Speaker 1: When we look back at humanity's path to understanding the universe,
Speaker 1: it's never a straight line. We sometimes tell the story
Speaker 1: that way Galileo, Newton, Einstein, et cetera. But the truth
Speaker 1: is that it's a zig zaga set of paths that
Speaker 1: branch and fade or intersect. It's an unguided exploration through
Speaker 1: all the possible ways of understanding this beautiful universe. And
Speaker 1: there's a lesson in that not just about how to
Speaker 1: learn more about the universe, but how each and every
Speaker 1: one of us should look at their own.
Speaker 2: Path through life.
Speaker 1: Hi, I'm Daniel. I'm a particle physicist and a professor
Speaker 1: at UC Irvine. Welcome to the podcast. Daniel and Jorge
Speaker 1: Explain the Universe in which we do exactly that, try
Speaker 1: to understand and explain the entire universe to you. We
Speaker 1: think that everything out there deserves understanding, and everyone out
Speaker 1: there deserves to understand the nature of the universe, both
Speaker 1: all of the beautiful and glorious mysteries that we have
Speaker 1: unraveled and the mysteries that remain, the questions that stand unanswered.
Speaker 1: We want to take you to the forefront of knowledge
Speaker 1: and help you understand what we do and do not know.
Speaker 1: And something that we talk about a lot on the
Speaker 1: podcast is that science is of the people, by the people,
Speaker 1: and for the people. It's not some huge, impersonal institution
Speaker 1: pumping out knowledge. It's just a bunch of people being
Speaker 1: curious about the world and dedicating their lives to try
Speaker 1: to scratch that itch to figuring it out. So when
Speaker 1: you re a study about how spiders fight wasps or
Speaker 1: how crystals forming clouds on venus, you should think about
Speaker 1: the person behind that study, the person who spent years
Speaker 1: squatting in damp forests watching spiders or building a sensor
Speaker 1: that would fly on a mission of venus. There's a
Speaker 1: life there, a human who decided to do that instead
Speaker 1: of becoming a novelist or a hedge fund zillionaire. In science,
Speaker 1: as we know, it emerges out of all that the
Speaker 1: same way that the tuing and froing of the little
Speaker 1: particles somehow weaves itself together to emerge as a rock
Speaker 1: or a baseball. When you zoom out, all of those
Speaker 1: people working in their little niches weave themselves together to
Speaker 1: move science forward. But it's never a straight line. It's
Speaker 1: always a zigzag. As science lurches from one idea to another.
Speaker 1: And it's also a zigzag for the individuals involved, the
Speaker 1: people who are succeeding or struggling, winning awards or nearly
Speaker 1: dropping out. The path of an individual scientist, how they
Speaker 1: find their niche and figure out a way to contribute.
Speaker 1: It requires luck and creativity, the same way research does.
Speaker 1: And today on the podcast, I want to dive into
Speaker 1: a fascinating story that weaves those two threads together. My
Speaker 1: friend and colleague, Professor Iau Mowa Shields, who studies the
Speaker 1: atmosphere of exoplanets, has written a gorgeous book about her
Speaker 1: science and her life and her very unusual path to
Speaker 1: be an astronomy professor. And so today on the podcast,
Speaker 1: we'll be talking about life on other planets, the story
Speaker 1: of Iau Moa Shields. All right, it's my great pleasure
Speaker 1: to introduce the podcast Professor ol Mowa Shields, my friend
Speaker 1: and colleague here at UC Irvine. A. Professor Shields has
Speaker 1: her PhD from the University of Washington and then she
Speaker 1: was an NSF postdoctoral fellow at Harvard. She's been a
Speaker 1: Covely Fellow and a Ted Fellow, and she now holds
Speaker 1: the Claire Booth loose assistant professorship at UC Irvine that
Speaker 1: she was recently promoted to tenure. Well, welcome to the podcast,
Speaker 1: and thank you very much for joining us.
Speaker 2: Thank you for having me. It's great to be here.
Speaker 1: I've been very much looking forward to talking to you
Speaker 1: about this wonderful book you wrote, Life on Other Planets.
Speaker 1: I love how weaveseing your research story and your personal story,
Speaker 1: and it tells us so much about life on other
Speaker 1: planets and life on this planet. And so I was
Speaker 1: hoping to talk to you first about your science and
Speaker 1: then getting in a little bit more into your personal story.
Speaker 2: I love that.
Speaker 1: So the question that seems to motivate your science is basically,
Speaker 1: where can we live or where can life exist on
Speaker 1: planets in our universe? Is that the thing that drives you?
Speaker 2: It is that old question are we alone? In the universe?
Speaker 2: I have filtered it a little bit more through my
Speaker 2: own lens, you know, like, which is how do we
Speaker 2: choose planets to target and prioritize in that quest to
Speaker 2: answer the question are we alone? And the thing the
Speaker 2: way that I do it, the way that my team
Speaker 2: does it is once the planet is found by the observers,
Speaker 2: and of course finding that planet is super hard. That's
Speaker 2: a euphemism really, I mean, it's as I mentioned in
Speaker 2: the Ted talk, it's like trying to, you know, figure
Speaker 2: out what color a fruit fly is on a headlight
Speaker 2: that's you know, trillions of miles away.
Speaker 1: That sounds easy when I'm talking about it.
Speaker 2: Do it in a day. So like that that, I
Speaker 2: don't mean to underestimate it all the amount of work
Speaker 2: that observers have to take. However, once that work is
Speaker 2: done and they found a planet that exists in a
Speaker 2: particular region of space around its star that we call
Speaker 2: the habitable zone, that's only the first step. Because just
Speaker 2: because a planet is in the habitable zone doesn't mean
Speaker 2: that it's habitable, And just because it's habitable doesn't mean
Speaker 2: it's inhabited. Like let's be clear about that because often
Speaker 2: that that gets confused in the media. But like you know,
Speaker 2: we find a planet that's in the habitable zone, that
Speaker 2: doesn't mean that we know anything about what kind of
Speaker 2: atmosphere it has, or what kind of surface it has,
Speaker 2: or what kind of environment that it really has that
Speaker 2: might allow liquid water to stay liquid on the surface.
Speaker 2: And that really is our overwhelming criterion for habitability. When
Speaker 2: we say, you know, let's look for other habitable planets.
Speaker 2: It's let's look for planets that might be warm enough
Speaker 2: to have liquid water, because we know on our planet,
Speaker 2: everywhere there's water, there's life, and every single life form
Speaker 2: from the tiniest microbe to the largest elephant, requires liquid
Speaker 2: water to survive.
Speaker 1: So you're starting from the planets that other folks have found,
Speaker 1: all this list of five thousand or so exoplants we've
Speaker 1: discovered so far, and you're trying to figure out which
Speaker 1: ones to focus in on to understand whether there's water
Speaker 1: on them.
Speaker 2: Yes, because from that subset of five thousand plus planets
Speaker 2: that we've found, maybe a few dozen of them to
Speaker 2: maybe tens of them are in the habitable zone. And
Speaker 2: we're going to keep finding more and more of these
Speaker 2: potentially habitable planets because we now have another satellite, another
Speaker 2: observatory called TESTS, the Transiting Survey Exoplanet Survey satellite, and
Speaker 2: it's already found additional planets. It's going to be finding more.
Speaker 2: So we find this, we get a planet that's been
Speaker 2: discovered and we don't know anything about for the Earth
Speaker 2: size planets, what's actually in their atmospheres. So what my
Speaker 2: team can do is we can use climate models that
Speaker 2: were historically used to predict climate and weather on the
Speaker 2: Earth to predict climate and weather on exoplanets, and we
Speaker 2: can say, Okay, we don't know anything about this planet's
Speaker 2: atmosphere or surface. What kind of atmosphere or surface would
Speaker 2: it require to have above freezing surface temperatures for liquid water?
Speaker 2: If we throw an Earth atmosphere, Earth like atmosphere at
Speaker 2: this planet and run our simulations, is it habitable? Is
Speaker 2: it warm enough for liquid water? And if it is,
Speaker 2: that's a result. If it's not, it's what kind of
Speaker 2: atmosphere would it need a little more carbon dioxide? Because
Speaker 2: you know, while on our planet we have way too
Speaker 2: much carbon dioxide, other planets might actually benefit from it
Speaker 2: if they're on the colder side. And I have to
Speaker 2: make this very clear when I talk to my students,
Speaker 2: because carbon dioxide is a greenhouse gas. By definition, a
Speaker 2: greenhouse gas is a gas that both absorbs and emits
Speaker 2: infrared radiation. And on our planet, we we're no longer
Speaker 2: in energy balance because we have now added to our
Speaker 2: current complement of CO two and that's us doing that,
Speaker 2: and so we have more than we need. We don't
Speaker 2: need any more. We're hurting ourselves. For other planets, CO
Speaker 2: two can be a benefit if they are way out.
