Planetary Radio: Space Exploration, Astronomy and Science - A Planetary Mystery is Solved, and it’s Bill Nye’s Anniversary!

Episode Date: September 9, 2020

JPL’s Marc Rayman, former Dawn mission director, reveals the secrets of those bright spots on dwarf planet Ceres. First though we celebrate Bill Nye’s 10th anniversary as CEO of The Planetary Society. Chief Operating Officer Jennifer Vaughn is followed by the Science Guy himself. And there’s a Nye invention at the heart of this week’s What’s Up space trivia contest. Links and more are at https://www.planetary.org/planetary-radio/0909-2020-marc-rayman-ceres-bill-nye-jennifer-vaughn-10th-anniversarySee omnystudio.com/listener for privacy information.See omnystudio.com/listener for privacy information.

A planetary mystery solved, and a Science Guys anniversary celebrated, 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. JPL's Mark Raymond is back. His retired Dawn spacecraft discovered and has now enabled us to explain those brilliant white spots on dwarf planet Ceres. We'll talk to Mark in a bit, but first we'll mark Bill Nye's 10th anniversary as leader of the Planetary Society. Society Chief Operating Officer Jennifer Vaughn will join us before we hear from the science guy himself. The celebration will continue as Bruce Betts introduces a Nye-centric space trivia contest that is going to win someone a rare and valuable rubber asteroid. Did you know that Martian dust devils can reach eight kilometers into that pink sky. The little devil captured recently by a camera on the Curiosity rover

isn't nearly as ambitious, but it still tops the September 4th edition of The Downlink. And here is some of the space news in that week's newsletter, beginning with the ongoing saga of the mole. The InSight Mars lander's burrowing heat probe is fully buried for the first time, thanks to help from the spacecraft's robotic scoop. Keep digging, little one. Artificial intelligence has helped discover 50 more exoplanets.

This pioneering achievement was accomplished with data from the Kepler Space Telescope. Northrop Grumman has successfully test-fired a solid rocket booster for the giant space launch system. The huge five-segment engine will help get later SLS missions off the ground. You'll find much more at planetary.org slash downlink. It has been 10 years since Louis Friedman, the Planetary Society's founding executive director, since Louis Friedman, the Planetary Society's founding executive director, literally handed the keys to someone who was, till that transition, vice president of the nonprofit's board of directors.

Bill Nye became a charter member of the Society at the invitation of his Cornell professor, Carl Sagan. Chief Operating Officer Jennifer Vaughn has probably worked more closely with Bill than anyone else. We'll hear from the science guy himself after Jennifer reflects on the age of nigh. Jennifer, welcome to the show. I am really glad to have you on because I think you are the very best person to help us celebrate this 10th anniversary of our CEO. of our CEO. Well, I don't know about that, but I certainly appreciate the chance to be able to be here and celebrate what is really an extraordinary period for the Planetary Society under Bill's leadership. I second that. And I will tell you that I've already had a conversation with him that we're going to be hearing in a few moments. He gives the most credit for the success of those 10 years, as of course you would expect Bill would, because he's not going to talk as much about himself to you. Oh, well, that's so very kind and so very Bill.

So he is always gracious and always very giving and generous to our team, because it really is a team effort. But as everyone knows, it starts at the top. And so that's Bill. And Bill has done a lot for this organization to refresh and rethink about where we are headed and what we should be focusing on and giving us all the enthusiasm and the passion instilled in the team and in our membership. So he is so very gracious that way. And it's one of the things I think about first when I think about Bill. How would you describe your relationship with him? This is something he also talks about, I'll warn you, as the CEO and you as COO.

I think we've developed a really nice partnership and rhythm over the years. I think with all team members, what you look for is you want to lean into one's strengths and then balance appropriately. And I think that Bill and I are very nicely balanced. Bill is a visionary. He is an eternal optimism about all the great things the planetary society can achieve. I want to say I have that too.

I'm not trying to say that I'm not those things, but at the same time, I am also more of the pragmatic. I'm operations. So I'm trying to figure out how we are going to actually implement these things. So I think between the two of us, where I'm focused more on the day-to-day implementation of activities, he is setting the goals. He is setting the direction. He is clearly raising the profile. He's making the relationships. So he is very much at the helm of the organization. And I, along with the rest of the team, are working to make that vision a reality. talked about organizational managerial considerations. I'd love for you to say something also about how Bill represents the society as our spokesperson extraordinaire. I'm not alone here. A lot of people like to ask what it's like to work with Bill Nye. I get it all the time. Exactly. I often say, well, probably exactly what you think it's like, because the Bill Nye that

