Planetary Radio: Space Exploration, Astronomy and Science - Astrobiologist David Grinspoon on life, the universe and everything

Episode Date: February 23, 2022

Astrobiologist, planetary scientist, author and science communicator David Grinspoon has just been named a lifetime fellow of the American Association for the Advancement of Science. He returns to Planetary Radio for a wide-ranging conversation about the state of our search for life across the solar system and beyond. We also learn what it was like to grow up in a home visited regularly by Carl Sagan and Isaac Asimov. Plus, get out your pencils and calculators! Bruce Betts delivers another cosmic arithmetic challenge in the space trivia contest. Discover more at https://www.planetary.org/planetary-radio/2022-david-grinspoonSee omnystudio.com/listener for privacy information.

Astrobiologist David Grinspoon and the search for life, 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. David Grinspoon was last heard here when he joined Alan Stern to talk about their book, Chasing New Horizons, the best-selling chronicle of the New Horizons mission to Pluto and beyond. David has written other popular books over the years as he has continued his research at the Planetary Science Institute. Now he has been named a Lifetime Fellow of the AAAS, the American Association for the Advancement of Science. David will join me in a few minutes for a conversation that will run the gamut from

the possibility of past life on Venus to what it was like growing up with Carl Sagan and Isaac Asimov as regular houseguests. Then, you asked for it, the chief scientist has another cosmic arithmetic challenge for you, and Bruce has a rubber asteroid for the winner. What light through yonder prism breaks? I couldn't resist parroting that headline at the top of the February 18 edition of The Downlink, the Planetary Society's free weekly newsletter. Beneath it is the complete visible light spectrum of our own star,

and a teaser for the new article about spectroscopy that's also on our website. And then there's the truly beautiful video my colleagues have produced about the same topic. It's all at planetary.org slash downlink, where we also wish a happy first anniversary on Mars to Perseverance. Check out the rover's terrific accomplishments over the last Earth year. It was the announcement by the AAAS that reminded me to invite David Grinspoon back. It also led me to David's great 2003 book, Lonely Planets, that I'll have more to say about in a moment. Others have already said a lot about it. Astronomer and pioneer SETI researcher Frank Drake described it as superb.

Everything is here, theories of planetary formation and evolution, the origin of life, the origin of complex life, and even the evolution of intelligence and technology. David has succeeded marvelously at producing a comprehensible and enjoyable overview of astrobiology, the epitome of multidisciplinary research. Apollo astronaut and planetary defense expert Rusty Schweikert adds, David has written the book I wanted to write, and he's done it so very well that I'll be forever thankful I never got to it.

David Stile is so direct, so personal, and so punctuated with delightful humor that reading this book feels like a living room conversation. Let's start our conversation. David Grinspoon, welcome back to Planetary Radio. It is such a pleasure and an honor to congratulate you on your recent election as a 2021 Fellow of the AAAS, the American Academy for the Advancement of Science. So congratulations and welcome. Thanks very much. And it's great to be here, wherever here is, and have a chance to talk with you some more. You said in your book, Lonely Planets, which we'll talk a lot about, I'm sure, and I've already said some nice things about, You say you picked up degrees in the two least practical things you could think

of, philosophy and planetary science. But I say, thank the maker, because they enabled you to think the way you do and to share those thoughts with the rest of us. Lonely Planets, which, as I told you, I finished a couple of days ago, has profoundly affected my own thinking. And I'm now reading your 2016 book, Earth in Human Hands, Shaping Our Planet's Future. Here's what my boss, Bill Nye, says about it. In his wonderful writing style, Dr. Grinspoon spells it out. A single species is inducing more profound changes to our planet than any other organism in geologic history. It's us. If you have family and friends here on Earth, read this book, The Earth is in

Our Hands. Wow, nice work. Nice work, boss. And nice work, David. Yeah, thanks a lot. It's always nice to hear that, and I appreciate the words coming from somebody like Bill. Wow. It's gratifying. I do see a sort of line between all these things you mentioned, because I feel like planetary science does give us a unique perspective on ourselves, on this planet and the point of view of astrobiology, of thinking deeply about the relationship between life and its planetary home, which to me is really what astrobiology is about. It's about the relationship between a planet and its life. It gives us a different cast on thinking about ourselves and our challenges as we face the future. So to me, there's some way in which it all fits together, the philosophy and the planetary science and the astrobiology, and then kind of worrying about how all that can

affect how we can go about trying to solve our problems as we confront the fact that, hey, we live on a planet and we are a force on this planet. We're realizing that. What are we going to do about it? I promise we will come back to this topic because it is so much at the core of this book, Earth in Human Hands. I'm thinking of this honor that has just been paid you by the AAAS. The popularization of science by a scientist is clearly not as dangerous a path as it was not that many years ago. I'm thinking now of the National Academy of Sciences and how it snubbed a very accomplished researcher named Carl Sagan back in 1992, who you happened to kind of grow up with, or at least he was a figure in your household. He was just a little too far ahead

of his time, do you think? Yeah, I was very aware of that, you know, when I was a student studying planetary science and somebody that knew Carl and was kind of in his orbit, because I would hear those snubs, you know, not just in the high-profile media places, but even, you know, I had a physics professor, a cosmology professor when I was an undergraduate at Brown, who would go out of his way to make gratuitous anti-Sagan comments. It was puzzling, but it definitely was not considered to be sort of correct for a serious scientist at that time to spend too much of their energy on communicating with the public. The word was popularizer. It was a pejorative term. If you were just a popularizer, then you were obviously not a serious

scientist. Some of that was probably tinged with jealousy because Carl was on the Johnny Carson show. My cosmology professor wasn't. And he was obviously doing very well materially through all this. But I think it gradually also dawned on the community that he had done us a huge, huge favor, because ultimately what we do is dependent upon public support. So beyond issues of whether it's, you know, a valuable thing in its own right, which of course it is to try to talk about what we do and spread the word and spread understanding. If you want to maintain your support, it's tax dollars that are supporting us. And of course, you need to share the knowledge and share the wonder. Carl was better at doing that than anybody.

