Planetary Radio: Space Exploration, Astronomy and Science - Michel Mayor, Discoverer of the First Extrasolar World

Episode Date: April 5, 2016

Michel Mayor and his team rocked the astronomy world with their 1995 announcement, but this modest man says it was a discovery whose time had come.Learn more about your ad choices. Visit megaphone.fm/adchoicesSee omnystudio.com/listener for privacy information.See omnystudio.com/listener for privacy information.

He discovered the first extrasolar world. Michel Mayor, this week on Planetary Radio. Welcome to the travel show that takes you to the final frontier. I'm Matt Kaplan of the Planetary Society. I was thrilled to sit down with the man whose team made the first discovery of a planet orbiting another star. You'll hear our conversation in a few minutes. Have you seen the amazing video of Blue Origin's latest suborbital flight?

Bill Nye has, and he'll share his thoughts. Who was best in show? Bruce Betts will help me celebrate the winners of our Like a the Dog acronym contest. We begin, as usual, with the latest from senior editor Emily Lakdawalla. Emily, it's a return to the Lunar and Planetary Science Conference this week and to Ceres, that huge object in the asteroid belt, which apparently, according to your March 30th entry in the blog at planetary.org, we now have lots of data about and a lot of pretty pictures that some of which you've included, but not a whole lot of understanding. That's true, mostly because scientists just

haven't had time to digest all of the data that's come back from Ceres. There is an awful lot of it. So Dawn has been examining Ceres for more than a year now, first on a long approach where it saw Ceres as just a pretty small world tumbling in the distance. And then it entered orbit and began to survey it and has been getting lower and lower orbits. And finally now is in its low altitude mapping orbit. And it has just completed a global map of the entire world at 35 meter resolution. It boggles my mind because the satellite image data that I first learned how to process for Earth was 30 meter resolution. So we have the kind of data for Ceres that we had for understanding Earth as a globe many years ago, but we've gotten it all at once. And so you just want to look over here

and over there and, ooh, there's a bright spot and, ooh, what's that funny crack? And what's that weird mountain? And so all these questions are going through scientists' heads and they don't really have answers yet, but they're beginning to try to see patterns and understand how everything fits together. There is an animation of the formation of that map as the spacecraft passed over this dwarf planet. And it's really fascinating, kind of hypnotic to watch. What are some of the other highlights out of what you wrote about? Well, they've been digging into the problem of Ceres bright spots, trying to understand what exactly they are. My money was always on exposed fresh ice

and I would have lost that money. I was wrong. There's actually only one spot on all of Ceres where the spectrometers think there is the clear signal of water, but even that may not be water ice. It could be water bound into minerals that are being exposed to the surface.

Most of the bright spots are probably some kind of salt material, which could have gotten there in a number of different ways. I saw several different mechanisms proposed. None of them I was terribly satisfied with yet. They're just beginning to tell these stories. There are lots of cracks and fissures that form global sets. Some of them seem to be coherent and have to do with geologic features that may have affected the entire globe. Others, their origin is really hard to explain.

Another odd thing about Ceres is that it's covered with craters, as most things are, but its big craters are missing. And that's just weird. You can understand how you can obliterate small craters. You could flood them. You could fill them. You could cover them up. But it's always been really hard on planets to get rid of big craters. And why Ceres seems to be lacking big but not small craters is a total mystery to me and to scientists right now.

But it'll be a fun puzzle to try to solve. Though we're running long, I have to also ask you about this mysterious mountain. Ah, yes. Ahuna Mons, this strange little pyramidal mountain that seems to be poking up out of nowhere. Its flanks have a blue color that is similar to the ejecta of fresh craters, and that one really confused the spectroscopists. It's relatively easy to explain a bluish fresh ejecton craters, but why it would also show up on the flanks of this isolated mountain that they can't explain. It's, again, just a mystery.

Much more waiting for you in this March 30th blog entry. It's over 4,000 words with lots of images accompanying, and already more than 2,300 words from commenters, people who were impressed by this work. And yet another thing to look at, our colleague Tanya Harrison, who helps to get this show up on the air each week, she wrote about the surface of Mars because she was also at the Lunar and Planetary Science Conference along with Emily and others. Emily, thanks so much. I'll talk to

you again next week. Thank you, Matt. She's our senior editor, planetary evangelist for the Planetary Society and contributing editor to Sky and Telescope magazine. Here is the CEO of the Planetary Society, Bill Nye the Science Guy. Bill, when you suggested talking about Blue Origin's latest flight and return, I hadn't seen the video. Now I have. It is, I won't say incredible. It's beautiful.

