Planetary Radio: Space Exploration, Astronomy and Science - The Pale Red Dot: A Planet Called Proxima b

Episode Date: August 30, 2016

The announcement was made just days ago. Co-discoverer Michael Endl tells us about the discovery of a roughly Earth-mass planet orbiting in the habitable zone of the closest star to our own.Learn more about your ad choices. Visit megaphone.fm/adchoicesSee omnystudio.com/listener for privacy information.See omnystudio.com/listener for privacy information.

Hi there, podcast fans. Just checking in, saying hi, because I haven't done that for you folks in a while. You know, we just keep growing as a podcast. It's incredible. No, it's not incredible. It's credible, but amazing and wonderful how big Planetary Radio is now on the web. And you're largely responsible for that. After all, you're listening.

And some of you have taken the trouble to review us, post something on iTunes or Stitcher or SoundCloud or wherever you find us. Maybe it's at planetary.org slash radio. But I will ask, as I have a few times in the past, if you have not given us a rating or gone even beyond that and done an actual review, I would be extremely grateful if you would do so. It makes a huge difference to those sources of the program and to other at least potential listeners who might only blunder upon us online and need a little peer pressure,

a little peer assistance to find out just how much fun we have with this show. Thanks very much for the help. I hope you enjoy this week's Out of This World program. Ha ha, here it is. An Earth-like world right around the corner, this week on Planetary Radio. Welcome. I'm Matt Kaplan of the Planetary Society with more of the human adventure across our solar system and beyond. There's a pale red dot out there just beyond our grasp. Proxima b is the nearly Earth-mass planet that was announced with justified fanfare last week. We'll talk with Michael Endel, one of

its discoverers. Bill Nye has the week off, but senior editor Emily Lakdawalla is here with an early report on Juno's swing past mighty Jupiter. Jupiter's moon Europa is just one of the venues a few of you would like to see added to the Olympics someday. Bruce Betts and I have the winners of this interplanetary competition in our What's Up segment. Emily is at the starting block. Emily, Juno made it at least through the first of its close passes. What do we know so far? Well, we know that the spacecraft is sending data after its first close pass by Jupiter after entering orbit. And I want to emphasize that, you know, it's an orbiter, it's going to keep orbiting no matter what. It's no surprise that the spacecraft

survived. But because Juno went into safe mode twice after its Earth flyby, I think there are plenty of people who were wondering if it could do this first Jupiter close approach safely with all its instruments on taking all the data without putting itself into a protective safe mode. And the fact that it did that shows that the engineers understand how the spacecraft operates, managed to get it through this highly unexplored environment so close to Jupiter, with a spacecraft performing as expected. So that really is the best news on Juno's first close pass by Jupiter. Where are those images? Well, we don't have the images yet because Juno is a pretty deep space mission. It's out at Jupiter.

There's a lot of instruments that gathered a lot of data at close approach, and there's a bottleneck. All that data has to come back through the deep space network. There are certainly more images on the ground than we have seen. I don't know what they are,

and they said that they'll be releasing them later in the week. But we can expect data and images to be trickling out slowly, I think, over the next two months, because Juno has another very long orbit to do before the next close pass by Jupiter, at which point it's going to dramatically shorten its orbit to only a two-week one. Boy, shades of new horizons waiting for those images to come trickling back in. Now, there is one that you included in your blog post on the 28th of August. Yeah, they released one image, which I think, if I understand the timing correctly,

is the very last frame in what they call the marble movie. So there should be lots and lots more images on the ground showing Jupiter slowly increasing in size, spinning away as the spacecraft gets closer and closer to it. And now we just have to wait and see those higher resolution pictures that will be the real first from JunoCam, getting the best resolution views on the clouds and unusual views on the poles of Jupiter, things that we've never seen before. I can hardly wait. Thank you, Emily.

Thank you, Matt. She is our senior editor at the Planetary Society, also known as the Planetary Evangelist, and she's a contributing editor to Sky and Telescope magazine. Let's talk next about the discovery of a planet circling the star closest to our own, the pale red dot. We now know that a world resembling our own in some important ways revolves around the nearest star to our own sun.

