Planetary Radio • Jul 20, 2022

Science from the Moon, and former NASA chief scientist Jim Green looks back

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James Green

Senior Advisor to NASA and host of Gravity Assist

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Bruce Betts

Chief Scientist / LightSail Program Manager for The Planetary Society

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Mat Kaplan

Senior Communications Adviser and former Host of Planetary Radio for The Planetary Society

Host Mat Kaplan leads with a special announcement. Then we spend a fascinating hour with the former director of NASA’s Planetary Science division and retired chief scientist Jim Green, who reports on a recent workshop that explored the potential of radio telescopes on the Moon’s farside. He also shares anecdotes from his long history of space science and NASA service.

Group photo from the Unique Science from the Moon in the Artemis Era Workshop
Group photo from the Unique Science from the Moon in the Artemis Era Workshop An exploratory workshop focusing on the feasibility and value proposition of using the Moon as a platform for unique astronomical science observations, while addressing key engineering challenges and risks.Image: NASA
James Green underwater
James Green underwater James Green in a pool at NASA's Marshall Space Flight Center where he served as a safety diver.
Jim Green Curiosity anniversary
Jim Green Curiosity anniversary Jim Green speaking at a public event on Aug. 6, 2013, at NASA Headquarters observing the first anniversary of the Curiosity rover's landing on MarsImage: NASA

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Trivia Contest

This Week’s Question:

What was the first published scientific work to include telescopic observations of the Moon? It included drawings.

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A Planetary Society KickAsteroid r-r-r-rubber asteroid!

To submit your answer:

Complete the contest entry form at or write to us at [email protected] no later than Wednesday, July 27 at 8am Pacific Time. Be sure to include your name and mailing address.

Last week's question:

Generally speaking, what goal does the JWST heat shield share with the packaging of the now retired McDonalds McDLT hamburger?


The winner will be revealed next week.

Question from the July 6, 2022 space trivia contest:

27 stars are displayed on the national flag of Brazil. Only one of these is displayed above the white band crossing the center of the flag. What star and what Brazilian state does it represent?


The only one of 27 stars displayed above the white band crossing the flag of Brazil represents the star Spica and the Brazilian state of Pará, part of which is north of the equator.


Mat Kaplan: A visit with former NASA chief scientist, Jim Green, this week on Planetary Radio. Welcome. I'm Mat Kaplan of The Planetary Society with more of the human adventure across our solar and beyond. Jim Green headed NASA's Planetary Science Division for an unprecedented 12 years before becoming the agency's chief scientist. He has returned to tell us about a recent workshop that considered doing big science from the moon. But Jim and I will mostly look back across his rich and fascinating career. You're in for some great stories.

Mat Kaplan: I'll get to space headlines from the Downlink in a couple of minutes. First though, I have something to share with you. Here's how I express it in a message we've posted for all to see at I had been working at The Planetary Society for two years when co-founder and executive director Louis Friedman gave me the thumbs up. It was only a few weeks later that Planetary Radio premiered. Lou was my first guest on that November 25, 2002 episode. It also featured what would become a regular visit with our former colleague, Emily Lakdawalla. We closed the show as we have now ended over 1,000 episodes with What's Up. My friend, Bruce Betts, told us what to look for in the night sky, looked back across the history of space exploration, provided a reverberating random space fact, and offered an entertaining space trivia contest challenge.

Mat Kaplan: That show could only be heard on a single radio station and our primitive website. The series has changed very little since then. The most significant upgrade was the addition of our monthly Space Policy edition six years ago. So other than a new theme, listeners who had only heard that first episode would have no difficulty recognizing Planetary Radio today. My pride in this achievement is far greater than anything else in my professional life. We're now in the top half percent of podcasts. The broadcast version of each episode is aired by about 100 public stations. We have presented more than 2,000 space exploration leaders to an eager audience. We've gone on stages around the world to present Planetary Radio live. And I visited many of our planet's most important and inspiring sites where space science and exploration are advanced.

Mat Kaplan: It has been a glorious odyssey, and it's time to step back. I told our wonderful chief operating officer, Jennifer Vaughn, many months ago that two decades of hosting and producing Planetary Radio would be enough. I'll mark the 20th anniversary in November of this year by handing over the reigns to a new host. Our search for this person has already begun. I'm very grateful to know that the Society will still keep me busy. Jennifer and others have asked me to use some of the time I'll reclaim to participate in other important Society work. And I very much hope that my voice will still be heard on Planetary Radio now and then.

Mat Kaplan: My greatest joy in this job has always been the opportunity to talk with my guests. I regard all of them as heroes, and I look forward to more conversations. There will be another opportunity to express my gratitude to everyone who has made Planetary Radio a success and a personal joy. For now, I'll simply thank all of you who listen and who have supported the Society so generously. We will keep you informed of our progress toward this transition. I promise that the best is yet to come. Ad Astra. That's it. As always, you can write to me at [email protected].

Mat Kaplan: Now those Downlink headlines beginning with the marvelous images from the James Webb Space Telescope. As you'll hear from Jim Green, they now include preliminary studies of Jupiter. Jim will talk about how observations within our solar system were added to the list of targets for the JWST. NASA's Perseverance rover collected its ninth sample from Jezero Crater. This one came from an ancient river delta. Then there's that big rocket that blew up. SpaceX was not planning to ignite or launch the super heavy booster on the launch pad at its Texas facility, but things happen. We've got more from the July 15 edition of our free newsletter at

Mat Kaplan: Jim Green was in Portugal when we met online a few days ago. As you'll hear, he was there to teach in this summer's International Space University session, something he has been doing for many years. This may explain the poor audio quality. It's one of those planned rad conversations that is so special I think you'll put up with it. I certainly hope so. Jim Green, welcome back to Planetary Radio. It is always a pleasure.

Jim Green: Well, thanks so much, Matt. I'm delighted to be here.

Mat Kaplan: I have so many questions for you. Then I realized we have to start with the most obvious one. As the audience hears this, it will have been barely a week since that glorious revelation that came out of Goddard Space Flight Center and around the world, those images from the James Webb Space Telescope. You're out of the country. Were you watching? What was it like for you?

Jim Green: I did. I did log on to and was one of the gazillions that watched it live. I really thoroughly enjoyed it. I'd also seen President Biden's release of the deep field the night before, so I was ready for some even more excitement.

Mat Kaplan: We could spend an hour just talking about those images and what this telescope promises over the next, let's hope, 20 years at least. But I just want to ask you about one, since, after all, you did run Planetary Sciences. That spectra that we got from that big exoplanet, WASP-96b, what does that say to you about both what it actually revealed, that spectrum, but also the potential for other exoplanet observations?

Jim Green: I loved it. There's all kinds of stuff in there, but what they did, of course, was just show us the water vapor bands.

Mat Kaplan: We heard from one of the JWST co-investigators on last week's show, Tom Greene at Ames Research, about his high hopes for the exoplanets that he and others want to look at in the future and that maybe we'll be finding things at least as and maybe much more interesting than water in future spectrum.

Jim Green: Oh, we will. Oh, yeah. Oh, yeah.

Mat Kaplan: Thank you. Oh, I like that.