Speaker 2: You know, the outer edges of the habitable zone are
Speaker 2: even farther outside because greenhouse gas is warm things up.
Speaker 2: So we can figure out what kind of atmosphere a
Speaker 2: planet would need and what kind of surface, because surfaces
Speaker 2: also have their own different reflective properties, and they can
Speaker 2: absorb different kinds of light from stars. And we do
Speaker 2: this for planets that have been discovered. We can say, Okay,
Speaker 2: how habitable is this planet really? Over it? And the
Speaker 2: planets that are the most habitable, over the widest range
Speaker 2: of different atmospheres and surface types and shapes of their
Speaker 2: orbit and axial tilts, those are the planets that we'd
Speaker 2: want observers to put at the top of their list
Speaker 2: to look at with these next generation telescopes to try
Speaker 2: to find evidence of life.
Speaker 1: So you mentioned that twice. Now, the putting things at
Speaker 1: the top of their list or focusing on things, why
Speaker 1: do we need to do that? I mean, we all
Speaker 1: have only a few thousand of these planets. Why don't
Speaker 1: we just look at all of them to prioritize.
Speaker 2: Yeah, and I wish we could, and I'd love it
Speaker 2: if we could. Unfortunately, we don't have infinite telescope time.
Speaker 2: We can't follow up on every single potentially habitable planet
Speaker 2: to look for signs of life in their atmospheres, in
Speaker 2: its atmosphere, and so we do need to do this prioritization,
Speaker 2: especially given that we're going to continue to find more
Speaker 2: and more.
Speaker 1: So what kind of observations are we talking about the
Speaker 1: original observations that discover the exoplanet. Is there are not
Speaker 1: the same kind as the ones that can tell us
Speaker 1: about the atmosphere.
Speaker 2: That's right, yes, So finding a planet in space we
Speaker 2: have different choices. We have maybe five techniques, and the
Speaker 2: techniques that all that are finding most of the planets
Speaker 2: these days are something called radial velocity and the transit technique.
Speaker 2: Most of the planets we've found have been used using
Speaker 2: the transit technique, and that is we look at light
Speaker 2: that's coming from a star and if there's a planet
Speaker 2: around that star that we see transit, you know, go
Speaker 2: in front of that star. From our viewing angle. We
Speaker 2: know all planets transit their stars, but we may not
Speaker 2: see the transit. It depends on if we're lined up
Speaker 2: in such a way that we can, and when we do,
Speaker 2: we see the light dip because something a planet is
Speaker 2: passing in front of it and it's taking a little
Speaker 2: chunk of light out of that star.
Speaker 1: It's a mini eclipse, right, that eclipse.
Speaker 2: Yeah, And we can measure that the depth of that eclipse,
Speaker 2: the depth of that transit, and that tells us information
Speaker 2: about the planet, like how large the planet is, but
Speaker 2: it doesn't tell us anything about out what's in that
Speaker 2: planet's atmosphere. To do that, we need another kind of
Speaker 2: technique called using a spectroscopy. That technique is employed by
Speaker 2: James Webspace Telescope, and we'll be employed by other future
Speaker 2: missions as well, And that is when we can sort
Speaker 2: of measure. Again, we're measuring light coming from a star,
Speaker 2: but if the planet is lined up in such a
Speaker 2: way from our viewing angle, we see that starlight filtered
Speaker 2: through the planet's atmosphere, and that starlight little chunks of
Speaker 2: it are taken out by atmospheric molecules that exist on
Speaker 2: that planet, and we can look at those chunks of
Speaker 2: light taken out and match those to where we know
Speaker 2: certain atmospheric gases absorb. We know that from the laboratory
Speaker 2: measurements measurements of our own sun, and that can tell
Speaker 2: us what's in the atmospheres of the planets that are
Speaker 2: transiting these stars.
Speaker 1: So each of our telescopes is sort of good. It's
Speaker 1: something like we have ones that are good at finding
Speaker 1: these exoplanets, and then another one you would use to
Speaker 1: follow up to measure the atmospheric signals of that planet.
Speaker 1: You can't do both with the same telescope.
Speaker 2: Usually not. And this, you know, this technique of transit
Speaker 2: transmission spectroscopy is this fancy word for that kind of
Speaker 2: a technique. When we're looking for atmospheric fingerprints of life,
Speaker 2: those fingerprints we call bio signatures or biomarkers. Sometimes those
Speaker 2: terms are used interchangeably, but it's basically biologically generated global
Speaker 2: impacts to a planet's atmosphere or surface. That doesn't have
Speaker 2: to be the atmosphere. People are really big on the
Speaker 2: atmosphere because they think that's probably all that we're going
Speaker 2: to be able to see, if that at all for
Speaker 2: Earth planets. But a lot of my works, you know,
Speaker 2: from the book, has been about saying the surface matters.
Speaker 2: You know you can, and you can't assume that it doesn't.
Speaker 2: And we've been able to prove with our simulations that
Speaker 2: in fact it matters a lot.
Speaker 1: So are we looking for habitable planets planets that might
Speaker 1: have water and service gravity that's reasonable, et cetera. Or
Speaker 1: are we looking for biosignatures of inhabited planets or both.
Speaker 2: Ultimately, it's the biosignatures that would allow us to answer
Speaker 2: that question how we're going to answer are we alone?
Speaker 2: While it's finding something, measuring something that life could excrete
Speaker 2: into the atmosphere or onto the surface that tells us
Speaker 2: only life can do that, and coming up with that
Speaker 2: recipe of gases that only life together could produce is
Speaker 2: its own sub field of astronomy and astrobiology. That's not
Speaker 2: what I do, but it is crucial to that enterprise.
Speaker 2: Is Okay, what are we going to look for? Not
Speaker 2: just what are we going to look at?
Speaker 1: So once we've discovered this planet, then your job is
Speaker 1: essentially figure out whether it's likely to have the conditions
Speaker 1: for life by simulating possible scenarios and seeing whether they
Speaker 1: fit the data that we know about the planet.
Speaker 2: Yes, that's exactly what I do. Alongside another part of
Speaker 2: our world, which is not necessarily having a planet that
Speaker 2: has been discovered to work with. So one of the
Speaker 2: fun things I enjoy doing is creating fictional planets that
Speaker 2: I don't know that might exist, but that could, you know,
Speaker 2: like a hypothetical planet. Say we say, let's put a
Speaker 2: planet around a different type of star than the Sun,
Speaker 2: which therefore emits a different type of light overall, and
Speaker 2: see what the planet's climate does. That was really what
Speaker 2: my dissertation work was all about, is let's put planets
Speaker 2: around different types of stars and see if their climates
Speaker 2: would be different. And yes, they would be, and we
Speaker 2: got to show how and why. And now as a professor,
Speaker 2: we ask questions like, could there be a planet that
Speaker 2: exists that has too hot of a day side it's
Speaker 2: a permanent day side, too hot of a night side
Speaker 2: that's a permanent night side, and only a habitable surface
Speaker 2: environment along the dividing line between them, which we call
Speaker 2: the terminator. Could such a planet exist and would its
Speaker 2: climate be stable? And in my post dot Ana Lobo
Speaker 2: showed that that kind of climate can in fact be stable,
Speaker 2: and it's more likely to exist around a drier planet
Speaker 2: than a wetter planet. And I love doing that kind
Speaker 2: of stuff because it allows me to turn knobs and
Speaker 2: see what factors are really the most critical to governing
Speaker 2: habitability and to realize that these environments could exist out.
Speaker 2: Not only could they exist out in the universe, but
Speaker 2: they could be more conducive to supporting life than the
Speaker 2: more traditional kinds of environments that we're used to seeing
Speaker 2: within our own solar system.
Speaker 1: Can you talk for a little bit about the role
Speaker 1: of simulations here, because I think listeners are hearing that
Speaker 1: you start with some parameters of a planet, but then
Speaker 1: you're doing some sort of calculation to figure out like
Speaker 1: what's likely to be there. How do we go from
Speaker 1: here's the structure of a planet to understanding what its
Speaker 1: climate might look like. I mean, we can't even predict
Speaker 1: the weather here in southern California. How can we predict
Speaker 1: the atmosphere of an exit planet.