He was a master at that. anybody. He was a master at that. You know, there's one more element while we're talking about why Kara was ostracized a little bit in the community that I think is often not mentioned, and that is he was also a political activist. He got arrested at the test site, the nuclear test site, and was involved in several anti-war causes and anti-nuclear weapons causes. That was also seen as maybe not quite proper, that if you were an academic, you shouldn't be an activist and out there protesting. But I think, again, for Carl, it was just he was a principled person, and he saw it as important, and he saw that he had a platform. And I think that, you know, there's a line between that and today, some of the really visible climate activists are scientists who are thinking, hey, it's not enough to just people about it and talk to our representatives because we see an emergency here and you can't just sit back and make notes and write journal articles when you see an

emergency happening. You have to get out there and try to be involved. And that was the way Carl approached things and not everybody liked it back then. He certainly did my audience and me a great favor because now it's the rare scientists that I talk to who doesn't think that talking to somebody like me and my audience, just, you know, that's part of the job. That's what we're supposed to do. Thank you, Carl. Yeah, there's been a sea change. And now certainly professional scientists and students, students coming up and early career scientists are all about science communication and using lots of platforms, using social media and really good at it. There are a lot of really good science communicators.

It's largely because it's become something that is valued, that it's seen as not just okay, but you get points for spending time on it and being good at it. And Carl really did. That's one of the ways in which he changed the world was to, he was really influential in leading the way and showing how you could be a quote, serious scientist and really put yourself into communicating well as he did. Sounds like you're speaking personally as well. Well, yeah, I think so. I mean, it's always been my career has been kind of unusual. You know, I've been a university professor. I've been a museum curator. I've been a research scientist. I've worked in a government lab. But I've always had, you know, I would say roughly

50-50 balance between spending my time on research and spending my time on things that can broadly be considered communication and education. And at times, it's been a bit of a juggling act, and you feel like you're going to sort of drop the balls because you've got too many of them up in the air. But when it's working well, every part of it enriches the others. Because in order to be a good communicator, you really have to have a broad base of knowledge and stay educated yourself, not just on the specific thing you do, but on the field in general. And for a field like astrobiology and planetary science, that's good for your research because you stay educated about what everybody's doing and what's

happening in different areas of the field. And then that comes in and helps you. You can draw upon things that you wouldn't be able to if you were staying more narrow. So there are, you know, at its best, the communication and the research feed each other. You talk about planetary science, that it may be, I don't know if you put it exactly this way, the highest expression of why a multidisciplinary approach is so important in science, but especially in planetary science, and maybe even more so, little circle living inside that Venn diagram circle, astrobiology? Well, there wouldn't be any planetary science or astrobiology without an interdisciplinary approach. If you look at the history of planetary exploration,

when we first started sending spacecraft to other planets, there was no such thing as planetary science. It was an interesting question. Well, who's going to do the science? Who's going to interpret the data? I mean, there were astronomers and there were planetary astronomers. But what they did was look through telescopes and make drawings or photographs and spectroscopy from telescopes and try to figure out a lot about a distant object far away. try to figure out a lot about a distant object far away. And then when we're sending cameras and other instruments to get close-up data about the planets, that wasn't really a suitable activity for somebody who had only looked through telescopes their whole life. And we needed to draw upon

astronomy, but we also needed to draw upon the earth scientists, because earth science had the knowledge of geology and meteorology, which we had to apply to other planets. So the initial science teams of the first missions were these interesting hybrids of some astronomers, but then they brought in some geologists and some meteorologists. And those people who I consider sort of the first generation, the people that were on the science teams of the mariners, the pioneers, they had to forge this new multidisciplinary discipline of planetary science. And so that really came about of the necessity to do the science that became possible because we were starting to send missions to the planets in the 60s and 70s. And then I see astrobiology in a way as an extension of that.

There was already this multidisciplinary effort of planetary science, but then when astrobiology became not just a sort of a fringe extension of planetary science, which it was at one point when it was exobiology and a few brave souls, Sagan and some others were daring to do it on the side, when astrobiology became an accepted and embraced part of NASA and other space agencies, what became mainstream, it required another melding where that sort of multidisciplinary edifice of planetary science, which had been built up already, then incorporated biology and biochemistry and origin of life studies and all this sort of extremophile studies. Basically, it broadened the circle again to include these other disciplines, but the ground had been paved by the fact that planetary science

was already this multidisciplinary collection of viewpoints and sources of expertise. You are an astrobiologist and proud of it. It's your chosen field. But you talk in Lonely Planets, you speculate about whether, at least at that time, this book was, you know, it was a few years old now and I published 19 years ago, whether maybe the focus on astrobiology, eventually the pendulum swung too far that way and caused us to focus too much on places where we might find life, Mars, Europa, to the exclusion of other fascinating worlds. And I think we're going to be talking about Venus in a couple of minutes here. Do you still feel that way? Has the pendulum swung back? Well, it is interesting to sort of trace fads in our field. Don't want to be too pejorative on anyone's work, because there's a quote that I also use in the book from

a Greek philosopher, all is a woven web of guesses, that there's, even though we're building on an edifice of knowledge, when it comes to life in the universe. We're profoundly ignorant. And so there is the danger of groupthink where everybody's thinking about Mars and we've got this expectation we're going to find subsurface life on Mars. And then we find something that's encouraging, a whiff of methane or hints of underground water and everyone gets excited. They go, oh, we're just around the corner from finding extant life on Mars. Well, there may be or there may be Mars may be completely lifeless. We tend to focus, get excited about certain areas and neglect other areas. And for a while,

