I just was like, "Not now, Cindy." 16:52.666 --> 16:55.500 align:left position:27.5% line:89% size:62.5% [audience laughing] 16:55.500 --> 16:57.500 align:left position:25% line:89% size:65% But she's very nice. 16:57.500 --> 17:00.466 align:left position:27.5% line:83% size:62.5% So there's a couple of exciting things about Webb. 17:00.466 --> 17:03.333 align:left position:22.5% line:83% size:67.5% One of them-- and this still boggles my mind, 17:03.333 --> 17:06.800 align:left position:22.5% line:83% size:67.5% even having known this for, you know, years, right-- 17:06.800 --> 17:11.166 align:left position:25% line:83% size:65% is that Webb is about three times as large as Hubble, 17:11.166 --> 17:13.833 align:left position:32.5% line:83% size:57.5% but the mirror weighs half as much, right? 17:13.833 --> 17:16.433 align:left position:22.5% line:83% size:67.5% And the collecting area you get from a mirror 17:16.433 --> 17:18.533 align:left position:27.5% line:83% size:62.5% is the area, right, so if it's three times larger, 17:18.533 --> 17:21.300 align:left position:27.5% line:83% size:62.5% that means you get almost 10 times as much light 17:21.300 --> 17:22.733 align:left position:17.5% line:89% size:72.5% in the same amount of time, 17:22.733 --> 17:24.866 align:left position:22.5% line:83% size:67.5% so it's about 10 times more powerful than Hubble. 17:24.866 --> 17:26.033 align:left position:22.5% line:89% size:67.5% It weighs half as much. 17:26.033 --> 17:27.633 align:left position:37.5% line:83% size:52.5% It's really an incredible machine, 17:27.633 --> 17:31.566 align:left position:17.5% line:83% size:72.5% and the amount of attention to detail and design 17:31.566 --> 17:34.033 align:left position:30% line:83% size:60% that went into it really just boggles the mind. 17:34.033 --> 17:35.666 align:left position:25% line:83% size:65% The other difference from Hubble is that Webb 17:35.666 --> 17:37.233 align:left position:20% line:89% size:70% is an infrared telescope. 17:37.233 --> 17:41.200 align:left position:27.5% line:83% size:62.5% So Hubble observes a little bit into the infrared, 17:41.200 --> 17:43.200 align:left position:30% line:83% size:60% but fundamentally is an optical telescope, 17:43.200 --> 17:45.033 align:left position:22.5% line:83% size:67.5% but observed very close to the wavelengths-- 17:45.033 --> 17:47.233 align:left position:25% line:83% size:65% to the kind of light that we see with our eyes. 17:47.233 --> 17:48.666 align:left position:27.5% line:83% size:62.5% And Webb's observes very different wavelengths 17:48.666 --> 17:51.666 align:left position:22.5% line:83% size:67.5% and longer wavelengths, the infrared, you know, 17:51.666 --> 17:56.533 align:left position:27.5% line:83% size:62.5% closer to the heat that you see in images of heat. 17:56.533 --> 17:59.033 align:left position:17.5% line:83% size:72.5% So one thing this allows us to do is it allows us 17:59.033 --> 18:02.366 align:left position:25% line:83% size:65% to probe deeper into the atmospheres of exoplanets. 18:02.366 --> 18:04.733 align:left position:12.5% line:83% size:77.5% So this is a picture of Jupiter taken in the infrared. 18:04.733 --> 18:07.833 align:left position:15% line:83% size:75% You can see the sort of bands and clouds where, you know, 18:07.833 --> 18:11.566 align:left position:15% line:83% size:75% you maybe are used to seeing in optical images of Jupiter. 18:11.566 --> 18:14.300 align:left position:17.5% line:5% size:72.5% Here's the Great Red Spot, just for reference, right, 18:14.300 --> 18:16.333 align:left position:27.5% line:5% size:62.5% that sort of dark, circle-ish thing. 18:16.333 --> 18:18.433 align:left position:25% line:5% size:65% The bright parts here 18:18.433 --> 18:21.000 align:left position:25% line:5% size:65% are really hot parts of Jupiter, right? 18:21.000 --> 18:22.766 align:left position:27.5% line:5% size:62.5% What that means is, those bright parts are 18:22.766 --> 18:24.433 align:left position:32.5% line:5% size:57.5% you are seeing through the clouds 18:24.433 --> 18:27.166 align:left position:10% line:5% size:80% into the interior of the planet, where it is hotter. 18:27.166 --> 18:29.033 align:left position:27.5% line:83% size:62.5% So the darker parts are the upper clouds 18:29.033 --> 18:31.433 align:left position:12.5% line:83% size:77.5% that usually that's what we see when we look in visible light 18:31.433 --> 18:33.133 align:left position:22.5% line:89% size:67.5% and hotter and deeper, 18:33.133 --> 18:35.166 align:left position:27.5% line:83% size:62.5% we can actually see with these infrared images, 18:35.166 --> 18:37.300 align:left position:15% line:83% size:75% and we usually can't see that in the optical. 18:37.300 --> 18:39.500 align:left position:12.5% line:5% size:77.5% We also see different molecules in the infrared. 18:39.500 --> 18:41.100 align:left position:12.5% line:5% size:77.5% We get to see a lot of methane. 18:41.100 --> 18:45.100 align:left position:15% line:5% size:75% We get to see a lot of ozone and water and carbon dioxide, 18:45.100 --> 18:47.100 align:left position:20% line:5% size:70% which we couldn't really see easily, 18:47.100 --> 18:49.700 align:left position:32.5% line:5% size:57.5% particularly in exoplanet observations. 18:49.700 --> 18:52.033 align:left position:20% line:5% size:70% As a little bit of color, 18:52.033 --> 18:55.066 align:left position:27.5% line:5% size:62.5% so launch for Webb was Christmas morning, 18:55.066 --> 18:57.166 align:left position:25% line:5% size:65% and then we all spent 18:57.166 --> 19:01.200 align:left position:15% line:5% size:75% the next six months traveling out to Baltimore one week-- 19:01.200 --> 19:04.566 align:left position:15% line:5% size:75% a little over a week a month for six months straight 19:04.566 --> 19:06.700 align:left position:20% line:5% size:70% to operate the telescope during commissioning, 19:06.700 --> 19:08.000 align:left position:27.5% line:89% size:62.5% because it launches 19:08.000 --> 19:10.200 align:left position:22.5% line:83% size:67.5% and then it needs to be checked out before NASA will, 19:10.200 --> 19:12.333 align:left position:27.5% line:83% size:62.5% you know, accept it as an operating observatory. 19:12.333 --> 19:14.133 align:left position:20% line:89% size:70% So, as some local color, 19:14.133 --> 19:16.133 align:left position:25% line:83% size:65% here's what my office looked like 19:16.133 --> 19:19.266 align:left position:15% line:83% size:75% for most of those six months during commissioning, 19:19.266 --> 19:20.833 align:left position:15% line:89% size:75% helping to run the telescope. 19:20.833 --> 19:22.500 align:left position:10% line:89% size:80% The really helpful thing, right, 19:22.500 --> 19:24.866 align:left position:25% line:83% size:65% is that most of this is color-coded, right? 19:24.866 --> 19:27.266 align:left position:22.5% line:83% size:67.5% It turns out that there are actually very few people 19:27.266 --> 19:29.433 align:left position:32.5% line:83% size:57.5% that know what all those numbers mean, 19:29.433 --> 19:30.600 align:left position:27.5% line:89% size:62.5% right, not even me. 19:30.600 --> 19:32.700 align:left position:32.5% line:83% size:57.5% I knew my part, but most of these, 19:32.700 --> 19:36.033 align:left position:20% line:83% size:70% what was happening, like, other people understood. 19:36.033 --> 19:38.533 align:left position:15% line:83% size:75% It was sort of a fascinating project that no one person 19:38.533 --> 19:40.300 align:left position:22.5% line:83% size:67.5% can really hold it all in their head, 19:40.300 --> 19:42.166 align:left position:10% line:89% size:80% except there was one guy, right? 19:42.166 --> 19:45.066 align:left position:15% line:83% size:75% The real job that we all had was to look at these screens 19:45.066 --> 19:49.166 align:left position:12.5% line:83% size:77.5% and if anything turned red, we were gonna call Carl, right, 19:49.166 --> 19:52.700 align:left position:30% line:83% size:60% 'cause Carl knows what all these numbers mean 19:52.700 --> 19:55.333 align:left position:17.5% line:83% size:72.5% and knows if they turn red, what to do about it, 19:55.333 --> 19:58.733 align:left position:25% line:83% size:65% or at least he knows who to talk to, right? 20:00.133 --> 20:02.266 align:left position:22.5% line:71% size:67.5% I'll also say that we-- 20:02.266 --> 20:04.266 align:left position:27.5% line:71% size:62.5% most of the shifts, they were eight-hour shifts, 20:04.266 --> 20:05.966 align:left position:30% line:71% size:60% and we were there most of the day. 20:05.966 --> 20:07.300 align:left position:22.5% line:71% size:67.5% We did have to observe. 20:07.300 --> 20:09.100 align:left position:15% line:71% size:75% We had to be there overnight some weeks, 20:09.100 --> 20:11.600 align:left position:15% line:71% size:75% which I felt was particularly unjust for a space telescope 20:11.600 --> 20:14.200 align:left position:20% line:71% size:70% where you don't actually usually have to be up overnight. 20:14.200 --> 20:15.833 align:left position:22.5% line:71% size:67.5% The one nice thing is, 20:15.833 --> 20:19.666 align:left position:15% line:71% size:75% we actually ended up watching a fair amount of movies, 20:19.666 --> 20:22.366 align:left position:15% line:71% size:75% and this is a photograph of-- 20:22.366 --> 20:24.800 align:left position:32.5% line:83% size:57.5% So we were all in a room called Science-- 20:24.800 --> 20:28.000 align:left position:15% line:83% size:75% the Science Instrument Room, the SI Room, 20:28.000 --> 20:29.800 align:left position:25% line:83% size:65% and right next to us in a separate room 20:29.800 --> 20:31.600 align:left position:22.5% line:83% size:67.5% was Flight Operations, Flight Ops. 20:31.600 --> 20:34.566 align:left position:25% line:83% size:65% This is a photograph of all the Flight Ops desks. 20:34.566 --> 20:36.233 align:left position:25% line:83% size:65% They were the people who actually sent commands 20:36.233 --> 20:38.733 align:left position:27.5% line:89% size:62.5% to the spacecraft. 20:38.733 --> 20:42.766 align:left position:25% line:83% size:65% And you will notice, if you look very carefully, 20:42.766 --> 20:44.933 align:left position:15% line:89% size:75% right up here at that image, 20:44.933 --> 20:49.300 align:left position:22.5% line:83% size:67.5% Flight Ops is currently watching Olympic curling 20:49.300 --> 20:52.266 align:left position:27.5% line:83% size:62.5% on the big screens at the front of the room, right? 20:52.266 --> 20:54.866 align:left position:25% line:83% size:65% So most of the movies we watched were actually stuff 20:54.866 --> 20:56.533 align:left position:22.5% line:83% size:67.5% that Flight Ops set up and put on, 20:56.533 --> 20:58.800 align:left position:30% line:83% size:60% and they also get to choose the movies, 20:58.800 --> 21:01.266 align:left position:27.5% line:83% size:62.5% and they had a very interesting-- 21:01.266 --> 21:03.633 align:left position:27.5% line:83% size:62.5% I really wanna know who was in charge of this 21:03.633 --> 21:05.233 align:left position:32.5% line:83% size:57.5% 'cause we spent about a week working through 21:05.233 --> 21:07.666 align:left position:20% line:83% size:70% all the Princess Diaries  movies. 21:07.666 --> 21:10.533 align:left position:20% line:83% size:70% Then we did really trashy sci-fi movies. 21:10.533 --> 21:12.933 align:left position:22.5% line:83% size:67.5% Have you guys ever seen Moonfall? 21:12.933 --> 21:15.500 align:left position:17.5% line:83% size:72.5% Like, the moon comes alive and crashes into the Earth. 21:15.500 --> 21:17.700 align:left position:15% line:71% size:75% Yeah, that's what we watched. 21:17.700 --> 21:20.400 align:left position:32.5% line:71% size:57.5% It was not what I would have expected 21:20.400 --> 21:25.066 align:left position:15% line:71% size:75% for a bunch of NASA engineers in the other room. 21:25.066 --> 21:28.333 align:left position:15% line:71% size:75% Okay, so that's a little bit of color from commissioning, 21:28.333 --> 21:31.666 align:left position:12.5% line:71% size:77.5% but to get back to the serious part of the talk, right, 21:31.666 --> 21:34.666 align:left position:27.5% line:71% size:62.5% how can we use JWST to search for life, right? 21:34.666 --> 21:37.433 align:left position:12.5% line:71% size:77.5% Now that we have this machine, this observatory in space, 21:37.433 --> 21:41.766 align:left position:17.5% line:71% size:72.5% we want to use it to search for life with its giant mirror. 