We journalist types were warned a few days early that a major announcement was coming from the European Southern Observatory that gave me time to arrange a conversation with Michael Endel. We talked just a half hour or so before the announcement became official. Michael is a research scientist and lecturer for the University of Texas at Austin's McDonald Observatory. As you'll hear, he led work several years ago that delivered a tantalizing hint of a planet at Proxima Centauri just four and a half light years from Earth. Now he's a member of ESO's worldwide Pale Red Dot team that has confirmed Proxima b.

Pale Red Dot, that's a tribute to Carl Sagan, of course, who referred to distant Earth when it was imaged by a rapidly receding Voyager spacecraft as a pale blue dot. It was actually called during the press conference a possibly momentous discovery. I agree with that. All I can do is congratulate you. Thank you very much. I'm very, very happy. You know, Proxima Centauri is an old friend of mine. I've been looking at that star with my colleagues for quite some time, looking at that star with my colleagues for quite some time. And I'm the happiest person today that seeing this data helping so much to get this planet detected. And you have many very happy colleagues around the world. I hope we can talk a little bit about that team a little bit later. Your colleague, Ansigard Reiners, I hope I got his name right. He said, Proxima b, the name of this newly discovered world is indeed our neighbor.

So let's get used to it. Are you used to it yet? Well, I'm not used to it yet. No, it is, you know, the universe gave us a huge gift. I mean, this is the holy grail in astronomy. We really want to, or in exoplanet research at least, we really want to find Earth 2.0. And so meaning a planet that has the correct composition and correct atmosphere and other conditions for life to exist. And we always

speculated about these planets also orbiting these very low-mass end dwarfs, as we call them, like Proxima Centauri. And that there, the habitable zone is much closer to the star because the star is a thousand times fainter than our sun. But we would have never imagined that we find one right around the nearest one, the next-door neighbor, really. We find one right around the nearest one, the next door neighbor, really. And that opens up the door to enormous, wonderful opportunities of, you know, follow-up observations. We will be able to hopefully directly detect it. Then we can feed the light of the planet into our instruments and analyze it and see maybe, you know, the chemical composition of its atmosphere and things like this. Maybe even search for biosignatures in the future. This would be extremely exciting.

I would be very, very interested in doing this. Well, you just mentioned several of the other topics that I'm hoping we can also talk about. But first, tell us a little bit more about this newly discovered world. Mm-hmm. Proxima Centauri itself is a star very different to the Sun. It's much smaller. It has a mass of only 12% of the Sun's mass. It's much fainter.

Like I said, a thousand times fainter intrinsically. That makes it, although it's the closest star to us, we can't see it with the naked eye. It's much too faint to be seen. But it's, of course, close to the Alpha Centauri A and B binary, which is one of the brightest stars in the southern hemisphere. And what we did was, once we had the possibility to use large telescopes and the proper instruments to take these Doppler

velocity measurements with the sufficient precision to detect planets, we knew that if you use Proxima or a similar star as the target, then even very low-mass planets would become detectable, because they induce a much larger velocity variation in stars with such a low mass than they would, for instance, for the sun. So to give you an idea, the Earth, for instance, imparts on our sun only a velocity variation of plus minus 10 centimeters a second per year, over one year. that's beyond our capability at the moment but if you go to something like proxima again the planet moves closer in in the habitable zone and the low mass of the star makes the reflex motion much bigger and the amplitude is now

actually for this particular planet 1.4 meters second, which is a little bit above the measurement precision that we get. So what happened was that over the years, Proxima was observed first by our project with the ESO 8-meter VLT and the U-Vis spectrograph. We had seven years of data. I looked at the data, we analyzed it, and we didn't see anything convincing. I looked at the data, we analyzed it, and we didn't see anything convincing. Now, in retrospect, we saw actually that 11-day signal at very low confidence level in our data,

and that becomes important for now, for today. Anyway, I did a calculation to see what can be ruled out just based on our data. That was about two to three Earth masses in the habitable zone. Then we stopped our U.S. program, and the Geneva Group started their HARPS program using the ESO 3.6-meter telescope. And HARPS, we should say, is that divinely sensitive spectrograph that has been used so successfully in these Doppler or radial velocity shift searches for exoplanets. That's correct, yeah. It gives currently still state-of-the-art top-of-observation capability.