Titan was considered to be really off limits because it's just, you know, well, there can't be any liquid water there, at least on the surface. And even if there's chemistry, it's in these weird methane lakes. And I think now there's more openness to what we call weird life and possible places like Titan. And I'm sure we'll get to talking about the clouds of Venus, which is one of my favorites. I would even go so far. And I talked about this a little bit in Lonely Planets, even places like like Io. OK, like why would you possibly consider life on Io? Well,

there's liquid and there's interesting chemistry. And who says it has to be carbon? You know, there's interesting possible sulfur chemistry on Io. So not that I'm saying, oh, I think there's life on Io and we should go look for it. But I I definitely advocate casting a wide net. And I think the only places we can really rule out for life in our current ignorance are places where nothing is happening. Like there's no motion of any matter. There's no transfer of any energy, a totally quiescent place because whatever life is, and we could get into the whole natural philosophy question of that, But whatever it is, it obviously involves transformation and organization and energy flow of some kind. So if there's nothing happening, and there are places in the universe, including in the solar system, where there's basically

nothing happening, then I would say, okay, there's no life there. But any place where there's flow and transformation and phase change occurring in our current ignorance, I don't think we should entirely rule out. You said look for disequilibrium and lots of it, and Io would qualify. Mars, not so much. Yeah. Well, Mars is an interesting case because there may be micro environments where the necessary conditions are met. We know, you know, there's some energy flow. There's some internal activity, not very much.

Mars to me is an interesting test because my hunch and all anyone really has in this field are educated hunches in a sense, is that life requires a certain level of planetary activity, that life is a planetary property that's much more likely to endure for billions of years, for long periods of time on a planet that's active where there are active geological flows and active atmospheric phase changes and geochemical flows. I mean, the Earth has its carbon cycle, its sulfur cycle, its nitrogen cycle. And Mars is just very quiescent. It has a lot of atmospheric activity and a lot of stuff blowing around and condensing on the surface, but no really internally generated geological activity to speak of.

I mean, there's little puffs of it's not entirely dead, but it's largely dead. So that biases me towards thinking that Mars maybe is completely lifeless. But I'm enough of a scientist and enough of a philosopher of science to realize that we really don't know. And then to me, that sets up a really interesting test. I'm very supportive of the search for life on Mars because nearby we can search for life there. And I want to know if I'm wrong about this and Mars can support life in its current moribund state as a planet, that would be a really interesting thing to learn. Then I would learn that I'm completely wrong in my hunches about where life can exist in the universe. And I want to know that. And also, of course, Mars has, there's every reason to believe

that we may find fossils on Mars, because obviously it wasn't so moribund in its early history. And because it's been so quiescent, it's preserved that early history much better than most other places in the solar system. So it's a great place to look for fossil signs of early life. I'm a big fan of Mars exploration. I'm just not holding up great hopes for finding extant life there today. And of course, we could get onto another tangent about this. But if you're somebody that's hoping that humans can go and live on Mars and do things on Mars in the future, then not having any Martians living today, I would also argue is really good news if that's true. It just makes it much ethically simpler to worry about what we're going to do on Mars if there

aren't any Martians there today. Yeah, it certainly cleans things up for people like Elon Musk. You've given me a good opening here to mention something I haven't yet about Lonely Planets, and I suspect also about your other, well, I know about the other book, and that is the humor that you drop in and the popular culture references, which pop up all the time and really made it not just a profound experience for me to read, but very entertaining. I was laughing out loud periodically. And you said about Mars and Lonely Planets that the absence of disequilibrium on Mars indicates it is dead, that it is perished, deceased. This is an ex-biosphere, with apologies to Monty Python. Yeah. Yeah. Well, I mean, you know, life is too short to not laugh whenever you can. And I do love

humor and things that I consume, whether it's books or any media. And I also love to use humor when I can. I find it, for instance, giving a public talk. If you get the audience laughing near the beginning, then they're on your side. So this is one of my tips for public speakers. If you have any nervousness or stage fright, start off near the beginning with a joke. It can be a preplanned one if you don't feel like you can make a spontaneous one. And it just loosens everybody up and makes people feel good and then makes them more receptive to whatever else it is that you want to talk about. I share that advice with you as well.

Where were you on August 8th, 1996? I'll tell you where I was. I was driving along the central California coast with my family coming back from a vacation when I heard something on the radio that made me stop the car, jump out and do a little dance. Yeah, I know what you're talking about. I had kind of a funny experience that day. I had actually, I had just turned in my previous book, Venus Revealed. And I was, you know, waiting to hear back or I was at some late stage, I turned in page proofs or something. And I, I was taking a little vacation because, you know, finishing up a book is stressful. And so I was unplugging for a few days.

My wife and I went to these hot springs in western Colorado in this kind of hippie town where we would go hang out. And there'd be these hot springs and everybody, you know, clothing optional. And you'd be floating around naked with all these other friendly naked people. And you're just relaxing far from the world, far from any care. And I overheard floating in the hot spring. I overheard this woman say to her friend there in the hot spring, hey, did you hear, I heard on the radio, scientists have discovered life on Mars. And I was floating there thinking, yeah, right.

Because this is the kind of thing one often hears when, you know, floating in a hot spring in Western Colorado. And so I didn't really take it very seriously. Then a little bit later, we, you know, got tired of soaking, put our clothes on, drove into town to get some lunch. And as we drove into the little town of Ouray, Colorado, I remember seeing the newspaper boxes on the side of the road. And the first one I saw, there was a big headline that said, life on Mars. And I thought, oh my God, what? And especially, you know, among all the many thoughts that flooded, I thought, oh, great. I just turned in my book and now it's obsolete. But then, of course, there was the excitement and running out and fumbling in my pocket for the change, because in those days there were still, you know, you still had to like get the newspaper. I didn't have an iPad yet.

