Pondering Distant Suns with Munazza Alam

HMSC Connects! Podcast, Episode 6
SPEAKERS Munazza Alam, Jennifer Berglund 

Jennifer Berglund 00:04
 Welcome to HMSC Connects! where we go behind the scenes of four Harvard museums to explore the connections between us, our big, beautiful world, and even what lies beyond. My name is Jennifer Berglund, part of the exhibits team here at the Harvard Museums of Science and Culture. And I'll be your host. This Saturday is a very important day, the summer solstice, the longest day of the year. It's a celebration of the thing we literally cannot live without. It's the thing that makes life possible, and summer days delightful. It's our very own star, the Sun. But our sun isn't the only star in the sky, and not even close to the brightest. Today, I'm speaking with Munazza Alam, a PhD student at the Harvard- Smithsonian Center for Astrophysics, as well as a National Geographic Young Explorer. She calls herself an exoplanetiere, because she studies the atmospheres of exoplanets, or planets outside of our solar system. But get this. She does it using the light of their suns using data from the Hubble Telescope. Munazza Alam, welcome! 

Munazza Alam 01:38 
Thank you so much for having me. It's great to be here. 

Jennifer Berglund 01:46
 Give me a brief overview of who you are and what you do. 

Munazza Alam 01:53 
I like to think of myself as studying the weather on other worlds. So I study the atmospheres of exoplanets, and our observations and our analyses kind of tell us about the clouds and the hazes and what the atmospheres are made of. It kind of reminds me of the forecasts that we hear on the on the news when we try to figure out the weather for the next day. And so my research is a little bit like figuring out the forecast on these faraway worlds. From my work studying the atmospheres of these distant worlds, it has proven to me that nature is the ultimate creative mastermind, because, in particular, the planets that I study don't have any solar system analogues, meaning there's nothing like them in our own solar system. So the planets that I studied in particular are called Hot Jupiters, and they're called that because they are similar to our own solar systems' Jupiter in terms of their their composition and their makeup. They are gas giant planets, but they're so close to their stars, that they're very hot. And when I say that they're close to their host stars, I mean that, in some cases, a year on these planets could be a day or two or even less than a day in some cases. 

Jennifer Berglund 03:07 Whoa, that's crazy. 

Munazza Alam 03:08 Yeah. And so because of these kind of intense and extreme conditions of being super hot and being blasted by this radiation from their stars, the chemistry and the physics of what happens in the atmospheres of these planets is also extreme or intense. And so we end up with atmospheres on these planets that are very exotic. We've discovered, for example, planets that have clouds that are made up of corundum, which forms rubies and sapphires. And so when it rains on this planet, the raindrops are ruby raindrops. We've also discovered planet.

Jennifer Berglund 03:41 That's insane. 

Munazza Alam 03:42 
Yeah, it's crazy to think about. We've also discovered planets that are so dark, they're considered charcoal black, and we've also found a planet that is very hot and when it rains out silicates from its clouds, their raindrops are essentially raindrops of molten glass. 

Jennifer Berglund 04:00 Oh my God. 

Munazza Alam 04:01 
It's really wild to think about because these sound like fictional science fiction worlds. 

Jennifer Berglund 04:06 Absolutely. 

Munazza Alam 04:07 
But they exist within our own galaxy. 

Jennifer Berglund 04:13 
So when you study these Hot Jupiters, you have to study them in the context of their suns, right? 

Munazza Alam 04:20 
So because these planets are orbiting these very bright stars, we can't actually see them directly. It's kind of like trying to look at a firefly next to a bright lamp. So, in dark sky, if you just see a firefly by itself, you can see it glowing very brightly. But next to a brighter source of light, it'll be difficult to discern the firefly. And so similarly, because these planets are orbiting stars that are much brighter than them, we can't actually directly see and observe these planets. And so we have to kind of infer the presence of these planets, and kind of what's going on these planets in their atmospheres indirectly. And so we use these combined light techniques--cmbined star and planet light techniques. And in particular, the technique that I use to detect and to characterize exoplanet atmospheres relies on observing planets when they transit or pass in front of their host stars. So from our vantage point on Earth, what we'll see is a dip in the starlight corresponding to when the planet is in front of the star. And that's because when a planet transits, it's going to block out a fraction of the starlight proportional to the size of the planet, it's kind of like the the planet is casting a shadow on the planet. Then depending on what wavelength or color of light that we're looking at, the planet's atmosphere, if it has one, can appear more or less opaque. At wavelengths where the atmosphere is more opaque, the planet will appear larger. And that's because that is where absorption by atoms and molecules that are present in the planet's atmosphere will occur. So we can actually figure out what the planet's hemisphere is made of by observing the size of the planet at different wavelengths, and from these observations, we can infer what atoms and molecules make up a planet's atmosphere. And also, if there are any clouds and hazes on the planet. 