21:41.766 --> 21:43.733 align:left position:27.5% line:89% size:62.5% How do we do that? 21:43.733 --> 21:46.000 align:left position:17.5% line:89% size:72.5% So one thing is that often 21:46.000 --> 21:48.866 align:left position:12.5% line:83% size:77.5% when we think about other life in the universe, right, 21:48.866 --> 21:52.800 align:left position:12.5% line:83% size:77.5% a lot of what we think about is other intelligent life, right? 21:52.800 --> 21:55.633 align:left position:17.5% line:83% size:72.5% Like, we're thinking about some sort of, like, 21:55.633 --> 21:58.666 align:left position:10% line:83% size:80% face-sucking alien that's gonna, like, read your mind 21:58.666 --> 22:02.566 align:left position:15% line:83% size:75% or, like, you know, the alien from Aliens, right? 22:02.566 --> 22:06.066 align:left position:12.5% line:5% size:77.5% But there's other kinds of life out in the universe, right? 22:06.066 --> 22:08.533 align:left position:15% line:5% size:75% And when we're talking about in the astronomical context 22:08.533 --> 22:11.733 align:left position:15% line:5% size:75% searching for life, we're not just meaning intelligent life. 22:11.733 --> 22:15.133 align:left position:10% line:5% size:80% We also mean plants and bacteria and animals and, really, 22:15.133 --> 22:18.433 align:left position:30% line:5% size:60% any kind of life, any kind of life out there 22:18.433 --> 22:21.100 align:left position:22.5% line:5% size:67.5% that would be something like life on Earth. 22:23.233 --> 22:25.400 align:left position:17.5% line:71% size:72.5% So what that means is that a lot of people 22:25.400 --> 22:27.500 align:left position:27.5% line:71% size:62.5% spend a lot of time thinking about 22:27.500 --> 22:30.066 align:left position:32.5% line:71% size:57.5% what, exactly, do we mean by life, right? 22:30.066 --> 22:31.800 align:left position:25% line:71% size:65% Like, what does that actually mean? 22:31.800 --> 22:33.466 align:left position:27.5% line:71% size:62.5% Like, what is that? 22:33.466 --> 22:35.666 align:left position:20% line:71% size:70% And I'll say it's a topic of a lot of debate. 22:35.666 --> 22:37.500 align:left position:27.5% line:71% size:62.5% I've gone to a lot of conferences where people 22:37.500 --> 22:40.300 align:left position:12.5% line:71% size:77.5% spend a lot of time discussing exactly what it means. 22:40.300 --> 22:43.200 align:left position:25% line:71% size:65% My personal favorite definition-- 22:43.200 --> 22:44.800 align:left position:25% line:71% size:65% Well, I've written it on the slide, right? 22:44.800 --> 22:45.966 align:left position:22.5% line:5% size:67.5% It's, life is some sort 22:45.966 --> 22:48.633 align:left position:30% line:5% size:60% of self-organized chemical structure 22:48.633 --> 22:52.133 align:left position:17.5% line:5% size:72.5% that alters its environment and can reproduce. 22:52.133 --> 22:53.300 align:left position:22.5% line:5% size:67.5% To me, that seems like 22:53.300 --> 22:56.033 align:left position:30% line:5% size:60% a pretty general, basic statement 22:56.033 --> 22:57.733 align:left position:10% line:5% size:80% that tries to be pretty agnostic 22:57.733 --> 22:59.833 align:left position:15% line:5% size:75% about what, exactly, life is, right? 22:59.833 --> 23:01.500 align:left position:20% line:71% size:70% So we're not just looking for intelligent life. 23:01.500 --> 23:05.433 align:left position:12.5% line:71% size:77.5% We're looking for just life as a general category of objects. 23:05.433 --> 23:08.166 align:left position:20% line:71% size:70% On Earth, all of the life on Earth 23:08.166 --> 23:11.900 align:left position:22.5% line:71% size:67.5% is based fundamentally around DNA, right, 23:11.900 --> 23:16.400 align:left position:22.5% line:71% size:67.5% which is some assembly of hydrogen, oxygen, 23:16.400 --> 23:18.933 align:left position:30% line:71% size:60% nitrogen, carbon, and phosphorus, right? 23:18.933 --> 23:22.333 align:left position:15% line:71% size:75% The backbone of most of these molecules are carbon molecules. 23:22.333 --> 23:25.000 align:left position:22.5% line:5% size:67.5% That's why we say that life on Earth is carbon-based. 23:25.000 --> 23:27.333 align:left position:17.5% line:5% size:72.5% It's why organic chemistry exists as a subfield. 23:27.333 --> 23:29.900 align:left position:30% line:5% size:60% Organic chemistry is just carbon molecules 23:29.900 --> 23:32.966 align:left position:15% line:5% size:75% and carbon chemistry, right, because it's a fundamental part 23:32.966 --> 23:34.966 align:left position:27.5% line:5% size:62.5% of all of our lives of everything on Earth. 23:37.300 --> 23:41.033 align:left position:12.5% line:83% size:77.5% And life on Earth also requires liquid water, right? 23:41.033 --> 23:43.666 align:left position:17.5% line:83% size:72.5% The reason for that is that all the chemical reactions 23:43.666 --> 23:47.133 align:left position:15% line:83% size:75% that happen in your body need some sort of liquid suspension 23:47.133 --> 23:48.966 align:left position:17.5% line:89% size:72.5% for it to occur in, right? 23:48.966 --> 23:50.633 align:left position:30% line:83% size:60% It's hard to get chemistry to happen 23:50.633 --> 23:52.100 align:left position:22.5% line:89% size:67.5% just dry on the floor. 23:52.100 --> 23:54.766 align:left position:27.5% line:83% size:62.5% We need some liquid to allow things to mix, 23:54.766 --> 23:57.133 align:left position:17.5% line:83% size:72.5% and you can dissolve a lot of things in water, right? 23:57.133 --> 23:59.633 align:left position:12.5% line:83% size:77.5% Water is sometimes referred to as the universal solvent. 23:59.633 --> 24:01.933 align:left position:30% line:83% size:60% So life on Earth, we need liquid water. 24:01.933 --> 24:04.300 align:left position:20% line:83% size:70% We need a lot of carbon, oxygen, nitrogen, 24:04.300 --> 24:06.600 align:left position:27.5% line:83% size:62.5% maybe a little bit of phosphorus. 24:06.600 --> 24:09.033 align:left position:20% line:83% size:70% Okay, so what about life on other planets, right? 24:09.033 --> 24:11.033 align:left position:22.5% line:83% size:67.5% If we think about what life looks like on Earth, 24:11.033 --> 24:13.233 align:left position:17.5% line:83% size:72.5% then what does that tell us about where do we look 24:13.233 --> 24:15.300 align:left position:17.5% line:89% size:72.5% for life on other planets? 24:15.300 --> 24:18.766 align:left position:25% line:83% size:65% Well, first thing is, we need an ocean, right? 24:18.766 --> 24:20.566 align:left position:22.5% line:83% size:67.5% If we want to find life like the Earth, 24:20.566 --> 24:23.266 align:left position:15% line:83% size:75% we need to have liquid water present on the surface, 24:23.266 --> 24:25.266 align:left position:17.5% line:83% size:72.5% enough liquid water for it to be a fundamental part 24:25.266 --> 24:28.433 align:left position:32.5% line:83% size:57.5% of the biology, just like it is for us. 24:28.433 --> 24:31.166 align:left position:35% line:83% size:55% It's actually an interesting point 24:31.166 --> 24:32.800 align:left position:10% line:89% size:80% about the Earth's oceans, right? 24:32.800 --> 24:35.200 align:left position:15% line:83% size:75% And it's actually a very fine point that a lot of people 24:35.200 --> 24:37.700 align:left position:12.5% line:83% size:77.5% are thinking about as we think about oceans on other worlds. 24:37.700 --> 24:39.500 align:left position:15% line:83% size:75% 'Cause if you think about it, if Earth had 24:39.500 --> 24:42.166 align:left position:20% line:83% size:70% a little bit more water, just a little bit more water, 24:42.166 --> 24:44.666 align:left position:15% line:83% size:75% the surface would be entirely covered by ocean, right? 24:44.666 --> 24:45.833 align:left position:27.5% line:89% size:62.5% There'd be no land. 24:45.833 --> 24:47.633 align:left position:22.5% line:83% size:67.5% It would just be water all the way down. 24:47.633 --> 24:49.200 align:left position:27.5% line:83% size:62.5% Well, until you hit the sea floor. 24:49.200 --> 24:51.000 align:left position:35% line:83% size:55% And if we had a little bit less water, 24:51.000 --> 24:52.266 align:left position:15% line:89% size:75% there wouldn't be any oceans. 24:52.266 --> 24:54.166 align:left position:15% line:83% size:75% We'd be something like Mars, where there is water, 24:54.166 --> 24:55.833 align:left position:32.5% line:83% size:57.5% but it's frozen into the polar icecaps, 24:55.833 --> 24:57.400 align:left position:17.5% line:89% size:72.5% or it's in ice underground. 24:57.400 --> 24:59.900 align:left position:15% line:83% size:75% It's not just standing water on the surface. 24:59.900 --> 25:02.966 align:left position:15% line:71% size:75% So Earth, at least right now, seems to be 25:02.966 --> 25:06.633 align:left position:20% line:71% size:70% a pretty finely balanced midpoint 25:06.633 --> 25:08.966 align:left position:17.5% line:71% size:72.5% between those two extremes, and it seems very convenient 25:08.966 --> 25:10.766 align:left position:22.5% line:71% size:67.5% that we happen to live on the one planet 25:10.766 --> 25:14.233 align:left position:20% line:71% size:70% that just happens to hit that exact point. 25:14.233 --> 25:16.033 align:left position:20% line:71% size:70% Now, maybe that's reading too much into it, right? 25:16.033 --> 25:17.200 align:left position:20% line:71% size:70% We only have one example. 25:17.200 --> 25:18.400 align:left position:12.5% line:71% size:77.5% Maybe we're gonna go out there, 25:18.400 --> 25:20.000 align:left position:20% line:71% size:70% and we're gonna discover tons of ocean worlds, 25:20.000 --> 25:22.000 align:left position:20% line:71% size:70% and it's gonna be great, or maybe we're gonna discover 25:22.000 --> 25:24.466 align:left position:12.5% line:71% size:77.5% tons of life that lives on ice and melts it-- 25:24.466 --> 25:26.400 align:left position:15% line:71% size:75% or I don't know what, right? 25:26.400 --> 25:28.066 align:left position:27.5% line:71% size:62.5% But just something to think about. 25:28.066 --> 25:29.866 align:left position:20% line:71% size:70% But the fact that we have oceans on Earth 25:29.866 --> 25:33.366 align:left position:12.5% line:71% size:77.5% is actually very coincidental, seems to be very finely tuned. 25:35.366 --> 25:36.866 align:left position:12.5% line:89% size:77.5% Another thing we also need is, 25:36.866 --> 25:39.000 align:left position:12.5% line:83% size:77.5% we need the right temperature, right? 25:39.000 --> 25:40.400 align:left position:42.5% line:83% size:47.5% We need the right amount of water. 25:40.400 --> 25:41.666 align:left position:12.5% line:83% size:77.5% We need the right temperature, right? 25:41.666 --> 25:44.066 align:left position:22.5% line:83% size:67.5% If Earth gets too hot, if it moves in a little bit 25:44.066 --> 25:46.500 align:left position:10% line:83% size:80% closer to the Sun, all the water boils off into steam. 25:46.500 --> 25:48.800 align:left position:20% line:83% size:70% If it moves too far out, it all freezes, 25:48.800 --> 25:52.200 align:left position:27.5% line:83% size:62.5% it turns into ice, and we're a giant snowball. 25:52.200 --> 25:54.200 align:left position:20% line:71% size:70% So one of the fundamental things we wanna look for 25:54.200 --> 25:57.133 align:left position:22.5% line:71% size:67.5% when we're looking for potentially habitable planets 25:57.133 --> 25:58.333 align:left position:15% line:71% size:75% is we wanna look for planets 25:58.333 --> 26:00.566 align:left position:12.5% line:71% size:77.5% that are at the right distance from their stars, 26:00.566 --> 26:03.433 align:left position:12.5% line:71% size:77.5% that are in the habitable zone, or the Goldilocks zone, 26:03.433 --> 26:06.266 align:left position:25% line:71% size:65% the right temperature so that liquid water can exist 26:06.266 --> 26:08.266 align:left position:10% line:71% size:80% on the surface of these planets. 26:09.266 --> 26:11.500 align:left position:25% line:83% size:65% And we actually have a bunch of these, right? 26:11.500 --> 26:13.866 align:left position:12.5% line:89% size:77.5% These are actual real planets. 26:13.866 --> 26:15.366 align:left position:12.5% line:89% size:77.5% The images are not real, right? 26:15.366 --> 26:17.033 align:left position:22.5% line:83% size:67.5% These are all artists' conceptions, 26:17.033 --> 26:20.500 align:left position:10% line:83% size:80% but these are all actual planets that we have detected 26:20.500 --> 26:23.100 align:left position:22.5% line:83% size:67.5% and are about the size of the Earth 26:23.100 --> 26:25.066 align:left position:15% line:83% size:75% and are at the right distance from their stars 26:25.066 --> 26:28.000 align:left position:22.5% line:83% size:67.5% to support liquid water on their surfaces, right? 