Speaker 2: Well, it requires us to make sure that our model work,
Speaker 2: that they're valid for a given set of circumstances. So
Speaker 2: we our models always have to be validated for the
Speaker 2: one planet whose climate we can be fairly certain within
Speaker 2: a twenty four hour period or you know, to be
Speaker 2: relatively stable. And of course it's the climate is different
Speaker 2: than the weather. Let's be clear about that so like, yes,
Speaker 2: weather is very variable over a span of hours, let
Speaker 2: alone days, but the overall climate of our planet has
Speaker 2: been relatively stable over hundreds thousands of years, and we
Speaker 2: largely we have different reasons for that. Some of the
Speaker 2: reasons include the kind of axle tilt we have, the
Speaker 2: fact that we have a certain obliquity that allows our
Speaker 2: planet not to swing wildly in that regard. We also
Speaker 2: have a moon. People have thought that, you know that
Speaker 2: that of course helps us to help the obliquity to
Speaker 2: be stable. There have been some simulations to show that
Speaker 2: without a moon we probably wouldn't vary as wildly in
Speaker 2: obliquity as was once thought. But those aspects and the
Speaker 2: fact that we have a silicate weathering feedback. We have
Speaker 2: a carbonate silicate cycle which when there's a lot of precipitation,
Speaker 2: you know, that washes CO two out of the atmosphere,
Speaker 2: locks it into rocks and cools temperatures. And then when
Speaker 2: temperatures get too cool, we got volcanoes that outgas CO
Speaker 2: two back into the atmosphere and warm temperatures. So we
Speaker 2: have this built in feedback that allows our climate to
Speaker 2: be relatively stable over long time scales. So we can
Speaker 2: predict our climate relatively straightforwardly with these models. You're absolutely
Speaker 2: right that with these exoplanets, you know, how can we
Speaker 2: propose to predict their climates with these models? We don't.
Speaker 2: First of all, we don't know what their atmospheres are like.
Speaker 2: That's why our work is so important because we can say, okay,
Speaker 2: so let's run a whole suite of different atmospheres and
Speaker 2: see what the climates would be. But there is a
Speaker 2: key thing that we can't prove yet that exoplanets have,
Speaker 2: and that is this carbonate silicate cycle that's pretty important.
Speaker 2: Habitable zone, this like region of space around each star.
Speaker 2: It assumes that we do have a carbonate silicon cycle
Speaker 2: on these extra planets. And the fact is that's why
Speaker 2: the habitable zone is a first order approximation and it's
Speaker 2: self limiting because it assumes circular orbits of planets. We
Speaker 2: have many, many planets elsewhere around other stars that have
Speaker 2: very very eccentric orbits and certainly beyond zero, and we
Speaker 2: have no proof that any kind of silicate weather and
Speaker 2: feedback is active on these planets to regulate the amount
Speaker 2: of carbon dioxide and precipitation in our atmosphere. With temperature,
Speaker 2: but we have to assume that it is for these
Speaker 2: climate models. So we assume that there is like a
Speaker 2: we start with an Earth and we can simulate our
Speaker 2: planet and say, run your model, and do you get
Speaker 2: an atmosphere a surface temperature pattern similar to what's actually
Speaker 2: here on Earth and has been measured with satellites. Yes
Speaker 2: you do. Okay, great, we know the model is valid.
Speaker 2: Now what are we going to change. Let's change the
Speaker 2: star and have an actual spectrum of the star that
Speaker 2: the planet is orbiting. We can put that in and
Speaker 2: all the different sellar properties and to some degree, and
Speaker 2: then the planet's properties that we know of like it's radius,
Speaker 2: maybe it's mass, if we've gotten Doppler measurements as well,
Speaker 2: and then we are filling in the gaps. And that's
Speaker 2: why I'm so big on theoretical simulations as well, because
Speaker 2: without those, the amount of things we would know about
Speaker 2: exoplanets would be you could count on one hand. Right,
Speaker 2: we need to be able to fill the gaps between
Speaker 2: what we do not know and what we need to
Speaker 2: know to be able to come closer to answering this
Speaker 2: question about these environments. So yeah, it's important. We can't
Speaker 2: sort of put a paper out and say this planet
Speaker 2: has this atmosphere, has this surface, and is habitable. But
Speaker 2: we can say this planet, if it has this atmosphere,
Speaker 2: if it has this surface, or if it has this
Speaker 2: set of atmospheres, here's how habitable it would be. And
Speaker 2: that allows for the range of possible atmospheric and surface
Speaker 2: and dynamical environments that might exist around this planet, while
Speaker 2: also being able to quantify their impact on habitability.
Speaker 1: And then can you analyze more deeply once you have
Speaker 1: the spectrum. Now you've looked at the planet, Do you
Speaker 1: have the spectrum? You have an idea of what's there?
Speaker 1: Does that allow you to model what's going on over
Speaker 1: there and have a deeper sense of whether it's habitable
Speaker 1: or maybe even inhabited.
Speaker 2: So you mean once we were to get some kind
Speaker 2: of a transit transmission spectroscopy that measurements, Yeah, yeah, I
Speaker 2: mean we've been able to do this with James web
Speaker 2: And this was a surprise as far as I know.
Speaker 2: Back five ten years ago and people were talking about
Speaker 2: JAWST and what it would be able to do for earths,
Speaker 2: those are pretty short sentences. People were like, that's going
Speaker 2: to be able to do some stuff for the larger
Speaker 2: like Jupiter sized planets. But people were very skeptical about
Speaker 2: how much information we'd be able to get out of
Speaker 2: James Webb when it comes to Earth's and it turns
Speaker 2: out we're surprising ourselves because not only have we confirmed
Speaker 2: the discovery of Earth sized planets with James web we've
Speaker 2: also measured atmospheric constituents of you know, in Earth sized
Speaker 2: planet's atmospheres. Now I believe that those measurements are some
Speaker 2: additional measurements that were taken earlier this year. And the
Speaker 2: point is that we are able to you know, to
Speaker 2: start to get this kind of information for a smaller
Speaker 2: region or a smaller regime of planets than I think
Speaker 2: we thought, and we're doing it already. So if we
Speaker 2: were to get, you know, a spectrum from an Earth,
Speaker 2: you know, an Earth around another star and it had
Speaker 2: these sort of whether it's carbon based molecules like methane,
Speaker 2: it becomes the question of what is going to tell
Speaker 2: us exactly that life's there, and that is that's an
Speaker 2: ongoing quest. You know, It's like you need methane along
Speaker 2: with oxygen, perhaps maybe ozone two, maybe some other kind
Speaker 2: of lesser known gases like dimethyl sulfide, things that come
Speaker 2: from plankton. There are people that are that are thinking
Speaker 2: about all of these different I said recipe earlier, these
Speaker 2: different kind of combinations of gases. But if we were
Speaker 2: if we were to come up come up with this
Speaker 2: like set of these different gases that would say that,
Speaker 2: and we could say only life can do that, then yeah,
Speaker 2: we would have answered this question.
Speaker 1: I have lots more questions for our guests, but first
Speaker 1: let's take a quick break. Okay, we're back and I'm
Speaker 1: talking to Professor Aumwa Shields, professor of astronomy at UC Irvine,
Speaker 1: about her book Life on Other Planets. I love how
Speaker 1: you describe sort of fleshing out the habitable zone from
Speaker 1: a first order approximation. Like the simplest calculation is just
Speaker 1: where is there enough solar radiation to melt water and
Speaker 1: make sure it's not steam. But as you say that,
Speaker 1: it's more subtle than that. Right, It depends on so
Speaker 1: many details. One planet would be habitable if it was
Speaker 1: closer in. Another planet would be habitable is further out.
Speaker 1: So the habitable zone has to depend on the planet, right,
Speaker 1: the size of the planet, certainly, the atmosphere and its surface.
Speaker 1: So can you, in broad strokes, give us an understanding
Speaker 1: and what we've learned about habitability of planets, like what
Speaker 1: conditions are required beyond just like you have to be
Speaker 1: in some zone around your star.