Of course, this is how I learned of the story that you're talking about of the announcement that in these meteorites from Mars, they had found these little shapes and other indicators that suggested to them that there was fossil life in these Mars rocks. Very exciting announcement. And they had a presidential press conference with President Clinton to announce this. That, of course, was ALH 84001. I will tell you something that I've never mentioned to anybody, so keep it to yourself. I actually got the whole, years later, a tiny fragment of that Mars meteorite with tweezers at a lab here in San Diego. There was a moment that passed through my mind. I could pop this in my mouth and swallow it before

anybody could stop me. As my friend, Kim Stanley Robinson likes to tell people, he went up on his roof and ate a piece of Mars once. But those fossils, they're a great illustration of how science works or should work, right? Because what's the current consensus? Yeah, absolutely. I mean, it was a very exciting announcement. The scientists that published that paper in Science Magazine that led to that, you know, there certainly weren't crackpots. They had found some very intriguing pieces of evidence and sort of a confluence of unusual things about that rock that suggested to them that there had been ancient life there.

The current consensus is that there are other explanations, that the little squiggly things they saw that could have been microfossils probably were the result of some unusual geological, geochemical formation when there's water trickling through a rock and things are being deposited, and that there were also non-biological explanations for the other things they found. I would say we don't know that 100%. The consensus is that it probably wasn't life that they found. And that's probably true. However, we don't know that for a fact. I think one of the things we would love to do as we continue exploring Mars is to find examples of exactly what they found, but find them on Mars in their indigenous context and see what really happened locally, geologically there. see what really happened locally, geologically there. You know, what those scientists did, they really did us all a favor, because even though the pendulum eventually swung towards thinking, well, no, there are probably other explanations. You know, it's sort of our job

to come up with other explanations, because like Sagan's old adage, extraordinary claims require extraordinary evidence. And you look for a less thrilling explanation so that you don't get fooled by wanting the thrilling explanation to be true. But they did us all a favor because I think it caused a lot of people to think about that and ask themselves, well, could there be signs of ancient life on Mars? And then when you thought it through, you had to say, yeah, well, there could be. Why not? Everything we know about early Mars suggests that it had conditions similar to the time on early Earth when, as we understand it, life was forming. And so there wasn't any logical reason why we

couldn't find evidence of life on early Mars. It ended up invigorating the field of exobiology and really helping to birth the field of astrobiology because it got people thinking. It stirred the imagination. I regard it now as probably a mistaken result, but a very fruitful and useful and productive mistaken result. Lost the battle, but won the war. Right. You don't want to leave now.

David Grinspoon and I will be right back with more of life, the universe and everything. Greetings all, Bill Nye here. Missions of discovery are underway right now, thanks to the Planetary Society, the world's largest independent space advocacy organization. And now is the time to join our space advocacy network to keep NASA's planetary science going strong. Help us fight for missions that matter. First, visit planetary.org slash take action to make your donations. Right now, your gift will be doubled thanks to a generous member. U.S. residents can also sign the petition asking your representatives to support space science and exploration.

With your backing, we'll keep advocating for space. Please go to planetary.org slash take action today. Thank you. If you were writing Lonely Planets now, or if you ever come out with a new edition of it, would you be including Enceladus? Oh, absolutely. you be including Enceladus? Oh, absolutely. Yeah. Enceladus is one of the delights of solar system exploration, which, you know, there were hints, even with Voyager in the early 80s, that there was something weird about Enceladus because it's so bright, so anomalously bright, like it's being coated with fresh snow, which it turns out it is. But then with Cassini, of course,

we saw that Enceladus is squirting bits of its interior out into space and has anomalous heat flow. And clearly, not only is there something unusual going on inside, which has to do with liquid water that seems to have organics in it. But there's a, you know, unusual energy source and heat flow. It's the kind of place where not only might there be life, but there might be life that's sort of accessible for us to find because it's squirting its insides out and splattering them on its surface. So, you know, in theory, you could go and scoop up some snow and find microfossils on the surface of Enceladus. That discovery was tremendously exciting.

I actually had kind of an unusual window into that, if I can share a brief story. I used to work at the Southwest Research Institute in Boulder. One of my good friends and colleagues there, John Spencer, was on the Cassini team. And he was on the team that operates the infrared thermal instrument, thermal sensor on Cassini. And one night, I was in my office late at night, and John's office was just down the hall. And he said, Hey, come into my office, I want to show you something. And he had on his screen a thermal map that he had been making of the South Pole of Enceladus. And he said, you know, I can't get this to go away, but it doesn't make any sense that there was this massive heat flow at the South Pole of Enceladus that shouldn't be there.

It's not like it's overly illuminated by the sun. It's less illuminated by the sun. He said, you know, and it's strange. I've been looking at some of these images from the imaging team, and I could swear it seems as though there's something maybe coming off of the south pole. So because John called me into his office and shared this with me, I think I was maybe among the first people on earth to be aware of the fact that there's something really weird going on in Enceladus. And, you know, those are the moments that you just kind of treasure looking back now and everything that we've learned about Enceladus

and how important it's become in astrobiology. I feel like that, you know, that night with my colleague in his office where, you know, this was all unpublished and everything, he was just like, I think I found something. You know, and like, that was, it's really cool now to just think back on that and look at what's happened. This reminds me of, and I think it's a quote from Isaac Asimov, another gentleman who had an influence over you very early on in your life. If it was Asimov, he said something like, science progresses less by shouts of eureka than, ooh, that's strange. Right, right. No, it's so true. It's always at first that strange because you have a lot of those that strange moments where then you realize, oh, that was a mistake. I calibrated that wrong or I put in the wrong line of code and it goes away. So whenever you first have that strange moment, you don't believe it. You try everything you can to make it go away before you show someone else. So yeah, that strange always happens before Eureka.

always happens before Eureka. We already said Carl Sagan. I think you met him or he met you when you were like six years old. Isaac Asimov was also a regular at your house, a friend of the family. Two of the three people I most regret never having had the chance to interview, Asimov, Carl Sagan, the other one being Neil Armstrong. My gosh, I'm so envious. Yeah. I mean, it is, it is pretty amazing to think back on that. Of course, when I was a kid, they were just like these people that your parents knew that they were fun and likable, but you didn't realize that they were like, oh, wow, you weren't in awe of them, you know, which I guess is good. But the, actually the thing about Asimov, how he came into my family's life is pretty interesting because it was totally separate from any of these other connections. My grandmother, Sally, my dad's mother, her husband died pretty young. My dad's father died the day before my had to find a job, had to go back to work. And she applied for this secretary job, which turned out to be a secretary for a biochemistry professor at Boston University named Isaac Asimov.