Jennifer Berglund 06:12
 That's amazing that you can tell all of that just from what is basically, would it be correct to say an atmospheric sort of silhouette? 

Munazza Alam 06:20 
Yeah, he's kind of like a silhouette because the, essentially, we are gleaning all this information about what the atmosphere is made of, and kind of what chemistry and physics is going on in these atmospheres, by filtering starlight through the atmosphere. It's not it's an indirect detection. So yeah, it kind of is like a silhouette. 

Jennifer Berglund 06:39 
If some sort of distant alien colony in another solar system were studying our atmosphere in the same way, what would they see? And why? 

Munazza Alam 06:50 
Oh, that's, that's an interesting question. So I will say this, depending on how advanced this alien colonies telescopes are, they may or may not be able to detect anything. So the best case scenario involves the biggest planets around the brightest stars with the puffiest kind of extended atmospheres. Those are the kind of best conditions for us to get the highest quality data, to get the most precise kind of constraints on what the planet's atmosphere is made of. But in that instance, there 

Jennifer Berglund 07:22 
So were basically two puny is what you're saying. 

Munazza Alam 07:25 
Yeah, exactly. Because in the best case scenario, the the size of what bumps and wiggles that we'll see if we split the light of the planet's atmosphere in the way that I described using that technique, the best case scenario for a large planet orbiting a bright star with an extended atmosphere, puffy atmosphere, is a 10th of a percent. 

Jennifer Berglund 07:44 Oh, wow. 

Munazza Alam 07:46
 So it's like a very, very small signal that we're looking for. And if you go down to smaller-sized planets, like something Earth sized, that number, that 10th of a percent, is going to drop by a factor of three or four orders of magnitude. 

Jennifer Berglund 08:02 
Well, then what about our Jupiter? Is it too far away? 

Munazza Alam 08:06 
Yes. And so our Jupiter's too far away. It would also be difficult to observe in this way because we have to wait for it to pass in front of its star, or if the alien civilization missed it, for example, then it would they would have to wait quite a while for it to come back around. We say that these are like periodic observations. And so the closer in to the star that the planet is, the more opportunities we have to observe it passing in front of its star.

Jennifer Berglund 08:32
 Oh, okay. Okay, this is all so fascinating. So what's the closest hot Jupiter to us that you study? 

Munazza Alam 08:41
 The closest hot Jupiters that I studied to us are like 10s of light years away. So still pretty far. 

Jennifer Berglund 08:49 
In looking at the atmospheres of these distant planets, are you trying to see if they're habitable? 

Munazza Alam 08:57
 So habitability is one of the long term goals of kind of studying exoplanet atmospheres. But we're not quite there just yet in terms of the instruments and telescopes that we have. We have some upcoming facilities that will be able to see at wavelengths that are sensitive to absorption by what we call the biosignatures, or fingerprints of life. And that will help us, or begin to help us, address these questions of habitability on these distant worlds. But at the same time, even if we see evidence of these biosignatures, these fingerprints of life, that's not a definitive answer as to whether or not there is life on those planets, because geological processes or other things going on those planets could also change the composition of the atmosphere such that we are detecting these atoms or molecules. And also, it's possible, I mean, we've seen just with the first types of planets that we've found outside of the solar system, these hot Jupiters, we didn't have anything like that in our solar system. Prior to the discovery of the first exoplanet, the first hot Jupiter, we wouldn't have even fathomed that such a planet could exist. And so it's possible that that the lifeforms that exist outside of the solar system, if they do exist, are very different from anything we can fathom, and so our idea of what are these biosignatures, these fingerprints of life, and kind of what it means for a planet to be habitable is very much shaped by carbon-based life forms, and life on Earth. 

Jennifer Berglund 10:23 The life we know. 