people got to know on TV is really an extension of Bill Nye the human. He is a teacher. He is enthusiastic. He is empowering. He is fun. He is friendly. He is thoughtful uh he's all those things all the time and so it's such a such a wonderful environment to be around it starts with this kind of warm friendly encouraging team environment but that just spreads out into all that we do so i think as a as a leader he's always been one to live by his motto of everyone you meet knows something that you do not. So he treats everyone with tremendous respect and empathy. He is always a very curious person, wants to know about you, wants to know your perspective, wants to know your experiences, and does not pretend that he knows better. So I think for all those reasons, he's not just the right person for the organization, but he's the right person for today as well. needs more of. People who are willing to listen and build teams and bridges versus what we are

experiencing a lot with the divisions. So we're lucky to have them. I'll say, and that's lovely. It may be too much to hope for, but I'm going to hope for anyway. Another 10 years, much like the last 10 with Bill and with you, Jennifer. And I hope I'm around for most of that as part of the organization because it's been a swell time. I hope so too. We are having a really good time together. And organizations, they're always growing. They're always developing. Clearly, we've had a growth spurt because there was new leadership. That's what happens. It's not that, you know, it's just you have new people, new things happen. We've had that excitement. We're not done.

We have a lot more lined up for the next five to 10 years. So I hope to see all this continue as well with many of the players that we have right now as the organization grows. Thank you, Jennifer. Thank you, Matt. That is the Chief Operating Officer of the Planetary Society, Jennifer Vaughn. And now let's hear from the CEO. Bill, I was there for the start, and I am so glad to still be with you and the society

10 years later to celebrate this auspicious occasion. Happy 10th anniversary. Thank you, Matt. 10 quick years. What in the world? No, it's a very surprising result, as we say in geometric proofs. No, I just, I did not anticipate being around the society as the CEO for 10 years. But boy, time has flown.

And speaking of flying, something we did do the last 10 years is get two solar sail missions up on orbit. And we got down some fantastic pictures. We moved from a pretty cool, a pretty nice site for nonprofits, the Court of Appeals courthouse in Pasadena to our fabulous, I'll call it new headquarters. That is a really, really comfortable workspace. So those are the stuff that's happened. I'm crossing off my question. Ask Bill the top two things he is most proud of.

Well, what I'm most proud of. No, Matt, what I'm most proud of is hiring Jennifer Vaughn to hire you. So one day, Matt, I don't know if you know this, was this eight years ago, eight and a half years ago, I said to Jennifer, whom I had promoted, like I had the power to do that or something. And I said, you know, we should hire Matt full time. He's working at the University of Cal State, Long Beach, and he's working at part. Oh, she's oh, yeah, I did that. I did that a few weeks ago.

No, everybody just understand my title is CEO. When I started, I was executive director, E.D., which we had a focus group. It was agreed that executive director was an old fashioned or British term. And we should change my title to CEO, chief executive officer. And so what I ended up doing was hire Jennifer Vaughn, promoting Jennifer Vaughn to be chief operating officer. And that has changed everything. She is so thoughtful. She has gone back to school, learned all sorts of management things, really trained herself on the software required to manage the budget of a nonprofit like ours, and set just really reasonable or concrete or achievable goals. And Jen is all about measurement, metrics, deliverables.

And that has just transformed the place. And we certainly have had impressive metrics, impressive deliverables. Well, and you're one of them, Matt. Planetary Radio is going wild. I mean, we do okay. You send us those testimonials from listeners. It is really gratifying, man. It chokes me up. And the eye on the prize is still for me to find out more about the cosmos and our place within it. I would like to be alive when we find evidence of life on Mars, if it's there to be found. And I want the world to embrace the idea that the Earth could get hit

with an asteroid, a big one. And we don't want that to happen. And it's going to take everybody working together by everybody. I mean, space agencies, taxpayers and voters around the world to ensure that we're ready if there's an incoming. So these things are still very much on my mind. I know that they are on the minds of our members and probably everybody else who listens to this show. Of course, they're all members, right? If you're not a member out there, if you're not a member, if you're just, you know, check us out. There's donate buttons all over the website. Oh, that's another thing. We greatly upgraded the website several times. And most recently, we've really upgraded what is under the skin, as they say in the web design world.

The back of house software is so much better than it ever was. I'll say. And some nice cosmetic improvements up front as well. Yeah, yeah. This streamlines things. And it means you, the donor, you, the supporter, get more for your donation. We're much more, weirdly more efficient than we were even three years ago because of this latest upgrade. And another thing, when I took over, latest upgrade. And you know, another thing, there were, when I took over, there were two Lus. Many listeners may be very familiar with Lou Friedman, who's still around, kicking around,

designing his amazing orbits to send a solar sail very near the sun and out into deep space. But there was Lou Koffing, a different spelling. And Lou Koffing was our accountant, Lou Koffing, a different spelling, and Lou Koffing was our accountant, our head of accounting. And I changed her title to Chief Financial Officer, CFO. Lou Koffing said to me, you know, Bill, what you ought to do is hire Brandon Schultz full time. He worked for us part time. He's our IT guy, internet technology, information technology guy. IT guy, superb. Yeah. Man, oh man. So everybody's central casting. When you go into Brandon's office, he's got a Rubik's cube. Sure, he does those without even looking, but he's got the 10 by 10 Rubik's cube.