It gives typically for bright stars radio velocity measurement precision of a little less than a meter a second. At the time when we looked with U.S. at Proxima, we had about 2 meters a second, 2.5 meters a second precision on our measurements. Guillaume Anglade, the lead author of the paper in Nature and the leader of the whole team, he and his colleagues, they looked at these archival data coming from UVIS and from HAARPS. We analyzed it also a little bit, improved the precision even. And then they saw that there is a pretty interesting stable signal at these 11 days, but still it was not significantly detected that we would be able to announce it as a planet. So what Guillaume and his core team did, they were doing the right thing.

They were saying, okay, what do we do now? Well, the best thing is now to design actually an observing campaign that is specifically designed to confirm such a candidate signal. And that was the origin of the Pale Red Dot campaign. It was using HARPS earlier this year to take a spectrum or take a radio velocity measurement of Proxima every night. So they got lots and lots of data at the beginning of 2006, and fortunately for everybody involved, that signal was indeed very easily confirmed. It's highly significant now, and the older data sets are important now because going back, you can check whether that signal was present. So when you combine everything now, the signal is even boosted even further. And that is the telltale sign of a planetary signal.

Because we have to be very careful with these, especially with these stars. They are magnetically very active. signal because we have to be very careful with these especially with these stars they are magnetically very active and these magnetic activity that produces sunspots or star spots or flares and and other cycles can influence our radio velocity measurements so we did all we could to check whether there's any correlation, any dependence of our radio velocity measurements with the stellar activity. Proxima rotates with about 83 days. So it's a very slow rotation period. And then the signal that was actually detected is at 11.2 days.

From the amplitude of that signal, we get a minimum mass of the planet, which is 1.3 Earth masses. 1.3 times the size of Earth at minimum. The mass. Sorry. That's right. So this is in a nutshell the whole discovery. And the big exciting news is, of course,

because it's really around the closest star, which makes it actually so exciting because of the opportunities that we will have in the future. In the habitable zone, but close enough to the star that it is very likely tidally locked to the star. So much like our moon, always facing one side of this world toward its star. That's correct. That was the main argument in earlier times to say that now these red dwarfs will not be good candidates for habitable planets because the atmosphere will boil off at the day side and freeze out on the night side. It's very likely it is tidally locked, but there are ways coming out of the tidal locking

as well for instance if it has an own moon which we don't know or if there are other planets in the system which we don't know yet but the the main issue is that that over time now pretty sophisticated 3d climate studies models have shown that these atmospheres wouldn't collapse. There would be enough heat transport between the day side and the night side to allow the atmosphere to stay stable. It would be very windy, though. I imagine so. It's probably unlike our climate here on Earth, which is very quiet in comparison.

More of Michael Endel, member of the Pale Red Dot team, is just ahead. This is Planetary Radio. Bill Nye here of the Planetary Society. Now, this is the 100th anniversary of the National Park Service. So for 100 years, the Park Service has been preserving our natural wonders so that we can go to the parks and wonder. Wonders would drive so much of science. And as astronomer Tyler Nordgren likes to say, half the park is after dark. So when you're in our national parks, please look up at the night sky and wonder, because we want everyone in the world to know the cosmos and our place in space. Hi, Emily Lakdawalla here with big news from the Planetary

Society. We're rolling out a new membership plan with great benefits and expanded levels of participation. At the Planetary Society, passionate space fans like you join forces to create missions, nurture new science and technology, advocate for space, and educate the world. Details are at planetary.org forward slash membership. I'll see you around the solar system. Welcome back to Planetary Radio. I'm Matt Kaplan. Proxima b is the just discovered world that circles Proxima Centauri, the dim red dwarf that is the closest star to our own solar system. Michael Endel of the MacDonald Observatory is part of the PaleRed.team

that made its big announcement on August 24th. It is, as I said, a very international, a very diverse team. People all over the world taking part in this. That's right. There are people in Australia, there are people in South America, in Europe, in the U.S.

I probably don't even know all the countries on the team. It's a huge team. You've seen the offer list, I think it's like 30 people. Yeah, it's a long list. We'll put up a link to the press release about this announcement, and you can see the names of all of the investigators, which, of course, Michael is one of those co-investigators on this study. I have to ask, because I know I will be asked by audience members, if Proxima B will, now that we know it's really there, perhaps get another name someday.