Speaker 2: Yeah, when I was a grad student, my advisor, the
Speaker 2: Key Meadows, had this workshop where she invited everyone who
Speaker 2: she knew who worked on habitability to Seattle and we
Speaker 2: all like sort of stayed in about three different rooms
Speaker 2: at a conference center and hashed out this question of
Speaker 2: what are all of the different factors that can influence
Speaker 2: the long term presence surface liquid water on a planet?
Speaker 2: And we came up with this very intricate web and
Speaker 2: I still show it in my talks today and it
Speaker 2: always gets like this sort of gasp from students or
Speaker 2: like or a or an oh like that, because it
Speaker 2: is overwhelming. And that's really the point of the showing
Speaker 2: that slide is that we are meant to be overwhelmed.
Speaker 2: There are a lot of factors that can influence that.
Speaker 2: You know that that criterion of surface liquid water, yes,
Speaker 2: planetary distance from a star, which is what the habitable
Speaker 2: zone is, you know, is that expression of that's one
Speaker 2: and broader stellar environment that could be stellar activity, and
Speaker 2: you know rotation rate of the star and of course
Speaker 2: planetary rotation rate. So there's stellar environment, there's planetary environment,
Speaker 2: there's stellar effects, there's planetary there's you know, the dynamics
Speaker 2: of the planet's environment, whether there are siblings, like whether
Speaker 2: planets planets can push and pull on each other, and
Speaker 2: just like our own Solar System, planets are often not
Speaker 2: alone in their systems. And so there's the gravitational effects.
Speaker 2: There's how reflective different surfaces are. There's how the age
Speaker 2: all of the system itself. This web of different factors
Speaker 2: is something that many of us in the field of
Speaker 2: exoplanet climatology have been slowly chipping away at for the
Speaker 2: last I would say, like, you know, fifteen twenty years
Speaker 2: that we've been people have been doing this, and we
Speaker 2: still don't know what are the most critical factors. I mean,
Speaker 2: there are sort of the heavy hitters, like how much
Speaker 2: light you get from your star, because yeah, it's true,
Speaker 2: if you put a planet, no matter how much atmosphere
Speaker 2: it's got, how thick, what's its composition, you put it
Speaker 2: far enough away from a star and it will freeze.
Speaker 2: So like stellar distance, our planetary distance from a star
Speaker 2: matters and the atmosphere. Of course, the composition of the
Speaker 2: atmosphere is a critical piece as well. But we one
Speaker 2: thing that we've seen from this web and from kind
Speaker 2: of looking at different aspects is that it's a lot
Speaker 2: more complex than orbital distance. It's a lot more complex
Speaker 2: even than atmospheric composition. You know, you change one factor
Speaker 2: about a planet and it can change everything about its future.
Speaker 2: And that that's important for us to know for our
Speaker 2: own planet. And I think it also can drive home
Speaker 2: that reality of how lucky we all are that we're
Speaker 2: on a planet that, for whatever reason, all the different
Speaker 2: possible combinations kind of that combination generated something that allowed
Speaker 2: life to start here.
Speaker 1: So as you survey like the parameter space of planets,
Speaker 1: does that make you feel like we are unusual or
Speaker 1: do you feel like, oh, there's lots of ways that
Speaker 1: a planet could end up with liquid water in the surface,
Speaker 1: or do you feel like, wow, it's an exquisite balance.
Speaker 2: It was the second option you mentioned. It's the one
Speaker 2: there's a lot of ways to do it. I mean,
Speaker 2: we've had books written about how rare some scientists think
Speaker 2: this planet is. There's a book called Rare Earth that
Speaker 2: was written by Peter Ward and Don Brownlee that really
Speaker 2: talk about how it was a super rare thing to
Speaker 2: have happened the way it happened, and it's probably not
Speaker 2: going to happen much or have happened much elsewhere. I
Speaker 2: take a different view because you know, when we think about,
Speaker 2: for example, seventy percent of all stars in the galaxy
Speaker 2: are not like the Sun. They are these small, cool
Speaker 2: M stars. And the great thing about that is that
Speaker 2: they're so numerous that we may end up finding that
Speaker 2: next habitable planet around an M. We have got a
Speaker 2: lot of opportunities to do that, and it's easier to
Speaker 2: find planets around these stars. There's a lot of pros,
Speaker 2: but one of the cons is that these stars are
Speaker 2: very long lived. None of them have ever died, because
Speaker 2: their lifetimes are longer than the current age of the universe.
Speaker 2: They have lifetimes of hundreds of billions and in some
Speaker 2: cases trillions of years. I actually find myself oney ask
Speaker 2: you questions about the latest results about James Webb, which
Speaker 2: says which will challenge how old the universe really is.
Speaker 2: But I'm going off of like what we have known
Speaker 2: you to date, which is slightly less than fourteen billion years,
Speaker 2: and so these because these stars are so long lived,
Speaker 2: they can be very active for a really long time.
Speaker 2: And I always use that I think I used it
Speaker 2: in the book to that analogy of like the Terrible
Speaker 2: twos phase for stars. This Terrible twos phase can last
Speaker 2: for billions of years, and during that time any planets
Speaker 2: that formed around these stars could be pelted with harmful
Speaker 2: X ray UV radiation. And this often comes up in
Speaker 2: a talk when people ask that, you know, how likely
Speaker 2: do you think it is to find life on a
Speaker 2: planet orbiting an m star, given that that life could
Speaker 2: be subjected to that kind of environment, And I say, well, yeah,
Speaker 2: that could be a problem. Seriously. There's been a lot
Speaker 2: of papers that talk about this. However, we see life
Speaker 2: at the bottom in deep ocean hydrothermal vent vironments on Earth.
Speaker 2: Life finds a way. So that is an example of
Speaker 2: how many different ways life can survive. And that's one
Speaker 2: of the reasons why I think that we could end
Speaker 2: up finding life within our own Solar system. And we've
Speaker 2: got moons right at Jupiter's moon Europa, where we know
Speaker 2: there's liquid water. It's underneath an ice crust, but it's there,
Speaker 2: and we're going to go back and actually drill something
Speaker 2: through the ice and see if we can find anything
Speaker 2: swimming around in there. And Saturn's moon Enceladus, and we've
Speaker 2: got examples within our own Solar system of places that
Speaker 2: could be habitable and or do fit the criterion for
Speaker 2: hosting liquid water not on their surfaces, so it's subsurface.
Speaker 2: But mincing words.
Speaker 1: Tell us a little bit more about the role of
Speaker 1: the surface, because I think that's something a lot of
Speaker 1: people haven't thought about or heard about. I loved how
Speaker 1: you treated it in the book. What is the importance
Speaker 1: of having the right surface on your planet to make
Speaker 1: it habitable?
Speaker 2: It is important. A lot of the times that these models,
Speaker 2: we assume there's an ocean, and we often go one
Speaker 2: step further and assume that ocean is a slab ocean,
Speaker 2: which means it's like fifty meters deep and there's no
Speaker 2: ocean heat flux. And we do that. There's justifiable reasons
Speaker 2: for doing that. First of all, we're not going to
Speaker 2: be able to get any kind of bathometric information about
Speaker 2: an exoplanet anytime soon, and simulating a four thousand meter
Speaker 2: deep ocean takes a lot longer than a fifty meter
Speaker 2: slab ocean and people there are exoplanet astronomers that are
Speaker 2: looking at the role of ocean circulation on habibility, and
Speaker 2: that's important too, And those models take months to run,
Speaker 2: so it can be very useful as long as you're
Speaker 2: willing to say, Okay, here are the results using a
Speaker 2: slab ocean, and if we assume there's ocean heat flux
Speaker 2: and a depth there, here's how the results might change.
Speaker 2: You know. As long as we include that, then we
Speaker 2: can make sure that we've communicated some meaningful science and
Speaker 2: information whilst also being able to generate a lot of
Speaker 2: simulations and go in depth in terms of the climate
Speaker 2: and atmospheric dynamics involved. But the thing is that this
Speaker 2: is a generalized and highly idealized scenario to assume a
Speaker 2: planet has ocean and nothing else. In reality, we step
Speaker 2: out our front door and we see how much more
Speaker 2: surface topography and compositional variety there exists, you know, within
Speaker 2: this planet. We have to be able to move in
Speaker 2: that direction when it comes to simulating exoplanet environments. So
Speaker 2: what we do is we start with, okay, we know
Speaker 2: that an ocean is very absorptive across the em spectrum.