26:28.000 --> 26:29.466 align:left position:30% line:83% size:60% We actually know about a whole bunch 26:29.466 --> 26:31.300 align:left position:10% line:83% size:80% of potentially habitable planets that we could go 26:31.300 --> 26:33.633 align:left position:15% line:89% size:75% and search for life on them. 26:33.633 --> 26:35.866 align:left position:17.5% line:83% size:72.5% So, okay, so we've detected a whole bunch of planets. 26:35.866 --> 26:37.266 align:left position:30% line:83% size:60% We have this nice light curve, right? 26:37.266 --> 26:38.600 align:left position:27.5% line:89% size:62.5% What happens next? 26:38.600 --> 26:40.800 align:left position:25% line:83% size:65% How do we figure out if we have a beach vacation 26:40.800 --> 26:43.666 align:left position:17.5% line:89% size:72.5% or if we have Venus, right? 26:43.666 --> 26:45.466 align:left position:30% line:83% size:60% Now that we know these planets are out there, 26:45.466 --> 26:47.133 align:left position:32.5% line:83% size:57.5% how do we look at their atmospheres 26:47.133 --> 26:50.333 align:left position:22.5% line:83% size:67.5% and figure out if they actually might have life? 26:50.333 --> 26:52.500 align:left position:15% line:83% size:75% Well, we primarily wanna look for three things 26:52.500 --> 26:53.666 align:left position:27.5% line:89% size:62.5% in the atmosphere. 26:53.666 --> 26:56.800 align:left position:27.5% line:83% size:62.5% So first, we wanna look for water, right? 26:56.800 --> 26:58.333 align:left position:15% line:89% size:75% We wanna confirm that there's 26:58.333 --> 26:59.833 align:left position:27.5% line:83% size:62.5% some sort of water in the system. 26:59.833 --> 27:01.566 align:left position:10% line:83% size:80% Well, it's the right temperature for liquid water, 27:01.566 --> 27:06.400 align:left position:17.5% line:83% size:72.5% but we don't know if liquid water is there until we see it. 27:06.400 --> 27:08.666 align:left position:25% line:83% size:65% We also want to look for oxygen, right? 27:08.666 --> 27:10.866 align:left position:12.5% line:83% size:77.5% 20% of the air you're breathing right now is oxygen. 27:10.866 --> 27:13.600 align:left position:22.5% line:83% size:67.5% It's a major component of our atmosphere on Earth. 27:13.600 --> 27:15.000 align:left position:22.5% line:83% size:67.5% And we also wanna look for methane, 27:15.000 --> 27:17.666 align:left position:30% line:83% size:60% but probably not too much, right? 27:17.666 --> 27:22.266 align:left position:10% line:83% size:80% It's one of the major biological products from life on Earth. 27:22.266 --> 27:24.766 align:left position:15% line:89% size:75% The main biosignature, right, 27:24.766 --> 27:28.033 align:left position:10% line:83% size:80% thing you would want to look for in an atmosphere, is oxygen. 27:28.033 --> 27:31.566 align:left position:25% line:83% size:65% It's often considered a primary biosignature, 27:31.566 --> 27:36.633 align:left position:12.5% line:83% size:77.5% and the reason for that is that without life on Earth, 27:36.633 --> 27:38.500 align:left position:12.5% line:89% size:77.5% the level of oxygen in our air 27:38.500 --> 27:40.933 align:left position:12.5% line:83% size:77.5% would be about a million times lower, right? 27:40.933 --> 27:42.300 align:left position:12.5% line:89% size:77.5% So when the Earth first formed, 27:42.300 --> 27:45.600 align:left position:15% line:83% size:75% there was almost zero oxygen in the atmosphere of the planet, 27:45.600 --> 27:48.600 align:left position:12.5% line:83% size:77.5% and the only reason why the air you are breathing right now 27:48.600 --> 27:51.966 align:left position:35% line:83% size:55% is 20% oxygen is because life evolved 27:51.966 --> 27:56.833 align:left position:12.5% line:83% size:77.5% and started photosynthesizing, so the fact that 1/5 of our air 27:56.833 --> 27:59.400 align:left position:20% line:83% size:70% is composed out of oxygen molecules is solely due 27:59.400 --> 28:00.633 align:left position:30% line:89% size:60% to life on Earth. 28:00.633 --> 28:01.833 align:left position:20% line:5% size:70% If all the life on Earth 28:01.833 --> 28:03.466 align:left position:25% line:5% size:65% suddenly blinked out of existence tomorrow, 28:03.466 --> 28:05.266 align:left position:15% line:5% size:75% all the oxygen would be gone from our atmosphere 28:05.266 --> 28:07.833 align:left position:32.5% line:5% size:57.5% within probably a couple thousand years, 28:07.833 --> 28:10.200 align:left position:37.5% line:5% size:52.5% very quick on an astronomical time scale. 28:10.200 --> 28:13.066 align:left position:25% line:71% size:65% So if we were looking at an exoplanet 28:13.066 --> 28:14.833 align:left position:25% line:71% size:65% and we saw some water in the atmosphere 28:14.833 --> 28:18.166 align:left position:27.5% line:71% size:62.5% and we saw oxygen, 28:18.166 --> 28:20.366 align:left position:20% line:71% size:70% I mean, there's probably a couple more steps, 28:20.366 --> 28:22.066 align:left position:22.5% line:71% size:67.5% but you could probably think about writing 28:22.066 --> 28:25.300 align:left position:17.5% line:71% size:72.5% your Nobel Prize acceptance speech at that point, right? 28:25.300 --> 28:28.633 align:left position:17.5% line:71% size:72.5% It's a really strong signal that we've got 28:28.633 --> 28:31.400 align:left position:15% line:71% size:75% a good, promising candidate. 28:31.400 --> 28:33.200 align:left position:17.5% line:71% size:72.5% One of the best candidates to look for this, 28:33.200 --> 28:35.800 align:left position:15% line:71% size:75% a lot of people are spending a lot of time looking at this, 28:35.800 --> 28:38.100 align:left position:12.5% line:89% size:77.5% is a system called TRAPPIST-1. 28:38.100 --> 28:39.666 align:left position:22.5% line:83% size:67.5% These are a whole bunch of planets, 28:39.666 --> 28:42.200 align:left position:27.5% line:83% size:62.5% and a bunch of them are in the habitable zone, 28:42.200 --> 28:43.833 align:left position:17.5% line:89% size:72.5% so it's a very small star. 28:43.833 --> 28:45.000 align:left position:17.5% line:89% size:72.5% They're all very close in, 28:45.000 --> 28:47.200 align:left position:32.5% line:83% size:57.5% but they're all in the habitable zone. 28:47.200 --> 28:51.633 align:left position:20% line:83% size:70% Two of these have already been looked at with James Webb. 28:51.633 --> 28:54.066 align:left position:22.5% line:83% size:67.5% I was actually involved with looking at-- 28:54.066 --> 28:58.300 align:left position:22.5% line:83% size:67.5% the team that looked at the innermost one, TRAPPIST-1b, 28:58.300 --> 29:01.433 align:left position:20% line:83% size:70% where we measured what it looked like for the first time, 29:01.433 --> 29:03.266 align:left position:27.5% line:83% size:62.5% and, unfortunately, the answer was, 29:03.266 --> 29:05.933 align:left position:35% line:83% size:55% it looks like a bare rock in space, 29:05.933 --> 29:08.533 align:left position:15% line:83% size:75% that the atmosphere has been completely blasted off. 29:08.533 --> 29:11.866 align:left position:12.5% line:83% size:77.5% I was actually sitting with the guy who was analyzing the data. 29:11.866 --> 29:13.600 align:left position:25% line:71% size:65% The whole observation was designed to take, 29:13.600 --> 29:15.233 align:left position:15% line:71% size:75% like, five separate transits, 29:15.233 --> 29:17.333 align:left position:22.5% line:71% size:67.5% and we were gonna have to add them all together 29:17.333 --> 29:19.966 align:left position:20% line:71% size:70% before we thought we were gonna get anything, 29:19.966 --> 29:22.166 align:left position:15% line:71% size:75% and I was sitting next to him when he first downloaded 29:22.166 --> 29:24.633 align:left position:22.5% line:71% size:67.5% the first data from the first observation, 29:24.633 --> 29:28.333 align:left position:17.5% line:71% size:72.5% and you could just see it, like, in the first one. 29:28.333 --> 29:30.333 align:left position:27.5% line:71% size:62.5% And we both looked at each other, and we're like, 29:30.333 --> 29:33.666 align:left position:27.5% line:71% size:62.5% "Well, that is not really the answer we wanted," 29:33.666 --> 29:35.766 align:left position:30% line:71% size:60% because it means it was a very hot rock, 29:35.766 --> 29:37.766 align:left position:15% line:71% size:75% the fact that we could see it the first time. 29:37.766 --> 29:40.866 align:left position:15% line:71% size:75% So actually, it's telling us a lot about how planets 29:40.866 --> 29:44.033 align:left position:17.5% line:71% size:72.5% lose atmospheres if they're very close to their stars, 29:44.033 --> 29:45.266 align:left position:20% line:71% size:70% and then the second one, 29:45.266 --> 29:47.933 align:left position:32.5% line:83% size:57.5% TRAPPIST-1c, is more Venus-like, it turns out, 29:47.933 --> 29:50.766 align:left position:15% line:89% size:75% from other Webb observations, 29:50.766 --> 29:54.800 align:left position:15% line:83% size:75% but there are a lot of people looking at E and F and G to try 29:54.800 --> 29:58.433 align:left position:12.5% line:83% size:77.5% and get much finer observations of their atmospheres. 29:58.433 --> 30:00.733 align:left position:17.5% line:5% size:72.5% So there's a lot of people looking for Earth-like life. 30:00.733 --> 30:03.066 align:left position:22.5% line:5% size:67.5% Another thing we can do is look for life, 30:03.066 --> 30:05.233 align:left position:35% line:5% size:55% but maybe not quite as we know it, right, 30:05.233 --> 30:06.700 align:left position:20% line:5% size:70% not quite like the Earth. 30:06.700 --> 30:08.100 align:left position:27.5% line:71% size:62.5% And so I mentioned that the Earth-- 30:08.100 --> 30:09.500 align:left position:12.5% line:71% size:77.5% We seem to be very finely tuned 30:09.500 --> 30:11.866 align:left position:27.5% line:71% size:62.5% in terms of having land and an ocean, right? 30:11.866 --> 30:14.600 align:left position:25% line:71% size:65% What if we looked not at planets like the Earth, 30:14.600 --> 30:16.433 align:left position:25% line:71% size:65% but what if we looked at water worlds, 30:16.433 --> 30:18.066 align:left position:27.5% line:71% size:62.5% giant water worlds 30:18.066 --> 30:21.033 align:left position:15% line:71% size:75% that are somewhere in between the Earth and Neptune? 30:22.566 --> 30:25.400 align:left position:27.5% line:71% size:62.5% So these are called hycean planets. 30:25.400 --> 30:27.200 align:left position:30% line:71% size:60% This was sort of a category of planets 30:27.200 --> 30:29.566 align:left position:27.5% line:71% size:62.5% that was suggested a couple of years ago, 30:29.566 --> 30:31.966 align:left position:20% line:71% size:70% and the idea is that it's not a planet like the Earth. 30:31.966 --> 30:34.066 align:left position:27.5% line:5% size:62.5% It's probably about five or even ten times 30:34.066 --> 30:35.666 align:left position:15% line:5% size:75% more massive than the Earth, 30:35.666 --> 30:38.166 align:left position:35% line:5% size:55% much larger, but there's a lot of water, 30:38.166 --> 30:39.533 align:left position:10% line:5% size:80% and there's a hydrogen envelope, 30:39.533 --> 30:41.733 align:left position:25% line:5% size:65% a hydrogen atmosphere that insulates that water, 30:41.733 --> 30:43.733 align:left position:27.5% line:5% size:62.5% and so you can have a liquid water ocean 30:43.733 --> 30:46.333 align:left position:20% line:5% size:70% at the right temperature, at about room temperature, 30:46.333 --> 30:48.400 align:left position:35% line:5% size:55% and you could maybe have volcanism 30:48.400 --> 30:49.866 align:left position:25% line:5% size:65% or something going on underneath, 30:49.866 --> 30:51.666 align:left position:25% line:5% size:65% and so you could have a liquid water ocean 30:51.666 --> 30:53.666 align:left position:20% line:5% size:70% at the right temperature with energy being put into it, 30:53.666 --> 30:58.833 align:left position:12.5% line:5% size:77.5% and you could have life present on these planets, right? 30:58.833 --> 31:00.700 align:left position:25% line:5% size:65% That wouldn't be life like the Earth. 