It looks like animation. It looks like something out of The Martian or CGI. I know. The landing's so straight. This rocket ship falling out of the sky comes down at such a high speed and then slows down so dramatically. It really is spectacular, but this is significant for all of us in big ways. It's just a cool thing. I mean, this is advancing space science and exploration. I'm just as interested in the capsule that they want to put on top of this new Shepard for suborbital flights. Huge windows, big room inside, and apparently they want to start taking up to six people up into, not low-earth orbit, but into suborbital space as soon as a couple of years from now. Sign up.

Meanwhile, speaking of signing up, the gang, that is to say several staff members from the Planetary Society and I were at the National Science Teacher Convention. Big fun. Oh, my goodness. Big fun. And we are finally, Matt, the Planetary Society

engaging this huge audience. Science teachers love to teach about space because we all love space. So it's been a big week for the society and for space exploration writ large. Yes, I highly recommend people take a look at this coverage of the Blue Origin latest flight of the New Shepard, and we have all kinds of stuff about your and the rest of the team's visit to NSTA on the Planetary Society Facebook page, including some video. Thank you, Bill. Thank you, Matt. He is the CEO of the Planetary Society. That's Bill Nye, the science guy. A little history now, very significant history, a conversation with the discoverer of the very first extrasolar planet.

San Diego, California is already one of the most popular destinations in the United States. I thought I knew of pretty much everything the town has to offer, but I hadn't heard of the Kyoto Prize Symposium. This unique event is co-hosted by four outstanding universities and is made possible by the Inamore Foundation of Japan and the Kyoto Symposium Organization of San Diego, with additional participation by many other supporters. Each year, the symposium brings the winners of the Kyoto Prize to the city. The Kyoto Prize is Japan's international award honoring scientific, cultural, and spiritual contributions to humankind. In 2015, the awardees were a groundbreaking chemist,

a choreographer of soaring achievements in dance, and the man who led the discovery of the first extrasolar planet, or exoplanet as we commonly call them in the U.S., astrophysicist Michel Mayor has achieved worldwide renown for his work. He was a professor at the University of Geneva in 1995 when his team's paper in the journal Nature rocked our world with its announcement of 51 Pegasi b, a giant world circling close to its star. They used the radial velocity, or Doppler technique, detecting subtle changes in the velocity of the star caused by the tug of the planet. More than two decades later, with thousands of extrasolar planets confirmed, Professor Emeritus Mayor is a revered elder

statesman. I met him a few hours before his symposium lecture at UC San Diego, though it was on the beautiful campus of Point Loma Nazarene University, overlooking the Pacific Ocean, that we sat down for a chat. You'll hear him mention the TPF, that's the Terrestrial Planet Finder, one of several spectacularly powerful instruments that one day may help us find life on one of these myriad worlds. Dr. Mayor, thank you very much for joining us on Planetary Radio and congratulations on this latest recognition of a truly tremendous world or worlds changing discovery.

Thank you very much. I'm very proud to be here. It's the first time I'm in San Diego. Well, it's a nice place to visit, isn't it? This is my home away from home. My grandparents lived about two miles from here. I fully agree. This is unique, this symposium that has brought you here, along with your colleagues, the fellow awardees who've received the Kyoto Prize this year, the recognition that you have received over the last, now almost 21 years, for this discovery of the first extrasolar planet, I think it has been absolutely justified.

I don't know if you feel the same. It's difficult to me. What I can say is that I'm very happy to receive all this recognition. And in some sense, it's so unfair because you see that you have so many people working in science, in their lab, in their office and so on,

doing incredibly nice research, but without any impact for the general public. Maybe having a huge impact on science, but not on general public, and these people will never be recognized for such. And so,

I'm very happy to, but I feel as though, okay, a little bit troubled by this question. And I understand. But I think it is in recognizing these most visible accomplishments that we also generate greater support for those scientists who may never be celebrated as you have. What I can evidently understand is that the question of extraterrestrial planets is so old question. For more than 2,000 years, people are dreaming, discussing of the possibility of the old terminology

of the plurality of world in the universe and more in the possibility of plurality of inhabited worlds. So it's evident I'm completely sensitive on this subject. But I'm also extremely concerned by the fact that I just arrived at the good time where the technology allows to answer this question. So because it's evident, discovery of extrasolar planet is really the result of the technology development, development of instrumentation.