But at that time was not a famous science fiction writer. He hadn't even written any science fiction yet. And she got the job. And she was Isaac's secretary for many years. And then they became good friends. And long after he was no longer a biochemistry professor, he was a famous writer. And long after he lived in the Boston area, because he moved to New York, they remained friends. And he was a friend of the family ever since. But so that was just kind of a random thing where she answered an ad for it because she needed a job. Your Grammy, right? Yes, that's right. She lived from 1900 to 1995.

Wow. Just imagine that, like what she saw in terms of technology, born before automobiles and lived well into the space age. Amazing. She drew me a picture of a comet Haley that she remembered from when she was 10 years old and it filled the sky. We were talking about it. She's like, oh, I'll show you. She drew me a little picture on a napkin. I hope we get one of those before we check out. Yeah. Let's go to Venus and we'll bring it right up to date because it was only a few days ago as we speak that we learned that the Parker Solar Probe on one of its swings past Venus actually managed to cut through the clouds in visible light and show us the surface of our hot sister.

That must have been exciting for you. You've been a Venusophile, Venusphile, I don't know, a fan of Venus for a long, long time. Yeah, it's really exciting. And honestly surprised me because we've known for a while that there are these bands in the near infrared that allow you to see the surface of Venus at night from the thermal glow. the surface of Venus at night from the thermal glow. You know, the surface is hot and so it's glowing in the infrared and in the visible to some extent, but mostly that's completely blocked by the thick atmosphere and the clouds. But there are some wavelengths where the light makes it through, enough light makes it through, sort of in between the water and CO2 bands. There's some wavelengths of infrared light. And we know there's a window around one micron, which is just a little bit

longward of the red edge of the visible. So it's near infrared. It's just a little bit longer wavelengths than you can see. And so we've been able to image Venus at that one micron wavelength on the night side. And we've done that from the Venus Express spacecraft and from the Akatsuki spacecraft. But nobody thought that that extended into the visible. Then these images came out and they said, this is invisible light. And we all looked and said, no, it's not. They did something wrong. But apparently, there are windows that extend a little bit into the visible more than we thought, or their instrument is going out into the infrared a little bit more than they thought. And honestly, I'm still trying to figure it out. But either way,

it's very cool, because you're definitely, you look at the images, and it fits with the top topography of Venus that we know is there from Magellan and from other things. They're definitely seeing the surface of Venus with this instrument that we thought wouldn't be able to. Again, we're back to, well, that's weird. And then I think at this point now with that, we're like Eureka. So there's a new way that we can see the surface of Venus in the red, right at that edge between what is red light that you can see and what is infrared light that you can only sense with detectors. I know what I should have called you, a Venusian. You wrote Venus Revealed, the book you just, you mentioned a few minutes ago, back in 1998.

24 years later, are we finally beginning to see the attention paid to this sister world that is so different and yet so much like us that you and so many others want to see the attention paid to this sister world that, that is so different, and yet so much like us that, that you and so many others want to see? I think so. Yeah. I mean, it's been a, it's been a long road for, uh, for the, the Venus freaks of the community. Um, we, um, we've been advocating for a long time that we need more Venus missions. I mean, the history is interesting because Venus was the first place we went with spacecraft and the first place that the Soviets went. You know, Mariner 2, the first ever successful interplanetary spacecraft went to Venus and there was a whole rush of Venus exploration early in history of planetary exploration. And then it

sort of stopped and the focus went elsewhere. And that's partly because Venus is an easy place to get to in terms of celestial dynamics. It's the quickest trip. It's the least amount of energy you need to, least amount of delta V, you know, velocity that you need to get to anywhere in the solar system. But then what we learned about it on those early missions was that once you get there, it's one of the toughest places to actually explore because you can't see the surface from orbit, at least we thought until these recent revelations. And of course, going down into the atmosphere is very forbidding because the temperature and pressure are so extreme and because the clouds are made out of concentrated sulfuric acid. So it's an easy place to get to, a hard place to do much more than sort of gawk

from orbit once you get there. Because of that, there was a bit of a hiatus. And then I also think that once you have that hiatus and the attention goes elsewhere, that sort of feeds on itself because then you have this whole community of people that are excited about Mars and elsewhere, and they're bringing up graduate students who want to keep doing what they're doing. And so there's this sort of feedback where if you don't do something for a while in space exploration, it gets harder to go back and start doing it. But then what happens is there's such a gap in your knowledge, which is what we have for Venus now compared to elsewhere in the solar system, that it's kind of an embarrassment. And you can really make the case, look, if we want to progress in our knowledge of comparative planetology,

really make the case. Look, if we want to progress in our knowledge of comparative planetology, and especially now with the exoplanets, of which we know there are some exo-Venuses, and which increase our desire to fill in these gaps in comparative planetology, that we have to go to Venus if we want to crack this sort of uber puzzle of how do planets work, and how does Earth fit in with the other planets? We just can't keep ignoring Venus. Some of us have been making those arguments for a while, but they've become persuasive enough recently so that NASA's announced two new Venus missions and the, they're all talking about possible new Venus missions. So, and of course, the Japanese have Akatsuki, which is there now. So it's become, for whatever combination of reasons, it's Venus has become hot again, so to speak. And, you know, I'm really, really excited about these upcoming missions. Do you think that there is a decent chance that all of