And he doesn't just solve it. There's patterns you can work into the Rubik's Cube that are not all one color, not monochromatic on each face. He does that. He, along with Mark Roberta, have just done extraordinary things with our Internet presence. And then the other thing, Matt, we have really transformed our relationship to donors, our member relationships. We hired Rich Chute, and he's just had tremendous experience at the Claremont Colleges here in California, these five colleges that are just famous for the quality of their academics. And that's a result of the money they have to throw at the problem. And so Rich has just really taken it up a notch. And Danielle Gunn, my goodness, she's our head of communications.

She has just figured it out, man. She is just so passionate about it. And I guess what I'm proudest of, Matt, is our service to our members. We are improving the product to our members, whether the product is our website, flying our own spacecraft, proving an extraordinary hypothesis that we could tack a solar sail spacecraft fast enough to work in Earth orbit for $7 million, not $150 million, which is what it would cost at a space agency. So we have realized the dream of the founders and I think the expectations of our modern members. And as I like to say, Matt, the best is yet ahead. We are going to provide service to young people, to kids, students, and families to get people excited about space exploration, and to really know and appreciate our place in space.

I'm going to mention just one other area, and it's one in which you have played a major role, and that's our enormous success over the last 10 years in carrying on a tradition that goes back to the beginning of the society in Washington, D.C., our advocacy and policy efforts. Three things I like to say we do, Matt. We innovate. There's LightSail. We educate. There's a tremendous website, the long-form journalism about planetary science like you

will find nowhere else. Jason Davis and his guys and gals, they just do. Emily Lachter-Wallet just does amazing things. Our little niche of gigantic solar systems. And then the other thing we do is advocate. So we go around the world, but especially to Washington, D.C., to influence space exploration policy. And we've been just extraordinarily effective. It just shows you what you can do when you throw money at the problem.

do when you throw money at the problem. By that I mean when you hire the right people who have the right personalities to make the right contacts. As the old saying goes, Washington, D.C. is a small town based on trust and relationships. It's giving people information they need, congressmen, congresswomen and their staffs, how money is spent in planetary science, the great value of planetary science, the relative cost of planetary science, and planning. You know, NASA gets pulled in all directions for political reasons. But we help the administrator, no matter whether she or he is conservative or progressive. We do our best to help the administrator make good decisions about planetary science. And we do that because we have set aside a part of the organization chart, the org chart, for advocacy.

Innovate, educate, advocate. That's what we're doing. these last few minutes talking to us about our achievements and putting them in terms, in large part, of the people that we work with, the colleagues, many of whom you and Jennifer hired. So Matt, just everybody, we have a nice headquarters. We do. And thanks to one eccentric donor, we have a very nice coffee machine. But that's not what we have. What the Planetary Society is, is people. It's our staff that is so valuable. Everybody's so dialed in and so

passionate about planetary science, planetary exploration, that we're able to do this. And that's what I'm proudest of. And I'm glad that you're proud of that. It is utterly true. But I have learned in my many years working in many organizations that this stuff flows from the top. So I give you enormous credit, my friend, for getting us to where we are today. And sure, you had lots of help. But you put a lot of that help in place and you let it work and you add your own unique brew to making the society what it is today. And I'm just proud to be part of it. And I look forward to the years ahead. Well, thank you, Matt. Thank you indeed.

I'm really excited about the future and our staffing opportunities and how we're going to work to include more and more people on the staff and on the board of directors, but especially in our membership. Oh, by the way, the board of directors is something else, everybody. Yeah. Take a second, look on our website and just look at the credentials. This is your 10th anniversary. You've mentioned everybody else in the world. Well, I did my best, man. So just everybody know out there, my contract with this society is officially halftime.

And so there's some times when I feel like I hardly do anything. The other times, it's really more than full-time focus. So it really is an honor. And, you know, you play the hand you're dealt. I went to Cornell. I had one class from Carl Sagan. It changed my life. And now I'm CEO of the organization that he started.

And I am honored to serve, Matt, honored to serve. And I'm honored to serve under you. Thank you, Bill. Thank you to serve. And I'm honored to serve under you. Thank you, Bill. Thank you for everything. And happy anniversary. Many more to come that we can celebrate, I hope, and many more accomplishments by the society and our members and everybody else you've talked about. Thanks a lot, Matt. Let's change the worlds. I was waiting for that. That's Bill Nye. He is the planetary guy, the science guy, the CEO of the Planetary Society for 10 years and counting. We're moments away from a visit with the former chief engineer for the Dawn mission. Mark Raymond will tell us what's underneath those brilliant, formerly mysterious white spots on dwarf planet Ceres.