The idea was already existing from decades, but now we have the tools to do it. But even having said that, when you were doing your work and developing these revolutionary optics, you and your team, we should say, in the mid-1990s, it was still very much cutting edge. And I sometimes wonder, I mean, I'm sure someone, some other team would have reached this point, but your team was the first. Yes. In the 90s, the number of people working in the field was very low. And I can recognize maybe three, four teams of two people. It's always very small teams working in different places in California,

but as well as a place. but also in other places. And it was not considered probably as the highest topics in astronomy due to bad experiences in the past. We have several claims in the last 50 years of the erroneous detection and so on. So the domain was not really promoted as a very big issue. And suddenly we just have these new tools, new spectrographs, having the capability to detect extremely small wobble of the velocity of stars due to the gravitational influence of planets. So this was a dramatic change in this domain because at the time, in the 90s,

the paradigm was that giant planets could only exist with a period larger than 10 years because they have been to be formed with agglomeration of ice particles. And ice particles do not exist close to the star. So when we discovered 51 pegs with 4.2 days, so it's a factor of 1,000, too small. So it was not a small error, it's not a small problem, it was a big problem. So we have been extremely perturbed by the possibilities that we were sure of the quality of

our measurements, but what was really the physical interpretation? It looks it was a planet, but with completely crazy parameters. So this was really the first impact for us, all this discovery,

and it was the reason why we have decided not to publish immediately this discovery, but to postpone the analysis and publication to the next season. And we have the first hints of something interesting in fall of 94, winter of 94, but we did some new measurements in July of 95 to be sure that we have a stable period, stable amplitude, stable phase of the phenomena, all signature requested if it is a planet. And it's only when we got this confirmation, okay, we decide, okay, we just publish.

And okay, we were quite sure that it was interesting because if we decided to publish in nature, it was not because it was not considered to be interesting. So we rushed to publish the paper. But we did the announcement a little bit before the official publication, what is called the Cambridge workshop. It was in Florence, in Florence, in the north of Italy. The first week of the… That we know as Florence, yes. So this was the time of the announcement, and we have a big audience. This was more than 300 astronomers

working on LOMA stars in the room. So it was a big question for me to see what could be the answer of our colleagues. And it was evidently, as many cases, a mixed answer because some was very convinced, some said, oh no, it's only a position of the stars. With this first discovery, right from the start,

you overturned a lot of the existing theory about planetary system development, right? I love this kind of question because you see that already in, I believe it was at Caltech, in 1980, Peter Goldreich and Scott Tremaine, two big names of astronomy, and Scott Tremaine, two big names of astronomy, studied what happened to a small body embedded in the disk of a large system. It could be a small galaxy embedded in the disk of the Milky Way, or it could be a new planet embedded in the disk,

crescent disk around a star. The answer of this paper was that you have a strong orbital migration. And the last sentence of the abstract of this paper was, the phenomena is so efficient that Jupiter was not born where it

is today. So a lot of people read this paper, but mostly with interest for galactic frame which you were also working on yes exactly and it's strange because I read this paper at the time

because I was working in spiral galaxies but I do not have any remembrance of the extrasolar planet impact of these things and it's only after the discovery of 51 Peg that you have people here, Daglin from Santa Cruz,

Richardson, Bodenheimer, immediately jump and say, oh, this is the good explanation, is the presence of orbital migration. And today, this is one of the largest impacts on this first discovery on the theory of exoplanets. Today, all scenarios of planetary formation have to take into account orbital migration. That's Michel Mayor, lead discoverer of the very first exoplanet found by humans.

He'll return after the break. This is Planetary Radio. This is Robert Picardo. I've been a member of the Planetary Society since my Star Trek Voyager days. You may have even heard me on several episodes of Planetary Radio. Now I'm proud to be the newest member of the Board of Directors. I'll be able to do even more to help the Society achieve its goals for space exploration across our solar system and beyond. You can join me in this exciting quest.