Jim Green: No question about it. But before we leave this topic, we should really talk about another image that's been released, and that, of course, is of Jupiter.

Mat Kaplan: Oh, yes, yeah.

Jim Green: I really love that. It shows several things, that Jupiter is hot. It radiates in the infrared and I mean a lot. So this tells them the planet is still cooling off from when it was made 4.6 billion years ago. More important is that we track them. JWST actually looked at things in our solar system and moved with them to be able to get the image.

Mat Kaplan: That is just mind blowing. I know that they were talking about what a challenge it would be to capture these solar system objects, partly because they're so bright. I never thought about the tracking.

Jim Green: Oh, yeah.

Mat Kaplan: It's just amazing.

Jim Green: I know all about it. I have the back story you need to know.

Mat Kaplan: Oh. Well, do tell.

Jim Green: In 2007, I was head of Planetary Science. John Morris was the head of astrophysics and Alan Stern was the associate administrator. As we typically do when we view these big strategic missions, they came in and they gave us a wonderful overview of what was going on. So after about an hour, I raised my hand and I said, "This is fantastic. I love it. But what about objects in the solar system?" The reason why I said that, planetary scientists get about 8% of the Hubble time even though about [inaudible 00:09:00] percent of their press releases come from solar system objects.

Mat Kaplan: Oh, yeah. There's an interesting comparison.

Jim Green: It just happens. Things happen in the solar system, Hubble's able to capture it, and that draws a lot of attention to it. Hey, nothing wrong with that. When I asked my question, the project returned and said, "This is an astrophysics mission. This is not a planetary mission. What are you talking about?" I'm paraphrasing it. Alan Stern tasked them to take a look at what it would take to be able to observe things in the solar system. So a month or two later, they came back and they said, "You caught us at the perfect time. We're developing the requirements for this work, and we can fit it right in. We know how much code. We've taken an estimate of that. It will cost about $12 million." Alan turned to me and said, "Jim, what are you going to do about it?" I said, "Who do I make the check out to?"

Mat Kaplan: I think that's a bargain. By the way, last time I checked, the solar system was part of the cosmos, so I do think it's appropriate.

Jim Green: It is.

Mat Kaplan: I'm going to thank Alan next time I talk to him, and I thank you now because I'm looking forward to what's happening in our own neighborhood.

Jim Green: Yeah, me too. We've got to be able to make these kind of measurements of our planets as comparison to what JWST is going to do to exoplanets, apples to apples.

Mat Kaplan: Great way to start out. Let's get to at least the first of the topics that I knew I wanted to talk to you about today, and that is this recent workshop, which I mentioned to the audience in my opening. Azita Valinia, who directs the NASA Engineering & Safety Center, I think she organized the workshop working with people like you. She is attending a conference in Europe. Was unable to join us today. She was very happy to have you tell us about this. This recent gathering happened in early June. I noted on the agenda you delivered an overview on the first day of the workshop. I hope that listeners will take a look at your slides because they describe really, to me, an awe-inspiring spectrum of science mysteries that extend from our own solar system out to the borders of the cosmos really.

Jim Green: They do. They do.

Mat Kaplan: First of all, is this evidence of the science, of the potential of science that could be done from the moon?

Jim Green: Oh, yeah. The concept of doing these kind of workshops is really important for NASA. We have to be able to think ahead about what might be possible from different venues. Of course, what's happening that we [inaudible 00:11:56] out in the [inaudible 00:11:56] region that there are parts of the radio spectrum that we use, but we're using it so heavily it dominates any natural signal and that there's parts of the radio that we can't see, and those are also extremely importantly areas of the cosmos that we need to interrogate. It is kind of like the last vestiges of open wavelength that we really haven't had a chance to look at.

Mat Kaplan: I guess this explains why we're seeing radio telescope systems like ALMA built as high up as we can get them on Earth for one thing. But I also think back to when I was a kid and I started seeing way back then these artists's concepts for radio telescopes on the far side of the moon.

Jim Green: Me too.

Mat Kaplan: This is a good piece of what we're talking about. I mean, this is a long-held dream.

Jim Green: In fact, I remember specifically reading a Scientific American article about the possibility of radio telescopes on the moon. Here, I had the privilege to be able to summarize in this important frequency range, what could we see? It's really exploded the kinds of things that we can't observe from the Earth, stuff up to 10 megahertz, exoplanet magnetospheres.

Mat Kaplan: Wow.

Jim Green: The radio aurora that occurs in those magnetospheres tells us all kinds of things about the importance of the magnetic fields in creating habitable planets. Also, the sun kicks out a bunch of stuff in these radio frequency ranges, and so that's important for us to monitor for space weather purposes. Then, of course, we know right after the Big Bang there's a special event that happened. Of course, we've never probed it. So astronomers call it the Dark Ages, but let's shine some light on that. So in the 100 kilohertz to several megahertz range, we can look back and see how hydrogen right after the Big Bang is emitting in this 21 centimeter line that's Doppler shifted to us into this frequency range and how that matter comes together then to start stars.

Mat Kaplan: Wow. What are some of the other things that came up at this workshop?

Jim Green: Well, right now the big mystery in fast radio bursts are, what the heck are they? Are they neutron stars? Are they black holes? These are some of the things that we can monitor better than we ever have before. When we look at the sun, we know that there's a [inaudible 00:14:50] that generates extreme ultraviolet radiation. This is important because it heats our atmosphere and rises up, sweeps out fast, and is a very important part of the solar cycle. But we can get an indication of what's going on in this radio frequency range of hundreds of megahertz. Now we can see hundreds of megahertz.

Jim Green: But the problem is there's so much interference with other things going on on the ground that by going to the far side of the moon, we get this radio window we've never seen before up to about 10 megahertz. Then from 10 megahertz up to 100 gigahertz, we then can see our own planetary magnetospheres' radiation belts, solar activity monitoring, fast radio bursts. In fact, the really spectacular observations of the black hole [inaudible 00:15:53] occurred, we can compliment that. It really is all about getting another radio observatory at a higher altitude and further away from the Earth that then the radio interferometry technique could work so we could extend the Event Horizon Telescope concept all the way to the moon, so the resolution that we can get is enormously different.

Mat Kaplan: Wow. That'd be a heck of a baseline, wouldn't it?

Jim Green: It would be.

Mat Kaplan: Was there a discussion also with the workshop about the kinds of science that we need to do on the moon just to understand that body better?

Jim Green: Well, we've done those kind of workshops several times before. As head of Planetary, I was also supporting workshops where, going back to the moon, humans can collect more samples where we can understand much more about the interior of the moon, tease out bombardments that's happened on the moon, and do a better job on dating things elsewhere in the solar system. There are so many things like that. This is a step that we've never really looked at before, and the workshop was a perfect venue to be able to do it.

Mat Kaplan: Do you now see within NASA a real commitment to making sure that this coming new era of humans on the moon, Artemis, that it enables and really supports the kinds of science that you're describing?

Jim Green: I think so. What we do when we do these kind of workshops is really get the creative juices flowing not only in the science community, but in the engineering community, precursor missions that could be laid down that may be robotically [inaudible 00:17:41] controlled can get us a tantalizing glimpse before then we make this bigger [inaudible 00:17:47] about having human tended radio systems that we could build.