I hope you'll stick around. Greetings once again, Plan Red listeners. White Spots on Dwarf Planet Earth. We need you on our planetary defense team. It's the only large-scale natural disaster we can prevent. Donate today at planetary.org slash defend Earth to power our crucial work with your gift. That's planetary.org slash defend Earth. Thank you for helping us save the world. Welcome back. Mark Raymond wasn't just chief engineer for the Dawn mission. He also served as mission director and project manager for the ion-powered spacecraft that first visited Vesta and then departed for Ceres, the second largest and largest objects in our solar system's asteroid belt, out there

between Mars and Jupiter. The Dawn spacecraft finished its work nearly two years ago, but we got proof that it is still delivering exciting science last month. Mark also continues to deliver at the Jet Propulsion Lab. He was promoted to Chief Engineer for Mission Operations and Science. Add this latest honor to the many awards he has received across his career, including the Collier Trophy, the highest U.S. honor for achievement in space or aviation. It's on permanent display at the National Air and Space Museum in Washington, D.C. Mark, it is always a pleasure to welcome you back to Planetary Radio. Thanks

for returning and congratulations on the new job at JPL. Thanks, Matt. And it's always a pleasure to be here with you. I love your show and I'm always happy to talk with you. Well, you are one of our most frequently recurring guests, I'm happy to say, and so this won't be the last time. our most frequently recurring guests, I'm happy to say, and so this won't be the last time. When did you make this transition from leader of the Dawn mission to chief engineer for mission operations and science? Well, Dawn ended late in 2018. So it was early 2019 that I took this new position at JPL. And it's a lot of fun. I bet it is. I know at least one other chief engineer there, and he has a good time too. So I'm sure you are as well. Before we talk about Don a little bit, tell me more about this position. I mean, obviously, it carries a lot of authority,

but what does it really mean? Are you a go-between still between the scientists and the engineers who put together and design and operate these spacecraft? Well, that's something I've always done. But for me, the fun thing about this new position is that I get to be involved in many different projects. I'll tell you, to me, there's nothing cooler than being responsible for one of JPL's many, many exciting missions. But as much as I love that, I've been a space enthusiast my whole life. And in fact, my only real disappointment about my career is that it has interfered with my lifelong hobby of learning about space exploration. And so now, instead of being in charge of one mission, I get to be involved in many.

I've accumulated a fair amount of worthwhile experience at JPL. And so I can pass some of that along to people who are focused on their individual missions. So it's a lot of fun. Sounds pretty fun and pretty thrilling to me, actually. Let's turn to Don. I figured we'd spend a few minutes reintroducing the mission to listeners, but you've saved me that trouble because you shared with me this terrific video produced by JPL that also features your colleague, Carol Raymond, who, of course, became principal investigator for the Dawn mission. But it opens with you.

And I think we'll just play the audio. And then I will explain to people why they hear an interesting sound effect in the beginning of the video. So here it is. Did you know that cereal comes from the word Ceres, the Roman goddess of agriculture and grain? Well, you may not know that there's a distant solar system world, Ceres. It was discovered 200 years ago, and it's had a sort of identity crisis. It used to be known as a planet, and and then an asteroid and now a dwarf planet. Well, whatever you call it, Dawn with its

xenon ion propulsion system is about to call it home. Dawn is truly an historic mission. It's the first mission to orbit a main-belt asteroid and it's the first mission to orbit two interplanetary bodies, two fossils from the very beginning of our solar system and thus it's telling us part of the story of our own beginnings. Dawn orbited Vesta and spent 14 months exploring that alien world. We saw a crater there 300 miles in diameter and in the center of that crater there's a mountain that's two and a half times the height of Mount Everest. It's very young, it formed very hot, but we also found that there was water on Vesta and that water had to

come from somewhere else. And now we're on the verge of exploring an even larger alien world, Ceres. Thanks to Dawn's unique ion propulsion system, it has a different way of going into orbit around Ceres from what we're used to. It will slowly creep up on Ceres and gently use its ion propulsion system to gracefully slip into orbit. Dawn is going to be revealing to us this mysterious world that for more than two centuries has just been a faint smudge of light amidst the stars. We're now getting pictures that are better than the best we'd ever had before. The bright spot that's been seen in the approach images is very interesting because it's in the same region where the Herschel Space Observatory

detected water vapor emission from Ceres' surface. It's possible that objects like Ceres brought water to the Earth. It has a rocky core and an ice mantle, and in the past had an ocean like Europa and Enceladus. Dawn carries a suite of sophisticated instruments that will allow us to determine not only what Ceres looks like, but what it's made of and what its interior structure is. So we're going to learn about the geology and the chemistry, what minerals are on Ceres, all about the nature of this world. And it's like a time capsule from the dawn of the solar system.