It occurred to me that there's a film director named James Cameron who might have a nomination for you for that name. Pandora? As far as I remember, the movie Pandora was around Alpha Centauri A. It was also a moon of a large planet. Exactly, it was a moon of a giant planet. And it was very funny for me because for my PhD thesis, I actually calculated the limits that we can set for giant planets around Alpha Centauri A and B. And they showed that there is no gas giant planet in the habitable zone of A or B. So apparently, James Cameron didn't read my paper. Sorry about that, Jim. You mentioned the possibility of directly imaging this world. You mentioned the possibility of directly imaging this world.

How soon do you think that might actually happen? And are we getting close to having the tools to do that? Yes, we actually do. Because of the proximity of Proxima, it's still very, very difficult, very challenging. I mean, the separation is very, very small on the sky because the planet is so close to the star. But it's not totally out of reach of current technology. So I'm already talking to experts in the field to see what they can do. And some say that their instrument is not able to do it.

The other ones say that, yeah, it might be possible. It's just really on the verge of what what can be done and the problem is we have no idea about the size of the planet and the albedo which means its reflectivity because we would try to detect it in reflected light so it's it's kind of hard to estimate but we are running those numbers now and currently it looks like it's probably not possible within the next few months or a year or so. But if you would design now, for instance, a small space telescope to do specifically this, that's not a problem at all. It will take, of course, longer time. But a dedicated space mission now to image this planet around Proxima would be fantastic.

And then of course we will have the next generation of large aperture ground-based telescopes. So the University of Texas at Austin is partnering the giant Magellan telescope project, the GMT that will be built in Chile. So it will have direct side to Proxima. Yeah, construction already underway on that project. That's right, yeah. To be completed sometime in the mid-2020s. And then it will have a very high-powered so-called adaptive optics system,

which will compensate mostly for all the atmospheric turbulences and with such a large aperture telescope you have a very very high spatial resolving power so probably at that stage we will be able to hopefully to directly detect it. If the transit is not detected earlier, I mean there is a small chance that the planet even transits Proxima Centauri. If that would be the case, then that would be just absolutely fabulous.

And that is something I bet you would be involved with because you've spent a good deal of time confirming results from Kepler and now the K2 mission, right? Which uses that transit technique. That's right. Yes. So currently, I'm actually not directly involved in any transit technique. That's right, yes. So currently I'm not, I'm actually not directly involved in any transit search. What I would like to do, if the transit is detected, first I mean there would be a completely new type of information coming in. We would have a radius estimate for the planet. So together with the mass, which we would then know is the true mass, 1.3 Earth masses and, I don't know, 1 Earth radius or 1.5 Earth

radius, we would get a mean density. Then we can really talk about the composition of the planet. But what I would specifically would like to do is then to do what we call transmission spectroscopy, which is also, of course, very challenging because the atmosphere of such a small planet would be very, very small. But we do this already with bigger planets where we see the starlight filtering through the atmosphere when the planet transits. And from what the atmosphere takes out, we can infer some kind of the chemical composition of the atmosphere. So this would be something I would be very interested in doing. Something that we've talked about recently on this program, that we are now gaining this ability to

actually analyze the atmospheres of some exoplanets. Do you think one of the things to look for in that atmosphere on Proxima b would be oxygen? yes so if you really can you know if it transits and we can get transmission spectroscopy with the high enough quality and then there's also of course the James Webb Space Telescope will be launched in in the year or two which will be an exquisite instrument if we see oxygen carbon dioxide water vapor methane, the combinations of these chemicals, these molecules, then the likelihood that there is some kind of life, even apparently similar life to Earth life, even if it's just microbial, this would be the discovery of all time history. This would be the discovery of all time history. You said that you spend much of your time studying exoplanets around dwarf stars of various varieties.

This happens to be a red dwarf. And this, of course, has also been very much in the news lately. The preponderance of dwarf stars across the galaxy and therefore probably across the universe. What does this say to us about the likelihood of other Earth-like planets, very possibly like Proxima b? Yeah, it paints a very optimistic picture. This is one of the things that makes it so exciting. The sheer number of these M dwarfs, they just completely outnumber stars like the sun by a large factor in the galaxy and probably in the universe at large, of course. We will get a lot more information about this. And I don't know, you're probably familiar with the Drake equation.

Oh, yes. are of course really trying to to determine that one parameter eta sub-earth which is the parameter how frequent are earth-like planets uh in the habitable zone if you add the whole number of the m dwarfs then to this this this would make it just a very very big likelihood that you know at least i wouldn't say primitive life, but at least, you know, single cellular life that existed also on Earth for a very long time before complex life evolved. I wouldn't be surprised if in our lifetimes we find signatures with this. I sure hope you're right.

