Planetary Radio: Space Exploration, Astronomy and Science - A Cosmic Odyssey: Decades of Discovery at the Palomar Observatory

Episode Date: February 3, 2021

Astronomer Linda Schweizer spent countless hours interviewing the explorers who revolutionized astronomy through observations made at California’s Palomar Observatory. She tells their fascinating stories and shares their science in her new book Cosmic Odyssey: How Intrepid Astronomers at Palomar Observatory Changed our View of the Universe. Attention space poets! You might win a Planetfest ’21 t-shirt as Mat and Bruce invite your best efforts in the new What’s Up contest. Hey, it could be verse! There’s more to discover, including a link to Planetfest ’21, at https://www.planetary.org/planetary-radio/0203-2021-linda-schweizer-cosmic-odysseySee omnystudio.com/listener for privacy information.See omnystudio.com/listener for privacy information.

The Cosmic Odyssey of Discovery at Palomar Observatory, this week on Planetary Radio. Welcome, I'm Matt Kaplan of the Planetary Society, with more of the human adventure across our solar system and beyond. Cosmic Odyssey, how intrepid astronomers at Palomar Observatory Changed Our View of the Universe. That's the new book by astronomer Linda Schweitzer. It documents how George Ellery Hale's crowning achievement, including the 200-inch Hale telescope, changed our view of everything from our own solar system to the outer reaches of the cosmos. Linda joins me today for a fascinating conversation.

Get your quills out. Bruce Betts wants your poems about spacecraft at or arriving at Mars. Five of you will get the new PlanetFest21 t-shirt for your troubles. PlanetFest is almost upon us. Our virtual celebration of the Perseverance rover, the United Arab Emirates Hope Orbiter, and China's Tianwen-1 begins on Saturday, February 13. Details are at planetary.org slash planfs21. Readers of The Downlink, our free weekly newsletter, know that the Red Planet isn't having all the fun in the neighborhood. We learned last week that NASA's OSIRIS-REx probe will leave Bennu for Earth on May 10th. That will give the spacecraft one more flyby of the asteroid. Astronauts completed yet another spacewalk outside the International Space Station.

Did you know the ISS will soon be getting upgraded solar panels? The originals are starting to show their age. We also learned that NASA's TESS and the European Space Agency's CHEOPS spacecraft have discovered a distant solar system with five planets locked in a dance that makes them align now and then, which must be some kind of holiday for anybody living there, wouldn't you think? You can find much more at planetary.org

slash downlink. Linda Schweitzer says she fell early and hard for the stars. That love affair would lead her to a Ph.D. in astronomy from UC Berkeley, observations made at three observatories in Chile, where she lived for a while, and research published in the Astrophysical Journal. Her favorite job, though, was teaching science writing at Caltech, which happens to be the operating entity for the Palomar Observatory, not quite 200 kilometers southeast of the university. Long-time listeners know of my long-time love of Palomar. Linda feels the same way.

She also loves the stunning and revolutionary science that has flowed from the collection of telescopes on the mountain. Now she has captured the stories and the humans behind that science in Cosmic Odyssey, published by the MIT Press. Linda and I talked a few days ago. Linda, welcome to Planetary Radio. It is a pleasure to have you on and an even greater pleasure to have read this book, Cosmic Odyssey. Thank you for joining us. I'm very happy to participate. Thank you for inviting me. I'm excited. Let me just read a paragraph that shows up early in the book, because I think it sets the theme for the book, both in terms of your approach to your topic and the style in which your tales are told. Just as Mount Wilson astronomer Edwin Hubble opened up the boundaries of the universe in the 1920s,

so astronomers at Palomar wrote and rewrote the textbooks of astronomy in the mid to late 20th century. Through the big eye, the world encountered quasars, if you prefer, and super massive black holes, understood the chemistry that turns stardust into life, and pressed the limits of the known universe relentlessly outward. That is some lovely prose. Thank you. Well, my purpose in writing the book was to restrict the stories to the science. So I presented the more basic material in the first chapters, and then I followed threads of discovery, some of them from pre-Palomar all the way to today. I tried to provide context for the discoveries, and I showed the broad data and first images. I conducted several hundred hours of interviews, and I had to navigate some serious

egos to get the real story here. And curiously, while writing, I became attached to many of the characters. So I vicariously lived through their epiphany and uncertainty. I would wake up in the middle of the night trying to work out kinks in the storyline, sometimes I felt like I was writing a novel, even though it was about science. But science is novelesque. And you do have some marvelous characters in this book. While it is largely about the science, as you've said, there are just some wonderful men and women, as we will talk about, who are part of this history. There was a reference in that paragraph to the big eye. And while it is not the only telescope at Palomar, it is certainly the one that has gotten