31:00.700 --> 31:02.633 align:left position:37.5% line:5% size:52.5% It may not even be intelligent life, 31:02.633 --> 31:04.100 align:left position:15% line:5% size:75% but it would be life, right, 31:04.100 --> 31:05.833 align:left position:30% line:5% size:60% and that would be very exciting to find, 31:05.833 --> 31:07.833 align:left position:35% line:5% size:55% and these are much bigger planets, 31:07.833 --> 31:12.066 align:left position:15% line:5% size:75% and so they're much easier to measure the atmospheres for. 31:14.566 --> 31:18.900 align:left position:30% line:83% size:60% And so actually, at University of Wisconsin, 31:18.900 --> 31:22.100 align:left position:25% line:83% size:65% we actually have time on a telescope out in Arizona. 31:22.100 --> 31:25.766 align:left position:15% line:83% size:75% We get about 20 nights a year on the WIYN telescope, 31:25.766 --> 31:27.900 align:left position:25% line:83% size:65% and one of the things that I do is 31:27.900 --> 31:33.766 align:left position:22.5% line:83% size:67.5% I use some of that time to look for planets like these, 31:33.766 --> 31:36.233 align:left position:15% line:83% size:75% and I actually have a student working with me right now 31:36.233 --> 31:37.866 align:left position:22.5% line:89% size:67.5% who's working on this. 31:37.866 --> 31:39.900 align:left position:32.5% line:89% size:57.5% He's actually-- 31:39.900 --> 31:42.933 align:left position:10% line:83% size:80% Pretty excitingly, he's actually found two of these this spring 31:42.933 --> 31:46.566 align:left position:10% line:83% size:80% where we're starting to write up that paper right now, right? 31:46.566 --> 31:50.133 align:left position:10% line:83% size:80% Two new planets in this category that this fall, 31:50.133 --> 31:51.733 align:left position:30% line:83% size:60% we're gonna apply for James Webb time 31:51.733 --> 31:54.933 align:left position:22.5% line:83% size:67.5% to try and look at what the atmospheres are like, right? 31:54.933 --> 31:56.933 align:left position:30% line:71% size:60% We're actually-- 31:56.933 --> 31:58.800 align:left position:35% line:71% size:55% Well, Arizona is two hours behind us, 31:58.800 --> 32:00.966 align:left position:12.5% line:71% size:77.5% so they're probably opening up 32:00.966 --> 32:02.366 align:left position:30% line:71% size:60% probably in about an hour from now 32:02.366 --> 32:03.966 align:left position:17.5% line:71% size:72.5% to start observing tonight, and they're gonna be 32:03.966 --> 32:06.600 align:left position:12.5% line:71% size:77.5% observing again for us tonight, as well, right? 32:06.600 --> 32:09.766 align:left position:30% line:71% size:60% So we're actually doing this search tonight 32:09.766 --> 32:12.766 align:left position:12.5% line:71% size:77.5% to look for planets like these. 32:12.766 --> 32:15.100 align:left position:17.5% line:71% size:72.5% And the exciting thing is, 32:15.100 --> 32:18.366 align:left position:30% line:71% size:60% is that, because these are so large, 32:18.366 --> 32:19.933 align:left position:20% line:71% size:70% they're actually pretty-- 32:19.933 --> 32:21.566 align:left position:32.5% line:71% size:57.5% the atmospheres are pretty detectable 32:21.566 --> 32:23.333 align:left position:15% line:71% size:75% with James Webb observations, 32:23.333 --> 32:26.833 align:left position:22.5% line:71% size:67.5% so JWST in one to four transit observations, 32:26.833 --> 32:30.266 align:left position:15% line:71% size:75% which is a pretty reasonable request to ask for time 32:30.266 --> 32:33.000 align:left position:30% line:71% size:60% on the telescope, could look at these planets 32:33.000 --> 32:36.166 align:left position:30% line:71% size:60% and could detect signatures of life 32:36.166 --> 32:39.033 align:left position:20% line:71% size:70% in the atmosphere, right? 32:39.033 --> 32:43.400 align:left position:12.5% line:83% size:77.5% And this is actually something that's happening, right? 32:43.400 --> 32:46.866 align:left position:32.5% line:83% size:57.5% These two have both been observed, right? 32:46.866 --> 32:49.766 align:left position:25% line:83% size:65% This one, the results were announced last fall. 32:49.766 --> 32:52.000 align:left position:17.5% line:83% size:72.5% This one, the results were announced last spring. 32:52.000 --> 32:53.800 align:left position:32.5% line:83% size:57.5% Top one hasn't been looked at yet, 32:53.800 --> 32:55.733 align:left position:17.5% line:83% size:72.5% but there's a lot of people putting in proposals. 32:55.733 --> 32:57.566 align:left position:17.5% line:89% size:72.5% We're putting in proposals 32:57.566 --> 32:59.400 align:left position:30% line:83% size:60% and getting time to look at these planets, 32:59.400 --> 33:01.100 align:left position:17.5% line:89% size:72.5% and we're finding new ones 33:01.100 --> 33:03.266 align:left position:25% line:83% size:65% to try and find life on these planets, 33:03.266 --> 33:07.400 align:left position:15% line:83% size:75% and we think we have a pretty good shot if it's there. 33:07.400 --> 33:09.766 align:left position:27.5% line:83% size:62.5% The really fun part is gonna be 33:09.766 --> 33:12.833 align:left position:25% line:83% size:65% once we get something that we think might be life 33:12.833 --> 33:17.433 align:left position:15% line:83% size:75% because I've been describing to you how we need to understand 33:17.433 --> 33:19.000 align:left position:30% line:83% size:60% the biosignatures in the atmosphere: 33:19.000 --> 33:20.400 align:left position:17.5% line:89% size:72.5% We need to look for water; 33:20.400 --> 33:23.466 align:left position:17.5% line:83% size:72.5% we need to look for oxygen, maybe a little bit of methane-- 33:23.466 --> 33:27.333 align:left position:22.5% line:83% size:67.5% and what's gonna happen if we do this successfully is, 33:27.333 --> 33:28.500 align:left position:20% line:89% size:70% we're gonna get something 33:28.500 --> 33:29.900 align:left position:15% line:83% size:75% that looks like an atmosphere like Earth, 33:29.900 --> 33:32.700 align:left position:20% line:83% size:70% and then we're gonna have to figure out if all those gases 33:32.700 --> 33:34.133 align:left position:30% line:83% size:60% and things we see in the atmosphere 33:34.133 --> 33:36.166 align:left position:25% line:83% size:65% are produced by life or if they're produced 33:36.166 --> 33:39.266 align:left position:20% line:83% size:70% by things like volcanoes or geologic processes. 33:39.266 --> 33:42.500 align:left position:12.5% line:83% size:77.5% And figuring that out is gonna require not just astronomers 33:42.500 --> 33:44.933 align:left position:27.5% line:83% size:62.5% and people who know how to operate JWST 33:44.933 --> 33:47.333 align:left position:22.5% line:83% size:67.5% and know how to measure exoplanet atmospheres. 33:47.333 --> 33:49.100 align:left position:30% line:5% size:60% We're gonna need planetary scientists. 33:49.100 --> 33:52.066 align:left position:15% line:5% size:75% We're gonna need geologists, biologists, 33:52.066 --> 33:54.800 align:left position:30% line:5% size:60% ocean scientists, everybody, right? 33:54.800 --> 33:57.600 align:left position:25% line:5% size:65% All these other bits of the puzzle that we all need 33:57.600 --> 34:00.633 align:left position:12.5% line:5% size:77.5% to get together and figure out what's going on, 34:00.633 --> 34:03.266 align:left position:27.5% line:5% size:62.5% and that's the idea behind this thing 34:03.266 --> 34:06.533 align:left position:17.5% line:5% size:72.5% called the Wisconsin Center for Origins Research, WiCOR, 34:06.533 --> 34:10.833 align:left position:27.5% line:5% size:62.5% that is, hopefully, starting this fall. 34:10.833 --> 34:12.666 align:left position:12.5% line:71% size:77.5% We're provisionally starting-- 34:12.666 --> 34:14.300 align:left position:27.5% line:71% size:62.5% We're provisionally a center right now, 34:14.300 --> 34:16.166 align:left position:27.5% line:71% size:62.5% but we're hopefully officially gonna be a center 34:16.166 --> 34:19.100 align:left position:30% line:71% size:60% this coming fall that is specifically designed 34:19.100 --> 34:21.533 align:left position:17.5% line:71% size:72.5% to do just that, to get all these different people together 34:21.533 --> 34:24.633 align:left position:20% line:71% size:70% from all these different departments at UW-Madison 34:24.633 --> 34:26.833 align:left position:12.5% line:71% size:77.5% to start talking and figure out 34:26.833 --> 34:28.566 align:left position:32.5% line:71% size:57.5% how can we plan for detecting life 34:28.566 --> 34:30.633 align:left position:25% line:71% size:65% and how can we design observations 34:30.633 --> 34:31.800 align:left position:25% line:71% size:65% that are gonna do it? 34:31.800 --> 34:33.166 align:left position:22.5% line:71% size:67.5% And once we've done it, 34:33.166 --> 34:35.666 align:left position:12.5% line:71% size:77.5% how do we prove that it's life in a way that's convincing 34:35.666 --> 34:37.633 align:left position:37.5% line:71% size:52.5% to the rest of the scientific community? 34:37.633 --> 34:40.366 align:left position:20% line:71% size:70% And it's a project that's gonna be extremely difficult, 34:40.366 --> 34:43.000 align:left position:22.5% line:71% size:67.5% and it's gonna require a lot of different people 34:43.000 --> 34:45.833 align:left position:15% line:71% size:75% all working together, sharing their own specialized knowledge, 34:45.833 --> 34:47.633 align:left position:15% line:71% size:75% but we think it can be done. 34:48.866 --> 34:50.033 align:left position:45% line:89% size:45% Okay. 34:51.466 --> 34:55.800 align:left position:22.5% line:89% size:67.5% I like this flowchart. 34:55.800 --> 34:58.300 align:left position:12.5% line:83% size:77.5% Usually, actually, when I show this slide, 34:58.300 --> 35:00.133 align:left position:32.5% line:83% size:57.5% I don't really have much to say here. 35:00.133 --> 35:01.633 align:left position:17.5% line:89% size:72.5% I just sort of like the way 35:01.633 --> 35:04.500 align:left position:20% line:83% size:70% it schematically lays out what's going on. 35:04.500 --> 35:07.200 align:left position:17.5% line:83% size:72.5% It actually reflects a lot of my thinking on this as well. 35:07.200 --> 35:10.133 align:left position:20% line:5% size:70% I will say, my particular favorite is that 35:10.133 --> 35:11.533 align:left position:10% line:5% size:80% the successful detection of life 35:11.533 --> 35:14.500 align:left position:12.5% line:5% size:77.5% is just labeled by "champagne," right? 35:14.500 --> 35:17.166 align:left position:10% line:5% size:80% Right, this is the basic outline of what we need to do. 35:17.166 --> 35:18.866 align:left position:20% line:5% size:70% We need to find planets. 35:18.866 --> 35:20.866 align:left position:25% line:5% size:65% We need to figure out if they're like the Earth. 35:20.866 --> 35:23.266 align:left position:12.5% line:5% size:77.5% We need to run through a bunch of tests in the atmosphere 35:23.266 --> 35:25.666 align:left position:25% line:5% size:65% to see what's in it, and at the end of the day, 35:25.666 --> 35:28.166 align:left position:15% line:5% size:75% hopefully, we'll work our way down to champagne 35:28.166 --> 35:30.833 align:left position:12.5% line:5% size:77.5% and then have to start talking to the geologists 35:30.833 --> 35:32.366 align:left position:17.5% line:5% size:72.5% and the oceanography people 35:32.366 --> 35:35.566 align:left position:25% line:5% size:65% to figure out if this is actually feasible. 35:37.833 --> 35:43.300 align:left position:22.5% line:83% size:67.5% Okay, so I'm gonna end with this picture again, right? 35:43.300 --> 35:47.133 align:left position:27.5% line:83% size:62.5% So, as I mentioned at the start of the talk, 35:47.133 --> 35:50.133 align:left position:30% line:83% size:60% you know, people have been thinking about 35:50.133 --> 35:52.166 align:left position:22.5% line:83% size:67.5% is there life elsewhere in the universe, right? 35:52.166 --> 35:55.100 align:left position:12.5% line:83% size:77.5% The question "Is there a planet like the Earth somewhere else?" 35:55.100 --> 35:58.666 align:left position:10% line:83% size:80% for at least 2,500 years, right, over 2,000 years, 35:58.666 --> 36:00.733 align:left position:12.5% line:89% size:77.5% probably more than that, right? 