And I do love to congratulate researchers like yourself who are attempting to fill in those variables in the Drake equation with real numbers. Michel Mayor was my guest last April. Have you ever met that first discoverer of exoplanets? Oh yeah, I know him actually quite well, yeah. So you have something else in common. If I remember correctly, Michel talked about a mishap he once had on a mountain in the Alps, the Swiss Alps, that could have ended his time on this planet or any other planet. You had a similar experience. Oh, you mean the kawas on top of the summit ridge of Aconcagua? Yeah. Yes, that's true. I think my leg was already halfway in there before I realized this thing is bigger and wider. Yeah, these hidden crevasses are really, really a big danger, and every mountain climber is, of course, aware of it.

It could have ended a very beautiful day in a very nasty way. I hope this is not a rite of passage for exoplanet explorers. Please be careful next time you're up there, because we need this work to continue. Michael, thank you so much. And once again, congratulations. Thank you very much. Michael Endel. He is a research scientist and lecturer at the famed McDonald Observatory, part of the University of Texas at Austin.

Donald Observatory, part of the University of Texas at Austin. And he has devoted most of his professional life to the discovery, confirmation, and also the characterization of exoplanets, these world-circling other stars, including the one just announced, Proxima b, by far the closest to our own solar system and one that no doubt will be worthy of much, much more study. We will study the night sky in this week's edition of What's Up with Bruce Betts in just a few moments. Time once again for Bruce Betts on Planetary Radio. He is the master of all things in the night sky, which is why he joins us each week for What's Up. And he's the director of science and technology for the Planetary Society.

I mean, if you care about such things, hi. Hi. We got a big contest we're going to be naming the winners for in just a couple of minutes. So go ahead, tell us what's up. September 1st, there's an annular solar eclipse visible from parts of Africa and Antarctica. Venus is getting higher and higher just after sunset in the west, low in the west. It will be near the crescent moon on September 3rd. And we've still got Mars hanging out near Saturn and Antares in the south in the early evening as well. We move on to this week in space history.

In 1976, Viking 2 landed successfully on the surface of Mars. We move onwards to something that you may have been thinking about recently. Random Space Hack! You really should be working in cartoons. Yes, I should. Many people have said that, but it had nothing to do with my voice. So, Proxima Centauri, have you heard of it, Matt?

I have, faintly. Funny you'd say that. It is much, much dimmer than the sun. It is far less than 1% the luminosity, the brightness of the sun. And most of that, most of the luminosity it has actually falls at infrared wavelengths because it's much cooler. And it's only about one-seventh the diameter of the sun. See, faintly, that's going to be one of those people will think we scripted that joke,

and they're really giving us far too much credit. It's just your brilliance. No, I'm pretty faint, actually. All right, let's get on to that contest, because we had far too many really good answers. I mean, it's really not bad, but just impressive. So we asked you, if you were designing an Olympic event for another world in our solar system, what would it be and where would it be? We did great, Matt. I read through them. It was hard to decide.

Yeah, and you didn't even get to see all of them because it just would have taken over your day, as it did mine. So many great ones. As always, I apologize for the fact that we won't have time to mention all of these. We'll just have five. It's such a shame. I mean, you've got people like Katie Fritcher, who's totally out of touch with reality, who talked about jumping into the jets on Enceladus and seeing how high you could go, which I did enjoy. So creative. So six, six that we'll mention. Number five, this is a runner-up,

and he gets it because it's Alex Hayes at Cornell University in New York, who two weeks ago was talking to us about those canyons on Titan. The guy is obviously Titan nuts. He says contestants would strap bat-like wings of a specified surface area, strap them on, and see how far they could fly under their own power.

He says he's often told his undergraduate classes, you can almost fly on Titan by flapping your arms really fast. By putting on vinyl wings, think of base jumpers, you would be able to make short hops under your own power. And I've tried that on Earth, and it really is not very effective. But it looks great. What a laugh. Here's number four, Randy it really is not very effective. But it looks great. What a laugh. Here's number four. Randy Bottom in Brighton, Ontario.