So that was Mark Raymond and his colleague, Carol Raymond, in there in that little video describing very, very well the Dawn mission. But this is radio or a podcast, audio podcast. So they missed out on one of the greatest little visual jokes I've ever seen in a video like this. And it's because you are sitting at a table with a bowl in front of you at the beginning of the show. Mark, tell people what you're doing. I'm having breakfast. You could call it breakfast at dawn. Pouring my Ceresos cereal. Enjoying breakfast and enjoying talking with my breakfast companions about this exotic alien world.

And there actually is a connection, right, between serial and series? There is a connection because series and serial are etymologically derived from the same word. And it's just a fun way to help people remember the name of the first dwarf planet that was ever discovered. Kudos to your colleagues at JPL who made that cereal box for you because it's perfect. It looks like it could be on the shelf at a supermarket and maybe it should be too. I don't know if I'd want to eat the little gray spheres that you pour out of it, but they are appropriate. Yeah. Whether Ceres O's taste good or not is a separate question. I can tell you that that cereal box is on a shelf somewhere. It's not at a grocery store. It's in my office at JPL, which unfortunately I haven't seen in six months, but I have no doubt that the cereal inside won't taste any worse when I get back to my office than it did when I was last there. I'm sure it's loaded with nutrient-packed minerals, just like Ceres is.

Yeah, you and me both. I sure miss my office. I look forward to going back when we're all vaccinated. And by the way, this video, we will put up a link to it on this week's show page. You can get there from planetary.org slash radio, and you'll find other relevant resources to this week's episode. Here's why I got ahold of you again, Mark. It's because of a press release that came out from JPL and NASA just a few weeks ago. Mystery solved bright areas on series come from salty water below. And of course, we are talking about those bright spots, which mystified many and fascinated all who saw them.

I guess now we seem to understand what they are. Would you tell us what's going on here? Yeah, I think this is really exciting. And before I tell you what we learned, let me tell you how we learned it. What we learned, let me tell you how we learned it. When Dawn was orbiting Ceres, so Dawn got to Ceres in 2015, our prime mission there lasted a year and a half or so. And we mapped the body and took a tremendous number of measurements and accumulated a vast wealth of data.

But clearly these bright areas that you mentioned were the most intriguing. And so in Dawn's second extended mission, that is after the prime mission had ended, NASA approved our continuing our exploration of Ceres, we focused on that bright region and maneuvered Dawn to an orbit that once every 27 hours dipped down to just a little more than 20 miles above the ground. So only about three times higher than you are when you fly a cross country on a commercial aircraft. This was an extremely challenging but incredibly rewarding part of the mission because we got a fantastic view of this area. The crater that we're focused on here is called Akator. It's 57 miles across.

We know that it was formed about 20 or 22 million years ago, something like that. But these bright areas in the interior of the crater are younger than that, significantly younger. We now understand that what happened is when the impact formed the crater, it melted some of the material there. So I should take a step back and remind people that Ceres has a substantial inventory of water, most of it frozen, as well as salt and rock. So the impact melted that material and made what's called a melt chamber underground. And some of that material came up to the surface. And when it froze and the water dissipated, we have this bright reflective material left on the ground, salt flats in some sense. But the impact also created fractures underground that connected with a deeper reservoir of liquid that is perhaps 25 miles down, a large reservoir of this brine

that is salt-enriched water that could be hundreds of miles wide. Then through those cracks, the water subsequently made its way up to the ground and has continued to replenish what was left from after the impact. So we know that this melt chamber that was formed would have frozen long ago, millions of years ago. It would have taken millions of years to freeze, but still would have frozen long before the present. long before the present. But the material that we see on the ground could only persist on the ground in Ceres for a matter of maybe tens or maybe a few hundred years. We see it now, which means it has continuously been, not necessarily continuously, but it has repeatedly been refreshed. I think that is really, really cool. We know now that indeed there is subsurface liquid and it has this path up to the surface. Absolutely fascinating. How is this possible? We know that the liquid water ocean

under the surface of Europa is kept warm and liquid by the tidal stress from Jupiter. We talk about that a lot. But Ceres, it has no giant nearby worlds to keep its innards from freezing. How is this happening? Yeah, that's one of the things so cool about this. Ceres is the largest body that isn't a planet or moon on which we now know there's liquid. And as you observed on places like Europa and Enceladus, of course, one of the moons of Saturn, the gravitational interaction with the planet and