Speaker 2: It's just if you were to look at this a
Speaker 2: plot of you know, how reflective ocean is, It's just
Speaker 2: a straight line across you know, most wavelengths. But that's
Speaker 2: not the case for other surfaces. If you put water
Speaker 2: ice on a surface, water ice, as I'm very big
Speaker 2: and talking about in the book, is extremely absorptive of
Speaker 2: a type of radiation that's longer, redder wavelengths infrared, and
Speaker 2: very reflective of visible near UV radiation. And that basic principle,
Speaker 2: that basic phenomenon about water ice and about the vibrational
Speaker 2: modes of the water molecule. When you apply that to
Speaker 2: host stars which emit different types of light, and you
Speaker 2: think about that interaction, it completely affects planetary climate and habitability.
Speaker 2: So you know, we have quantified that we've changed the
Speaker 2: surface and say, okay, say it's land, Well, what kind
Speaker 2: of land? You know, it could be a clay, it
Speaker 2: could be calcite, it could be graphied, it could be
Speaker 2: you know, a different kind of combination of basalt. And
Speaker 2: each of those surfaces have their own wavelength dependent properties
Speaker 2: and behave different ways depending on what kind of light
Speaker 2: they receive from their host star environments. So we have
Speaker 2: been able to do this kind of work for not
Speaker 2: only water ice, but also ice that has a lot
Speaker 2: of salt in it, because it turns out if temperatures
Speaker 2: get cold enough, there can be an there's a little
Speaker 2: bit of salt in the ocean, well, there's a lot,
Speaker 2: but if you know, even is a little bit, that
Speaker 2: salt can precipitate to the top of that layer and
Speaker 2: form a crust so reflective it's even more reflective than snow.
Speaker 2: And no one had applied that phenomenon to looking at
Speaker 2: exoplanets and deciding, you know, could these exoplanets, even in
Speaker 2: the habitable zone, get cold enough on their surfaces for
Speaker 2: this type of ice to form. And we were able
Speaker 2: to show that yes, they could, even in the habitable zone,
Speaker 2: and that climate models needed to incorporate parameterizations for the
Speaker 2: formation of these types of surfaces if they wanted to
Speaker 2: really produce accurate assessments of planetary habitability. And so we
Speaker 2: did that for different land surfaces as well, and now
Speaker 2: we're looking at alternative ices like, of course you can
Speaker 2: get cold enough for not only water ice to form,
Speaker 2: but or this sort of salty ice, but carbon dioxide ice,
Speaker 2: methane ice, ammonia ice, and people in the past have thought,
Speaker 2: you know, who cares about that? Because if the the
Speaker 2: planet's that far away from the star that it gets
Speaker 2: that cold enough, like it's not going to be habitable,
Speaker 2: Like why would we even want to invest money? And
Speaker 2: that it turns out that these planets, if they're eccentric, yes,
Speaker 2: they can get far enough away from their star. They
Speaker 2: can also get very very close to their star, and
Speaker 2: they can go in and out of that traditional habitable zone.
Speaker 2: And you know, what would that do for life? Could
Speaker 2: you have a planet whose atmosphere, entire atmosphere like condenses
Speaker 2: out on the surface at its farthest point from the star,
Speaker 2: which we call appo astron and then like sublimates back
Speaker 2: into the atmosphere at perry Astron at the closest approach,
Speaker 2: you know, and people are you know, hadn't really thought
Speaker 2: about that beyond the sheer fact that yes, the planet
Speaker 2: can go in and out of the state. But what
Speaker 2: would that do to the actual atmosphere, Like we're starting
Speaker 2: to be able to simulate that and look at the
Speaker 2: optical and other properties of these ices. You know, that
Speaker 2: could form and then sublimate back into the sky in
Speaker 2: the atmosphere and then form again, Well.
Speaker 1: I love that you're not just ruling out candidates, you're
Speaker 1: also opening the door. You're like, oh, there are other
Speaker 1: ways to make habitable planets, things that we might have
Speaker 1: not considered. That's very cool, and I love seeing the
Speaker 1: sort of errative process of science in action. You start
Speaker 1: from a simple model and new ad bills, and you
Speaker 1: add whistles and you keep making things more and more realistic.
Speaker 1: How far do you think we are from, like really
Speaker 1: having anything that describes those planets, And how confident would
Speaker 1: you be that our model is describing anything that's happening
Speaker 1: over there, or do you feel like, wow, there's so
Speaker 1: much complexity we still haven't added that. Really, it's still
Speaker 1: a big question.
Speaker 2: The main uncertainties that I would want to prioritize really
Speaker 2: is there are two models. These climate models have historically
Speaker 2: been I want to say bad at but that's we're
Speaker 2: still struggling with cloud microphysics. So really, how clouds are
Speaker 2: formed on these planets, how they change, how their properties
Speaker 2: are expressed with them a model, because clouds, you know,
Speaker 2: they form at different heights. We have low clouds, medium clouds,
Speaker 2: high clouds on our planet. And we're just talking about
Speaker 2: water clouds, and of course getting into other types of
Speaker 2: compositional cloud microphysics as something else, but really, how you
Speaker 2: form these droplets, how drop how the cloud droplets are
Speaker 2: parameterized in a model is something that still requires a
Speaker 2: lot of work. And the other thing is this surface compositional complexity,
Speaker 2: because still where we're at is being able to say, okay,
Speaker 2: we're putting large swaths of a type of surface over here,
Speaker 2: and large swaths of a type of surface over here,
Speaker 2: but being able to really incorporate a complex surface environment
Speaker 2: where we have vegetation and different land surfaces and ice
Speaker 2: and ocean and topography and orography, putting that all into
Speaker 2: a model is important. We can do it with the
Speaker 2: Earth's environment any thing, you know, having some idea of
Speaker 2: how if we changed that different combination or that different
Speaker 2: orientation for both surfaces and topography, for example, and how
Speaker 2: that would influence climate, weather patterns, atmospheric circulation when circulation
Speaker 2: that remains to be seen. And we need to be
Speaker 2: able to do that in a much more smoother, much
Speaker 2: more systematic way. And right now it's pretty clunky.
Speaker 1: Okay, I want to get more into that, but first
Speaker 1: let's take another break. We're back and we're talking to
Speaker 1: Professor Alamawa Shields about her book Life on Other Planets,
Speaker 1: her research into exoplanets, and the story of how she
Speaker 1: got where she is. Awesome. Well, thanks sover much for
Speaker 1: telling us about your science. I'd love to know talk
Speaker 1: a little bit about your story about how you got
Speaker 1: to where you are, how you got to be who
Speaker 1: you are. If that's her, I'd take us back to
Speaker 1: your sort of original inspiration, like what is it that
Speaker 1: got you young o moha into science thinking that this
Speaker 1: was going to be the path for you.
Speaker 2: As long as I can remember, I have been that
Speaker 2: person who was looking up and I always preferred looking
Speaker 2: up to looking straight ahead. And as I wrote in
Speaker 2: the book, I was often bumping into things on the
Speaker 2: street because I was My neck was craved up. So
Speaker 2: like I grew up in a part of the country,
Speaker 2: you know, in the US where there was a lot
Speaker 2: of there were planes being flown. My grandmother worked at
Speaker 2: Miramar Air Force Base and that was where the Blue Angels,
Speaker 2: the Aerial Flight Team, were stationed, and so we used
Speaker 2: to go to Blue Angels shows on the weekends and
Speaker 2: we'd see these amazing planes doing these just like death
Speaker 2: defying acts and that was like that was football for us.
Speaker 2: We would tailgate and like sit on the on the
Speaker 2: lawns and look at these planes. And that was also
Speaker 2: Miramar was also where Top Gun was shot and was filmed,
Speaker 2: and I remember seeing that movie and being very inspired
Speaker 2: by Kelly McGill's character, who was an astrophysicist and just
Speaker 2: an all around badass. You know. It was just like
Speaker 2: that's who I want. And then it kind of all
Speaker 2: came together when I saw this movie called Space Camp, which,
Speaker 2: though not an OSCAR contender, it was like very very
Speaker 2: influential for me, you know. You know. I was like,
Speaker 2: if kids can get launch into space, then I thought,
Speaker 2: like I was a kid, it could happen for me.
Speaker 2: And that's like when I decided I was going to
Speaker 2: be an astronaut.
Speaker 1: So not a scientist. You wanted to be an astronaut.