The journey starts at planetary.org. I'll see you there. Do you know what your favorite presidential candidate thinks about space exploration? Hi, I'm Casey Dreyer, the Planetary Society's Director of Space Policy. You can learn that answer and what all the other candidates think at planetary.org slash election2016. You know what? We could use your help. If you find anything we've missed, you can let us know. It's all at planetary.org slash election2016. Thank you. Thank you. solar or exoplanet, but for a long career of leadership in astronomy and astrophysics. Got a few extra minutes? I highly recommend watching Michelle's Kyoto Prize lecture.

We've got the link on the show page at planetary.org slash radio. You said something so interesting during your lecture in Kyoto when you received the prize. Something in all of the other planetary scientists I've talked to I never thought to ask, that we're really not in the business anymore of discovering more of these exoplanets, extrasolar planets. We of course know about thousands

now, but you said we've really moved beyond that. Yes. At the beginning, all the team working in the domain was extremely happy when they have a new planet, discovered a new planet. Okay, today we still have this,

but I believe this is not what is more important. I believe what is really important today is to have good statistical view. What is the frequency occurrence of low mass planet, of big planet? If they are rocky and gaseous planet, what is the distance, the limits of rocky planet? What and all these things. If we want to, okay, we have discovered that the theory of the formation of planets, planetary systems, is much, much more complicated than believed at first.

We need to have constraints coming from observations. These kinds of statistical discussions are absolutely necessary to give this constraint to the development of the theory, to understand the formation of planetary systems. So this is the meaning of my, it's not one object in addition, but it's to have a global view. And the second point, evidently, is to try to push the instrumentation to detect Earth twin. Because always, evidently, everybody have in mind the possibility to set, I would say, a small catalog of bright stars being good candidates to have planets with a mass of about one Earth mass,

with a good temperature and so on. Because any kind of experiment we will have in the future will need to know in advance where to look for. Because if you have, let's say, a space interferometer like TPF or Darwin-type instrument, you cannot search for this object. You need to know... You have to know where to look.

Exactly. And so, at least for me today, this is my first interest, is to try to contribute a little bit to set a list of this object. You have different possibilities. You have a lot of people interested in low-mass stars. Evidently, the habitable zone of low-mass stars is extremely close to the stars. Like the so-called red dwarf stars that there are so many of. Exactly.

It's much easier to detect good candidates, good rocky planet, orbiting this kind of star. But are you sure that life could be on this kind of low-mass planet? Because it's extremely close to the star, so you have different kind of phenomena. You can have difficulty with big atmosphere, and recently you have papers showing that, oh, maybe you will have trouble with inhabitability on this subject. So personally, I'm more interested to try to detect rocky planet orbiting solar-type stars.

Just to offer the possibility, if low-mass stars are not a good object, maybe we have also a list of few candidates. And I'm just looking with my colleague in Geneva to explore this possibility. When you worked with your spectrograph in the mid-90s, it was cutting edge. When you look at the technology that is being used in these searches and characterizations of planets today, like harps, and the things that are happening with space-based astronomy, do you see this technology continuing to progress

to the point where finding Earth analogs will become commonplace? Finding Earth analogues, I believe, is already possible today, but sometimes these kind of Earth twins are extremely at very remote distance. So the follow-up of this object to determine the mass, because maybe by transiting planets only you have the radius, so to get the mass could be already difficult, but after to separate the planet from the star, it would be almost impossible. Personally, I'm more interested in today's Texas scan of the rocky planet orbiting extremely close stars. And so, we'll see if we succeed. But it's true that we have

an ARPS-type instrument that already has the possibility to get sub-meters per second, precision better than one meter per second. Today we have a new kind of spectrograph built on the same kind of principle presently developed in Geneva in the frame of a big consortia to be connected to four eight-meter telescopes. But the real difficulty will be the jitter of the velocity of stars or the due to the magnetic magnetic activity of the of the star so despite the precision of you have with your instrument you still have the problems of the difficulty due to the star itself

of the difficulty due to the star itself. And this is also at the level of one meter per second. And what you are looking for is 0.1 meter per second. So I believe what is very important is the effort presently done to try to correct the velocity of the star using some kind of physical information due to the magnetic activity. Okay, this is a little bit for the future, but you have some teams working on that line. And okay, I'm quite confident. When you mention even one meter per second, to say nothing of one tenth of a meter per second,

our ability to measure that kind of exquisitely small, nearly infinitesimal change in the velocity of a star, I'm still left in awe. Yes. A priori, it looks impossible to measure. It's so small, and you have to maintain this precision during several years sometimes. Because if you are looking at a period of one year, let's say, you need not to have only one period, but maybe two or three to be sure. So you need to maintain the stability of the instrument on several years. And it's extremely, it corresponds to few atoms of silicon in the plane of the spectrograph.