the most attention, the most good press over the years. Which one are we talking about here? So we're talking about the 200-inch telescope, which was the largest telescope in the world for something like 45 years, twice as large as the Mount Wilson 100-inch. You could see twice as far into the universe, and everybody was just incredibly excited about it. You also mentioned up front that others have written histories of the Palomar Observatory itself

and George Ellery Hale, the man who was responsible for it and previously the three previous largest telescopes on Earth. Your purpose really was something else, and you've started to address that. But again, what were you trying to document here? Well, no one has yet written a book about the comprehensive scientific history of Palomar. They've written about the construction and some science, and then there are bits and pieces of the science in various other works. And sometimes the discoveries made at Palomar

are not even attributed to Palomar. It's like everybody forgot about Palomar once bigger telescopes came out. So this is a forgotten but very important history of 20th century astronomy. And that is abundantly clear as you read the stories in this book. And I do think of them as stories, detective stories, really. Sometimes they thread back 10, 20, 50 years across continents to other teams and telescopes. It's a quote, actually, to retrieve a relevant clue, as you say in the book. Do you think of these as sort of cosmic detective stories? Yes, and that's because real-life research is a detective story. I mean, you're just naming what is, and that's an important concept for me to portray with the agony and ecstasy that goes

along with it. For example, radio astronomers and optical astronomers collaborated for years at Palomar to identify strange radio sources. So you had people from different continents and different wavelength regions collaborating over many, many years. That's probably, it's a very long thread, in fact. And since the Palomar Observatory Sky Survey images, known as the POS, were shared with an international community. Others had a chance to explore and discover. It was very generous of Palomar to share those. One Russian astronomer who had subpar data, he had photocopies, Xeroxes at the time, of these survey images. But lots of determination contradicted.

Alan Sandage just claimed that all Type I supernovae reach the same maximum brightness. It turns out that he won, he was right, and Sandage was wrong. So there was a lot of work done over, as I said, many continents and over many decades, collaborations. survey that you mentioned and others that followed it, how much do they represent essentially the foundation of a lot of the other work that you document? I think you could say that basically we're blind without such survey telescopes like the Schmitz. They produce a roadmap with which we can visually identify sources discovered at other wavelengths. We can find transient objects. We can survey and just find what is out there so that the big eye can find it. So the Schmitts were used to photograph and identify radio sources, gamma ray sources. They allowed astronomers to compile catalogs of stellar data,

interacting galaxies, galaxy clusters, quasars, etc. And one of the longest threads involves the supernovae that I just mentioned. They'd been discovered in Andromeda in 1885, the first one. And yet there were very few studies of supernova until the Schmidt cameras. So for a long time, Vicky was a record holder of supernova discoveries. I think he got up to 120 of them. And now there are soon to be over 10,000 found per year. Wow.

Yeah. So they're pretty fundamental. And that's Fritz Zwicky, of course, who, well, we're going to bring him up again in a minute. But you also need to say more. You've referred to the Schmitz, the Schmitt cameras. And not everybody out there is going to know what we're talking about. I'm lucky enough to own a Schmitt, a Schmitt-Cassegrain, but I didn't know the story behind the Schmitt who came up with this system of optics. Why are these two other, quite a bit smaller telescopes at Palomar up there?

They share the mountain with the Hale, the 200-inch. They have been very, very important. And they weren't planned from the beginning because nobody knew about them. It wasn't until Walter Bada, who was friends with Bernhard Voldemar Schmidt when he worked in Germany, heard from his old friend that he had been able to solve a major problem in astronomy, that he had been able to solve a major problem in astronomy, which is being able to achieve good focus and clarity out to the very edge of a field of view. And Bada found this out in, I think it was about 1934,

that 200-inch was still under construction. The design was brought to Palomar, and the decision was made with money from the Rockefeller Foundation to build a small one, like kind of a test Schmidt, 18-inch test Schmidt. And Zwicky took that on, and he was the sole sentinel on Palomar observing with this Schmidt for 12 years before the 200-inch came aboard. It was so successful that they decided to build the 48-inch that would be more closely matched to the 200-inch in terms of

being able to be the scout for that telescope. And that's the relationship, isn't it? It's one has this wide view and therefore sort of is the scout, as you say, and then the 200-inch and now, of course, other telescopes even larger can sort of zoom in. Is that fair? can sort of zoom in. Is that fair? The other telescopes, yes, they zoom in. They have a much, the 200-inch has a very tiny field of view. I mean, it's like looking through a keyhole at the universe. So it can see very long and far out into the universe. But if you wanted to cover the whole sky, it would take several human lifetimes to do so, whereas the Schmitz can cover it very quickly. Before we go on to talking about the science, which as we said, is really the core of this book, we have to talk a little bit more about Palomar because like you,