Speaker 2: Yes, that's right, it was an astronaut. And in my
Speaker 2: mind it was, Okay, I'm going to go to space
Speaker 2: and I'm going to study space. So then I put
Speaker 2: two and two together and said, okay, because I knew
Speaker 2: I had to study something before I applied to NASA.
Speaker 2: That much I knew at the age of twelve, and
Speaker 2: so I was like, well, I'm going to study the
Speaker 2: thing that I want to go to. So that told
Speaker 2: me from looking that up in the World Book Encyclopedias
Speaker 2: that we had at home, that that meant astronomy, Studying
Speaker 2: space meant studying astronomy. Then the two and two, I mean,
Speaker 2: they went hand in hand, and they did for that
Speaker 2: the next few years until I ended up stumbling into
Speaker 2: an audition at the prep school I was going to,
Speaker 2: which I had decided to go to because they had
Speaker 2: their own observatory. But when I got there, it was
Speaker 2: like my second year. I was dragged to an audition
Speaker 2: for the play Steel Magnolias with some girlfriends and I
Speaker 2: ended up getting cast, Like I didn't really care if
Speaker 2: I got cast, like most of the girls that I
Speaker 2: knew really wanted to get cast, and I couldn't care less.
Speaker 2: I was like, homework break, Sure, I'll go. And I
Speaker 2: ended up getting a part, and I realized how much
Speaker 2: I loved it, you know, and it brought me back
Speaker 2: to when I was ten and had auditioned for a
Speaker 2: play at the La Joya Playhouse because we lived there
Speaker 2: in San Diego and had been an understudy. But really
Speaker 2: hadn't thought seriously about it. But it's like, once I
Speaker 2: started to act in high school kind of thought about
Speaker 2: how formative those experiences of being on stage were for me.
Speaker 2: And it became more than just being on stage when
Speaker 2: I got that part and saw what it took to
Speaker 2: put together a story, to work with people, to present
Speaker 2: something that we were then going to share with the world.
Speaker 2: Our world was, you know, was this school. But it
Speaker 2: gave me something that I didn't have as a budding astronomer.
Speaker 2: It gave me that sense of community and connection. Astronomy
Speaker 2: at that point felt very isolating and something that I
Speaker 2: did on my own with a telescope, and I loved that.
Speaker 2: And yet I also had this other aspect of with
Speaker 2: the acting, of like we work together day and day out, rehearsing,
Speaker 2: learning things about each other, using our personal backgrounds to
Speaker 2: tell a story, and then little people's heads off with
Speaker 2: that story, you know, in a good way. So like
Speaker 2: that was the beginning of Okay, I have two things
Speaker 2: now that I really love to do, and how do
Speaker 2: I make that work? You know?
Speaker 1: And was it hard for you to be in sort
Speaker 1: of two worlds already? I mean, imagine the drama kids
Speaker 1: and these space nerds probably didn't have a lot of overlap.
Speaker 1: Was that weird to be sort of like in two
Speaker 1: groups of kids and two communities and two sort of
Speaker 1: sets of you know, life goals in front of those kids.
Speaker 2: It's interesting. And at Exeter it wasn't. It wasn't strange.
Speaker 2: No one ever made me choose or looked at me funny.
Speaker 2: Because I had I was doing those things. It seemed
Speaker 2: like it was a it was a wonderful environment to
Speaker 2: be able to do many things. It wasn't until I
Speaker 2: got out of that environment and you know, needed to
Speaker 2: choose a school and got into college and it was
Speaker 2: like you had to choose a major, and like it
Speaker 2: became clear that those two things were very far apart,
Speaker 2: and you know, one was going to have to win.
Speaker 2: And that was the That was sort of the next
Speaker 2: phase of it for me. It was, Okay, I'll choose this.
Speaker 2: I've been wanting to do astronomy and be an astronaut
Speaker 2: for the longest of the time of the two, so
Speaker 2: let's stay with that. But one without the other never
Speaker 2: felt fully right, and I kept going back and forth.
Speaker 2: And this the book is that journey of that of
Speaker 2: thinking Okay, I'm going to choose this that's not working.
Speaker 2: I'm going to go choose this. Hmmm. I missed that thing,
Speaker 2: and you know, and ultimately realizing that it was never
Speaker 2: about choosing, It was really more about owning, you know,
Speaker 2: who I was.
Speaker 1: So in the book you talk about how you started
Speaker 1: grad school you're on this path to become an astronomer
Speaker 1: or scientist, but after your first year you left. You
Speaker 1: decided you're going to go the other direction, back into acting.
Speaker 1: Tell us about that choice. Was that difficult?
Speaker 2: Yes and no, it was very difficult. The way it happened.
Speaker 2: I was divided when I started that PhD program, I
Speaker 2: more I sort of did it on autopilot, because that's
Speaker 2: what you do, you finish undergrad If you're going to
Speaker 2: be a scientist, you need that PhD. But I had
Speaker 2: already recognized at MIT that I needed the arts again
Speaker 2: in my life, and I'd even applied to some acting
Speaker 2: schools that during my senior year. But I shot for
Speaker 2: the moon and hadn't gotten into those three schools, and
Speaker 2: so I was like, all right, I'm being told that
Speaker 2: it's astrophysics, so I'll do that. But just just because
Speaker 2: I made a choice, didn't mean that that dream was
Speaker 2: going to like listen and like just die, you know.
Speaker 2: So like during that first year I was there were
Speaker 2: four people on my cohort. The other three all lived together.
Speaker 2: They had invited me to live with them in one
Speaker 2: in the house, but I was like, no, no, I
Speaker 2: want to be on my own and I wanted my independence.
Speaker 2: But what I didn't realize was they were all working
Speaker 2: on problem sets together, you know, and I was not.
Speaker 2: So like I immediately set myself up for being a part.
Speaker 2: And then I started to sort of daydream about acting
Speaker 2: and films and stuff. And I did well in certain
Speaker 2: courses like atomic physics and some other ones, but like
Speaker 2: I was struggling in this course called basic astrophysics, which
Speaker 2: I always loved to make fun of. But there was
Speaker 2: that professor who suggested that I consider other career options.
Speaker 2: And so that was a difficult moment for me. And
Speaker 2: I thought that that confirm all the things that all
Speaker 2: the reasons I was using to feel up separate and apart.
Speaker 2: I was like, Okay, that confirms it. Plus I didn't
Speaker 2: really see many people who looked like me in my
Speaker 2: environment doing astronomy, so I sort of on the downlow
Speaker 2: applied to acting schools again and rode these sort of
Speaker 2: secret buses to Chicago and got in this time, and
Speaker 2: so decided to leave. And that's the part that I
Speaker 2: felt when I said yes and no, because in many
Speaker 2: ways that part was like such a relief. When I
Speaker 2: finally decided I was leaving, it was like I didn't
Speaker 2: want to have that conflict anymore because I saw it
Speaker 2: as a conflict that's something I hit I needed to
Speaker 2: work out. And so, okay, I'm getting signs that I
Speaker 2: shouldn't be in astronomy, like fine, you know, f it,
Speaker 2: I'm going to go, but I'm going to go to acting,
Speaker 2: and that I won't, you know, all done, I don't
Speaker 2: have any conflict anymore. So that I remember, like it
Speaker 2: just felt when I was taking the bus to the
Speaker 2: airport to leave Madison, Wisconsin, it was like it was like, oh,
Speaker 2: you know, the way to the world was gone. But
Speaker 2: of course what I didn't recognize was that, like the
Speaker 2: way I left, that wasn't a clean break. The reasons
Speaker 2: I know not only and I can't entirely blame that professor,
Speaker 2: although I you know, as I write, I would never
Speaker 2: tell that to a student today. It's not it's not
Speaker 2: my job. It's not my I don't have that power
Speaker 2: to determine if someone should choose a different career or not.
Speaker 2: I don't believe that we as faculty should wield that power.
Speaker 2: But I was the one who listened, and that's on me,
Speaker 2: you know. And so there was a lot of forgiveness
Speaker 2: to do, both of that professor and of myself. And
Speaker 2: it ultimately had to be about going to something, not
Speaker 2: running away from something, you know. And that's what I
Speaker 2: discovered later on, when you know, when I chose acting
Speaker 2: and was like, wow, this is this is hard in
Speaker 2: a different way. In some ways, it's like it's easy,
Speaker 2: no problem sets, but a lot, a lot of work
Speaker 2: and all the things that it didn't seem like science
Speaker 2: cared about, like my feelings and who I was, as
Speaker 2: long as I could do the problem set or write
Speaker 2: the paper, Acting cared about a lot, you know, And
Speaker 2: so I needed to bring up all those experiences from childhood,
Speaker 2: all through you know, through early adulthood and use those
Speaker 2: to embody these different characters. And it was very challenging
Speaker 2: and also extremely rewarding. But again, it wasn't on its own.