So it's really, this is the beauty of science. You can do this kind of things. You asked a question also during your lecture in Kyoto that I want to ask you, knowing that you're an astrophysicist, not a biologist. One of your slides said, is life a cosmic imperative? And of course, this is also leading us toward, is there intelligent life out there? I'm sure you're familiar with the Drake equation, which is more of a statement than an equation. But we are filling in those variables.

If I ask you that question, is life a cosmic imperative, do you have any sort of an answer? Yes, I have an answer typical of a politician. So you have two ways to answer the question. You have the scientific answer that you don't know because you know that you have a lot, a lot of planets convenient for the development of life. No question about this. And so the Drake equation is certainly completely not necessary.

We observe today that we have a lot of low-mass planets. At a good distance, no problem. The real question, what is the probability of emergence of life when you have all the good conditions?

I'm not a biologist, and in any case, biologists have never given any probability you don't have any prediction coming from a biologist no data to base it on so one of my friends gave some lectures on this and the title was

infinity product with zero what is the answer so ok the scientific answer to a question is you have to do measurements. Look if your life exists. So after you have the second possibility to answer, what is my own feeling? Personally, I'm absolutely not offended to be a byproduct of the evolution of the universe.

So some can, okay. life is a normal development. It's a marvelous aspect of this, because sometimes you are disturbed, but you see the complexity of what is life. So I understand that people have some difficulty with this kind of statistic, not evolutionary predictions. But, okay, I don't know.

We have to do measurements. I share in that statement of faith. You have such a busy day lined up today. I just have one other question for you, more of a comment, because in your lecture you trace some of your early life, and you had an image from 1968. At least at that time, maybe you still do, like to participate in somewhat dangerous activities. We almost lost you, apparently, in 1968, and therefore might have lost the discovery of 51 Pegasi.

I'm glad that they managed to pull you up that precipice. I don't think so, because, okay, maybe I will not have discovered extrasolar planets, but the general tendency of the technology in the 90s was moving in the good direction. The first to have been really competitive was a group of Canadian people, Gordon Walker and Bruce Campbell. And they have not been,

how do you say, happy, because they received quite a small amount of telescope time, six to eight nights per year. So I discovered relatively recently this fact. So these people have been working during 10 years with so small amount of telescope time.

So it's exactly confirmed that it was not considered to be a so highest topic of science. But in any case, I believe that maybe a few months or a few years after, I'm sure that another team would have discovered. And now, as you said before we started recording, this community of colleagues that you have has grown and the public interest is quite obvious.

You must be gratified. Yes, and I'm always amazed because I was in a big conference on extrasurface in Hawaii in November. 360 people. And due to the location, many people from Europe

or Asia were not able to come. So, it's only a small fraction of the people working in this domain and some of them are young people extremely good at the beginning 20 years ago

I knew almost everybody and today I don't know it's more than 1,000 people and some of them, young people are incredibly good so I'm looking for big progress in the domain.

Dr. Moyor, thank you so much for joining us on Planetary Radio. It has been a pleasure and an honor to speak with you, and congratulations once again on reception of the Kyoto Prize. Thank you very much. Time for What's Up on Planetary Radio. Standing by on a big, big week for Laika the dog is Bruce Betts, the director of science and technology for the Planetary Society. Welcome back. Woof, woof. Woof.

Okay, well, we're going to get to the winners of our Leica acronym contest. But first, tell us what's up. Evening sky. Mercury, tough for the next few days. But depending on when you get this, we'll be getting higher, making its best evening appearance of the year over the next two, three weeks. So it'll be a bright object, very low in the west shortly after sunset. Jupiter up in the east and southeast in the early evening, very bright. And then a cool triangle going on around midnight or any time between then and the pre-dawn. We've got reddish Mars, much dimmer reddish star Antares, but still a bright star, and then

yellowish Saturn in a pretty tight triangle. So that'll be rising in the east around 11, between 11 and midnight in the evening. On to this week in space history. In 1961, Yuri Gagarin became the first human in space. And then in 1970, Apollo 13 launched and returned during this week after their harrowing experience, but successfully returned. Yuri's Night, for those of you who hear this, before the 9th of April, the celebrations all over the world, albeit the LA one, doing some stuff for Planetary Radio. Alright, we move on to Random Space Jack. I like that voice.