the other moons flexes the body, stretches and squeezes it. And that imparts energy to it to keep the liquid from freezing. Ceres doesn't have that because it's a dwarf planet. It's orbiting the sun and it's all by doing so basically by itself from the standpoint of gravitational heating. So the heat is what's left over from the radioactive materials that it incorporated when it formed. And the chemical composition of Ceres is such that it's able to retain that heat. That is, as the materials have decayed, the radioactive elements have decayed over the lifetime of the solar system, the heat has not been able to leak out from inside Ceres and escape out into space,

or not all of the heat has been able to. So it has retained much of that heat and the salts, particularly as people who live in parts of the country that get a lot of ice and snow know, the salts lower the freezing temperature of the water. That's why they salt roads to help melt that ice. Well, on Ceres, it works as an antifreeze there as well. is there as well. And so even though it can be below what people normally think of as the freezing temperature of water, 32 degrees Fahrenheit, it can stay liquid. And so this combination of the materials that are able to help retain the heat and the ones that keep the freezing temperature low have allowed Ceres to retain this liquid for the lifetime of the solar system. Pretty cool, huh?

Absolutely. Utterly fascinating. It is. And the coolest. Well, and not as cool as it might be otherwise, I guess. That's right. But how did you and the Dawn team figure out that there is this much bigger, I'll call it a sea, deeper below the surface of this dwarf planet.

Well, it's a combination of many different measurements, but a key one is measuring the gravity of Ceres. Of course, the gravity doesn't mean just what its overall mass is and thus how strongly it pulls on the spacecraft, but rather the variations as the spacecraft changes its location. So when there are underground regions of higher density, they pull more strongly on the spacecraft, and underground regions of lower density pull less strongly. And so with the exquisitely accurate sensitive measurements of the spacecraft's motion, when it gets down very close to the surface, scientists are able to determine the distribution of material underground. So combination of the gravity measurements, mathematical models that describe the movement

of heat inside Ceres based on the chemistry, measurements of things like the ratio between the depth of a crater and its diameter. So that tells you about the mechanical properties of the ground and how it both responds to an impact and how it changes the shape over time. And studies of the mineralogy, that is, what are the rocks and minerals there? All these different sources of information and methods of analyzing the data have combined to show that there's this large region that just happened to be located near where this impact occurred, that then these fractures were able to tap into. I never cease to be amazed when I hear these stories about what we can learn about the deep unseen interior of a body by orbiting something above it.

I mean, it just, when you talk about exquisite measurements of those Doppler shifts, right, in the radio signal, it's just, it makes me proud to think that we're capable of doing this kind of science. Yeah, I agree with that. I mean, it sort of makes you proud to be a human being. I agree with that. I mean, it sort of makes you proud to be a human being and part of humankind's collective effort to understand the cosmos, right? And it's no one person, and it's not even any one team, because it's the collective progress of science that allows this to happen. And I think that's deeply profound and incredibly exciting. And I think we're all lucky to be not only part of a species that can do that, but part of a culture that does do that. Well said. We stand on the shoulders of giants and then folks like you become the giants for others to stand on. I got to bring up one other thing that was in this press release, partly just because they have such a cool name and they have a relationship to Earth. And those are these features that you found on Ceres that resemble something very similar on our own planet.

You know what I'm talking about, right? I do. You're talking about pingos. And yes, they do have a neat name, P-I-N-G-O, pingo. It's a hill shaped like sort of a dome that forms in permafrost here on Earth from the pressure of groundwater that freezes and pushes up the frozen material in the ground. PINGOs have been observed on Mars as well, and now on dwarf planet Ceres. And for the same reason, right? That's right. Right.

Because of the pressurized frozen groundwater. I said up front that Dawn is, well, obviously the mission ended nearly two years ago now, but it's going to remain at Ceres forever, but not on Ceres, right? I mean, why is it still orbiting? Why didn't you let it impact? Yeah, well, the reason is because Ceres is of astrobiological importance. We've talked about the water. Dawn discovered a tremendous amount of organic materials on Ceres. These are chemicals that we know are important for life. And Dawn discovered many other chemicals that are, besides organics, that are also of interest for life, or at least the chemistry that leads to life. We just discussed a few moments ago, it still has this internal heat.