I think of Palomar, and I've said this before on the show, as sort of a shrine of science. I have climbed that catwalk up to the prime focus cage, way up there near the top of the dome. My colleague, Bruce Betts, who we'll be hearing from in a few minutes as part of What's Up, he observed from it as a grad student. He tells a literally bone-chilling story about the hazing he received there on his first night because nobody told him that you had to dress warmly to sit up there in the so-called cage. Do you feel the same kind of awe that I feel and so many feel when they visit and go inside that dome? Oh, absolutely. Every time I go up there, I always spend quite a bit of time standing inside the dome. All the lights are out. The slit is open. The telescope is rearing

their tiny red lights occasionally. And I just stand there and I just admire and I just feel the magnificence of this installation. It's a really spiritual connection. And I think that many people who observe there have it. From all my interviews, everybody just loves going there. In fact, I've been told it's their favorite observatory to observe at. You document some of these stories. You quote some of the people that you, thank goodness, were able to interview before we lost them, who talk about that experience of sitting up there. Who was it that had this transcendent experience that you mentioned in the book because he felt like he was alone in the universe? That was Martin Schmidt.

He was one of my favorite interviewees. Everyone who I knew had observed in the prime focus cage, I asked, what did you think? I know what you did up there. I read your papers. But what did you think about and how did you think? I know what you did up there. I read your papers. But what did you think about? And how did you feel? He was very open with me about his feelings. And he described his experience up there. And it was almost mystical. Yeah. There's another quote. I'll read this from Alan Sandage, who I think you spent quite a bit of time with. And he comes up

over and over in the book. He gave you this wonderful quote, during the period of explosive discovery at Palomar that lasted from 1950 to 1965, I was psychologically in a different world, part of something fundamentally magnificent that was so much bigger than everyday life. It's the way I suppose religious people would describe some sort of a revelation they have had, some sort of epiphany. It's never happened to me in religion, but it certainly did occur for 15 years straight in my research. Everything was opening, and it was like picking flowers in so many fantastic gardens. You weren't the only one who could come up with great prose in this book. Oh, Sandys was a fantastic writer. He was a voracious reader. But even though we were old friends, I had to ask him three times for an

interview before he agreed. Once he did, the first interview lasted six hours, interrupted with a lunch with Manhattans, which was his favorite drink. But I always heard stories. And the interviews would often open with a discussion of the book he had just finished reading. So he's quite well read. And he was incredibly passionate about astronomy. He was Edwin Hubble's assistant at the 200-inch when he was still a grad student, speaking of grad students. But he was the first and the only for quite a period of time,

a grad student to be able to observe with the 200 inch. He worked on several groundbreaking projects, including measuring the expansion rate of the universe. And his favorite was understanding how stars evolve. He proposed the first model of how our galaxy itself formed and evolved. And then he finished Edwin Hubble's Atlas of Galaxy. He was in the quasar game for a while, and he discovered a new class of objects. He received a lot of bites on the 200-inch telescope, like the telescope. He was relentless and tireless in his pursuit of his programs. Some of these characters are going to continue to come up, like I said, Fritz Zwicky, I'm sure. But let's turn more now toward the science, these tales that you tell, these detective stories.

our knowledge or revealed entirely new and studying objects, as you've already mentioned. We're not going to be able to cover everything, of course, but I'm hoping that we can talk about at least a couple, maybe more. And one of them is the strong, not just an impression I got, but the documentation you provide for the fact that Palomar and the astronomers who used it really expanded the universe. They kept making this place where we live bigger, didn't they? To make a joke, the universe was expanding long before there were humans to appreciate that. True enough. So the volume, you might say it is the volume of the known universe was enormously increased by discoveries from Palomar. And this was done through various standard candles, such as

cepheid stars and various types of supernovae, and more recently, superluminous supernovae. And these standard candles, I'm glad you mentioned them, these cosmological milestones. Can you talk about why it was that they were so important for finding our way around and seeing just how big the universe was, is? They are crucial. The sky appears two-dimensional to the human eye, but it's our smarts that must learn to distinguish between apparent and intrinsic attributes, such as size and color and distance and chemical composition, environment, motion, things like that.

So, for example, you might ask, is an object blue because it's hot or because the molecular structure of its surface absorbs red light? And you have to use standard CANZELs to find distances so that you can study objects with their appropriate size, temperature, etc. Otherwise, you're just seeing a screen full of colored dots and you don't know anything about them. And take into account Doppler, of course, right? The famous redshift. Yes, that's part of it.