Mat Kaplan: Do you get any good feeling, optimism encouraged by the success of China putting something on the far side and putting sort of a rudimentary radio telescope back there?

Jim Green: Well, sure. Any science that comes from observations from space that's open and public will be thought about, considered, talked about, and will be important for us to make decisions on how to build on knowledge that we gained.

Mat Kaplan: It's going to be expensive. It's going to be hard. If humans go, it's very likely, almost certainly going to be dangerous to do science on the moon. The potential benefits that you're talking about, the kinds of science we can do, do they outweigh these other factors?

Jim Green: Good question. It's very much like, I think, when we launched Hubble, and before we did that, make sure it was serviceable because we knew it was going to be revolutionary telescope. And it was. Now we're looking at in the same way how we can do science from the moon and do some revolutionary things. That's always a question that has to be weighed, and it's weighed against the knowledge we gain, and it's enormous in this case.

Mat Kaplan: It's not easy to do science at the South Pole or the Antarctic either, is it?

Jim Green: No, it's not.

Mat Kaplan: Your NASA colleague, former associate administrator and former astronaut, of course, John Grunsfeld, he delivered a keynote at this workshop titled Synergy between Robotics and Human Exploration, which you just hinted at there a moment ago. He included this provocative statement: "Robots don't discover anything." What was John getting at?

Jim Green: Well, what he was getting at is really our creation of robots and then those basically are the extension of ourselves, whether they're on the moon or on Mars, and making those kind of discoveries, it really comes back to enhancing our own knowledge. So that's what he was talking about. In addition to that, he was quite emphatic about when we are exploring the moon, we're going to have our pet dog Rover with us, maybe something the sizing of Curiosity. Who knows? But having the laboratory capability that you take a sample and can do a pre-analysis right there on mineralogy or composition and radio those results perhaps back to Earth or back to the habitat, something that then allows the astronaut to complement his already a massive ability to pick samples and make decisions in the field and rapidly go to places that we need to go and discover more, new, and exciting things.

Mat Kaplan: We're still talking about a few years down the line before, as NASA likes to say, that first woman and next man walk on the surface of the moon. But there's already some pretty cool stuff underway thanks to recent developments and projects at NASA, including commercial payloads going to the lunar surface. I just wonder what your thoughts are about the more immediate kinds of science that we can look forward to maybe in the next two or three years.

Jim Green: Oh, yeah. This is just an exciting era. What's happened has been a revolution in our understanding of what's going on at the moon. That started about 10 years or so ago where we really could tease out that there's some really important organic and volatiles that are in these permanently shadowed regions. The fact now that we have some indication that there's maybe hundreds of millions of tons of water, and perhaps many other things, is really quite exciting. This enables us then to think about leveraging that region to be able to provide resources for it. It's also an important place because we can get constant power like solar from the sun placed in the right places there. In addition to permanently shadowed, there are permanently lit areas. It really enhances our interest in going exactly there.

Mat Kaplan: Are you excited also about the new technologies that are being developed? The efforts of these companies, some of them very young companies, designing lunar landers. But I'm also thinking of the individuals, some of them funded by NASA through NIAC, we talk about them on this show, to do the kind of science that you're talking about, maybe to use robots, using institute resources, to build that radio telescope on the far side. This is pretty cool stuff if you're any kind of a geek.

Jim Green: But there's another thing going on, this concept of sustainability. This has really taken hold and because new technology helps facilitate that concept. Let me give you an example. Everything that we take up requires an extensive amount of resources to get it there, and we want to be able to use it, reuse it, and not throw it away. Things from packaging food to things that we do in a space station that ends up, at the moment, being garbage, we can jettison that. We're not going to fill up a crater with garbage on the moon. It's not going to happen. We're going to be able to take that packaging and then melt it and then put it, as part of a 3D printing technology, to make other things out of it. So we've got to continue to think about sustainability and the technologies that we want to implement to be able to turn one thing into another. We turn it into something else that's useful.

Mat Kaplan: I like that picture that you paint. As always, I love the passion that you bring to talking about these things, which is sort of a segue into, as we say in the business, changing gears here.

Jim Green: Are we in high gear or low gear?

Mat Kaplan: Always high gear I think in your case.

Jim Green: Okay, all right.

Mat Kaplan: You obviously enjoy sharing what my boss, the Science Guy, calls the PB&J, the passion, beauty and joy of science and space. A great example is your popular NASA podcast, Gravity Assist. I just wonder where your passion for all of this stuff, and sharing it, got started? For most of us, it was a very long time ago.

Jim Green: Well, even when I was at Marshall Space Flight Center, we were constantly thinking about how can we talk about esoteric topics as magnetospheric [inaudible 00:24:50] to a general audience, and we created some easy looking graphics that we lovedand used. So that was important, and I enjoyed talking about it. My PhD thesis advisor, Don Gurnett, always loved doing public talks, and he was so good at it that I also aspired to that. I learned a lot from him. So that really probably started early. But I have to tell you, it really kicked off in 2012 when we decided that we were going to bring everybody along with us landing Curiosity on Mars.

Mat Kaplan: Well, you know you had several thousand of us in the Pasadena Convention Center who were right there with you jumping up and down with joy when that rover got cranked down to the surface.

Jim Green: Well, we had enclaves of those thousands of people, as you said, everywhere, in museums. In fact, Times Square had like 5,000 people watching it on the jumbotron in the rain.

Mat Kaplan: We actually used a live shot of those people sitting on the ground in Times Square looking up at that big screen. We used it during our show. If that didn't demonstrate to any doubters out there the kinds of enthusiasm that the general public has for this stuff, given a little bit of encouragement and a little bit of information delivered the right way, it's there. I mean, you see it all the time.

Jim Green: This particular excitement was really infectious. I even got a lot of the scientists to get knowledgeable about what Curiosity is going to do, understand how the [inaudible 00:26:45] goes so that they could communicate back to their local public or their press. And that worked too. The more we can get people involved in this, telling people what they're getting for their money. We're really taking funds from taxes. We have to be good stewards of that money. What we return is wonderful knowledge that we can act on in many ways that help us understand the evolution of our Earth, what will happen. We now know what happened on Venus can happen on Earth. What's happened on Mars can happen on Earth. So comparative planetology is really important. These are things that we need to communicate. And it's just once, it's often.

Mat Kaplan: What do you think of what a lot of us see as this transition that has taken place over quite a few decades now that has taken us from Carl Sagan, a truly great scientist, but one that was held with such disdain by many of his colleagues because he dared to go on the Johnny Carson show, or he dared to make a popular television series of his own, to today and the change in attitude, not just by scientists, especially young scientists, but also by their managers toward this kind of activity?

Jim Green: It's a welcome change. I'm only sorry that Carl had to be the pioneer in that area and take that criticism from his colleagues, which is always hard to do, but he did it with enormous dignity, and he did an enormous job helping scientists really saying, "Hey, it's okay to talk about what you're doing."

Mat Kaplan: Now it sounds laughable, but back then, not so much.

Jim Green: Yeah, I know.