Munazza Alam 10:25
 The life that we know. Exactly. And so it's possible that the life that is out there is very different, very, very different from the life that we know. I said it before, nature is the ultimate creative mastermind, and so, yeah, it's possible that that what's out there is beyond what we can imagine. 

 Jennifer Berglund 10:46 
Do you think life exists out there? 

Munazza Alam 10:50 I do. I like to think so. 

Jennifer Berglund 10:54 
I'd like to think that we're not alone either. Even if that life is microbial, or some sort of equivalent. 

Munazza Alam 11:01
 Yes. Even if it's microbial life. Yeah, I'd like to think that we're not alone. 

Jennifer Berglund 11:07 
So basically your work, it's sort of laying the early groundwork for investigating ways in which to study planets that could host life as we understand it. 

Munazza Alam 11:17 
Yeah, it is definitely laying the groundwork. It's perfecting the techniques for being able to do that. And I also think in its most fundamental form, my work is important for contextualizing our place in our planet within the planets that exist in our galaxy and in the universe. 

Jennifer Berglund 11:35 
Were you always an admirer of the stars? 

Munazza Alam 11:39 
I was definitely a dorky kid. I was interested in fossils and dinosaurs, but I wasn't, I wasn't interested in astronomy and space as a kid. So growing up, I grew up in New York City, and so growing up, I didn't really see much of the stars, and I didn't have a backyard telescope. You know, growing up, I could only see a handful of stars at a time at best. So, we didn't have a backyard telescope. I wasn't one of those kids that watched space movies? I say that I found astronomy later in life when I was actually a college student. 

Jennifer Berglund 12:06 
Yes. And you're so advanced in your years. How old are you? 

Munazza Alam 12:10
 I'm 26 years old. But growing up, I was always a curious kid. I think my my parents said that the question I asked most frequently was "why?" And they said that sometimes it's very aggravating for me to always just be like, "why, why why?" But I think that curiosity really kind of did help me in terms of school. I was always interested in math and science because I liked the fact that those subjects helped me scratch that itch. Those subjects really helped me kind of get the answers to to the whys. And so, in particular, I found that I really enjoyed my high school physics class that I took in 11th grade. I enjoyed the material. I liked the idea of critical thinking and problem solving. I found that it was challenging, but that I was good at it. And my teacher was absolutely inspiring to me. She was very encouraging to all of her students in the class, and she was also the first woman that I knew who had a PhD in physics, and so after taking her classes, I knew that I wanted to study physics, to major in physics and undergrad. I went to undergrad at Hunter College in New York City, and that's where I connected with an astronomer who was running a research group in the astrophysics department at the American Museum of Natural History. 

Jennifer Berglund 13:30 That's amazing. 

Munazza Alam 13:31
 Yeah, it was really neat. And so I kind of started off the summer before my first semester of undergrad, so it was like the summer after high school. So I started off that summer kind of just hanging out with the more advanced undergrads who are doing research and attending seminars, and colloquia. I started off kind of being a part of the research community without actually contributing, but I loved listening to people talk about their research because I was engaging with people who were asking questions that no one knew the answer to. And I really like that idea, like, to me research very much seemed like working on a jigsaw puzzle where everyone's kind of working on trying to fit one piece of the puzzle in with the other pieces that we know. But we don't have the box. And so, it really takes teamwork and effort to kind of work together to see how the pieces fit together and what the big picture looks like. 

Jennifer Berglund 14:25 
Yeah, and the other thing about it is you don't have to be afraid to be wrong. 

Munazza Alam 14:29 
Yeah, like that's the difference between homework versus research. In homework, there's a solution set that will come out, and like one answer to one problem. And research is multifaceted. There's so many different angles to consider, and there's room for everyone to kind of bring their skillset to the table. What particularly drew me to astronomy was the fact that I could talk about astronomy with others, even if they weren't astronomers. And that's because it's fundamentally human, for us to be awe-inspired by the cosmos. And I found this accessibility of astronomy has particularly renewed my love for it over and over and over again. I've talked about my research with children in in grade schools, I've talked about my research with the general public. I've talked about my research to adults who are perhaps not scientists. And every time I have discussed my research inside of such a setting, I have been met with the same reaction of excitement and fascination and awe. And that's because it is the core of our human nature to look up at the stars and contemplate the cosmos. In particular, I found that exoplanets are really exciting to me because this question of 'are we are alone?' This ultimate question about whether or not life exists outside the universe, and what are the other worlds like out there? Has been a question that has been asked throughout history, throughout cultures, by some of the greatest thinkers, by everyday humans. I feel like, in some respects, I'm applying new techniques to an age old question. 