Hmm. I think of how the work to find these milestones and make sure that they were reliable standard candles, so-called, is a big part of the book. And there's even a story of a long effort to determine if one particular type of object was a standard candle, and it turned out it was not. Do you remember the one I'm talking about? Oh, there's so many answers to that or so many possibilities. One standard candle that Sandage tried to use was clusters of galaxies in the distance. He started observing clusters of galaxies and then he plotted their distance and their size and apparent magnitude until he realized, he was told, or learned, he learned really,

that they're not standard candles because clusters of galaxies have evolving galaxies within them. They have interacting galaxies that completely change the cluster over time and change the color of the light coming from the cluster, and you can't depend on them as standard candles. Which must have been quite a disappointment, but then that's how science goes. You mentioned interacting galaxies, and that reminded me of something else that I was fascinated by. I can faintly remember reading as a very young kid in the 1960s

that galaxies could almost certainly pass right through each other with barely a scratch. Apparently, we know differently now, as you talk about in one of the chapters. That's a great question. We know differently now, but Zwicky knew differently then, and that was frustrating to him. So this thought that galaxies could just sail right through each other was the wrong notion of two researchers who should have known better. One of them was a famous dynamicist. So they interpreted a dark gash that was in front of a bright elliptical galaxy as an edge-on spiral that was

just sailing right through the elliptical unscathed, and they didn't understand the concept of gravitational tides. So while it might be true that the stars themselves rarely collide because their size relative to their distances is very tiny, they're not likely to collide with each other, but their positions and velocities are altered in the changing gravitational fields of two galaxies that are moving past each other. changing gravitational fields of two galaxies that are moving past each other. Stars and gas can even be cleared out during this process. So that's why we see big arms pulled out, ridges and tails, they're called, in interacting galaxies. I have many more questions for astronomer and Cosmic Odyssey author Linda Schweitzer, and I'll ask them after this break.

Greetings, Bill Nye here. Saturday, Sunday, a fleet of spacecraft, including NASA's Perseverance rover, is arriving at Mars. Join our live online celebration. PlanetFest 21 is February 13th and 14th. I'll be there with explorers, including Jim Bell, Katie Mack, author of The Martian, Andy Weir, NASA JPL chief engineer Rob Manning, and my old friend Phil Blaine, the bad astronomer.

Get your tickets at planetary.org slash planetfest21. We are NASA JPL chief engineer Rob Manning and my old friend Phil Blaine, the bad astronomer. Get your tickets at planetary.org slash planetfest21. We're going to Mars! Matt, was that too much? I got into it there. No, you nailed it, boss. This realization by Fritz Zwicky, which was rejected by so many others who studied cosmology, it makes it a little bit easier maybe to understand that why he was kind of an irascible character. Can you talk about Fritz Zwicky? Oh my gosh. There've been many books written about Zwicky. I don't know what came first, you know, the chicken or the egg. Was he irascible to begin with,

or was he made irascible? He certainly had a lot of reason to be irascible. But on the other hand, he would swear and call his colleagues spherical bastards. If he disagreed with him, that's a bastard, a person who's a bastard from any angle you look at them. a person who's a bastard from any angle you look at them. I wouldn't judge Zwicky and I wouldn't judge his reactions. I mean, he did have some reason. He wasn't allowed to observe on the 200-inch because nobody wanted him on the 200-inch, so they made rules that made he couldn't.

So he had a lot of reason, and I don't know what came first. And yet, in spite of these limitations, self and externally imposed, he's another one who pops up over and over in the book because he contributed to so many discoveries. I think you probably would agree that he was one of the major influencers in the period that Palomar was king. Oh, absolutely. He was a physicist turned astrophysicist, which is important because he had a good, solid physics background. He was a genius of all trades. He was decades ahead of his colleagues. He compiled monumental catalogs of 40,000 galaxies and 10,000 clusters of galaxies. And especially because of his physics background, he noticed, and this ties into a story we just talked about, galaxies passing through. He noticed that peculiar looking or so-called damaged galaxies, those that aren't pristine and perfect, occur in pairs or small groups.

He thought that was a result of gravitational ties and interactions between them. He also proposed that there was dark matter in the universe. Unfortunately, his work was largely ignored until more recently, he was far ahead of the crowd. He was a rather pugnacious character, which may have been part of it. He didn't like anyone who had fossilized notions and who didn't look at things from a physics background. This is one of those stories that we could spend our entire time devoting to it. And another recommendation for the book there. But let's go to a different one.

You know, here we are talking about expanding at least our view of how big the universe is. And yet I find this irony of looking across more than 10 billion light years toward the beginning of the universe. But at the time, anyway, not being able to see a mere 25 or 30,000 light years to the center of our own galaxy, which is another of these great stories that you tell in the book. That is a very puzzling story when you look at it from the outside. Absolutely true. You couldn't see the center of our galaxy, even though we were seeing astronomers were chasing quasars. So the reason for that is that the disks of galaxies, spiral galaxies especially, including our own, is filled with a kind of smog that's made up of gas and dust, which absorbs visible light. The smog is

produced by the puffed off atmospheres of aging stars. So the smog is enriched with the products of nuclear burning, like sooty carbon compounds. I have a beautiful picture in the book of one of these stars with all of the shells around it as the stuff is puffed off. It has nitrogen, iron, or silicon, but they all absorb the blue light. And the soup gets enormously opaque in visible light, but it's not opaque in infrared light. A workaround for that was discovered in the late 50s with infrared sensitive detectors, which allowed us to see the nucleus of our own galaxy. And we could see these inside dusty stellar nurseries where star birth was taking place. And we could also see planetary surfaces.