Mat Kaplan: Fascinating. I got a quote from Lori Garver's new book that somebody said to her, I don't remember who said it to her, but it was that "The first person who goes through the wall always gets bloodier than the people who follow."

Jim Green: Yeah, there's an opening there that has to be made.

Mat Kaplan: You mentioned the great Don Gurnett and the influence he had on your life. I want to hear more about that. But, my gosh, that would've been enough. I know a lot of people out there who are leaders now who were lucky enough to study under him as you did. But you also were mentored by, my God, James Van Allen, the man the Van Allen belts are named after.

Jim Green: That's true.

Mat Kaplan: What a start for your career in this business.

Jim Green: They're all Iowans.

Mat Kaplan: Right, University of Iowa.

Jim Green: Well, Van Allen was born and raised in a small town just down the road called Mount Pleasant. If you go another 30 or 40 miles east, you end up in Burlington, Iowa, where I was born. Don Gurnett was born in the Cedar Rapids area. But it was really Van that, at the end of the Explorer series, who was offered the job and opportunity to stay in the Washington, DC, Maryland area, decided, "No, I'm going to go back to the University of Iowa, and I'm going to teach." With that, he bought the space program with. Don Gurnett was the next generation student that he had and really inspired him and Lou Frank and just a cadre of unbelievable, fantastic scientists. These scientists, anything they did in space was new. I'll give an example. A really good, solid scientific career is about a hundred peer review papers. When you think about that, between a [inaudible 00:30:41] and 35-year career, that's like three solid papers a year, and that's kind of tough to do. Don had more than 650 papers.

Mat Kaplan: Wow.

Jim Green: I would go in his office and we were talking about this and that and looking at data, and he was always working on a paper. How he did it is he just had a pad and a pencil, and he would just write it out. I'd walk in and there he is working on his latest paper. So he was an era for which anything they launch made huge discoveries. I knew what that was like. I had the privilege to be involved in [inaudible 00:31:27] image, in particular, a wonderful experiment, which was a Radio Plasma Imager called RPI. We generated radio waves, and then the plasma all around us would interact and reflect them back. We then can deconvolve and find out all kinds of stuff by this kind of remote sensing. I mean, one year I wrote 12 papers alone.

Mat Kaplan: Wow.

Jim Green: That's like one a month.

Mat Kaplan: What a start. Were you still an undergrad, or had you become a grad student by the time you were working with this image data?

Jim Green: Oh, I was a well-established scientist by that time.

Mat Kaplan: Ah, sorry.

Jim Green: I had about 50 papers by then. I was at Goddard Space Flight Center. I started out at Marshall and then spent five years there, and then 25 years at Goddard before I went down to NASA headquarters in 2006.

Mat Kaplan: Much more of my conversation with Jim Green is just ahead on Planetary Radio.

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Mat Kaplan: By the way, was it during your time at Marshall that you got to do a lot of time in the pool?

Jim Green: Yes.

Mat Kaplan: Tell people about that.

Jim Green: It's another thing that NASA does is human exploration and how they practice what they do in space is in a water tank. When I was at the University of Iowa, my roommate was a scuba diver. I ended up becoming the Scuba Club president for the University of Iowa after I got my certification. Really enjoyed that, but I dove in really horrible stuff, like rivers, quarries, lakes, visibility sometimes maybe four inches.

Mat Kaplan: It's Iowa. It's not Hawaii.

Jim Green: It's Iowa. It's Iowa. It's Iowa diving, always cold. But I loved it. Then had an opportunity to take a tour of Marshall. I walked into this 70-feet across 4 or 5-feet deep bathtub with the shuttle right in the bottom of it. "God, I got to get in that." Within year, I applied to be a diver, and I got in it. So I made about 150 dives and did some wonderful dives on Hubble repair, building space station, the repair of the Solar Max [inaudible 00:34:25]. One of the most spectacular mission that the public knows hardly anything about because it was the first use of the Manned Maneuvering Unit, this Buck Rogers backpack that you just fly over the place, the thing that George Clooney did in Gravity. We practiced that in the tank, really fabulous stuff.

Mat Kaplan: Very cool stuff. But I want to go back to Iowa for a moment or two. It sounded like they let you, and back then you were still a kid, but they let you get access to, what I assume were at the time, some of the most advanced computers available like three UNIVAC systems. Are those old mainframe systems that filled rooms?

Jim Green: Hey, you really did your background research.

Mat Kaplan: Oh, well, I [inaudible 00:35:18]-

Jim Green: I was a-

Mat Kaplan: ... back that far too.

Jim Green: ... computer operator. I did that part time. As a graduate student, I was taking classes, and I was paid to be a researcher. To make ends meet I got a part-time job, and that was being in the computer room, University of Iowa computer [inaudible 00:35:40]. It had three machines. They were all UNIVAC. This is a time when scientists and others learning how to use computers would type up their programs on cards. You put it in a deck, and then you go to a window and hand it to an operator. I'm the one on the other side that takes those decks and run them. I had the 4:00 to 12:00 shift.

Jim Green: I have to tell you, I really had a wonderful time doing that. I learned so much about managing computers, the importance of... I mean, I could add a teletype-like console, this is like in 1980, like you have in front of you is your computer keyboard, and I'm running these computers and run all kinds of programs. Then when I returned the data, I would say, "Oh, I think some neat things came out of this. You got great plots. What are you doing?" So I would learn about some new science from all these other scientists in the Physics Department that are using these computers. So I actually had a great idea as to what the University of Iowa was doing in space.

Mat Kaplan: Wow.

Jim Green: Not only that, I would work 4:00 to 12:00, and at 12:00, a young lady would come in. She was a single mother. She would do the 12:00 to 8:00 shift. [inaudible 00:37:05].

Mat Kaplan: We're talking midnight to 8:00 a.m., right?

Jim Green: Midnight to 8:00. Yeah, yeah, midnight to 8:00. Sometimes with childcare problems, she just couldn't do that. So she'd call me up and say, "Jim, I can't get in. Is that a problem?" I said, "Don't worry. I got it." So I would do her shift. Now, what was really great about it, don't tell anybody at the University of Iowa, but I would finish all her work by about 4:00 in the morning. So that means I got three fast computers, this is relative at that time, to my beck and call. Then I did my own individual research. That involved ray-tracing in anisotropic magnetospheres. This is really where I cut my teeth on taking theory and applying it to the observations we were making by simulations. And I did a lot. Oh, man, I had them at my beck and call-

Mat Kaplan: This is-

Jim Green: ... and I made huge progress.

Mat Kaplan: This is exactly where I was hoping to go with this. Now, I'm assuming the smart thermostat that's on the wall downstairs below me probably has more computing power than the UNIVAC that you worked with.

Jim Green: Oh, yeah. Oh, yeah.

Mat Kaplan: But did you begin to get an inkling of what computer resources would be able to do for us in terms of modeling the cosmos and a lot of the great questions?

Jim Green: Oh, it was just going to do nothing but improve. The three UNIVACs were like a view of history, but a short-term history. The UNIVAC I was really primitive, and it generated paper tape. We would run that to generate paper tape that would then go out to one of the radio observatories to track one of our satellites. That's how we tracked it.

Mat Kaplan: Good Lord.