So there's a rich combination of the ingredients that are of interest for astrobiology. We didn't want to take a chance in contaminating that pristine environment with the terrestrial chemicals that we call Dawn. So the plan at the end of the mission, which we did execute, was to leave the spacecraft in an orbit that would not allow it to impact for decades at least. And that would allow humankind, if it made the decision to do so, to conduct a follow-up expedition that wouldn't be misled by what it found on the ground, by the possibility that it was the materials brought there by dawn. This final orbit that we put it in that dips down to 22 miles,

then coasts up to 2,500 miles, and then plunges back down to 22 miles, and it completes each loop every 27 hours. We purposely designed that carefully so that it would not crash even in decades. Planetary protection, something else we talk about pretty regularly on this show. And there's a good explanation for why it's so important. You know, we talk with other folks who were key contributors to missions past. I mean, Linda Spilker still comes on regularly to tell us about science that is still flowing from the Cassini mission at Saturn. Are you still talking with other partners

in the Dawn mission from around the world? I am. Now, I should say that my current responsibilities don't allow me a lot of time to devote anymore to Dawn's legacy, but I do still talk to them. And I know that there are people working on further exciting questions that can be addressed with the vast treasure trove of data that Don collected. And I'm confident that scientists will continue to gain fascinating new insights for many, many years to come. I look forward to those. Mark, before I let you go, I want to bring up that hobby of yours that you said your job keeps you from. I'm going to put up a link to that terrific video we did when you gave me a tour of your home not far from JPL.

Yeah, that was a lot of fun. I particularly like our shared laugh right at the beginning. You got it off to a good start, and you did a nice job with that video, Matt. Thank you. We'll just tease nice job with that video, Matt. Thank you. We'll just tease the audience with that. But the video will be on the show page, once again, planetary.org slash radio for this episode of Planetary Radio. It was a lot of fun. How is that great space library of yours still growing?

It is, and it's my expression of my lifelong fascination with space. I just love it, and that's, of course, one of the reasons I love planetary radio. sharing all of this and for the great work you continue to do on behalf of those who believe so strongly in the science that is being conducted around our solar system and beyond it as well. That's very nice of you to say. Thank you. It is truly my pleasure. I recognize I'm extremely lucky. I really get to do something that I've wanted to do my whole life. So it's, it's truly a delight to be able to share it with you and, and the listeners, because I know, as I told you once before, these are my people, right? We're all the same. We share the same, the same fascination with the cosmos. So it's, it's really fun to be able to talk with you about it. And I, I feel some of that luck as well,

just for the opportunity to talk with folks like you. Thanks again, Mark. You're welcome. Thank you, Matt. That's Mark Raymond. He is now Chief Engineer for Mission Operations and Science at the Galactic Capital of Robotic Exploration of our Solar System and beyond, the Jet Propulsion Lab near Pasadena, California. And of course, he previously served, well, many jobs, but for the Dawn mission, he was chief engineer, mission director, and project manager. We'll be right back with this week's What's Up and Bruce Betts. Time for What's Up on Planetary Radio.

We are joined by the chief scientist of on Planetary Radio. We are joined by the Chief Scientist of the Planetary Society, that's Bruce Betts, of course, who's here to tell us about the night sky and resolve a question about the gods. Welcome. Yes, using my expertise in such things. Who's better qualified, frankly? You're the Chief Scientist. Scientist. World's foremost authority, I think.

Yes, on Greek and Roman mythology, that is I. No, on everything. Oh, finally. Finally, you acknowledged it. You know what I can tell you about? A lot of things, but I'm going to tell you about the night sky, and I'm going to emphasize once again all the glorious bright planets that are named after Greek and Roman gods.

We've got in the evening sky in the south, Jupiter looking super bright, Saturn looking yellowish to its left. Now in the early evening in the east is Mars getting really bright, brighter than the brightest star in the sky, looking reddish, moving towards its closest approach on October 6th. And then in the predawn sky, still got Venus just dominating over there in the east, looking super bright. The moon will hang out with Venus on September 14th. We move on to this week in space history. It was 1975 that Viking 2 was launched off towards Mars. And my yearly bow to you, Matt, and your interests. 1965, 55 years ago. Danger, Matt Kaplan, danger! Lost in Space premiered. Lost in Space premiered.

There must be episodes on YouTube. Even at its worst, I bet it was better than the movie version that came out with William Hurt, which was just god awful. Maybe I should say God's awful. You can find more of Matt's movie reviews. Okay, let's move on to space facts. I remember all those themes. Sorry, I don't have a Lost in Space random space fact for you speaking of bill nye ceo of the planetary society the mother of bill nye was a code breaker in world war ii his father spent four years in a japanese prison camp where he learned to tell time using shadows spurring his interest and later bill's interest

in sundials bill helped create the mars exploration rover's camera calibration targets to also be sundials or Mars dials, which were used by students in the Planetary Society's Red Rover Goes to Mars during those missions. Speaking of exciting, let's go on to this apparently controversial trivia contest question, where I said, assuming a combined Greek and Roman pantheon mythology within this mythology, which planet is named after the earliest or oldest god? How would you like to handle this, Matt? Well, let me just read this first one from Bjorn Gedda, a regular listener, because it gives you an idea of just how ridiculously complex this is. Bjorn says,

so the oldest deity in the solar system is in Roman, Terra or Tellus or Gaia in Greek, Mother Earth. She was the mother of Uranus. And then he adds, sorry, some of what follows is pure nitpicking. Uranus, together with Rhea, was the father of the Titans, of which one was Saturnus, Cronus. So if we are picky, we still haven't come to the gods yet. The oldest of Saturnus' children, where the gods start to have a planet, is Pluto. Oh, sorry, that's no longer a planet, he says. So the prize could be argued to go to Jupiter, Zeus, Saturnus's youngest son. Phew.