And since you've mentioned at least one of the illustrations, I should say the book is pretty richly illustrated and has lots of graphs and charts. And some of these graphs and charts were actually history-making. They remain famous today among astronomers, don't they? Yes, absolutely. One is Ellen Sandage's, I think it's the front page of one of the chapters, this chart he made showing how stars evolve, which fundamentally changed our whole concept of stellar evolution. And there are papers, too, that are just fundamental. Astronomers refer to them only by the first initials of the authors because they're so well known. Egan, Linden, Bell, and Sandage is a paper about the formation of our own galaxy.

It was the first global attempt to model how our own galaxy formed, how the entire Milky Way formed. Let me turn to a different chapter, chapter 10, which takes up the effort to understand the structure of the universe, something that continues today, doesn't it? Absolutely. Since light travels at a finite speed, a telescope is kind of like a time machine. So when we observe objects far away, we're actually looking at the past when the universe was much younger. With distant objects, astronomers can study the contents of the universe when it was young, when structure began to form, kind of like geologists reading a course sample.

We find that distant galaxies all connect to a cosmic web that's created by dark matter. And by studying the cosmic web and these distant faint galaxies, we can hope to disentangle the early history of our universe. Wrapped up with our discoveries, we're revolving around not just dark matter, but dark energy. Yes, yes. And that dark energy is a discovery or an implication based on the study of how the universe appears to be expanding. We've always thought that the universe is slowing down in its expansion, which is what you would expect with normal gravity. But when two teams of astronomers observed these type 1a supernovae, which I've mentioned, out to the very edge of the universe, they discovered that, wait a minute, the universe seems to be, the expansion

of the universe seems to be accelerating. We don't know what dark energy is, but to match dark matter, they grabbed the nomer dark energy to explain it, but we really don't know what it is. But the universe is accelerating. The expansion But the universe is accelerating. The expansion of the universe is accelerating. One of the great mysteries remaining in astronomy and astrophysics. We have to talk about chapter 11, because after all, I work for the Planetary Society, and it opens by recounting the work of one of our founders, not an astronomer, but a geologist. What was he doing in your book?

And who are we talking about? I adored Bruce Murray. He was one of the most fun people to interview. I liked him too. He was just a great, a great subject. He came to Caltech as a postdoc in geology. He came directly from the Air Force. He would later become the director of JPL.

But he loved to recount his experiences at Palomar, especially with his fellow buccaneer. I call them buccaneers, Jim Westphal. When he wanted to observe planetary surfaces in the solar system at Palomar, he drove out to the China Lake military installation. He still had his commission and security clearance. And so he glad-handed the personnel there. He had to explain what glad-handed meant to me. So he glad-handed the personnel with stories of all the wonderful things he might find at Palomar with the 200-inch, they were so impressed that they stuffed state-of-the-art infrared detectors into his pockets as he walked out. I know, this couldn't happen today, right? Probably not.

With the agreement that he would tell them how the detectors performed and what he found out about the planets. And this is a funny story. Once he took a friend of his to Palomar when Zwicky happened to be up there observing. After what must have been a raucous dinner at the monastery, the friend, who was a psychiatrist, whispered to Murray, why isn't Zwicky on a leash? So in general, during dinners, Murray and Westfall felt that they had to be obsequious so as not to rile the optical astronomers who weren't very happy about their being there. You know, they had these messy, long tubes snaking around that they had to pull into the telescope and all these coolers. And they weren't very tolerant until they realized that actually you can see better in infrared than an optical when you're looking through the dust,

like when you want to see the center of our galaxy, and then they lightened up a bit. And now we realize, I mean, infrared astronomy is an absolutely essential area of study, that portion of the electromagnetic spectrum. Absolutely. It allows you to see further back in the universe. It allows you to see, as I just mentioned, the dusty cocoons where starburst takes place. It allows you to see cool surfaces of planets. It really cuts through a lot of dust that otherwise would block the light and you couldn't observe anything out in the distant universe. Quite literally. Are you prepared to talk about some of the women who played a role? Am I ever?

Good. Not by accident. We have so far talked, I think we've only mentioned men who were lucky enough in beginning in the 1940s to work at Palomar, actually earlier than that. That's not because there weren't women who were very well qualified and certainly deserved to have access to these instruments. Why were they shut out? It's funny that you ask that, because I've been thinking about it. And why weren't there more female astronomers who were involved in some of these revolutionary discoveries? I realized that was in part because the monastery was set up for only men. The monastery being the place at Palomar and at Mount Wilson. The dormitory. Yeah, the dorms, right. The dormitories, yeah, where you sleep and you eat and everything.