Jim Green: Then UNIVAC II came in, probably a couple times faster, but it now had tape drives connected to it. Now you can do a lot more with it. Then when the UNIVAC III came in, man, that was just heaven. That was several times faster than the UNIVAC II. That was a matter of just a few years. That whole field was exploding, and I could easily see that.

Mat Kaplan: Well, Moore's law before Moore made it a law. I'm fascinated to hear how having this access to other scientists' data, because you were processing it for them. Did that also have something to do with helping you to understand how multidisciplinary studies, particularly planetary science, would need to be?

Jim Green: I think so. I always had that drive to learn many different things. That's kind of interesting in the sense that typically at this time your advisor says, "If you want to be a famous scientist, you have to burn a hole and steal and know everything about one topic. Ignore everything else." I never [inaudible 00:40:18] that. I wanted to apply what I knew to other disciplines, to other things, and combine them. So when I became the head of Planetary, that was just like heaven. I got to know new scientists. Even though I was a planetary magnetospheric scientist where I did work on Jupiter and Earth, I learned all kinds of things about the plants, the geology, the atmospheres, and it's all connected. That really excited me, and I really enjoyed the whole time I was there.

Mat Kaplan: How did that attitude then extend into your later job when you became the head of all science at NASA, the chief scientist?

Jim Green: Well, it probably helped me because I had an appreciation of everything that NASA was doing and a deep appreciation as a scientist for what human exploration was trying to do and the struggles that they were doing. In fact, as a head of Planetary, I went out of my way to try and connect our scientists and those human exploring engineers by developing a Lunar and Planetary Institute and venues where they could work together. That really helped me, I think.

Mat Kaplan: You may have just at least partially answered my next question, and that is to tell us the things that, from your time as a leader of Planetary Sciences and then as chief scientist, what are you most proud of, projects either that you were involved with or things that happened at NASA during that period? Give us some highlights here.

Jim Green: Well, I had the opportunity to invent NASA's first internet, which was SPAN. I'm very proud of that. In fact, by the end of 1980, I was doing email and remote log on. I was running jobs on computers all across the United States. Then in 1985, I extended it to the European Space Agency. Then in '87, we went to the Japanese space agency. In '92, we were in Moscow. So the ability to use computers in the way they can communicate just exploded during that time. We then developed proposals together and really began this process of connecting more of these disciplines and doing things that we couldn't have done otherwise via fax or telephone. Computers were really a central part of that.

Mat Kaplan: Or having to carry a paper tape to the radio telescope.

Jim Green: Yes, to the radio telescope. What were we thinking, right? That actually led me to a fabulous job at Goddard Space Flight Center. That was a wonderful opportunity to take the vast data reserves and archive that they had and put it online. I was able to develop the first online archive for NASA at the National Space Science Data Center that enabled them to run processes over the entire data set and provide a much more uniform calibration capability, and new things just exploded out of that, things that we take for granted today. We just did all kinds of stuff in that early days of probing how to use networks and online mass storages.

Mat Kaplan: I also think of how this probably has led us to today where we see, in fact, just a day ago as you and I speak, all of the images captured and processed so far by the James Webb Space Telescope put online where anybody, not just scientists, not just engineers, anybody can work with that data. It's very inspiring.

Jim Green: Well, one of the things that we see is there's been a gradual evolution of how scientists deal with their data and also pressure from NASA headquarters to make it more open sooner. When they do that and they see the benefit of doing that, they want to do that, and that's just the right thing to do.

Mat Kaplan: We're going to talk in a couple of weeks with two guys at JPL who have a new citizen science project called Cloudspotting on Mars. It's such a good example of this. The project's only two weeks old. They've already got 2,000 people around the world helping them analyze and discover these clouds, these beautiful clouds above Mars. Are there one or two other things that you want to call out out of this long and continuing career that you're most proud of?

Jim Green: Well, in the tank at Neutral Buoyancy Simulator at Marshall Space Flight Center, as I mentioned, I did about 150 dives. My role was a safety diver. I was responsible for the life of the person in the suit. We did a number of risky things in space that we have to practice in the tank. The water environment provides another risk element. On many days, had the opportunity to be at the right place at the right time to avoid disasters in the tank. So I'm quite proud of that. I'll have to write that up in my memoirs, I think.

Mat Kaplan: You sure do have to. I'll be talking with Laurie Leshin on next week's show. As you know, she's just become the first woman to direct the Jet Propulsion Laboratory.

Jim Green: Well, she was my boss at one point-

Mat Kaplan: I should know that.

Jim Green: ... at Goddard. I went from managing just the National Space Science Data Center into managing a division that had the NSSDC in it. It also had two other groups. It was during that time that Laurie became the director of [inaudible 00:46:28] the science director at Goddard Space Flight. So I had a wonderful opportunity to work with her. In fact, we were in the same building, must have been at least a year.

Mat Kaplan: She's not the first woman to head a NASA center, but she's the first at JPL.

Jim Green: Oh, she's highly qualified. I am just absolutely delighted that they hired her because she's going to be fantastic. I only wish that I was head of Planetary when she was head of JPL.

Mat Kaplan: More broadly, what does this say about the ongoing effort within NASA and affiliated agencies to provide more opportunities? You go back to those Apollo days and all those-

Jim Green: It's moving in the right direction. Oh, absolutely. It's really wonderful to be able to have such a diversity in our planetary science field and many of other fields recognized through the promotion of women and other minorities to these wonderful positions. Men don't have a lack on it. We don't know everything. They bring a view that will be extremely important.

Mat Kaplan: You're talking to us, as we said up front, from Portugal because, I don't think it's your first time there, you're working with this summer session of the International Space University.

Jim Green: True.

Mat Kaplan: Again, it's like talking to people who've came through Don Gurnett's lab, the number of people that I've had on this show who are now leading space exploration who are ISU graduates. Why did you come back there this summer? What is it about ISU that made you want to devote another summer to it?

Jim Green: Oh, ISU is tremendously unique. It is a place where students come and learn about the space business over a broad experience range that they can only get here. For instance, if a scientist who only looks at science, doesn't really understand some of the engineering, space structures, satellite applications, space policy and law, what do they care about that? There are so many other aspects of learning about space. Students get exposed to that here, and that's really important. So they bring their depth, and they learn the breadth of the whole business.

Jim Green: What they end up doing is making fast friends because this is just a fire hose of information. They get tested on it. They have to pass. They work on a team project. They have to get that done. Then they go back to wherever they are, whether it's a space agency or it's industry or government. They end up with fast friends. When I first started in ISU in 1992, I had a fabulous time. I was asked to come and teach a couple courses, which I did, one of which was developing HTML. The reason why is I had just put the data center on the World Wide Web, and it was number 200 on the World Wide Web.

Mat Kaplan: Wow.

Jim Green: I also developed a structure for NASA's internet World Wide Web presence at every one of the centers. That was done in the early '90s. It wasn't until like 1998 that it got recognized that this is an important thing for communicating with the public. I'm quite proud of doing many of those things. ISU then provides this latest technologies. So one of the things I did is I taught a class, the very first one at ISU, in the metaverse.

Mat Kaplan: You're kidding. When was this?