Speaker 2: It was not fully representative of the person that I am,
Speaker 2: so I had to have that discovery.
Speaker 1: Thank you very much for sharing all of that. I
Speaker 1: also want to hear about your path back to science.
Speaker 1: I know that a lot of our listeners are folks
Speaker 1: who have always been interested in science, have always thought
Speaker 1: about physics and space, but their life took them some
Speaker 1: other way, And a lot of them right into me
Speaker 1: and ask me like, is it unforgiving? Is it possible
Speaker 1: to get back in? Could I still be a scientist
Speaker 1: if I'm already thirty, or I'm forty or I'm fifty.
Speaker 1: Are their paths back into acting it? Tell us about
Speaker 1: how you forged your path back in academune, because I
Speaker 1: feel like a lot of people think it's very unforgiving
Speaker 1: that once you step off it's impossible to get back.
Speaker 1: Tell us your story about how you decided to come
Speaker 1: back and how you made it work.
Speaker 2: And that's the reason. One of the main reasons I
Speaker 2: wrote this book was for others to know that they
Speaker 2: are not alone, because I felt alone for a long time,
Speaker 2: and I too get these emails from people who are like, yes,
Speaker 2: I've always wanted to do this thing, and I haven't
Speaker 2: known how to put it together with this other thing,
Speaker 2: and you know, and that's such a rewarding aspect of
Speaker 2: having shared my story in this way, because it's like,
Speaker 2: we know the more of us. Shame can't survive in community,
Speaker 2: you know, it only survives in isolation and in the vacuum.
Speaker 2: Once you connect to someone who has your experience or
Speaker 2: this has been my experience, you know, someone who has
Speaker 2: also has some aspect of my journey they share, then
Speaker 2: I'm no longer alone, you know, and there's absolutely a
Speaker 2: path back. It might be a challenging one for me.
Speaker 2: I was gone for over a decade. I say it
Speaker 2: was exactly eleven years, so it was a solar cycle
Speaker 2: that I'd been gone from academia, from astronomy in particular.
Speaker 2: I was in academia but for acting. So I think
Speaker 2: I write that I was. I had been cheating on
Speaker 2: astronomy with acting, and I hope that astronomy would take
Speaker 2: me back. And what I discovered was the biggest obstacle
Speaker 2: was myself. You know, there's no surprise now in retrospect.
Speaker 2: But because people were very warm in this second PhD program,
Speaker 2: and in the first one, in fact, most of the
Speaker 2: people there were very warm too, But the second time around,
Speaker 2: people were asking me about my background, my non traditional background.
Speaker 2: I was the one who was saying, can we talk
Speaker 2: about something else, like, because I, you know, I wanted
Speaker 2: to be taken seriously as a scientist, and I thought
Speaker 2: that my humanities, you know, that sort of stint I
Speaker 2: had done with acting like shouldn't be discussed because people
Speaker 2: might use it as reason to think that I wasn't,
Speaker 2: you know, a serious scientist. But when I had a
Speaker 2: mentor tell me, you know, your theater background is your superpower?
Speaker 2: That changed everything for me because I knew I didn't
Speaker 2: have to pretend that that didn't exist. I could again
Speaker 2: that that owning. I could own it. And then all
Speaker 2: of a sudden, I saw all the aspects about science
Speaker 2: that were, you know, very much applicable, where my acting
Speaker 2: background was super applicable. So it is true that because
Speaker 2: I'd been gone for over ten years, some things I
Speaker 2: had to I felt like I never learned an undergrad
Speaker 2: and so I was learning from the ground up and
Speaker 2: some things I had just forgotten. And so I worked
Speaker 2: really hard, and I had this a monumental case of
Speaker 2: imposter syndrome. And I write a lot about it in
Speaker 2: the book, and several earlier versions. I think I wrote
Speaker 2: so much. I was like, Okay, I got it, Like,
Speaker 2: got to take some stuff out because it's like eventually,
Speaker 2: like we need to have an upward trajectory here, and
Speaker 2: so like it was this trifecta of issues like African
Speaker 2: American woman in a field dominated by white men, older
Speaker 2: returning student. I was thirty four when I came back
Speaker 2: to grad school and classically trained actor, you know, so
Speaker 2: I had three reasons to feel different. But this time
Speaker 2: I did not isolate. I went after every single mentorship
Speaker 2: program that was available, and by this time there were
Speaker 2: a lot more, I think even than back then, and
Speaker 2: I you know, asked the questions that I was afraid
Speaker 2: would make me sound stupid. I went to the office hours,
Speaker 2: you know, because I was older. I actually, here's the thing.
Speaker 2: Being older, there's a big advantage there, which is this
Speaker 2: maturity factor. So like I brought that work experience, that
Speaker 2: real world experience. And I also was more settled in
Speaker 2: myself and who I was when I came back to
Speaker 2: grad school, so I knew I wasn't there to mess around.
Speaker 2: I knew exactly what I wanted to study. It wasn't
Speaker 2: like you know, I'm going to go to grad school
Speaker 2: because that's what you do, and what do I want
Speaker 2: to Like that was the first time. Around this time,
Speaker 2: it was like my husband and I had had left
Speaker 2: very well paying jobs in LA to move up to Seattle.
Speaker 2: So I had to want it bad and I did,
Speaker 2: and that meant, you know, I ended up finishing in
Speaker 2: five years. The normal amount is six. But I was
Speaker 2: I was afraid at every point. I was afraid that
Speaker 2: I was gonna, you know, confirm stereotypes about my race
Speaker 2: and my gender and then I would go get an
Speaker 2: A plus in extraglactic astronomy. You know, I was terrified
Speaker 2: that I was going to fail the qualifying exam, you know,
Speaker 2: that fearful, like god awful six hour exam at the time.
Speaker 2: Now it doesn't exist at U DUBB, but at the
Speaker 2: time it did. And it was a six hour exam
Speaker 2: covering thirteen courses and two years worth of coursework. And
Speaker 2: you know, the two black women who had taken it
Speaker 2: before I took it, you know, years before, had either
Speaker 2: failed and failed out of the program or had needed
Speaker 2: a third time to take it. And so like the
Speaker 2: pressure was like and I kept walking through. So it
Speaker 2: was like to the people out there who were like,
Speaker 2: I have this thing and I'd spent a long time
Speaker 2: and I don't want I'm afraid, Like it's okay to
Speaker 2: be afraid, and you're it's probably good afraid. It means
Speaker 2: you care. So what are you going to do about that?
Speaker 2: You know? We don't want to let the fear keep
Speaker 2: you from moving through, you know. And that's that's the
Speaker 2: thing I did the first time. I let the fear
Speaker 2: kind of paralyze or used it as a justification to
Speaker 2: do something else, which I wouldn't I wouldn't have changed
Speaker 2: for the world. It's how I became who I was,
Speaker 2: and how I met my husband and why we have
Speaker 2: our daughter. Like all these things they work out the
Speaker 2: way they're supposed to. But now moving forward, like we
Speaker 2: don't have to let the fear keep us from doing
Speaker 2: the thing that we're meant to do in the world,
Speaker 2: you know, and recognizing that, like no human being gets
Speaker 2: to tell any of us who we're supposed to be.
Speaker 2: No human being is that powerful. Just like feel the feelings,
Speaker 2: feel the fear, and then do the next next indicated action,
Speaker 2: whether that's fill out the application, you know, ask a
Speaker 2: mentor for a letter like, just keep moving through those
Speaker 2: big emotions. Well.
Speaker 1: One thing that strikes me about the path of your
Speaker 1: life is something I think for many people's lives, for
Speaker 1: my kids, is that it's something you could never have predicted.
Speaker 1: You didn't follow an existing track where you could predict
Speaker 1: exactly what's going to happen. Dot. It's a one of
Speaker 1: a kind life, like many lives are. But I wonder
Speaker 1: what twenty year old you would think if she could
Speaker 1: have seen where you are now. Would you think amazing
Speaker 1: I got to do both or would she think, ooh,
Speaker 1: that was tough. For what would she think about the
Speaker 1: path that your life has taken.