There's a library in there. For a while, women were denied observing time on that basis. So it was a matter of access as much as anything else. It's called the monastery, right? So until the 1960s, you couldn't stay there as a female astronomer because Palomar wasn't designed for cohabitation. The assumption being that only men would be doing this, that is observing, right? So it was a widely known secret that Margaret Burbage had her husband apply for 200-inch time, and she did the observing on her program while he sat in the library and read. So Vera Rubin was turned down on her first application for 200-inch time, and then she was able to return in the mid-60s to observe at the 48-inch Schmidt.

She stayed at the monastery. Her bedroom was on the second floor, and the stairs were closed off to men with a velvet rope. There are two stairwells going up to the second floor. So one half was all hers. Henrietta Swope, who worked with Walter Bada, was not allowed to join Bada at Palomar to observe. Instead, she had to sit in the offices at Santa Barbara Street measuring and calculating and plotting. Bada went off to Europe and unexpectedly died, and Swope was left doing all the reduction and the interpretation of the data and publishing the papers. And then she placed Bada's name first on that paper. She admired him, I guess. Vera Rubin didn't return to observe on the 200-inch telescope until the 1980s, although today an observatory is named after her with an eight meter telescope. So why were women invisible,

you ask? I think it's in part because they weren't allowed to be visible. It's that simple. Women weren't allowed into the, quote, fantastic gardens that Sandage mentions in order to pick the flowers of discovery. How different is the situation today? Oh, it's completely open today. Anybody can observe there. Anybody can stay there at the monastery. Thank goodness. As a graduate student at Berkeley, Jill Tarter worked on models predicting the colors of dwarf star atmospheres. And since her models predicted that dwarfs change temperature, she chose to label them brown because it's a mixture of blue, red, and yellow. So she covered all the bases. She didn't observe at Palomar, but the story of brown dwarfs continues with a team at Palomar that had a new instrument and they joined an international race that had already

been in progress for three decades, not being able to find brown dwarfs. And graduate student Rebecca Oppenheimer, then known as Ben R. Oppenheimer, was part of that team. And she ended up discovering the first brown dwarf in the mid-1990s, then told me that she began leaping with delight around the dome at the thought of what lay in store with this discovery. She, by that time, of course, was an accepted member at Palomar of the monastery. She could stay there any time. She then went on to lead a team to design and construct an ingenious state-of-the-art instrument that, for the first time can simultaneously take spectra and images of exoplanets. And she's doing this from Palomar. So she's a real success story and certainly a female presence at Palomar. Great evidence of how much things have changed since those days in the

40s and 50s and how much better it is for all of science and for these researchers like Rebecca. And of course, I think I had told you that I was surprised to read that old friend of Planetary Radio, Jill Charter, not only was an old friend of yours, but I didn't know that she had come up with the term brown dwarf. Yeah. Readers of Cosmic Odyssey should not stop at the end of the last chapter. You really need to read the acknowledgments that you've included.

They extend over several pages. And I'm very proud to say that you credit many people who have been guests on Planetary Radio. Right at the end, you provide a credit, sort of a statement of gratitude, and it allowed me to discover that you and I have something in common, and that is spending a good part of our childhood at the Griffith Observatory on that hill above Los Angeles. Oh, wonderful, wonderful. We may have bumped into each other. We might very well have, yes. We may have bumped into each other. We might very well have, yes.

There were times in our early family life when we lived very close to the observatory and my parents knew how much I loved going there. I mean, it had such a huge role in leading me in the direction that it did, talking to people like you. I sounded like it had a big role in you becoming the astronomer that you are now. It absolutely did. Yes. I mean, I was fascinated. I didn't understand everything at the beginning, but I worked at it and it led me to do every single school report was on some astronomical subject, spectroscopy or the planets or whatever, every single one. And my teachers tolerated it, fortunately. Good for them. Is there an ongoing role for Palomar? All of the instruments up there as we see ever larger telescopes, both ground and space-based coming online. I mean, here we go, hoping that the James Webb Space Telescope will unfold properly and begin its work this year.