36:00.733 --> 36:02.266 align:left position:30% line:89% size:60% That's a pretty-- 36:02.266 --> 36:03.766 align:left position:22.5% line:83% size:67.5% I can imagine somebody asked that question 36:03.766 --> 36:06.233 align:left position:25% line:89% size:65% a very long time ago. 36:06.233 --> 36:08.033 align:left position:32.5% line:83% size:57.5% And even in the astronomical community, 36:08.033 --> 36:11.233 align:left position:10% line:83% size:80% in exoplanets, people have spent the last three decades, 36:11.233 --> 36:12.900 align:left position:27.5% line:83% size:62.5% even since we knew about exoplanets, 36:12.900 --> 36:14.966 align:left position:27.5% line:83% size:62.5% looking for planets like the Earth, 36:14.966 --> 36:16.766 align:left position:27.5% line:83% size:62.5% and we're starting to find them. 36:18.600 --> 36:21.900 align:left position:12.5% line:71% size:77.5% And one of the big revolutions in astronomy is, 36:21.900 --> 36:24.200 align:left position:15% line:71% size:75% the search for biosignatures and the search for life 36:24.200 --> 36:27.100 align:left position:15% line:71% size:75% has progressed from something that, you know, 36:27.100 --> 36:29.933 align:left position:15% line:71% size:75% nobody really takes seriously to something that 36:29.933 --> 36:33.600 align:left position:17.5% line:71% size:72.5% a lot of people are trying very hard to do successfully, 36:33.600 --> 36:38.000 align:left position:22.5% line:71% size:67.5% and it's an incredibly exciting time 36:38.000 --> 36:39.533 align:left position:17.5% line:71% size:72.5% to be a part of astronomy, right, 36:39.533 --> 36:42.533 align:left position:22.5% line:71% size:67.5% 'cause, like, the stuff that we are doing at UW, 36:42.533 --> 36:44.266 align:left position:32.5% line:71% size:57.5% you know, we're assembling this team 36:44.266 --> 36:46.200 align:left position:35% line:71% size:55% that's gonna hopefully do this. 36:46.200 --> 36:49.033 align:left position:20% line:71% size:70% We're observing tonight, like I said, to try and find 36:49.033 --> 36:51.833 align:left position:12.5% line:71% size:77.5% new planets that we can look at with instruments 36:51.833 --> 36:55.233 align:left position:17.5% line:71% size:72.5% like the James Webb to try and find life elsewhere. 36:55.233 --> 36:56.800 align:left position:25% line:71% size:65% Like, the hunt is on, 36:56.800 --> 36:59.166 align:left position:22.5% line:71% size:67.5% and it's happening now as we speak, right? 36:59.166 --> 37:00.633 align:left position:17.5% line:71% size:72.5% Like, people are doing it. 37:00.633 --> 37:03.500 align:left position:15% line:71% size:75% This isn't some future thing maybe in a couple of years, 37:03.500 --> 37:05.833 align:left position:12.5% line:71% size:77.5% we could think about, you know, 37:05.833 --> 37:07.400 align:left position:30% line:71% size:60% looking for life on other planets. 37:07.400 --> 37:09.966 align:left position:27.5% line:71% size:62.5% People are actively searching right now, 37:09.966 --> 37:11.466 align:left position:25% line:71% size:65% and if it's out there 37:11.466 --> 37:13.966 align:left position:15% line:71% size:75% and if it's on some of these big, sort of, hycean planets, 37:13.966 --> 37:16.166 align:left position:32.5% line:71% size:57.5% I think we have a pretty good shot of doing it 37:16.166 --> 37:17.400 align:left position:25% line:71% size:65% in the next 10 years. 37:17.400 --> 37:21.600 align:left position:15% line:71% size:75% Probably earlier than that-- by 2030, I bet, right? 37:21.600 --> 37:24.666 align:left position:22.5% line:71% size:67.5% That means that we are right on the edge of answering 37:24.666 --> 37:29.233 align:left position:22.5% line:71% size:67.5% a question that people have thought of for 2,500 years 37:29.233 --> 37:31.400 align:left position:35% line:71% size:55% and wondered about the answer for. 37:31.400 --> 37:33.666 align:left position:17.5% line:71% size:72.5% And so it's a very exciting time to be in astronomy, 37:33.666 --> 37:35.866 align:left position:15% line:71% size:75% and it's a very exciting time to think about finally knowing 37:35.866 --> 37:38.400 align:left position:17.5% line:71% size:72.5% the answer to that question after over two millennia 37:38.400 --> 37:41.566 align:left position:15% line:71% size:75% of people wondering about it, and it's, you know, 37:41.566 --> 37:45.100 align:left position:15% line:71% size:75% it's why I get excited about going in to work in the morning. 37:45.100 --> 37:47.033 align:left position:25% line:71% size:65% It's also why I like giving these talks, right, 37:47.033 --> 37:49.700 align:left position:17.5% line:71% size:72.5% to tell you guys about that and hopefully get you excited 37:49.700 --> 37:54.500 align:left position:15% line:71% size:75% about how really close we are to actually doing this. 37:54.500 --> 37:58.500 align:left position:12.5% line:71% size:77.5% You know, I said it's gonna be very hard, right? 37:58.500 --> 38:00.900 align:left position:27.5% line:71% size:62.5% It's very difficult observations. 38:00.900 --> 38:03.166 align:left position:22.5% line:71% size:67.5% It's a very complicated analysis problem, 38:03.166 --> 38:05.766 align:left position:30% line:71% size:60% and it's gonna be a pretty subtle chain of logic 38:05.766 --> 38:07.866 align:left position:17.5% line:71% size:72.5% that's gonna get us there, 38:07.866 --> 38:09.733 align:left position:32.5% line:71% size:57.5% but, you know, I think it's gonna be 38:09.733 --> 38:15.966 align:left position:20% line:71% size:70% probably one of the most complicated and difficult 38:15.966 --> 38:19.500 align:left position:22.5% line:71% size:67.5% but probably greatest, you know, scientific endeavor 38:19.500 --> 38:23.600 align:left position:17.5% line:71% size:72.5% that astronomy has done for the last couple hundred years. 38:23.600 --> 38:25.966 align:left position:32.5% line:71% size:57.5% So, hopefully, we're gonna get to champagne 38:25.966 --> 38:28.833 align:left position:15% line:71% size:75% in the next couple of years, and if we do, I will come back 38:28.833 --> 38:32.500 align:left position:12.5% line:71% size:77.5% and tell you guys all about it in another Badger Talk. 38:32.500 --> 38:34.900 align:left position:35% line:71% size:55% So thank you, and I'll take questions. 38:34.900 --> 38:37.200 align:left position:25% line:71% size:65% [audience applauding] 38:41.933 --> 38:43.666 align:left position:40% line:71% size:50% Uh, yeah? 38:43.666 --> 38:46.400 align:left position:17.5% line:71% size:72.5% - Audience Member 1: Is it possible that some of the moons, 38:46.400 --> 38:50.633 align:left position:15% line:71% size:75% both within our solar system and outside, could contain life? 38:50.633 --> 38:52.833 align:left position:17.5% line:71% size:72.5% - Right, so is it possible that some of the moons 38:52.833 --> 38:54.966 align:left position:12.5% line:71% size:77.5% in our solar system or outside could contain life? 38:54.966 --> 38:59.500 align:left position:27.5% line:71% size:62.5% Yes, and, actually, the planetary science community 38:59.500 --> 39:02.566 align:left position:12.5% line:71% size:77.5% is very excited about going out 39:02.566 --> 39:05.566 align:left position:22.5% line:71% size:67.5% to the moons of Jupiter and Saturn, as well. 39:05.566 --> 39:08.966 align:left position:22.5% line:71% size:67.5% So there's one mission called Europa Clipper 39:08.966 --> 39:11.600 align:left position:12.5% line:71% size:77.5% that is launching in six months that's gonna travel 39:11.600 --> 39:13.966 align:left position:20% line:71% size:70% to Jupiter's moon Europa, and Europa is very exciting 39:13.966 --> 39:18.433 align:left position:27.5% line:71% size:62.5% 'cause it's covered in a surface of ice, right? 39:18.433 --> 39:22.033 align:left position:20% line:71% size:70% It's cold enough that ice on Europa is like rock on Earth, 39:22.033 --> 39:24.433 align:left position:15% line:71% size:75% so the surface is solid ice, solid water, 39:24.433 --> 39:26.533 align:left position:25% line:71% size:65% and then the mantle, what we have for lava, 39:26.533 --> 39:29.200 align:left position:25% line:71% size:65% is just liquid water, so it's liquid water ocean, 39:29.200 --> 39:31.366 align:left position:25% line:71% size:65% and there seems to be volcanoes underneath. 39:31.366 --> 39:34.733 align:left position:25% line:71% size:65%   We know that 'cause we can see ice volcanoes on the surface, 39:34.733 --> 39:36.633 align:left position:30% line:83% size:60% so it seems like it's a liquid water ocean 39:36.633 --> 39:39.766 align:left position:25% line:83% size:65% and there's volcanoes adding energy into that system, 39:39.766 --> 39:42.266 align:left position:20% line:83% size:70% and so it's very possible there's life there, 39:42.266 --> 39:44.533 align:left position:22.5% line:83% size:67.5% and so there's Europa, there's Enceladus, 39:44.533 --> 39:46.666 align:left position:22.5% line:83% size:67.5% which is around Saturn, is another exciting one, 39:46.666 --> 39:48.900 align:left position:22.5% line:83% size:67.5% and Titan around Saturn is in many ways 39:48.900 --> 39:50.833 align:left position:22.5% line:83% size:67.5% actually pretty similar to early Earth 39:50.833 --> 39:53.866 align:left position:25% line:83% size:65% before life evolved, or Archean Earth, actually. 39:53.866 --> 39:55.833 align:left position:10% line:89% size:80% That's very early life on Earth, 39:55.833 --> 39:58.066 align:left position:15% line:83% size:75% when we had a lot of methane in our atmosphere, 39:58.066 --> 40:01.766 align:left position:17.5% line:83% size:72.5% and so all three of those, people are spending 40:01.766 --> 40:03.933 align:left position:15% line:83% size:75% a lot of time thinking about and developing missions for 40:03.933 --> 40:06.000 align:left position:25% line:89% size:65% to try and find life, 40:06.000 --> 40:09.000 align:left position:25% line:83% size:65% and people have been searching for moons 40:09.000 --> 40:11.766 align:left position:20% line:83% size:70% outside the solar system, moons around exoplanets, 40:11.766 --> 40:14.100 align:left position:20% line:83% size:70% and there's been a couple of tentative detections, 40:14.100 --> 40:15.600 align:left position:22.5% line:89% size:67.5% but nothing quite yet. 40:15.600 --> 40:17.200 align:left position:22.5% line:83% size:67.5% But people are thinking about that as well. 40:17.200 --> 40:19.766 align:left position:22.5% line:83% size:67.5% So, yeah, moons in the solar system, people are-- 40:19.766 --> 40:21.766 align:left position:12.5% line:83% size:77.5% the planetary science community is thinking about that a lot 40:21.766 --> 40:23.566 align:left position:25% line:83% size:65% and actually getting stuff out there 40:23.566 --> 40:26.366 align:left position:25% line:83% size:65% 'cause Europa Clipper will launch soon. 40:26.366 --> 40:27.866 align:left position:40% line:89% size:50% Uh, yeah? 40:27.866 --> 40:30.366 align:left position:10% line:83% size:80% - Audience Member 2: What future telescopes are being planned 40:30.366 --> 40:32.300 align:left position:30% line:83% size:60% that you can get a closer look at these? 40:32.300 --> 40:34.433 align:left position:35% line:83% size:55% Is there any in the works right now? 40:34.433 --> 40:37.133 align:left position:22.5% line:83% size:67.5% - Yeah, so what future telescopes are being planned? 40:37.133 --> 40:40.733 align:left position:25% line:71% size:65% So the next big NASA telescope mission 40:40.733 --> 40:42.766 align:left position:12.5% line:71% size:77.5% will be something called Roman, 40:42.766 --> 40:45.600 align:left position:27.5% line:71% size:62.5% which is launching in '26 currently. 40:45.600 --> 40:50.833 align:left position:17.5% line:71% size:72.5% That's more of a exoplanet detection and population survey 40:50.833 --> 40:52.700 align:left position:10% line:71% size:80% than a characterization mission. 40:52.700 --> 40:55.566 align:left position:15% line:71% size:75% Probably, there are a couple of other missions 40:55.566 --> 40:57.066 align:left position:25% line:71% size:65% that are gonna launch that will do 40:57.066 --> 41:00.400 align:left position:25% line:71% size:65% exoplanet atmospheric characterization, 41:00.400 --> 41:03.933 align:left position:15% line:71% size:75% but they're not gonna greatly exceed JWST's capability. 41:03.933 --> 41:06.100 align:left position:22.5% line:71% size:67.5% The next big thing that everybody is thinking about 41:06.100 --> 41:07.900 align:left position:30% line:71% size:60% is a mission that right now is called 41:07.900 --> 41:14.033 align:left position:10% line:71% size:80% the Habitable Worlds Observatory that, you know, 41:14.033 --> 41:17.533 align:left position:22.5% line:71% size:67.5% is currently scheduled for 2035 for launch, 41:17.533 --> 41:19.933 align:left position:20% line:71% size:70% but put your own handicap on that. 41:19.933 --> 41:22.566 align:left position:12.5% line:71% size:77.5% It's probably later than that, but that is the idea. 41:22.566 --> 41:25.133 align:left position:12.5% line:71% size:77.5%   We're gonna put a very large, you know, eight-meter mirror 41:25.133 --> 41:27.533 align:left position:17.5% line:83% size:72.5% in space, and that will be, in principle, able 41:27.533 --> 41:29.500 align:left position:20% line:83% size:70% to directly image planets like the Earth 41:29.500 --> 41:32.500 align:left position:25% line:83% size:65% and actually measure the atmospheres directly. 