So for a long time, Titan, the moon of Saturn, and the second largest moon behind Ganymede, was believed to be the largest moon in the solar system from astronomical observations because of its very big atmosphere. Very high, very thick, which if one included it it would make it larger than Ganymede. But in terms of pure surface size, Ganymede wins. And while I would love to talk more about these moons, we need to get right on to the contest because we've got a bunch of people to acknowledge. To honor the first dog in space, come up with words to match the acronym LAIKA, L-A-I-K-A, and make it connected to something space-related. How did we do, Matt? I know how we did. I went through the entries. We did great. Awesome.

This is always so challenging to narrow them down. Every single one we got was at least NASA quality, which sadly is not saying much. They were good. They were very good. They really were. Let's start with the honorable mentions. And this is the honorable kiss-up award from Eric Halbeth of Novi, Michigan. Nice town, nice name.

He said, Light and I keep accelerating, which expanded is give me light and I keep accelerating. What am I? A light sail, of course give me light and I keep accelerating. What am I? A light sail, of course, a light sail called Leica. Hey, that's a Planetary Society mission, isn't it? It is, isn't it? Yeah.

Do these in front of you? Yes, I do. So from Eric O'Day in Medford, Massachusetts, he says, are you constantly pestered by your hungry pup while on orbit? Waste no more time on the boring chore of dog food distribution with Leica, the long-range automated integrated kibble accelerator delivering zero-g nutrition to your space pooch on demand. The new and improved, no doubt. Here's another honorable mention, mostly because it's another good poem from Dave Fairchild in Shawnee, Kansas. He had the Lunar Astrophysics Installation for Kuiper Astronomy.

But then he added, let's build a lunar base that studies Kuiper object brightness, learning their albedo based on composition whiteness. Then play a sad and haunting tune upon the balalaika, paying tribute to the Russian canine known as Laika. Try the balalaika, Laika. Bring it home. Now, the first of our two entrants, who is basically a runner-up, and we will be sending them a Rubber Planetary Society asteroid. Have you got Kurt Stolpa there?

Yes, I do. Kurt Stolpa from Marietta, Ohio gave us low-albedo infrared Kuiper Belt astronomy mission. What I liked about this was that it actually made some technical sense to use infrared for discovering low albedo objects. Here is the other runner up from Ginny Phanthome in Toronto, Ontario. Lovable animal is KGB astronaut. Truly a tribute to Leica. That cracked me up the first time I saw it, and it's still cracking me up.

So, Ginny, Rubber Asteroid comes to you. And our big winner from Richard Hercher of Chesterfield, Michigan. He recommends the Lifetime Achievement for International Canine Astronauts, the Leica Award, a small fire hydrant award 3D printed on the made-in-space printer flying on ISS to commemorate all the four-legged contributors to our space advancements.

We both like this one a lot, so congratulations, Richard. You will be the one receiving the itelescope.net account this week, that nonprofit network of telescopes around the world, a 200-point account, a Planetary Radio t-shirt, and the signed copy of Unstoppable from Bill Nye, his latest bestseller. So thank you very much, everybody, once again. And we're ready for the next one. Intellectual pursuits in space history. Who was the first person to vomit in space? Go to planetary.org slash radio contest. That'd sound more refined if I used a British accent.

Not really. Gives a whole new meaning to the rainbow smile. It's what a wonderful distinction for some lucky astronaut. And if you want to be our lucky winner, you'll need to get us that entry by Tuesday, April 12th at 8 a.m. Pacific time. And we're ready to finish this off. All right, everybody, go out there, look up at the night sky and think about dogs swimming in water. Thank you and good night. Or how about sheep sitting on the wing of a 747? Check out the latest random space fact from Bruce Betts.

He's the director of science and technology for the Planetary Society, and he hosts the RSF series. You'll find it at planetary.org. Planetary TV is where it lives. Bruce 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 Leica-loving members. Josh Doyle created the theme music.

I'm Matt Kaplan. Clear skies.