And then, of course, those new giant telescopes, which are under construction right now. Is this wonderful old shrine of science going to play a role? Absolutely. Palomar is an ideal testbed for the sophisticated instruments that are under construction. It's a short three-hour drive from Caltech to Palomar. So instruments can be built in the labs at Caltech and then checked out periodically at the telescope. Adaptive optics has brought Palomar up considerably, and it's played a big role in their sustainability, as has the coronagraph, which is a device that blocks out light from bright stars. The mirrors are intrinsically

very high quality. The telescopes are incredibly sturdy, so you can just hang whatever you want from those telescopes, and they'll still work like a Swiss watch. They were built like battleships. They're not going anywhere. I am so glad to hear that, and I look forward to making another. Someday, I hope that we can visit up there together. That would be wonderful, yes. Just one other observation that you make in your last chapter of the book, which is titled Astronomical Exotica, that captured my imagination, titled Astronomical Exotica, that captured my imagination. And it was about how so much of what you write about in the book lives on a sort of a continuum, if you will.

Could you talk about that? I was talking about how planets and stars had always been considered separate kinds of entities. But when brown dwarfs were discovered, astronomers realized that they had found the missing link between planets and stars. The highest mass are the stars and the lowest of planets, and they're linked by a sequence of brown dwarfs. So they all form a continuum of increasing mass from planets to brown dwarfs to stars. Only stars generate energy, but what a wonderful idea that is, right? Early on, when you've got only a handful of objects you've observed, then it's easy to categorize them and see their differences. But when you observe more objects, you realize there are fine gradations, which sometimes work into a continuum. I think of what you document in the book as sort of a continuum of human discovery that is representative of so much of science.

Yes. Discoveries are building blocks. Sometimes a block falls. Sometimes it's knocked off. But the general trend seems to be upward, that we're discovering more and more and putting things, putting all of these building blocks together to reformulate our picture of the universe. And building something magnificent with them. Yes. As I think you have with this book, Linda, thank you very much for writing it and for joining us on Planetary Radio to talk about it.

You are very welcome. That was a, I had a great time. I'm glad. The book is Cosmic Odyssey, How Intrepid Astronomers at Palomar Observatory Changed Our View of the Universe. It was just published in November of 2020 by the MIT Press. No surprise there. And you can find it in all the usual places. You can also find an opportunity to win your own copy when we get to this week's space trivia contest with Bruce Betts. Coming up in just moments, Linda Schweitzer has a Ph.D. in astronomy from UC Berkeley, and she has observed at many observatories around the world, published research in the Astrophysical Journal,

around the world, published research in the Astrophysical Journal, teaches science writing, and was a visiting scholar at Caltech, the California Institute of Technology, all while raising four daughters. Time for What's Up on Planetary Radio. So we are joined by the chief scientist of the Planetary Society, Bruce Betts, he who used to, a long time ago, go down to Palomar and apparently freeze. Have you ever warmed up? No, not really. Long time ago, yeah, I was back there when they were building it back in the 40s. Yeah, you really are well-preserved. You know, we had electric lights, Matt.

It was okay. I was so scared. They made, it's like, we're going to the prime focus. Take everything out of your pockets. Oh, why? You don't want to drop a coin on the Palomar 200-inch mirror. So it's a bad thing. And it turns out they keep those domes cold during the day.

Someone should have told the brand-new grad student who showed up in a T-shirt after the night that had been 30 degrees. You didn't have so much as a hoodie? No. I mean, I did. Next time we went up there, I was very, very warm. I'm glad you survived and a little envious. Although as I told Linda Schweitzer, I have walked up there. I learned a lot and spent 12 nights at Palomar not getting any data, but that left more time for exploring the telescope and playing cowboy billiards. Cowboy billiards?

All right, you'll have to describe that a different day. Let's talk about the night sky, that stuff you can see with your eyes. Let's talk about the night sky, that stuff you can see with your eyes. So in that evening sky, Mars is fading, but it's still looking like a bright reddish star in the evening in the south. And it is fairly close, if you look over to the left, to Aldebaran, which is a reddish star, that they're actually pretty similar in brightness right now. So the other way you can do it is find Orion, which is quite stunning, as always, in that evening sky, in the evening east-southeast. And if you follow the Orion's belt, you draw a line one direction, you come to Sirius, the brightest star in the sky. If you go the other direction, you come kind of close to Aldebaran, reddish star in Taurus, you go farther

and you'll see reddish Mars. So it's a whole little party. And if, here's a fun fact, Matt, the day that Perseverance is going to land on Mars, the 18th of February, the moon will be really close to Mars in the night sky. On to this week in space history, 50th anniversary of Apollo 14 landing on the surface of the moon and learning stuff with people and golf clubs. We've got a great article on our website, planetary.org. Matt may even put a link from the show page. He might indeed. On to... I hear you may have been speaking of the Palomar 200-inch Hale telescope. Indeed, and the other telescopes up there. The 200-inch Hale telescope is about 500 tons, but it's kept so well balanced that only

one to three horsepower motors are used for slewing and tracking. For the first 65 years, it was only a one twelfth horsepower motor that was used for tracking. Whenever they add instruments, they have to rebalance the telescope to keep it all perfectly balanced. As Linda Schweitzer said, like a fine Swiss watch, except built like a battleship. That's a good analogy. It feels, it seems like a battleship, but then it does these incredibly precise things. As to all those big telescopes out there, we move on to the trivia contest. And I asked you, what did Galileo want to name what became known as Io, Europa, Ganymede, and Callisto, also called the Galilean satellites? What or who did he want to name them after?