Jim Green: Just two weeks-

Mat Kaplan: Two weeks

Jim Green: ... ago.

Mat Kaplan: Oh, okay. Wow. Congratulations.

Jim Green: Thank you. That was Tara Ruttley and I. We talked about human performance in space. Worked with the group called the Metavisionaries. They created a spaceship for us in virtual reality. This spaceship orbited the Earth. It was sort of like a saucer with a clear dome so you could sit in the seats in an auditorium and see the Earth in the back room. Then the stage is where Tara and I would go and explain things about human factors in space. So when she talked about the circulatory system, she had a three-dimensional beating heart above her. Or she talked about inner ear problems, you had the entire ear that you could see and the canals, and then how the ear worked. We talked about the twin study, and we answered questions.

Mat Kaplan: I want to thank you for sending me a YouTube copy of the video of the lecture that you gave in the metaverse, which we will also put a link to on this week's show page at, because it's really fun. People really should take a look at it. This stuff is starting to be not just practical, but really exciting. I think, Jim Green, that I can draw a line from 40 years ago or more, I hesitate to say, when you were sitting at keyboards and looking at physical printouts from those UNIVAC super computers for the time and the passion that you're expressing now about this new technology, about teaching in this metaverse. Am I right about that?

Jim Green: You are. It's a view that I've always had that computers are there to help us, and anything we can do to leverage them really makes our job easier. I've seen that every time I have put new nodes on NASA's early network to connect to space agencies. We transferred commands over this network. We did testing in chambers. We were doing things like that in the '80s. Then when HTML came along, and this is the language of the World Wide Web, teaching that was a no-brainer, where the students then could create their own profiles. Now that's ubiquitous, of course. Every company has to have some sort of presence on the web. Phone books are gone if you want to look for somebody.

Jim Green: Well, the next version of course, I think, is that virtual reality, the ability for many organizations, and that includes space agencies, not just industries and companies, to have some sort of presence in the metaverse where you can walk in to see their laboratories, see the facilities that are there where they're soliciting, perhaps, instruments to come in and use their facilities to do testing, etc., that will end up, perhaps, on spacecraft or the International Space Station, or even that next generation, the commercial stations that are being planned by a number of companies. So I think this is a trend that's going to continue, and we just have to get involved in it, understand it, figure out where the best features of it really give us the opportunity to share information and to teach. So the time is now.

Mat Kaplan: It also strikes me that for people like you and me and some others out there, this is a new and much more immersive way to share that PB&J, that passion, beauty, and joy. You told me a secret a little while ago about that I shouldn't tell the University of Iowa. I will let you in on a secret. Don't share this with my bosses.

Jim Green: All right, okay.

Mat Kaplan: It is the joy of getting up in front of real people and talking about this stuff that we love. I think you feel this too.

Jim Green: Oh, yeah. Oh, yeah. I've had it for quite a while. I recognized when I started teaching at the International Space University, teaching wasn't my job at NASA, but I had this passion to tell people what I'm doing. I started by emulating Don Gurnett, who has such a wonderful way, as my thesis advisor, to talk about the science he was doing and really bring in people from different disciplines. Everyone wanted to go see a Don Gurnett talk. Whether you were a particle physicist or looking at the sun, you knew he was going to talk about magnetospheric plasma waves, really esoteric. Yet, you would walk away getting an appreciation for the field and understanding what's going on.

Jim Green: Well, I caught that bug, and I did that for, oh, I don't know, 10 years or so as a scientist. Then when I had a chance to talk at ISU, I took it and really enjoyed it. I have to tell you, probably the first couple years, I wasn't really good at it because I wasn't teaching at the level the students were. I was teaching at a science level. I soon recognized that, and I was able, I think, to make that transition. I must have because they keep inviting me back every year to teach.

Mat Kaplan: There's more evidence of that. In the wonderful podcast that you do, Gravity Assist, which I hesitate to talk about because it is a great podcast, which of course makes you competition. But I do recommend it, and we'll put a link to Gravity Assist-

Jim Green: Thank you.

Mat Kaplan: ... up also on this week's episode page. Before I leave this, asking you for your favorite moments, your highlights from your time particularly at NASA as the head of Planetary Sciences and the chief scientist, I hope you'll say something about those 12 years that you spent as the head of the Planetary Science Division.

Jim Green: Well, that's probably what I would say is my best moments at NASA, having the opportunity to literally help lead the planetary community to new heights. I think over those 12 years I ushered in a new golden age of exploration where we rejuvenated what we were doing at Mars and moved forward with the top things like sample return by creating that next set of missions. Also moving forward with not leaving out the outer planets, starting with Juno and then creating the Clipper mission, which we did, which is another huge step, but also the international connections I made where we're part of the JUICE mission, which is also a Jupiter mission, and doing all kinds of other things around the solar system that has really sparked so much interest in, not only the science community, but the general public, like Planetary Defense.

Jim Green: When I started in 2006 as head of Planetary, Planetary Defense had $4.5 million. We had a congressional mandate to do something from the only one part of Congress, and these are the people that are authorizers. "We authorize you to do this work." Then the appropriators appropriate money for you to do that. Well, the appropriators didn't give us much money, and so we constantly had to fight an uphill battle, but we were slowly successful. We built the budget. I grabbed every resource I could get. As astronomy was ending a mission called WISE, we were able to grab that mission and use it as a pathfinder to demonstrate, and I think clearly demonstrate, the importance of looking for near-Earth objects in the infrared from a space advantage, because right now all we do is look for those on ground-based observatories and that happens to be only at night. There's another hemisphere out there that we sort of ignore.

Jim Green: So huge steps have been taken. Making DART happen. DART is our Double Asteroid Redirect Test where we're going to go out and hit a moon of an asteroid and watch its orbit change. That'll give us an understanding of the size of asteroids, near-Earth objects, that if they are a potential threat, how we might be able to move them. That tells us when we need to be able to do it such that they miss the Earth. All kinds of stuff happened like that, and I was quite privileged to be able to have the job for 12 years. Prior to me, on the order of three years was about the average.

Mat Kaplan: That's an amazing tenure, 12 years.

Jim Green: It is. It'll be a record that'll stand for a while, I'm afraid.

Mat Kaplan: I bet it will. Of course, you were talking about WISE becoming NEOWISE with our friend, Amy Mainzer, who we're all looking forward to. This a high priority for the planetary side as well toward that NEO Surveyor mission that [inaudible 01:00:05].

Jim Green: Me too. Me too.

Mat Kaplan: You told me an anecdote before we started this that I hope you'll share here as we start to wrap up. That was about how we came to have this phrase "seven minutes of terror."

Jim Green: Well, I have to tell you, it was about 2012 when the prospects for the Planetary budget looked bleak. The administration at the time was saying, "Well, commercial activities like Elon Musk is going to be landing two Red Dragons on Mars in 2020, and we don't need to have an aggressive Mars program." The concept then of what can we do in this area... Scientists aren't great lobbyists. They're really not. In industry, they'll build a Earth science-based craft. They don't care if it's planetary or Earth science or whatever it happens to be so long as they're busy and they're going to be real busy.