41:32.500 --> 41:34.300 align:left position:22.5% line:83% size:67.5% We don't need to do it indirectly by waiting 41:34.300 --> 41:37.133 align:left position:27.5% line:83% size:62.5% for planets to pass in front of a star. 41:37.133 --> 41:40.566 align:left position:10% line:71% size:80% So Habitable Worlds Observatory, HabWorlds, 41:40.566 --> 41:42.800 align:left position:32.5% line:71% size:57.5% if it launches, should be able to do this. 41:42.800 --> 41:44.466 align:left position:27.5% line:71% size:62.5% But that's another good point, right? 41:44.466 --> 41:46.400 align:left position:17.5% line:71% size:72.5% HabWorlds, like, is just-- 41:46.400 --> 41:48.966 align:left position:10% line:71% size:80% It's just an engineering problem right now, right? 41:48.966 --> 41:51.500 align:left position:15% line:71% size:75% It's an engineering, and it's a "convince the Congress 41:51.500 --> 41:54.566 align:left position:20% line:71% size:70% to give NASA enough money to build it" problem, right? 41:54.566 --> 41:57.400 align:left position:15% line:71% size:75% We could do this very quickly if we wanted to. 41:57.400 --> 41:59.600 align:left position:20% line:71% size:70% It's just, we need to do a couple of engineering checks 41:59.600 --> 42:00.833 align:left position:30% line:71% size:60% and stuff, right? 42:00.833 --> 42:02.200 align:left position:30% line:71% size:60% This is no longer science fiction. 42:02.200 --> 42:03.600 align:left position:35% line:71% size:55% This is like, "Let's go to Congress 42:03.600 --> 42:05.400 align:left position:15% line:71% size:75% and ask for money to do it." 42:05.400 --> 42:07.800 align:left position:10% line:83% size:80% - Audience Member 3: You said if all life on Earth died... 42:07.800 --> 42:08.966 align:left position:40% line:89% size:50% - Mm-hmm. 42:08.966 --> 42:10.733 align:left position:35% line:83% size:55% - That within a couple thousand years, 42:10.733 --> 42:12.333 align:left position:15% line:83% size:75% the oxygen and the atmosphere would be gone. 42:12.333 --> 42:13.533 align:left position:32.5% line:83% size:57.5% - Thomas: Yeah. - Why? 42:13.533 --> 42:14.933 align:left position:12.5% line:89% size:77.5% What would it make it go away? 42:14.933 --> 42:17.666 align:left position:12.5% line:83% size:77.5% - Right, so why does the oxygen disappear if life disappears? 42:17.666 --> 42:20.033 align:left position:27.5% line:83% size:62.5% So oxygen, I mean, it's sort of the reason why 42:20.033 --> 42:21.366 align:left position:15% line:89% size:75% it's so fundamental to life, 42:21.366 --> 42:24.766 align:left position:30% line:83% size:60% 'cause oxygen is incredibly reactive with stuff. 42:24.766 --> 42:29.366 align:left position:15% line:83% size:75% So oxygen, it will disappear into rocks through rust. 42:29.366 --> 42:34.533 align:left position:15% line:89% size:75% It will, you know, go into-- 42:34.533 --> 42:36.833 align:left position:22.5% line:83% size:67.5% Sort of like acid rain, it will go into the water. 42:36.833 --> 42:40.366 align:left position:12.5% line:83% size:77.5% And it'll go into the seafloor in, like, lime or something. 42:40.366 --> 42:43.733 align:left position:25% line:83% size:65% It just gets absorbed into rocks and water 42:43.733 --> 42:46.566 align:left position:22.5% line:83% size:67.5% and geologic processes very quickly. 42:46.566 --> 42:48.766 align:left position:10% line:83% size:80% - Audience Member 3: So it's not that it would be-- 42:48.766 --> 42:51.166 align:left position:17.5% line:83% size:72.5% like, just drift away or be blown away by the solar wind. 42:51.166 --> 42:53.366 align:left position:15% line:83% size:75% - Oh, no, yeah, so it doesn't escape from the Earth. 42:53.366 --> 42:54.566 align:left position:35% line:83% size:55% It doesn't-- It still stays here. 42:54.566 --> 42:55.966 align:left position:27.5% line:83% size:62.5% Just, it's gonna go into the rocks. 42:55.966 --> 42:57.566 align:left position:17.5% line:83% size:72.5% We're gonna turn into Mars, effectively. 42:57.566 --> 42:59.466 align:left position:25% line:83% size:65% We're gonna turn into a rusty red planet 42:59.466 --> 43:03.066 align:left position:15% line:83% size:75% if all the life disappeared, yeah. 43:03.066 --> 43:04.233 align:left position:45% line:89% size:45% Yeah? 43:04.233 --> 43:05.833 align:left position:25% line:83% size:65% - Audience Member 4: So how many times 43:05.833 --> 43:07.233 align:left position:22.5% line:83% size:67.5% do you have to observe an exoplanet 43:07.233 --> 43:11.000 align:left position:10% line:71% size:80% before you actually confirm that you think it's an exoplanet, 43:11.000 --> 43:14.033 align:left position:20% line:71% size:70% and how do you track its location so that in the future, 43:14.033 --> 43:16.766 align:left position:25% line:71% size:65% you can have the Webb check back? 43:16.766 --> 43:18.700 align:left position:17.5% line:71% size:72.5% - Right, so how many times 43:18.700 --> 43:21.166 align:left position:27.5% line:71% size:62.5% do you have to look at an exoplanet to confirm it, 43:21.166 --> 43:24.100 align:left position:17.5% line:71% size:72.5% and then how do we track it so we can look at it later? 43:24.100 --> 43:28.900 align:left position:32.5% line:71% size:57.5% So confirmation observations are-- 43:30.200 --> 43:33.900 align:left position:20% line:71% size:70% So actually, the planets that I'm working on 43:33.900 --> 43:35.966 align:left position:20% line:71% size:70% with a student right now are probably a good way 43:35.966 --> 43:38.900 align:left position:12.5% line:71% size:77.5% to explain what the process is. 43:38.900 --> 43:41.333 align:left position:15% line:71% size:75% So there's a NASA mission up right now called TESS, 43:41.333 --> 43:44.166 align:left position:22.5% line:71% size:67.5% which is just scanning the sky for new exoplanets, 43:44.166 --> 43:45.566 align:left position:32.5% line:71% size:57.5% and so it finds something that looks 43:45.566 --> 43:46.733 align:left position:15% line:71% size:75% like a transiting exoplanet, 43:46.733 --> 43:48.533 align:left position:27.5% line:71% size:62.5% like a planet going in front of its star. 43:48.533 --> 43:50.500 align:left position:15% line:71% size:75% It's measuring the brightness of all the stars, 43:50.500 --> 43:52.566 align:left position:22.5% line:71% size:67.5% but one of the problems is that there's, 43:52.566 --> 43:54.966 align:left position:17.5% line:71% size:72.5% for lack of a better word, a lot of things that go 43:54.966 --> 43:57.733 align:left position:17.5% line:71% size:72.5% bump in the night that look like planets but are not. 43:57.733 --> 44:01.066 align:left position:22.5% line:71% size:67.5% There's a lot of things like stars and other, you know, 44:01.066 --> 44:04.000 align:left position:12.5% line:71% size:77.5% things that aren't planets that can mimic those transit signals. 44:04.000 --> 44:06.800 align:left position:15% line:71% size:75% So we get a lot of candidates and then we have to refine that, 44:06.800 --> 44:11.066 align:left position:25% line:71% size:65% so we look at it with telescopes like WIYN, right, 44:11.066 --> 44:13.466 align:left position:20% line:71% size:70% that we have in Kitt Peak to look for the star moving, 44:13.466 --> 44:15.466 align:left position:12.5% line:71% size:77.5% and if we see the star moving, that tells us 44:15.466 --> 44:18.033 align:left position:22.5% line:71% size:67.5% the mass of the object, and so we get a good mass. 44:18.033 --> 44:21.033 align:left position:22.5% line:71% size:67.5%   Usually, we'll look at it with bigger telescopes on the ground 44:21.033 --> 44:22.633 align:left position:17.5% line:83% size:72.5% to make sure it's happening on the star 44:22.633 --> 44:25.033 align:left position:17.5% line:89% size:72.5% we think it's happening on. 44:25.033 --> 44:27.033 align:left position:27.5% line:83% size:62.5% And so that's most of the confirmation process. 44:27.033 --> 44:29.433 align:left position:20% line:83% size:70% If you can see the planet go in front of the star, 44:29.433 --> 44:32.166 align:left position:17.5% line:83% size:72.5% if you can measure the mass from the star 44:32.166 --> 44:35.300 align:left position:20% line:83% size:70% wobbling back and forth, and if you can demonstrate 44:35.300 --> 44:38.300 align:left position:10% line:83% size:80% that there's no nearby star that you're getting confused with, 44:38.300 --> 44:40.266 align:left position:12.5% line:89% size:77.5% then you're pretty much there, 44:40.266 --> 44:42.966 align:left position:25% line:83% size:65% and you know there's a planet around that star. 44:42.966 --> 44:47.866 align:left position:22.5% line:83% size:67.5% And as a part of that, we generate what's called, 44:47.866 --> 44:50.733 align:left position:22.5% line:83% size:67.5% you know, an ephemeris for the planet, you know, 44:50.733 --> 44:53.566 align:left position:35% line:83% size:55% a prediction for when transits will occur. 44:53.566 --> 44:55.233 align:left position:30% line:83% size:60% And for the first couple of years, 44:55.233 --> 44:57.566 align:left position:22.5% line:83% size:67.5% those are probably good to a couple of minutes, 44:57.566 --> 45:00.166 align:left position:10% line:83% size:80% but over time, those will drift, and some of the planets 45:00.166 --> 45:01.833 align:left position:25% line:83% size:65% that were discovered 10 years ago, 45:01.833 --> 45:03.266 align:left position:30% line:83% size:60% we don't actually know the transits 45:03.266 --> 45:05.966 align:left position:17.5% line:83% size:72.5% to better than half an hour or maybe even hours. 45:05.966 --> 45:09.600 align:left position:20% line:83% size:70% So for JWST observations, you need to know it to minutes, 45:09.600 --> 45:13.100 align:left position:12.5% line:83% size:77.5% and so there's actually efforts that a lot of people work on, 45:13.100 --> 45:15.300 align:left position:15% line:83% size:75% that a fair number of people work on to go back 45:15.300 --> 45:18.600 align:left position:25% line:83% size:65% to older planets and look at them again to get more, 45:18.600 --> 45:20.900 align:left position:20% line:83% size:70% sort of reset that drift on the clock 45:20.900 --> 45:22.933 align:left position:32.5% line:83% size:57.5% and figure out when it's gonna happen 45:22.933 --> 45:27.033 align:left position:20% line:83% size:70% to refine the ephemerides so we don't lose 'em 45:27.033 --> 45:29.466 align:left position:20% line:83% size:70% and we still know exactly when they're going to transit. 45:29.466 --> 45:34.000 align:left position:12.5% line:83% size:77.5% So it's a lot of people working to do both parts of that. 45:36.366 --> 45:37.733 align:left position:40% line:71% size:50% Uh, yeah? 45:37.733 --> 45:40.400 align:left position:12.5% line:71% size:77.5% - Audience Member 5: In the red ring on the map 45:40.400 --> 45:44.533 align:left position:22.5% line:71% size:67.5% of the Milky Way, like, where you found the planets, 45:44.533 --> 45:47.533 align:left position:35% line:71% size:55% how far away are we talking about 45:47.533 --> 45:48.900 align:left position:15% line:71% size:75% as far as, like, light-years, 45:48.900 --> 45:51.700 align:left position:20% line:71% size:70% and how far back in time are we looking? 45:51.700 --> 45:55.333 align:left position:27.5% line:71% size:62.5% - Right, so how big is that red ring in light-years, 45:55.333 --> 45:57.733 align:left position:10% line:71% size:80% and how far away are we looking? 45:57.733 --> 46:01.533 align:left position:17.5% line:71% size:72.5% So most of the planets that we know about are probably-- 46:01.533 --> 46:05.200 align:left position:22.5% line:71% size:67.5% I'm doing a conversion in my head 46:05.200 --> 46:07.966 align:left position:27.5% line:71% size:62.5% 'cause most of us, a lot of astronomers 46:07.966 --> 46:09.833 align:left position:37.5% line:71% size:52.5% use parsecs instead of light-years. 46:09.833 --> 46:12.000 align:left position:22.5% line:71% size:67.5% Yeah, if you guys ever wanna be cool 46:12.000 --> 46:13.300 align:left position:22.5% line:71% size:67.5% at an astronomy party-- 46:13.300 --> 46:15.500 align:left position:20% line:71% size:70% I don't know why you'd be going to an astronomy party, 46:15.500 --> 46:20.033 align:left position:17.5% line:71% size:72.5% but if you want an invite, I think Mary has my email. 46:20.033 --> 46:22.033 align:left position:22.5% line:71% size:67.5% Yeah, talk about things in parsecs. 