How did we do, Matt? A huge response. The biggest one we've had in quite a long time. A bunch of first-time listeners. So welcome to all of you. First-time winner, although a long-time listener, Thomas Ancillary in New York. Thomas said the Galileo wanted to name the moons the Cosmian Stars after Cosmio de' Medici, or the Medician Stars, which would honor all four brothers in the Medici clan.

He eventually settled on the latter. And who are those brothers? Cosimo, Francesco, Carlo, and Lorenzo. I should have rolled the R on that one. Is he correct? He is correct. An early example of the fine tradition of naming things after your sponsors, which is not as popular elsewhere in the world. Hence the reason we came up with those mythological names tied to Jupiter. Thomas, congratulations. And it is about time you have won yourself a Planetary Radio t-shirt. So we'll check with you about what size shirt you would like to get from the Planetary Society store at Chop Shop. That's the chopshopstore.com if you want to check out all of our merchandise.

A lot of people speculated, what if those names had stuck? Marcel John Kriegsman in the Netherlands, he says, I can't wait for the Francesco Clipper mission. Pretty clever. Mark Moffitt in Georgia, he first read of Galileo's discovery as a child, took his telescope out, found the moons. He later took a certain Bruce Betts' online class about the solar system and learned so much more. Oh, good. It's still out there at planetary.org slash Betts class. Free, by the way. Joseph Ladd in Nevada just read all about this in Alien Oceans by Kevin Hand. Of

course, Kevin Hand at JPL, expert on ocean worlds, wrote that great book. We talked about it last year. To quote the book, he even named them the stars of the Medici in honor of the Medici family since they were funding his research and the ads and parentheses. Galileo was no idiot. his research and the ads and parentheses, Galileo was no idiot. Quite the opposite. Ian Jackson in Germany, not officially known, but Galileo visited the moons as excellently documented by Kim Stanley Robinson. It's true. You got to read Stan's book, Galileo's Dream. It's very entertaining. Stephanie Delgado in Arizona, within the family, according to Stephanie, not just Lorenzo, but Lore, the evil twin. Live long and prosper, Stephanie. Finally, from our poet laureate, Dave Fairchild in Kansas, when old Galileo unveiled how moons

around Jupiter sailed, we'll call them, he said, for the clan Medici. I'm glad that his naming scheme failed. We also got a great poem from Gene Lewin in Washington. It's too long for us to read here, but maybe we'll put it on the show page at planetary.org slash radio. And we're ready for another one. For our next contest, I will challenge your creativity to celebrate perseverance, hope, and Tianwen arriving at Mars. Your assignment is to write a poem about spacecraft, one or more, at or arriving at Mars. Write us a poem and we will, of course, judge it in a completely objective way or subjectively go with whatever makes us laugh or is profound.

We don't know. But write us a poem and submit it to planetary.org slash radio contest. What are they going to win, Matt? You might think that, boy, this one's in the bag for our poet laureate or some of the other people who regularly submit poems. or some of the other people who regularly submit poems. But we've got five prizes to give away, and each one of them is the brand new PlanetFest21 to Mars and back T-shirt.

Why? Because it's coming up. It's the 13th and 14th of February. You want to learn more, planetary.org slash PlanetFest21. It is a really cool, so I cannot wait to get my t-shirt and then our grand uh prize winner will get not only the t-shirt but a copy of cosmic odyssey by linda schweitzer not bad huh no it's good stuff when do they need to get those in by matt oh there's that isn't there by let's say febru? By, let's say, February 10th, Wednesday, February 10th at 8 a.m. Pacific time. All right, everybody, go out there, look up the night sky, and think about which extraterrestrial ocean you'd most like to scuba dive. Thank you, and good night.

There's so many to choose from. I think I'll go with the obvious one, Europa. And it sounds like it'd be a lot of fun. It's just the elevator ride down through the ice that I don't think I would enjoy very much. He's Bruce Betts, Chief Scientist of the Planetary Society, who joins us every week here for a warm and toasty What's Up. The recording of my great conversation with Her Excellency, United Arab Emirates Minister for Advanced Sciences, Sarah Alamiri, is now on YouTube. We've got that link and much more on this week's episode page at planetary.org slash radio. Planetary Radio is produced by the Planetary Society in Pasadena, California, and is made possible by its farsighted members. Join them at planetary.org slash membership. Mark Hilverde is our associate producer. Josh Doyle composed our theme,

which is arranged and performed by Peter Schlosser at Astro.