Jim Green: So I recognized, I really needed to talk to the public. I really needed to tell them what they were getting for their money. I needed actually to do that well before 2012, but it just occurred to me at that time I needed to really amp it up. So I was able to bring in Kristen Erickson who has a vast knowledge and outreach. I said, "All I want is one thing. It's, I want you to make sure every man, woman, and child on the face of the Earth knows that we're going to land a one-ton Rover on Mars. That's your job." It sounds easy, right?

Mat Kaplan: This was Curiosity, of course, back then.

Jim Green: This was Curiosity. Yeah, this was Curiosity. So she put in place an enormous number of events. She got a hold of the people that allowed us then to broadcast live in the control room and put that out everywhere into museums and libraries and even at Times Square where you have thousands of people that could walk around and see that the United States is landing a one-ton rover on Mars.

Jim Green: But I have to tell you, my supervisor at the time, Ed Weiler, was pretty concerned that we were doing too much of an outreach activity in this area without really talking about the downsides. And he was right. As a very positive person, probably more so than any other division director ever, I'm always very positive. Ed would tell me, "Jim Green, hope is not a management tool." Well, of course I knew that. I'm not going to hope that it's going to work. It's really based on solid engineering. So I really felt good about the landing of it. If it crashed, it must have been an act of God or something because I think we did everything we could to give it the best shot of landing.

Jim Green: But I wasn't telling that story. So I mentioned that to Kristen. I said, "Look, we really have to talk about the risks. We don't talk about them much." Soon after that, JPL did a wonderful job bringing in the right people, creating the right concept of discussing with the engineers. This is not a science discussion, which is what we usually have. This is an engineering discussion for what it takes to really land a one-ton rover on Mars. What came out of that was seven minutes of terror. I couldn't be happier.

Mat Kaplan: Oh, listen, this was the phrase of the day as thousands of us stood in the Pasadena Convention Center holding our breath, waiting through those seven minutes of terror and then jumping up and down, joining everybody in the JPL control room and all those people in Time Square. It could not have been more exciting. Maybe the greatest tribute to the success of that phrase is all the times when I talk to other mission leaders since then, and they say, "Well, this is like our seven minutes of terror, but it's really seven months of terror, because that's how long it would take James Webb to unfold or something like that." Definitely, you and Kristen, you sure were onto something there.

Jim Green: Well, JPL pulled it together. They really made it happen. They got the idea. They understood what needed to happen, and they were delighted to talk about it. Because as I said, a lot of that fantastic engineering that goes on just doesn't get really discussed in a way that shows how hard it is. When Ed Weiler was telling me, "Well, what happens if it crashes?" I said, "Well, this is a strategic mission. It's my responsibility. Someone's going to get fired, and that's probably me." He said, "Yes, that is. If that mission crashes, you're going to be history."

Jim Green: I was willing to take the chance that it was going to work right because I felt we did everything we could possibly do. I interacted with the JPL people all the time. Doug McCuistion, my Mars tsar, that's the branch within Planetary Science that manages all the assets, he was just working night and day with the JPL people. He felt really confident about it. I know where Ed was coming from. Of course, Ed was the head of the optical branch when Hubble was launched and had the mirror problem. So consequently, he was really beat up by the press a lot. That came through. He was able to live through that experience, and I'm sure he felt that that was so painful. Let's not do it again. But it's one of these things that everyone's going to know it crashes if that's what happens, or everyone's going to know it landed safely. So let's take that journey together. To me, that just made the most sense.

Mat Kaplan: Jim, you are still making history, fortunately for all of us, of the good kind. I got just one other question for you. Now that you have changed your status at NASA, gave up being chief scientist, and you told me the next day they made you a senior advisor. Well, what if they came back to you tomorrow and said, "Jim, we're going to the moon. We're going to do real science. We got a mission plan for about five years from now. We just figure with your multidisciplinary background and your enthusiasm, you are the right guy to go to the moon and conduct this research for us." So yes or no would you say?

Jim Green: Well, the answer would be yes. It's part of my character. I rarely say no. Some people would say that that's a character flaw. But I have to tell you, what I have learned by saying yes, even with things that don't sound like the right thing I should be doing, but I learn an enormous amount, and I've always constantly taken that in and applied it. NASA provides so many opportunities to learn so many different things. I was in source evaluation boards and technical advisory groups and things that sound like they're just yuck for a scientist. Why would you spend months of your time buried in a room and comparing the requirements against an individual proposal and making decisions right and left? The reason is we want the best value, we want the best partners, and when we get them, magic happens. This is the government process. I never was afraid about learning the government process and using it. So consequently, if NASA asked me to go to the moon and interview the astronauts that are there and asking them their gravity assist in 1-g, I do it.

Mat Kaplan: Jim, I will see you on the moon, I hope, someday, at least in the metaverse moon. I knew it would be a great pleasure, it always is, to talk, and you certainly have delivered. Thank you for this, and keep up the great work.

Jim Green: Well, thanks so much, Mat. I really enjoy your podcast. I listen to it all the time, and I hope everyone continues to do that.

Mat Kaplan: Thank you, Jim. That's very nice.

Jim Green: My pleasure.

Mat Kaplan: It's time again for What's Up on Planetary Radio. Here is the chief scientist who I referred to upfront when I read my special announcement today, the person who has been heard on all of these episodes of the show and will be hopefully for a long time to come. That's Bruce Betts. Welcome back.

Bruce Betts: Thank you. This is not fair because I don't know what people... What did you... I don't know how mean you were.

Mat Kaplan: I was nice.

Bruce Betts: [inaudible 01:09:03] would be mean or nice.

Mat Kaplan: No, I was nice.

Bruce Betts: Or be both.

Mat Kaplan: Tell them everyone. I was nice, wasn't I? Yeah, they say I was.

Bruce Betts: They're on your side. You're a nicer person. Eh, don't leave. Sorry, sorry, sorry.

Mat Kaplan: Well, thank you. It's tough. It's very tough. I love so much of what I do with this program including talking to you every week for What's Up.

Bruce Betts: I love it too, man. Let's just go on. I've got a few more months. Hey, dude. Hey, it's been cool. Beer me.

Mat Kaplan: Dude, what's going on up there?

Bruce Betts: Oh, there are four planets that are like super bright, dude. But seriously folks. Predawn sky, actually Saturn even coming up in the east in the mid-evening now. But in the predawn sky, you can see four planets going from super bright Venus down low by the horizon, and then up to Mars looking reddish, bright Jupiter and yellowish Saturn in a line, but that line continues to spread out across the sky. If you pick this episode up shortly after it comes out on July 21st, the moon is very close to Mars. Here, I got something different for you. If you can find bright, reddish Mars over in the east, between July 30th and August 3rd, if you got some binoculars, look around reddish Mars. There's a blue dot. It's Uranus.

Mat Kaplan: Oh, no kidding.

Bruce Betts: It'd work better if you find a sky chart and know exactly where to look. In those days, July 30th to August 3rd, there will be a bluish, star-like object that you will need binoculars to see or really good eyes and a really dark site.

Mat Kaplan: I will give it a shot. Thank you.

Bruce Betts: Onto this weekend in space history, nothing happened this week other than humans landing for the first time on the moon in 1969, and, more significantly, LightSail 2 successfully deploying its solar sail in 2019.