I would recommend the pentathlon, gravitational wave surfing, gamma ray bursting, Fraunhofer quantum jumping. This is my favorite. Protoplanetary disc throwing and Saturnian ring tossing. And then he finishes with, who would carry the iridium flare or torch? Any good plays on words? Yeah, a few, a few. Number three, and for his trouble coming in third, Nathan Hunter in Portland, Oregon,

will get a Planetary Society rubber asteroid. For the Olympics on Titan, we had a lot of people who would love to see sporting events on Titan. The methane triathlon. First, a run, long jump, difficult to distinguish in low G over frozen methane. Then a swim through liquid methane in an insulated scuba suit. Then an aerial race in pedal-powered light aircraft. Swimming in methane video is also included. We're going to put up a link to this. It's our friend Chris McKay talking about what it would be like to swim or scuba dive in methane. And it's really a pretty

fascinating video. You watched some of it, right? I did. What's interesting, which I actually was deriving because of questions people asked anyway, liquid methane is much less dense than water. So you become very sinky. That's the technical term, sinky. Sinky. I like it. Liquid methane. Here is our number two.

And we had so many that had some kind of variation on golf because, of course, of Alan Shepard and his line drive or his shot taken on the moon all those years ago. This from Chris Oldroyd in Wakefield, UK. My Olympic sport would have to be moon golf as, of course, Alan Shepard has already set the record for the longest golf drive so far. But here's what put Chris over the top, a ready-made course of bunkers and fairways. what put Chris over the top, a ready-made course of bunkers and fairways. Let's not forget, the golf carts are already there. Sweet. And just to compliment that, Norman Kassoon, who also said golf, said there was actually some work done by a physicist to determine that Alan Shepard could easily have hit that golf ball, get this, about four kilometers or two and a half miles, and the ball would have stayed in the air, would have stayed up for about 70 seconds.

Wow. Only you're taking the right driver. You ready for our big winner? I am. It is none other than Dave Fairchild in Shawnee, Kansas, our poet, our resident poet, poet laureate. He came up with a pentathlon as well. Saturn's Rings, Hurling the Discus, Titan, Kayak Race in the Hydrocarbon-Filled Canyons,

Mimas, Archery, targeting Crater Herschel, Enceladus, Marathon, following Kashmir Sulki. Did I pronounce that correctly? Kashmir Sulki. I have no idea. And Hyperion, the Sponge Squeezing Contest. Look it up that correctly? Kashmir Sulzi. I have no idea. And Hyperion, the sponge-squeezing contest. Look it up. You'll know what he means. But then Dave also added this.

A kayak race on Titan down the canyons, long and deep, in hydrocarbon heaven in those channels, rough and steep, with Saturn in the background through the haze that Titan brings, we'd have a set of seven of those proud Olympic rings. Dave Fairchild, you will be our grand prize winner, taking home the, not a gold medal, I'm afraid, but taking home one of those Planetary Society rubber asteroids, a Planetary Radio t-shirt, and an itelescope.net 200-point account for doing astronomy all over the world from their remote telescopes all over the world. That's it for this time. Phew, great stuff.

Very cool. Thank you all for the wonderful entries. So here's the new contest. What is the only space shuttle orbiter to have traveled by land, sea, and air? It's a little shady, a little bit of a shady contest, but I think it'll work. Shady was not a clue, by the way. Go to planetary.org slash radio contest, get us your entry. You have until Tuesday, September 6th at 8 a.m. Pacific time to get that answer. And you will get, if you're the winner, a Planetary Society rubber asteroid, a Planetary Radio t-shirt, and a 200-point itelescope.net account. We're done. All right, everybody go out there, look on the night sky, and think about what it would look like if you were lying on the bottom of a pool looking up. Thank you and good night. Through methane, no doubt. Let's make it seven. William

LeCalve, World Series Baseball. He's Bruce Betts, the Director of Science and Technology for the Planetary Society, who joins us each week here for What's Up. A brand new space policy edition of Planetary Radio will magically appear on Friday, September 2nd. I'll talk with Casey Dreyer and Jason Callahan about OSIRIS-REx, mining asteroids, near-Earth objects, and things that go bump in the night, if you're not watching for them. You'll find it at planetary.org slash radio, SoundCloud, iTunes, and elsewhere around the endless interwebs. Planetary Radio is produced by the Planetary Society in Pasadena, California, and is made

possible by its worldly members. Daniel Gunn is our associate producer. Josh Doyle composed the theme, which was arranged and performed by Peter Schlosser. I'm Matt Kaplan. Clear skies.