Jennifer Berglund 16:18 This week is Solstice week, our summer solstice, the longest day of the year, peak of summer. In studying Hot Jupiters, and their Suns, or studying them through their Suns, essentially, or the Suns through them, I guess would be the better way to say it. How have you grown to appreciate our own Sun as a star among an infinite number of stars in the universe? 

Munazza Alam 16:45 
This is a really interesting question because it actually reminds me of something that Giordano Bruno, who was a 16th century Italian thinker, wrote. He wrote, "there are countless suns and countless Earths all rotating around thir suns in exactly the same way as the planets of our system. The countless worlds are no worse and no less inhabited than our own Earth." And so these were his musings on this idea of, "are we alone?" And they highlight that our sun isn't anything particularly special, so perhaps life on Earth isn't either. And I think this is a really interesting mindset because I spend my days thinking about length scales and timescales and distances that are, quite literally, larger than life. W e're talking astronomical timescales and lengthscales and distances. And compared to astronomical timescales, for example, our human existence is nothing. But then, when I think about the span of a lifetime, and the experiences that I have in my, in my life, and that the experiences that we have in our lifetimes, all the days that pass us by, all the days that make up our lives, that's everything to us. And I think what's really special about that is looking at these larger than life, these literal astronomical scales, and just having those large distances and timescales remind us how meaningful our day to day experiences are. 

Jennifer Berglund 18:16 
Do you think we're special? And what do you think makes us special? 

Munazza Alam 18:20 
I think one of the things that makes us and life on Earth so special is the unique advances that we've made as humanity. I think about the catalogue of culture and poetry and music that has existed in our human history. And I think about the thoughts that people have had, the greatest thinkers, and those thoughts, and those ideas of thinking, and that art has all come about through a collective experience on a particular planet, and we can't recreate that in another planet with different conditions with different life forms. I mean, even if we look at like science fiction worlds and movies, and kind of those, that world building in a science fiction kind of framework, it's so different from the history of what we have on Earth. And I think that it's only natural for a planet with a different history and different kind of legacy to have a different flavor, to have a different kind of outlook. And I think it goes back to kind of like on the timescales of a lifetime, our everyday is very meaningful. 

Jennifer Berglund 19:31 
On the day of solstice, which is June 20, which I believe is a Saturday this year, as an astronomer who thinks about distant planets that are so different from our own and distant suns. Is there anything in particular that you are going to reflect on, or that you would encourage other people to reflect on? 

Munazza Alam 19:52 
Yeah, I'm just thinking about. I've been I've been speaking to a lot of close friends and family and reading in the news, and just thinking about what's going on in the world right now. We have a literal pandemic that has uprooted a lot of people's routines and fundamentally changed their everyday lives. But then we've also got a lot of unrest, and a lot of unfair and unjust things happening in the world. I will particularly be reflecting on the power of the human race, which, for centuries, has been sequestered to a small group of people, and how those with power and privilege, myself included, can use our voices to speak out and speak up for, and allow other people whose voices have been silenced to be heard. 

Jennifer Berglund 20:42 
Because we are one planet. We are one planet revolving around the Sun. 

Munazza Alam 20:48 
And it's the same planet, the same sky, the same Sun that we look at, everyone in human history has looked at. 

Jennifer Berglund 20:58 
Munazza Alam, it's been an absolute pleasure having you. I hope we get to see more of you at the Museums. 

Munazza Alam 21:05 
Thanks so much. It was great talking with you. 

Jennifer Berglund 21:15 
Today's HMSC Connects! Podcast was produced by me, Jennifer Berglund, and the Harvard Museums of Science and Culture. Special thanks to Munazza Alam for her wisdom and expertise. And thank you so much for listening. Before we go though, one quick thing. In normal years the HMSC usually throws a major party for the summer solstice. But in the interest of adhering to social distancing guidelines, we've moved this year's celebration online. That means everyone around the world can join us. So tell all your friends! There's a lot going on. So please check out hmsc.harvard.edu/summer-solstice to RSVP and see a listing of programs. And of course, if you liked today's podcast, please subscribe on Apple Podcasts, Spotify, Podbean, or wherever you get your podcasts. See you next week! 
Transcribed by https://otter.ai