Speaker 2: I think she would be pretty thrilled and surprised too,
Speaker 2: you know. And I think the most surprised or the
Speaker 2: thing that she'd be the most impressed by, is not,
Speaker 2: you know, the stuff on the resume, but that we
Speaker 2: got to find I'm saying we, me and her, we
Speaker 2: got to find a way through the difficult feelings because
Speaker 2: twenty year old me got stuck in them a lot
Speaker 2: and thought that they were the truth, or thought that
Speaker 2: the truth lay somewhere out there and someone else, a professor,
Speaker 2: a guidance counsel, or another student who performed better on
Speaker 2: that test than I did. I thought that the truth
Speaker 2: was someone else's job. And what I've learned is that
Speaker 2: the answers are usually right here. And you know, it
Speaker 2: may sound a little cheesy, but it's absolutely the case.
Speaker 2: And I still have to remind myself of that. I'm
Speaker 2: not always going to remember like, oh yeah, yeah, it's
Speaker 2: I already know what I'm being led to do. But
Speaker 2: I think that she'd be the most kind of relieved that,
Speaker 2: like a you know, finally we figured this out, like,
Speaker 2: because when the answers are somewhere out there, it's like
Speaker 2: there's no way to be steady. I'm for those listening,
Speaker 2: I'm like moving back and forth like a weather vane.
Speaker 2: But when the truth is here, then I can be grounded.
Speaker 2: I like to be influenced by a lot of different
Speaker 2: philosophies beyond the practice of science, you know, in terms
Speaker 2: of like especially some Buddhist stuff, you know, And that's
Speaker 2: this idea of like being mountain solid, that I can
Speaker 2: be solid in myself no matter and mountains all sorts
Speaker 2: of weather. You see it in the mountain ranges, and
Speaker 2: yet the mountain is the mountain, and like that that's
Speaker 2: how I can be in my life. I think that's
Speaker 2: the biggest victory really beyond any material wealth or achievement,
Speaker 2: is being comfortable in my own skin and knowing that,
Speaker 2: regardless of how things turn out, like, I'm okay, wonderful.
Speaker 1: Well, now I just want to ask you for a
Speaker 1: few minutes about the future. Obviously we're on the cusp
Speaker 1: of understanding a lot of things about the universe. Where
Speaker 1: do you see exoplanet research in ten years, in twenty years?
Speaker 1: Is it impossible to predict because there are so many
Speaker 1: surprises ahead. What are we going to learn in ten
Speaker 1: or fifteen years? It's going to blow our minds?
Speaker 2: Well, I mean, you know, it's impossible for us as
Speaker 2: scientists to really make predictions, or at least make predictions
Speaker 2: with very much, very much of a high percentage of confidence.
Speaker 2: But I have a belief. Okay, So I'm going to
Speaker 2: say right up front, this is a belief. This is
Speaker 2: not grounded in any kind of fact. I need evidence
Speaker 2: for that, and I don't have it. But knowing what
Speaker 2: I know about our capabilities and our current instrumentation, I
Speaker 2: think we're going to get a lot of exciting information
Speaker 2: in the next fifty years. I think some of that
Speaker 2: information could include an answer to this question. I've said
Speaker 2: something recently that I want to share here, which is,
Speaker 2: you know, think about the Apollo missions. We had a
Speaker 2: president at the time who gave us a mandate, which
Speaker 2: is to put a human He said man at the time,
Speaker 2: a man on the Moon by the end of the decade.
Speaker 2: And we did that. And we did that, and I
Speaker 2: think you've heard me say this before, but we did
Speaker 2: that with only a fraction of the world's population at
Speaker 2: the table allowed to participate at the table. And what
Speaker 2: I mean by that was, you know, the mission control
Speaker 2: was largely dominated in terms of gender and race. So
Speaker 2: what would it be like for someone, perhaps the president
Speaker 2: of some country, whether it's ours or another country, to say,
Speaker 2: we are going to not only put a human on
Speaker 2: the we're going to actually answer this question, maybe even
Speaker 2: put a human on another planet. But let's start with
Speaker 2: answering the question of are we alone. We're going to
Speaker 2: answer that question, whether it's by twenty seventy five or
Speaker 2: twenty one hundred, we're going to do this by this time.
Speaker 2: And we allowed every single person to be a part
Speaker 2: of this journey, regardless of their academic status, regardless of
Speaker 2: their race, their gender, whether they identify as any kind
Speaker 2: of gender, like age. You know, My Rising Stargirls program
Speaker 2: allows girls of all colors and backgrounds in the middle
Speaker 2: school age to create their own NASA inspired depictions of
Speaker 2: exoplanet environments. You know. So they're making their own artists
Speaker 2: depictions in the same way that NASA artists do, and
Speaker 2: some of their exoplanet art environments are environments that we
Speaker 2: could actually see out there, and they're making choices about
Speaker 2: what kind of you know, what kind of vegetation might
Speaker 2: be there. You know, just because they don't have that
Speaker 2: necessarily the academic status yet to be able to contribute
Speaker 2: in a quantifiable way to write a paper, does not
Speaker 2: mean that they don't possess the amount of imagination that
Speaker 2: could actually be quite inspirational in this effort. So I
Speaker 2: think it's important to expand or idea of who gets
Speaker 2: to participate, and we do that to some degree with
Speaker 2: citizen science projects. But I think we can learn a
Speaker 2: lot more about the universe if we invite a lot
Speaker 2: more people to be a part of it.
Speaker 1: Well. That leads directly to my second question, which is
Speaker 1: how do we do that how do we create more
Speaker 1: paths for creative students, students that have artistic background, students
Speaker 1: that have unusual paths, students that are not just white dudes.
Speaker 1: What do we do to open up this institution to
Speaker 1: make it easier for people like you coming in the future.
Speaker 2: You know what, I want to say that that is
Speaker 2: probably not my job to answer that question. I think
Speaker 2: it might be the job of the people who are
Speaker 2: in the dominant category. And the same way that you know,
Speaker 2: when we had our Black Lives Matter resurgence in the
Speaker 2: twenty and twenty twenty, I was grateful that UCI was
Speaker 2: one of I won't say few, but it was an
Speaker 2: institution that recognized that it wasn't the job of black people,
Speaker 2: whether faculty, your students, to devise ways to allow black
Speaker 2: people to thrive and institutions that the fact is that
Speaker 2: a lot of us carry a big burden just to
Speaker 2: be in the instant environments that we're in and to
Speaker 2: ask us to shoulder the you know, the burden of
Speaker 2: how do we get more diversity? Here is another burden
Speaker 2: and another example of how we have less time to
Speaker 2: do the actual work that we need to be able
Speaker 2: to stay in these institutions. What I will say is
Speaker 2: that having a progressive viewpoint and showing that progressive viewpoint
Speaker 2: to interested students is a start. So University of Washington,
Speaker 2: when I was a prospective student, one of the reasons
Speaker 2: why I wanted to come there is because they had
Speaker 2: a broader idea of who a grad student can be.
Speaker 2: They had people students there who had gone into the
Speaker 2: Peace Corps before coming back to grad school. One student
Speaker 2: had gone to pastry school, And so I thought, maybe
Speaker 2: I'm not as much of a rare magical unicorn as
Speaker 2: I think I am. You know, so the more we
Speaker 2: can maybe highlight those sorts of paths, the more people
Speaker 2: might be gravitate to our departments and say, Okay, there's
Speaker 2: a place for me here. Role models are powerful, and
Speaker 2: a lack of role models is a powerful thing too.
Speaker 1: Thank you one. Thank you for being a role model
Speaker 1: for the future, and thanks for coming on the podcast
Speaker 1: to talk about your science and your story and for
Speaker 1: doing it with such eloquance and such Kinder, thanks very.
Speaker 2: Much, Thanks so much for having me. It's been a
Speaker 2: real pleasure to talk with you.
Speaker 1: That was my conversation with Professor Almawah Shields her book
Speaker 1: Life on Other Planets is a fantastic read, not just
Speaker 1: for the science, but also for her fascinating story of
Speaker 1: an unusual path into act. I hope you all find
Speaker 1: it inspiring. Thanks very much for listening. Thanks for listening,
Speaker 1: and remember that Daniel and Jorge explain the Universe. Is
Speaker 1: a production of iHeartRadio. For more podcasts from iHeartRadio, visit
Speaker 1: the iHeartRadio app, Apple Podcasts, or wherever you listen to
Speaker 1: your favorite shows.