Mat Kaplan: Congratulations on that. We celebrated the launch a little while ago with Bill and Jennifer Vaughn. But really, if anything, this is at least as, maybe more significant, because this is when you and your colleagues got to start sailing, right?

Bruce Betts: Yeah. It went from just another CubeSat to the first controlled solar sailing demonstration of a small satellite. We move on to random space fact, random space fact, random space fact. Scott Kelly, well-known astronaut, almost a year in space, longest time for an American at one time. He retired from NASA after 20 years of being an astronaut. Mat Kaplan is retiring as Planetary Radio host after 20 years. Coincidence? You be the judge.

Mat Kaplan: Hey, Scott. I'll be in touch.

Bruce Betts: We move on to the trivia contest. I said the following, "On Brazil's flag, only one star of the 27 stars is shown above the white band. What star and what Brazilian state does it represent?" How did we do, Mat?

Mat Kaplan: Biggest response that we've had in quite a long time, so much of it from all over the world, and we'll have some representative samples of that. But first, Dave Fairchild, the poet laureate of Planetary Radio out there in Kansas, "27 stars are there upon a globe of blue. It's just about ad Astra as a flag is going to do. There's only one above the band. It isn't very cryptic. It's Spica and the Pará State above the white ecliptic."

Bruce Betts: Cool, nice. Yes, that conveys our correct answers.

Mat Kaplan: This is going to be a problem. We heard from several Brazilians, not surprisingly, in response to this question, including Francisco Racia and Eduardo Kitete. Oh Lord, my Spanish pronunciation is bad enough. Portuguese? Hopeless. "Pará is a neighbor of the Maranhão state," says Eduardo, "where the Alcântara launch site is." Eduardo added, "It's my first space trivia contest." Eduardo is a longtime listener, Planetary Society member since 1993 or so. He says, "I dare you to speak Pará like a Brazilian or a Portuguese would." Yeah, I'm not going to pick up that dare, I'm afraid, Eduardo.

Bruce Betts: I've got the Spanish thing. I mean, it took me a while to even remember to acknowledge the accent. So I'm going with Pará.

Mat Kaplan: And I'm going with our winner, a first time winner, Jeff Tune in California. Congratulations, Jeff. He said, "Spica, which represents the Brazilian State of Pará, which is partially in the Northern Hemisphere in Brazil, which explains why it's above the line." Congratulations, Jeff. You're going to get that copy of Lori Garver's really excellent new book, Escaping Gravity: My Quest to Transform NASA and Launch a New Space Age. Laura Dodd, long-time listener writes in, enters all the time. She says, "Thanks, Bruce. I hadn't looked at the Brazilian flag very closely before, so I hadn't thought about the stars on it. I keep learning things with a little help from you." Courtney Katz in Pennsylvania says, "Spica's actually a binary system," which I did not know.

Bruce Betts: I didn't either, but there are a lot of them out there.

Mat Kaplan: That's true. They're kind of a dime a dozen, aren't they? Pierre Louis Fan, our fan in France, "This represents the night sky of November 11, 1889, which was the day that Brazil became independent. But on this date, Venus should have been close to Spica. Poor Venus is always ignored."

Bruce Betts: Oh.

Mat Kaplan: Well, here's another one. Hayoon Woo Chang in Korea, "I just looked up some pictures of Spica. Dang, it's beautiful." He says, "Have a great day, everyone." Norman Kasun in the UK, another one of our every week entrants, "Both a rocket and crew capsule designed and under development by Copenhagen Suborbitals, a crowdfunded space program, are named Spica. Spica aims to make Denmark the first country to launch its own astronaut to space after Russia, the US, and China," something else I've never heard. You people out there are so good at this stuff. You're so smart. We learn from you too.

Bruce Betts: Well, I mean you do. I'm kidding. I learn every week.

Mat Kaplan: You get confirmation.

Bruce Betts: I find out when I'm wrong. I hate that.

Mat Kaplan: Ian Gilroy in Australia, "I think there are around 60 national flags that have one or more star or stars on them. Brazil, of course, 27, the second most after the US, 50 I think. Many Southern Hemisphere countries have the Southern Cross, the Crux, on their flag including Brazil and my home country of Australia." Edwin King in the UK, "I'll be tuning in next week for Dr. Bruce Betts Presents Fun with Flags."

Bruce Betts: I could go on. There's all sorts of good, weird stuff.

Mat Kaplan: We'll close with one more poem from Gene Lewin in Washington. "Into the night sky we peered with just the mortal eye. Stars were placed in constellations when they were first described. Their presence so inspires. They're used to represent locations here upon the Earth ascribed with an intent. Adorning the Brazilian flag, Spica, part of Virgo, connoting the State of Pará above motto, Ordem e Progresso. 27 stars in all matching positions astronomical upon a blue celestial field making these stars Vexillological.

Bruce Betts: Yeah, yeah. Study those flags. So the next week will be Dr. Bruce Betts's Vexillology Show. You're just done now, right? I mean, you're done with this show. You're retired, so I can do my vexillology show instead?

Mat Kaplan: Well, I think you should do it as a side. We'll just call it Planetary Radio, Vexillology Edition.

Bruce Betts: Nice.

Mat Kaplan: You're not rid of me yet. I'm here for at least four more months of actually sitting in this chair.

Bruce Betts: Oh. Well, I already did the tearful, sad goodbye.

Mat Kaplan: That's all right. It was rehearsal.

Bruce Betts: There are two other states that are above the equator. They were just made states in '92. Why don't they appear above the band?

Mat Kaplan: Beats me. I think it may have to do with why the United States never added a 51st state because it would screw up the flag.

Bruce Betts: The asymmetry would be awful.

Mat Kaplan: We did hear that from some people that it is not the only state in Brazil that has a portion of it above the equator. Brazilians, let us know.

Bruce Betts: All right, here we go into a different realm. What was the first published scientific work to include telescopic observations of the moon? As a hint, it included drawings. I don't know if that's much of a hint. Go to

Mat Kaplan: Fascinating. You have until the 27th. That'd be July 27 at 8:00 a.m. Pacific Time to get us the answer for this one. In honor of the announcement that I made today, let's give away another Kick Asteroid rubber asteroid from The Planetary Society. It could be yours. We're done.

Bruce Betts: All right, everybody, go out there and look up at the night sky and think about a caricature of Mat surfing. Thank you and goodnight.

Mat Kaplan: Body surfing. Only tried board surfing once in my life. Didn't like it. Probably shouldn't have used a long board. I'm still into that. I think the chief scientist of The Planetary Society, Dr. Bruce Betts, is still or was, at least at one time, a fellow California surfer. He joins us every week here for What's Up.

Bruce Betts: Windsurfing, dude.

Mat Kaplan: Did you really?

Bruce Betts: Hey, I was a windsurfing teacher.

Mat Kaplan: Planetary Radio is produced by The Planetary Society in Pasadena, California, and is made possible by its members like me. See you at Mark Hilverda and Rae Paoletta are our associate producers. Josh Doyle composed our theme, which is arranged and performed by Pieter Schlosser. Ad Astra.