A lot of this comes down to Titans versus gods, and then whatever the folks who came before the Titans were. My source, which is unimpeachable, is Wikipedia. Wikipedia. A latter-day god. Wikipedia. According to Wikipedia, those things are all called gods, including Uranus. Uranus, which is a very complicated Latinized version of a Greek god equivalent to the Roman Calus. So yes, we're in a mess of mythology, and I sort of regret it. But I thought it was interesting to me because Uranus, which is the answer I was looking for, again, in the combined mythology, Uranus was the father, as was mentioned. Uranus is the father of Saturn.

Saturn was the father of Jupiter and Neptune. So it's kind of a whole giant planet family tree. And they were all so loving within their families. Oh, man, were they. This from Darren Ritchie, one of the many people who said, well, he was going to go with Gaia or Terra, Earth, as the grandmother of us all. But, of course, those are not what we call Earth anymore, at least not for our purposes. Here's how much worse it gets. our purposes. Here's how much worse it gets. Uranus was in turn the son and the husband, ew, of Gaia Terra, the primordial Earth mother. So if Earth counts, she's the winner and looking great for her age. But then he said otherwise, Uranus. So he kind of covered his bets there.

Here is a portion of a poem, a fragment of a poem from Gene Lewin in Washington. Along these lines, I don't have time to read the whole thing. Known to us as Terra Gaia in Greek, then Mother Earth is the answer you seek, but that requires us all to construe. Is this something that Bruce would do? So not to assume and to avoid dubiety, Uranus is what my choice will be so he's with you and so was Paul Hoover and Paul Hoover is our winner Paul Hoover in my old hometown of Long Beach, California

who indeed said Uranus and also he thought it was fair, he did father Jupiter and then tried to eat him but I guess that didn't work out so well and he thanks us for sticking with all of this. He loves to listen to the show. Paul, congratulations. You're getting a copy of The End of Everything, Astrophysically Speaking, by Katie Mack, our guest of a couple of weeks ago. And boy,

were there a lot of people who enjoyed that conversation and hopefully are also going to enjoy the book. Yeah, I was throwing Earth out because we call it Earth, not Terra or Gaia officially as a planet name. One thing I should have done, however, was to specify that English was the language I was working with, because otherwise it just gets even more complicated. So sorry for all the confusion, everyone. But really, well, it's just confusing. Because, you know, it's mythology. I think I speak on behalf of almost all listeners in forgiving you

this, because it was still fun. It sure generated a lot of conversation. Todd Yampole in Arizona. I post this question to my 12-year-old, who knows a lot more about mythology than I do, after musing for a moment about whether Earth equals Gaia and deciding not, she chose Uranus. So good on your daughter, Todd. Sean Cain in New York, who but ringed Saturn, the richest of all the spheres, could be

eldest godfather of all his peers. And I read that little ditty from Sean partly because he says, love the show. He's a history PhD student studying first contact situations in the last age of exploration. Is that cool or what? That's quite cool. Much more tangible than mythology. Finally, this from Ertan Yuzak in Arizona. I'm going to say Saturn, but how can you be sure unless you see their birth certificates? Oh, see, I didn't even think of that. Thank you, everybody. This was fun. We're ready to go on.

Back to the CEO of the Planetary Society, Bill Nye. He holds three patents. One of them relates to shoes. What kind of shoes? Go to planetary.org slash radio contest. Wow, I only know about one of his patents, and it relates to baseball. But shoes? That's new for me.

I guess I can enter the contest, as long as I do that, by Wednesday, September 16th at 8 a.m. Pacific time. And I might just win myself. Are you ready, Bruce? We haven't done this in a while. I'm ready. How about a Planetary Society kick asteroid, rubber asteroid? Nice. Bringing back the rubber asteroid.

Thank you. Roll those R's. All right, we're done. Rolling them underwater. All right, everybody, go out there, look up at the night sky and think about what this show

would sound like underwater. Thank you and good night. Do I get to wear my snorkel? He's Bruce Betts. He is the chief scientist of the Planetary Society who joins us every week here for... I can't do it. That's terrible.

Planetary Radio is produced by the Planetary Society in Pasadena, California, and is made possible by its proud members. Mark Hilverde is our associate producer. Josh Doyle composed our theme, which is arranged and performed by Peter Schlosser. Ad Astra.