these missions, including the two NASA missions, are going to help us reveal that Venus might once a long, long time ago, and for different reasons, have been as hospitable a place for life as Mars was a long, long time ago? There's an excellent chance that we'll answer that question. And I think there's a good chance that the answer will be that it was hospitable. But if it wasn't, that's, of course, really, really important for us to know. Recent models that have been done using general circulation models, the same kind of models we use to predict climate change on Earth. You know, recently, we've been able to apply those to Venus really for the first time in a rigorous

way. And the results point us towards thinking that Venus may have been habitable for a long time. You know, we have every reason to think that Venus had water in abundance when it was formed. And of course, it's incredibly dry today. So it seems to be a story of water loss. But the big question is, when was that water lost? You know, was it lost early on in a rush of evaporation and solar irradiation? Or did the oceans last for a long time and escape into space more recently? Or there's a third possibility that Venus never had oceans, that it was just so hot and there was so much radiation that close to the sun that the water never condensed and was lost to space before oceans ever formed. So those are really, there

are three pictures. It never had oceans. It had oceans really briefly, but lost them quickly. Or it had oceans that persisted for much of its history and lost them more recently. When I say recently, I mean one or two billion years ago, which is recent in planet time. I think that the combination of all these upcoming missions will let us choose amongst those possibilities, and that is going to be great. Obviously, part of me is holding out for wanting it to have been habitable for a long time, because that's just such an enticing possibility. And it is a real possibility with what we know now, that Venus and Earth may have been these two next door neighbor planets that had habitable oceans for billions of years. And there could

have been life evolving on Venus, there could have even been exchange of material between the two planets carrying living organisms. Who knows? That picture is very enticing. But I also need to acknowledge that we're going there to find out, not to just confirm that enticing picture that I want to be true, but to possibly rule it out. that I want to be true, but to possibly rule it out, which of course would be really, really important as far as being able to contextualize how often Earth-like planets end up having stable oceans and stable surface conditions that could facilitate life for long periods of time. Either way, Venus is a big part of our learning how to put Earth in context as far as habitability in the universe.

Such an important point, and one that you have addressed over and over, the ability to look at these other worlds and how understanding them helps us understand our own. And I come back to Earth in human hands, shaping our planet's future, which is absolutely outstanding, as I said. Here's a sentence from the book, which may be key to your premise. And I'm jumping ahead a little bit. Many species have changed the planet to the benefit or detriment of others, but there has never been a geological force aware of its own influence. Do you think we're getting any better at managing our own planet? And as a part of that, how important is it that we study these other worlds?

Yeah, I mean, it's a frustratingly slow process becoming a species that not only is, a geological force that not only is aware of its own existence, but is able to use that awareness to alter its relationship with its home world. And I feel like, you know, we're probably at an early stage of that. And yet there's obviously some urgency, because we are definitely at the phase now where we've become, you know, not just a planetary force, but potentially a danger to ourselves. Arguably, we're not a danger to the biosphere. We're a perturbing force on the biosphere and the biosphere will go on without us. But if that's what happens, but we're definitely a danger to ourselves.

That's what happens. But we're definitely a danger to ourselves. You know, the good news is that we have the tools to understand that and we have the tools to change our you know, we're not helpless. We have the tools to change our energy supplies and we can see a lot of the components of real sustainable global civilization would look like. It would be much worse if we were in this problem and we had no idea how to solve it. That's not the situation we're in. Whether we have the social technology to solve it is a whole other question. And, you know, I'm an astrobiologist. Damn it, Jim, I'm an astrobiologist, not a world leader. But one can certainly see that we are becoming more aware of ourselves as a global entity. And even, you know, one doesn't have to be all kumbaya and say, oh, we're going to have perfectly functioning world government. One can appeal to just enlightened self-interest and

realize that the major players, the powers that be, ultimately don't want to destroy the systems that allow all of us to live. That awareness just needs to sink in. You know, you can talk about the Chinese, and I'm not a huge fan of the current Chinese government. But I do see that I've been to China and the cities are really polluted and they're aware of that and they want to stop burning their coal. They really want to for their own self-interest, if for no other reason, because you literally can barely breathe in Beijing. So there are these forces where it doesn't require a totally benevolent world government for that awareness of how the planet works to sink in enough to create the changes in behavior. And that's the way I see our evolving self-awareness influencing the kind of species

we're going to be on this planet. There's no doubt in my mind that 100 years from now, we'll be completely post-fossil fuels and we'll have modified our global energy resources and we'll have come to a different kind of a relationship with the planet. It's just that we're not doing it quickly enough. So there's going to be some damage. And we'll look back from 100 years from now and say, well, why do we take so long to do that? Just like we look at whaling now. We used to depend on whale oil. Most of us don't anymore. And we say, well, why do we take so long? There are still whales, but we did more damage than we needed to. I think fossil fuels, we're going to look back on it the same way. To the other part of your question, absolutely. Planetary exploration

really helps us get a handle on our relationship with the planet. For one thing, it validates our climate models by looking at climate on Mars and Venus and Titan. Number one, we get confidence that our models basically work, like they do predict the surface temperature of these planets in an overall sense. Number two, we learn things from the ways in which they don't exactly predict things on those planets. We learn things about climate that we might have missed just from looking at Earth now that help us predict future changes. And I won't go into a lot of technical details, but there are aspects of climate modeling that have been strengthened and phenomena that we've learned