46:22.033 --> 46:24.700 align:left position:27.5% line:71% size:62.5% That's how you know you're on the in-crowd. 46:24.700 --> 46:30.600 align:left position:20% line:71% size:70% So probably out to about 500 light-years, I'd say, 46:30.600 --> 46:33.100 align:left position:15% line:71% size:75% most of the detections, which means that most of the planets 46:33.100 --> 46:36.600 align:left position:22.5% line:71% size:67.5% we're seeing only about 500 years back in time, 46:36.600 --> 46:39.933 align:left position:10% line:71% size:80% which, on an astronomical scale, is pretty small. 46:39.933 --> 46:41.733 align:left position:20% line:71% size:70% Most of them are actually even closer than that, 46:41.733 --> 46:44.133 align:left position:32.5% line:71% size:57.5% probably within 50-ish light years, 46:44.133 --> 46:46.333 align:left position:25% line:71% size:65% so not very far away. 46:46.333 --> 46:48.900 align:left position:25% line:83% size:65% The time scales here, there's one planet we know of, 46:48.900 --> 46:50.900 align:left position:20% line:83% size:70% actually, that's decaying onto its star. 46:50.900 --> 46:53.533 align:left position:15% line:83% size:75% Like, the orbit is shrinking and it's falling onto its star, 46:53.533 --> 46:55.066 align:left position:27.5% line:83% size:62.5% and it's happening incredibly fast, 46:55.066 --> 46:56.600 align:left position:12.5% line:89% size:77.5% which means in 3 million years, 46:56.600 --> 46:58.633 align:left position:32.5% line:83% size:57.5% it's gonna hit the surface of the star. 46:58.633 --> 47:02.400 align:left position:25% line:83% size:65% So 3 million years is incredibly fast for astronomers. 47:02.400 --> 47:03.566 align:left position:45% line:89% size:45% Yeah? 47:03.566 --> 47:05.833 align:left position:12.5% line:83% size:77.5% - Audience Member 6: So how big is it in parsecs? 47:05.833 --> 47:09.966 align:left position:32.5% line:83% size:57.5% - It's probably about 200 parsecs, 300 parsecs. 47:09.966 --> 47:12.666 align:left position:17.5% line:83% size:72.5% I guess that's a little bit more than 500 light-years. 47:12.666 --> 47:16.266 align:left position:20% line:83% size:70% Yeah, about 200 parsecs, I'd say. 47:16.266 --> 47:19.100 align:left position:12.5% line:83% size:77.5% There's stuff much further out, but most of them are centered 47:19.100 --> 47:21.633 align:left position:30% line:89% size:60% closer than that. 47:21.633 --> 47:22.800 align:left position:45% line:89% size:45% Yeah? 47:22.800 --> 47:24.800 align:left position:25% line:83% size:65% - Audience Member 7: Is AI going to be able 47:24.800 --> 47:26.633 align:left position:17.5% line:89% size:72.5% to help you in your search? 47:26.633 --> 47:29.966 align:left position:20% line:83% size:70% - Is AI gonna be helpful in this search? 47:29.966 --> 47:32.166 align:left position:22.5% line:83% size:67.5% It's funny you ask that 'cause I actually was just part 47:32.166 --> 47:38.100 align:left position:22.5% line:83% size:67.5% of a very big proposal to do just that. 47:38.100 --> 47:39.833 align:left position:17.5% line:89% size:72.5% So there's a bunch of ways. 47:39.833 --> 47:42.333 align:left position:15% line:83% size:75% I think the thing that got me really excited-- 47:42.333 --> 47:46.066 align:left position:32.5% line:83% size:57.5% and this maybe is a little inside baseball-- 47:46.066 --> 47:49.166 align:left position:17.5% line:71% size:72.5% but one of the fundamental limitations we have 47:49.166 --> 47:50.633 align:left position:15% line:71% size:75% is that we have to compute-- 47:50.633 --> 47:52.000 align:left position:22.5% line:71% size:67.5% We get the observations 47:52.000 --> 47:53.800 align:left position:17.5% line:71% size:72.5% and then we need to compute atmosphere models, right? 47:53.800 --> 47:55.600 align:left position:30% line:71% size:60% We get the data, but to actually figure out 47:55.600 --> 47:58.066 align:left position:20% line:71% size:70% what's in the atmosphere, we need to compute models. 47:58.066 --> 47:59.800 align:left position:32.5% line:71% size:57.5% We need to run these complicated-- 47:59.800 --> 48:02.766 align:left position:17.5% line:71% size:72.5% We effectively need to run a weather model on a computer, 48:02.766 --> 48:04.600 align:left position:22.5% line:71% size:67.5% and we need to do that a million times 48:04.600 --> 48:07.100 align:left position:32.5% line:71% size:57.5% to try and run all these different parameters. 48:07.100 --> 48:10.000 align:left position:17.5% line:71% size:72.5% And so the sorts of systems I'm working on 48:10.000 --> 48:12.966 align:left position:32.5% line:71% size:57.5% typically take one to two to three weeks, 48:12.966 --> 48:15.800 align:left position:27.5% line:71% size:62.5% two to three weeks to run on a computer. 48:15.800 --> 48:18.566 align:left position:25% line:71% size:65% And that's on, like, a supercomputer-- 48:18.566 --> 48:22.233 align:left position:10% line:71% size:80% it's actually at Arizona State-- but it takes a long time to run, 48:22.233 --> 48:25.033 align:left position:20% line:71% size:70% and so one of the things we're particularly looking at 48:25.033 --> 48:27.466 align:left position:25% line:71% size:65% is how can we use AI to speed up that process 48:27.466 --> 48:29.666 align:left position:27.5% line:71% size:62.5% 'cause that's only a one-dimensional model. 48:29.666 --> 48:33.433 align:left position:20% line:71% size:70% We're not doing any sort of latitude/longitude modeling. 48:33.433 --> 48:35.366 align:left position:20% line:71% size:70% We're just doing straight up and down, 48:35.366 --> 48:37.966 align:left position:22.5% line:71% size:67.5% and running it out to a 3-D model, like we would have 48:37.966 --> 48:41.733 align:left position:17.5% line:71% size:72.5% on the Earth, would take-- you know, it would take months 48:41.733 --> 48:45.400 align:left position:17.5% line:71% size:72.5% to run one of these things, and we'd need to run 10,000. 48:45.400 --> 48:50.000 align:left position:30% line:71% size:60% So one thing that I'm interested in looking at 48:50.000 --> 48:52.633 align:left position:30% line:71% size:60% is how do we use AI machine learning 48:52.633 --> 48:55.966 align:left position:20% line:71% size:70% to try and speed that up and get it to run faster, 48:55.966 --> 48:58.966 align:left position:32.5% line:71% size:57.5% but right now, that's just an idea. 48:58.966 --> 49:01.200 align:left position:12.5% line:71% size:77.5% Nobody's actually done it yet. 49:02.966 --> 49:04.133 align:left position:45% line:89% size:45% Yeah? 49:04.133 --> 49:06.700 align:left position:17.5% line:83% size:72.5% - Audience Member 8: Do you anticipate getting 49:06.700 --> 49:14.600 align:left position:15% line:83% size:75% beyond the infrared look and closer to the microwave look 49:14.600 --> 49:18.833 align:left position:17.5% line:89% size:72.5% as far as the radio waves? 49:18.833 --> 49:20.700 align:left position:30% line:83% size:60% - Yeah, so are we thinking about moving 49:20.700 --> 49:22.733 align:left position:25% line:83% size:65% into, like, microwave or radio waves? 49:22.733 --> 49:25.800 align:left position:12.5% line:89% size:77.5% So there are people, actually, 49:25.800 --> 49:28.133 align:left position:30% line:83% size:60% who do that now, but they don't-- 49:28.133 --> 49:32.100 align:left position:15% line:83% size:75% They use radio and microwave and millimeter waves to-- 49:32.100 --> 49:33.666 align:left position:17.5% line:89% size:72.5% They don't look at planets, 49:33.666 --> 49:35.566 align:left position:22.5% line:83% size:67.5% but they actually look at protoplanetary disks, 49:35.566 --> 49:38.933 align:left position:10% line:83% size:80% so the stuff that forms planets, and there are beautiful images 49:38.933 --> 49:41.600 align:left position:22.5% line:83% size:67.5% taken by an observatory called ALMA 49:41.600 --> 49:43.533 align:left position:15% line:83% size:75% which just started operating a couple years ago 49:43.533 --> 49:47.800 align:left position:15% line:83% size:75% in northern Chile to observe protoplanetary disks, 49:47.800 --> 49:50.033 align:left position:30% line:83% size:60% and you can see-- Actually, it's amazing. 49:50.033 --> 49:53.533 align:left position:12.5% line:83% size:77.5% Guys, just Google search, like, "ALMA protoplanetary disk." 49:53.533 --> 49:55.266 align:left position:35% line:83% size:55% Remember that and Google search it 49:55.266 --> 49:58.066 align:left position:22.5% line:83% size:67.5% 'cause it's, there are these disks of material, 49:58.066 --> 49:59.666 align:left position:25% line:83% size:65% and then you can see there are rings. 49:59.666 --> 50:01.066 align:left position:15% line:89% size:75% There are gaps in the disks. 50:01.066 --> 50:03.066 align:left position:22.5% line:83% size:67.5% Those are planets that are forming that have sucked 50:03.066 --> 50:05.266 align:left position:30% line:83% size:60% all that material and that ring onto them. 50:05.266 --> 50:06.433 align:left position:25% line:71% size:65% Like, that's Jupiter 50:06.433 --> 50:07.833 align:left position:22.5% line:71% size:67.5% that's pulled all that material onto it. 50:07.833 --> 50:09.033 align:left position:15% line:71% size:75% And you can't see the planet, 50:09.033 --> 50:10.633 align:left position:27.5% line:71% size:62.5% but you can see all the gas missing 50:10.633 --> 50:12.433 align:left position:30% line:71% size:60% where the planet must be forming. 50:12.433 --> 50:14.066 align:left position:12.5% line:71% size:77.5% And it's these amazing images-- 50:14.066 --> 50:16.833 align:left position:30% line:71% size:60% There's a woman, actually here at UW, 50:16.833 --> 50:20.833 align:left position:17.5% line:71% size:72.5% Coco Zhang, who does this, so that's a big part 50:20.833 --> 50:22.900 align:left position:30% line:71% size:60% of understanding planet-formation processes. 50:22.900 --> 50:25.100 align:left position:15% line:71% size:75% That's a whole 'nother thing that I could talk forever about, 50:25.100 --> 50:26.966 align:left position:15% line:71% size:75% is trying to figure that out, but, yeah, 50:26.966 --> 50:28.966 align:left position:10% line:71% size:80% that's a big part of it as well. 50:28.966 --> 50:32.433 align:left position:37.5% line:83% size:52.5% All right, oh, we got one more, yeah? 50:32.433 --> 50:33.833 align:left position:25% line:83% size:65% - Audience Member 9: I was wondering, 50:33.833 --> 50:35.833 align:left position:20% line:89% size:70% on the original red disk 50:35.833 --> 50:40.166 align:left position:25% line:83% size:65% that it said, out of the 5,761 exoplanets 50:40.166 --> 50:44.000 align:left position:17.5% line:83% size:72.5% that have been discovered, what is the percentage 50:44.000 --> 50:47.133 align:left position:17.5% line:83% size:72.5% of systems that you scanned that actually come up back 50:47.133 --> 50:50.000 align:left position:25% line:83% size:65% and have an exoplanet within there? 50:50.000 --> 50:52.300 align:left position:32.5% line:83% size:57.5% - Oh, so, yeah, so how many stars 50:52.300 --> 50:54.500 align:left position:25% line:83% size:65% do we need to look at before we find a planet? 50:54.500 --> 50:59.800 align:left position:20% line:83% size:70% Yeah, so that was my PhD thesis, was finding exoplanets 50:59.800 --> 51:02.600 align:left position:37.5% line:83% size:52.5% and running a planet-detection survey. 51:02.600 --> 51:04.333 align:left position:32.5% line:83% size:57.5% That's why I'm particularly bitter 51:04.333 --> 51:06.966 align:left position:25% line:83% size:65% about not being able to name them after myself, 51:06.966 --> 51:09.633 align:left position:17.5% line:83% size:72.5% because it was specifically my PhD-- 51:09.633 --> 51:11.833 align:left position:22.5% line:83% size:67.5% I actually asked my PhD advisor if we could do this, 51:11.833 --> 51:13.300 align:left position:22.5% line:89% size:67.5% and he just was, like, 51:13.300 --> 51:16.366 align:left position:12.5% line:83% size:77.5% "Under no circumstances can you name this after yourself." 51:16.366 --> 51:19.366 align:left position:30% line:83% size:60% So the answer is, we probably looked at... 51:23.400 --> 51:27.033 align:left position:12.5% line:83% size:77.5% We looked at about 10,000 stars before we found one. 51:29.233 --> 51:33.500 align:left position:15% line:83% size:75% But, right, but there's a lot of what are called 51:33.500 --> 51:35.933 align:left position:25% line:83% size:65% observational biases that go into that, right? 51:35.933 --> 51:39.300 align:left position:15% line:83% size:75% So that doesn't mean that one star out of 10,000 has a planet. 