about through studying climate and weather on other planets that have really helped us do better at predicting what's going on in this planet. And then just, you know, sort of an overall sort of sense of gaining perspective, you can't really have a handle on yourself as a planetary entity unless you've looked beyond that and seen other unfolding examples of planetary evolution and realized that there are a lot of different ways that planets can evolve. of planetary evolution and realize that there are a lot of different ways that planets can evolve. And that helps us get a handle on the moment we're at in planetary evolution, where whether we like it or not, we have sort of our hands on some of the controls of what's happening on the planet. And rather than sort of hit the buttons at random, like we can try to understand how this contraption works and be a little more artful

in how we interact with it. There's a transition here that you talk about from Homo sapiens, wise apes, to Terra sapiens. What do you mean by that? Well, so Homo sapiens is the title that Linnaeus gave us, maybe thinking aspirationally, when he realized that we were related to the other great apes, but we weren't one of them exactly. He said, well, we're the wise ones. I guess you could quibble with looking at some of our behavior, but in thinking of how we are coming to see, how we need to come to see ourselves and what is really happening in the Anthropocene and what the, you know, sort of the best case scenario, the best outcome of that is that it's not just that we now realize that we are an influence on the planet, but we take control over what kind of an influence we want to be.

And it's my vision for the future of an Anthropocene where we've responded to the knowledge that we're gaining now in a way that allows us to continue in a healthy relationship with our biosphere. And when I say terrasapiens, am I talking about the human future or am I talking about the future of the planet? Because it means wise earth. earth? And my answer is it's really both because it's an identity with the planet, realizing that we have to see ourselves as an integral part of the functioning of this planet, that planetary systems are now in some sense an extension of human systems. It's sort of daunting to realize that, but it's the truth. If we respond to that knowledge by modifying our behavior in a way that, that allows us to, um, to integrate gracefully into those systems, that's then we've achieved the state that I call Terra sapiens. Again, there's no, there's no physical reason why we can't do that. There's nothing we know about the earth

system that will prevent us from doing that. It's just that we have to sort of spread the word and learn to think like the planet that we are. your feeling that science needs, or our sense of science needs to return to what people in the Enlightenment called natural philosophy. Fascinating topic. I hope you'll come back sometime. As I read Earth in Human Hands, I couldn't figure out why for days now, actually, as I finished Lonely Planets, which finishes with a chapter that you called astrotheology. Fascinating. And now with Earth in Human Hands, I've had this song running through my head. It's Pete Townsend's song, I Am an Animal. And I don't know if you know the tune, but it's a terrific song. I can't play it for you here on the show because we'd be sued. But it finally hit me last night as I was preparing for this conversation. That song could be an anthem for Earth in Human Hands.

Here's just a bit of the lyrics. I am a human being and I don't believe all the things I'm seeing. I got nowhere to hide anymore. I'm losing my way. And it goes on from there. I love it. You know, I don't know that song. I'm a big fan of Pete Townsend though.

So I know what I'm going to do right after we get off the phone here. I'm going to go check it out. You and others, I hope. I am an animal. I don't know if it's what Pete had in mind, but that's how I'm going to think about it from now on. Before we finish,

do you have that paragraph that I was hoping you could read from Lonely Planets? Frequently when you ask a guest to do something like this, it's right from the beginning or the very end of the book. But this one happens to be in the middle of the book, page 243. And it's a statement about astrobiology. Oh, yeah. The context is that I'm talking about how science, in a lot of ways, has been under pressure to be more and more pragmatic, that research needs to be justified by what it can produce commercially or practically. And that's sort of been a trend in science.

And then I write, swimming against this stream is astrobiology. It is not for profit and can't pretend otherwise. We explore space for reasons that are romantic and idealistic. The universe beckons. We want to go because we want to know. With astrobiology, there is no fronting that the rationale is practical or the benefits material. We do it out of our curiosity and longing to satisfy the human need to know the cosmos that spawned us. Fancy that, a scientific movement that is justified on fundamentally spiritual grounds. Wow. David, I so look forward to you coming back. We can talk about SETI. We can talk about natural philosophy. We can talk about life, the universe, and everything. But thank you for

this conversation. And again, congratulations on being named a fellow of the AAAS. Well, thanks very much. It's a pleasure to talk with you, and I'd be happy to come back anytime and talk about any of those topics. It is time for What's Up on Planetary Radio. Here's the chief scientist. That's Bruce Betts. He's going to tell us about the night sky and we'll have a contest and do some other fun stuff. Welcome back. Hey, good to be back, Matt.

Hi. Hi. I got off the ski jump okay, by the way. I was so scared. It looked like such a bad wipeout. That was really fun. I've been playing that for people because it was just such a cute ending for last week's What's Up.

We won't equal it today, but you'll equal it with whatever else you need to tell us. Why, yes, I will. For those of you hanging out in the pre-dawn, it's Planet Party Central over in the east. We've got super bright Venus and below it, reddish Mars. And on the morning of the 27th, the moon, crescent moon, will be hanging out with those. And if you've got a really clear view to the horizon, you can go to the lower left of those planets, and there's Mercury, and then yellowish Saturn. Mercury will get harder to see. Saturn will get easier as it rises up in the sky. In the evening sky, it is planetless.

Still a fun place. Lots of good stars. Of course, I've mentioned the constellation Orion. If you check out under Orion's belt is Orion's sword. Three, what look like three stars for those who aren't aware. The middle one is actually the Orion nebula. It's kind of fuzzy if you look at it even with your eyes, and certainly with binoculars or a telescope.

This week in space history, it was 1966 that Gemini 9's primary crew of Basset and Sea were tragically lost in a plane crash. But in happier news, in 2007, after about a year-ish of travel, New Horizons flew by Jupiter and got cool data at Jupiter as it readied for its long journey to Pluto. I'd forgotten how quickly it got to Jupiter. I mean, really, it set a solar system world speed record for getting to the outer planets, didn't it? It did, and also for leaving the Earth. But then Voyagers were trickier with their gravity assists and going for speed. So they're actually going faster at the equivalent distances these days.

Anyway, that's dangerously blurring into a fact. So instead, let's give you a random space fact. So the supermassive, supermassive black hole at the center of the Milky Way galaxy is thought to have the mass equivalent to 4 million suns. Bonus space fact. This is called Sagittarius A star, written as an asterisk. And it was originally part of a radio source that got isolated. There was Sagittarius A and then Sagittarius A star because one of the co-discoverers, Robert Brown, said in a 1982 paper,

because the radio source was exciting and excited states of atoms are denoted with asterisks. I had no idea. That's fascinating. And four million suns. Yeah, I'd say that qualifies as supermassive. Yeah, so do I, but hopefully that'll change. Let us move on to the trivia contest. I asked you, what Olympic athletes appear in pictures on the Voyager Golden Record? How do we do, Matt? People just love this. Elijah Marshall in Australia. Damn, Bruce, you guys weren't kidding when we called you master of the rabbit hole. Where do you discover this stuff? It comes out of my freaky brain and then out of the internet and straight to your rabbit holes at home. Well, let's fill that rabbit hole. Here is,

he's back, our poet laureate, Dave Fairchild in Kansas. Olympic athletes, five in all, appear on Golden Records riding out with Voyager in analog. They're pictured Borzov, Roberts, Suwen Ho, all sprinting with Moa Rossi and working on the balance beam. A stroboscopic Rigby, Kathy Rigby. She's actually got several images, right, because it's stroboscopic. You see her at different positions along this this routine that she was doing on the balance beam. Very cool. Indeed.

Very cool. She counts as one athlete, though, just to be clear. Okay. So five athletes. And we have a winner. She has not won in just over two years, but she is a past winner. In just over two years, but she is a past winner, Courtney Katz in Pennsylvania provided Valerie Borzov, Matsapi Morosi, Kathy Rigby, Edwin Roberts, and Sue Wen Ho. And four of them, I guess, all in one race? Yes, all in the, of course, it was Heat 3 of Round 1 of the 1972 Olympic men's 200-meter race, and the four captured running in that race. And then Kathy Rigby, as you mentioned, on the balance beam.

Courtney, congratulations once again. You are going to be getting a copy of this brand new book, Impact, How Rocks from Space Led to Life, Culture, and Donkey Kong. And it's by, and it's hard to say what he does, meteorist, meteoriticist? Meteoriticist. Oh, I like that. Thank you. Say it again. Meteoriticist. Greg Branecka. It's a fun book. I think I'd said before that he did some illustrations for it, little hand-drawn illustrations. And it's about the significant role that meteorites have played and continue to play in our life. So again, congratulations, Courtney. Norman Kassoon in the UK actually wrote to the Olympics Study Center, which is part of the Olympic Foundation, and got an answer to this question from the research coordinator, someone named Estelle Timofte. So it's brilliant. Thank you for providing the letter, Norman.

But now you know this was still missing Kathy Rigby in the separate image. So you'll have to go back to the Olympic Committee and complain. It won't be the only complaint they're hearing these days. Oh, that's true. Ooh, burn. But it was nice of them to do that and to respond so rapidly. Yeah, faster, higher, stronger, together. New and improved version, right, of the Olympics motto. Oh, I thought that was planetary radio motto. Oh, it should be, shouldn't it? Yeah, it makes so much sense. Here is Daniel Sorkin in New York. This question got me thinking about future off-Earth Olympics and what events might be possible in low gravity or microgravity, that's one for you to think about, Bruce. I think there might be potential.

Oh my gosh. Before I came up with this one, that was a rabbit hole. I went down, and my brain started breaking when I was pondering the physics of ice skating and how it would change on Europa, and I decided to move to something else. But I'll keep thinking. You know it's coming, right? Here is one other bit of poetry from Jean Lewin in Washington. Just one stanza. We don't have time to read the whole thing, but it's a lovely poem.

And here is the second stanza. For sprint 100 meters, one shows her strength and grace with greetings from our planet home and sounds of the human race. Oh, that's nice. Very nice. We're ready for another. Well, you claimed that people wanted another math question. It's not complicated math, but you do need to do combined research with math. We're going into Messier objects and Messier numbers, the deep sky objects that were first compiled by Charles Messier. And here's your math question. What is the answer to the following math problem? published in Charles Messier's 1781 catalog. There's a lot of subtlety here,

but it's the number of objects published and multiply that by the Messier number of the Trifid Nebula. Now subtract the Messier number of the starfish cluster. And that's what I'm looking for. Number of objects published in this catalog, Messier number of the Trifid Nebula multiplied and then subtract off the starfish cluster Messier number. How do they

enter? Go to planetary.org slash radio contest, or you can find it through the following mathematical algorithm. No, I'm just kidding. Well, for the three of you who will enter this time, no, prove me wrong. Prove me wrong, because we're going to add to that algorithm a Planetary Society kick asteroid, rubber asteroid, for anybody who works their way through that bit of math that has been handed to us by the chief scientist. That'll be coming your way, but you've only got until the second. That'll be Wednesday, March 2nd at 8 a.m. Pacific time to answer this one for us. Wow. Okay. No, I'm glad you did this. And we're done. All right, everybody go out there, look up the night sky and think about what Matt's Messier number might be. Thank you. Good night. It's a mess of Messier numbers

extra points if you can identify which cartoon character I'm paraphrasing there he's Bruce Betts he's no cartoon character he's the chief scientist of the planetaries nope who joins us every week here for what's up Planetary Radio is

produced by the Planetary Society in Pasadena, California, and is made possible by its lively members. You can add to evidence of intelligent life on Earth by visiting planetary.org slash join. Marco Verda, Jason Davis, and Ray Paletta are our associate producers this week. Josh Doyle composed our theme, which is arranged and performed by Peter Schlosser. Ad Astra.