51:39.300 --> 51:42.533 align:left position:15% line:83% size:75% It just means it's very hard to find transiting planets 51:42.533 --> 51:44.233 align:left position:22.5% line:83% size:67.5% 'cause we were looking for very big ones, 51:44.233 --> 51:45.633 align:left position:22.5% line:89% size:67.5% which are pretty rare, 51:45.633 --> 51:47.566 align:left position:27.5% line:83% size:62.5% very close-in ones, which are pretty rare, 51:47.566 --> 51:49.366 align:left position:25% line:83% size:65% and they needed to go right across the star, 51:49.366 --> 51:51.566 align:left position:15% line:83% size:75% which is pretty rare, right, so there's a lot of things 51:51.566 --> 51:53.500 align:left position:27.5% line:83% size:62.5% working against us when we do that search. 51:53.500 --> 51:56.033 align:left position:22.5% line:71% size:67.5% When people have tried to correct for that and say, 51:56.033 --> 51:58.500 align:left position:10% line:71% size:80% "Okay, we saw one out of 10,000, but, you know, 51:58.500 --> 52:00.166 align:left position:25% line:71% size:65% "we're only gonna see one out of ten 52:00.166 --> 52:02.700 align:left position:35% line:71% size:55% just because of the angle probabilities," 52:02.700 --> 52:04.600 align:left position:22.5% line:71% size:67.5% what's the actual rate? 52:04.600 --> 52:08.966 align:left position:17.5% line:71% size:72.5% Our actual guess for, say, how many habitable, 52:08.966 --> 52:12.066 align:left position:27.5% line:71% size:62.5% Earth-like planets are around an average star, 52:12.066 --> 52:16.966 align:left position:22.5% line:71% size:67.5% the current best guess is about one-half to two, 52:16.966 --> 52:21.566 align:left position:17.5% line:71% size:72.5% meaning that we think that, on average, 52:21.566 --> 52:24.500 align:left position:12.5% line:71% size:77.5% every single star like the Sun has a planet like the Earth 52:24.500 --> 52:27.166 align:left position:27.5% line:71% size:62.5% pretty close to its habitable zone, right? 52:27.166 --> 52:29.466 align:left position:35% line:71% size:55% It seems like planet formation happens, 52:29.466 --> 52:31.066 align:left position:15% line:71% size:75% and it happens all the time, 52:31.066 --> 52:34.200 align:left position:12.5% line:71% size:77.5% and it goes, and it makes a lot of planets around most stars. 52:34.200 --> 52:38.333 align:left position:17.5% line:71% size:72.5% So it's hard to find them, but that's sort of because 52:38.333 --> 52:41.066 align:left position:25% line:71% size:65% they're hard to find, not because they're rare. 52:44.566 --> 52:46.566 align:left position:25% line:71% size:65%   - Audience Member 10: What would make that job easier? 52:46.566 --> 52:48.133 align:left position:35% line:83% size:55% - What would make that job easier? 52:49.933 --> 52:53.866 align:left position:20% line:71% size:70% Uh... bigger telescopes. 52:53.866 --> 52:56.066 align:left position:15% line:71% size:75% Well, no, actually, you know what would make the jobs easier? 52:56.066 --> 53:02.900 align:left position:20% line:71% size:70% If the stars cooperated, 'cause, man, let me tell you, 53:02.900 --> 53:07.000 align:left position:17.5% line:71% size:72.5% like, the Sun, so to detect the Earth around the Sun, 53:07.000 --> 53:09.833 align:left position:15% line:71% size:75% the velocity you're measuring is about this fast, right? 53:09.833 --> 53:12.333 align:left position:32.5% line:71% size:57.5% I am walking at about two meters per second, 53:12.333 --> 53:13.766 align:left position:25% line:71% size:65% one meter per second. 53:13.766 --> 53:16.766 align:left position:12.5% line:71% size:77.5% That's about how much the Earth makes the Sun move in speed, 53:16.766 --> 53:18.400 align:left position:12.5% line:71% size:77.5% but you're measuring this speed 53:18.400 --> 53:20.566 align:left position:17.5% line:71% size:72.5% over the course of a year, right? 53:20.566 --> 53:24.166 align:left position:22.5% line:71% size:67.5% The surface of the Sun is burbling all the time. 53:24.166 --> 53:25.900 align:left position:20% line:71% size:70% It's just sort of flexing a little bit 53:25.900 --> 53:28.600 align:left position:30% line:71% size:60% from solar flares and all sorts of things, right, 53:28.600 --> 53:32.400 align:left position:15% line:71% size:75% and the Sun is doing its own, like, processes inside it. 53:32.400 --> 53:34.400 align:left position:15% line:71% size:75% And so the surface is moving, and you can imagine 53:34.400 --> 53:36.933 align:left position:15% line:71% size:75% that measuring the whole Sun moving at this speed 53:36.933 --> 53:40.233 align:left position:17.5% line:71% size:72.5% is pretty difficult if the entire surface is just flexing 53:40.233 --> 53:42.733 align:left position:20% line:71% size:70% and wringing and bending underneath you. 53:42.733 --> 53:45.566 align:left position:27.5% line:71% size:62.5% So if I could have anything in the world, 53:45.566 --> 53:48.366 align:left position:22.5% line:71% size:67.5% I would tell the stars to just stand still 53:48.366 --> 53:51.766 align:left position:12.5% line:71% size:77.5% for, like, two years so we can measure them exactly, 53:51.766 --> 53:54.566 align:left position:25% line:71% size:65% and then if we could figure that out, 53:54.566 --> 53:56.466 align:left position:25% line:71% size:65% then we could do it, and, actually, 53:56.466 --> 53:58.333 align:left position:22.5% line:71% size:67.5% the sort of less joking answer to that is, 53:58.333 --> 54:00.133 align:left position:30% line:71% size:60% there's actually a lot of people working on ways 54:00.133 --> 54:04.166 align:left position:17.5% line:71% size:72.5% to try and, like, separate those two signals 54:04.166 --> 54:06.166 align:left position:20% line:71% size:70% and get down to the level where we can measure 54:06.166 --> 54:07.566 align:left position:20% line:71% size:70% a planet like the Earth, 54:07.566 --> 54:10.600 align:left position:15% line:71% size:75% but it's a difficult problem to try and separate that out. 54:12.933 --> 54:14.566 align:left position:45% line:89% size:45% Yeah? 54:14.566 --> 54:16.066 align:left position:25% line:83% size:65% - Audience Member 11: When you actually 54:16.066 --> 54:18.033 align:left position:22.5% line:83% size:67.5% designed the camera... - Mm-hmm, yeah. 54:18.033 --> 54:19.666 align:left position:17.5% line:89% size:72.5% Well, helped design, yeah. 54:19.666 --> 54:22.066 align:left position:15% line:83% size:75% - Audience Member 11: Did it have a lens cap on it? 54:22.066 --> 54:23.666 align:left position:30% line:83% size:60% - Did the camera have a lens cap? 54:23.666 --> 54:25.766 align:left position:32.5% line:89% size:57.5% It did not, no. 54:25.766 --> 54:27.566 align:left position:20% line:83% size:70% Actually, the thing that was gonna really get us 54:27.566 --> 54:29.866 align:left position:17.5% line:89% size:72.5% was the sun shield on Webb 54:29.866 --> 54:33.600 align:left position:20% line:83% size:70% because the whole thing, it needs to deploy out. 54:33.600 --> 54:34.866 align:left position:25% line:89% size:65% Well, I can't have-- 54:34.866 --> 54:36.866 align:left position:15% line:83% size:75% If you look at it, a picture, there's the mirrors, 54:36.866 --> 54:38.066 align:left position:25% line:83% size:65% and underneath that, there's this big-- 54:38.066 --> 54:39.900 align:left position:37.5% line:83% size:52.5% it's almost a tennis court-size thing, 54:39.900 --> 54:41.233 align:left position:17.5% line:89% size:72.5% and that's what shields it. 54:41.233 --> 54:43.166 align:left position:32.5% line:83% size:57.5% All the cameras need to be kept very cool, 54:43.166 --> 54:45.533 align:left position:27.5% line:89% size:62.5% like -200 degrees. 54:45.533 --> 54:47.333 align:left position:30% line:83% size:60% And so if the Sun is shining on it, 54:47.333 --> 54:48.700 align:left position:17.5% line:89% size:72.5% you can't keep it that way, 54:48.700 --> 54:51.100 align:left position:17.5% line:83% size:72.5% so the sun shield is there to block out all the sunlight, 54:51.100 --> 54:53.300 align:left position:22.5% line:83% size:67.5% but the problem is, the sun shield is very thin Mylar 54:53.300 --> 54:54.466 align:left position:22.5% line:89% size:67.5% that rips very easily. 54:54.466 --> 54:56.300 align:left position:15% line:89% size:75% It's designed to be deployed. 54:56.300 --> 54:59.100 align:left position:12.5% line:83% size:77.5% It's, like, six layers that all pull out and then separate, 54:59.100 --> 55:01.500 align:left position:30% line:83% size:60% and it's designed to be deployed in zero G, 55:01.500 --> 55:03.066 align:left position:22.5% line:89% size:67.5% so it's very thin Mylar 55:03.066 --> 55:04.666 align:left position:32.5% line:83% size:57.5% that's designed to be deployed in zero G. 55:04.666 --> 55:08.966 align:left position:10% line:83% size:80% It's very hard to test on Earth, and I remember being in meetings 55:08.966 --> 55:12.266 align:left position:12.5% line:83% size:77.5% where they were trying to test it in Long Beach, California, 55:12.266 --> 55:14.300 align:left position:27.5% line:83% size:62.5% where the telescope was assembled, 55:14.300 --> 55:16.133 align:left position:17.5% line:83% size:72.5% and they'd say, "Oh, yeah, they tried another test, 55:16.133 --> 55:17.566 align:left position:12.5% line:89% size:77.5% "and just all the cables, like, 55:17.566 --> 55:18.933 align:left position:32.5% line:83% size:57.5% "jumped out of their cables trays, 55:18.933 --> 55:21.066 align:left position:25% line:83% size:65% and it stopped, like, halfway through," 55:21.066 --> 55:23.266 align:left position:15% line:83% size:75% and you could just see people around the table be like, 55:23.266 --> 55:24.633 align:left position:17.5% line:89% size:72.5% "What are we doing," right? 55:24.633 --> 55:27.333 align:left position:17.5% line:83% size:72.5% And the woman in charge of NIRCam, when I worked for her, 55:27.333 --> 55:28.666 align:left position:15% line:89% size:75% I still remember her saying-- 55:28.666 --> 55:30.366 align:left position:25% line:83% size:65% She saw this, right, and was like, "Look. 55:30.366 --> 55:32.933 align:left position:22.5% line:83% size:67.5% "Nothing that any of us do right here 55:32.933 --> 55:35.366 align:left position:15% line:83% size:75% "is gonna affect what happens with the sun shield, right? 55:35.366 --> 55:36.766 align:left position:32.5% line:83% size:57.5% "There's a lot of very smart people 55:36.766 --> 55:38.533 align:left position:30% line:83% size:60% "who know exactly how important this is, 55:38.533 --> 55:40.733 align:left position:17.5% line:71% size:72.5% "who are working very hard to make sure it works right 55:40.733 --> 55:43.266 align:left position:22.5% line:71% size:67.5% "the first time because we only get one shot at it, 55:43.266 --> 55:45.366 align:left position:35% line:71% size:55% "and it's not worth worrying about. 55:45.366 --> 55:48.733 align:left position:12.5% line:71% size:77.5% None of your worrying is gonna affect what they do," right? 55:48.733 --> 55:51.533 align:left position:17.5% line:71% size:72.5% And one of the nice things about Webb was, 55:51.533 --> 55:53.000 align:left position:37.5% line:71% size:52.5% over time, it was pretty delayed, 55:53.000 --> 55:54.666 align:left position:17.5% line:71% size:72.5% but one of the nice things was that 55:54.666 --> 55:56.466 align:left position:27.5% line:71% size:62.5% one of the reasons it was delayed is 'cause 55:56.466 --> 55:58.766 align:left position:15% line:71% size:75% everybody wanted to make sure it worked the first time, 55:58.766 --> 56:00.433 align:left position:37.5% line:71% size:52.5% and it did. 56:00.433 --> 56:01.800 align:left position:22.5% line:71% size:67.5% It was pretty amazing. 56:01.800 --> 56:04.400 align:left position:20% line:71% size:70% There was pretty much no problems during commissioning. 56:04.400 --> 56:06.900 align:left position:27.5% line:71% size:62.5% Sun shield deployed the first time, no problem. 56:06.900 --> 56:09.933 align:left position:17.5% line:71% size:72.5% It still sort of amazes me that we didn't actually hit 56:09.933 --> 56:12.000 align:left position:17.5% line:71% size:72.5% some sort of major problem during that whole process, 56:12.000 --> 56:14.766 align:left position:10% line:71% size:80% but it all worked the first time just like it should've. 56:19.433 --> 56:20.600 align:left position:12.5% line:5% size:77.5% All right, well, thanks, guys. 56:20.600 --> 56:21.766 align:left position:35% line:5% size:55% This was fun. 56:21.766 --> 56:24.166 align:left position:25% line:5% size:65% [audience applauding]