Planetary Radio: Space Exploration, Astronomy and Science - Ashwin Vasavada, Leader of Scientists Roving Mars

Episode Date: March 29, 2016

The new Mars Science Laboratory Project Scientist is not new to the mission. Ashwin Vasavada has worked on the Curiosity rover since 2004.Learn more about your ad choices. Visit megaphone.fm/adchoicesSee omnystudio.com/listener for privacy information.See omnystudio.com/listener for privacy information.

A Scientist on Mars, 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. Ashwin Vasavada took over as project scientist for Curiosity, the Mars Science Laboratory rover, just over a year ago. He visits with us this week. Everybody seems to be building new and improved rocket engines. Bill Nye will introduce us to a few of them.

A lively night sky and a rubber asteroid that just might have your name on it are also ahead when we talk with Bruce Betts. Emily Lakdawalla is the Planetary Society's senior editor. Emily, welcome back from LPSC. The Lunar and Planetary Science Conference, one of my favorite places to go every year. Yeah, you could tell just reading all of your tweets from there, and there are a lot of them if people want to check them out at

at eLakdawalla. A lot of stories to tell. We don't have time for a lot of those today. Where should we start, though? How about Ceres? I think Ceres is a great place to start because Dawn has been there for a while now and actually just a couple of weeks ago completed the global coverage of all of Ceres at 34 meter resolution, their highest resolution that they'll get an image map. And so there were a lot of talks that featured just gorgeous images. Some of those included the famous bright spots. Everybody keeps on asking me about the bright spots on Ceres, and I get irritated because I want to talk about something else. But

I have to say that the images that they released of the bright spots were stunning. Just imagine the center bright spot in Akator Crater is actually a pit. There are other pit craters on other worlds, including Mars and Ganymede, so it's not unique, but it's interesting. And then that pit is filled with a splash of this very bright material. But then in the center of the splash, there is a dome,

and the dome has cracks across the top of it, which any geologist worth her salt will tell you is some kind of structure that has been pushed up from below and expanded across the top. And I mentioned salt on purpose because it's possible that salt is part of the story here, that low-density salt may have been rising.

Certainly the materials on the surface are very likely salt and not ice, but it's just really lovely to look at. Wow. And there's more from that little world. What is this blue stuff? Yeah, so they're taking this high-resolution image map and combining it with lower-resolution color image data, and they're finding blue material all over the place. Now, blue is fairly common in the solar system. It's spectrally blue. It means that it's just not as red as most of the other

things in the solar system. And it's common to see it in crater ejecta, which is some of the places they see it on Ceres. But they also see it in weird places, like the flanks of that bizarre pyramidal mountain, Ahuna Mons. And so trying to explain how you can have blue material in crater ejecta and the flanks of this mountain that nobody can explain is actually a real head scratcher to everybody. Wow, this is just great. Not much time left. Let's go to Mars. But really more to Jim Green, who you had a conversation with Jim Green of NASA. Are there CubeSats maybe going to Mars someday? For sure, there are CubeSats going to Mars someday. There's a couple that I think are planned to launch with

InSight, if not InSight, then another future mission. But the reason this came up is because I always enjoy seeing Maria Zuber talk. Maria Zuber is the PI for a mission called GRAIL that used two spacecraft to measure gravity around the moon and is just doing amazing work seeing inside the moon. I casually remarked to Jim Green that I want to pay Maria Zuber to fly GRAIL to every other terrestrial planet. And he laughed and said that pretty soon they may be doing it with CubeSats in Earth orbit. And if they manage to do that, then they could do it with CubeSats at Mars. So I'm rooting for that. I hate to say that we've even scratched the surface with hundreds of presentations at LPSC.

Can we look forward to seeing additional coverage from you and others? For sure. This week, stay tuned to the blog for more from Lunar and Planetary Science Conference. All right. That's at planetary.org. Thanks, Emily. Thank you, Matt. She's worth her salt. She's our senior editor at the Planetary Society, the Planetary Evangelist, also a contributing editor for Sky and Telescope magazine, just back from the Lunar and Planetary Science Conference. Let's go to the CEO, Bill Nye, the science guy. Bill, we just spent a few minutes before we started recording

talking about this alphabet soup of rocket engines, but it's a good thing. Oh, yeah, it's a great thing. Competition breeds success, perhaps. You know, for years and years, the United Launch Alliance, which is a traditional rocket company, used the good old RD-180,

which is made in Russia. And there's all this talk about, should we be importing, should the United States be importing Russian engines? And the military uses these. The Atlas V, our beloved Atlas V, which took light sail into orbit was a RD-180 but meanwhile Blue Origins got your BE-4 and then I was in Midland Texas I was at Midland College last week and in the lobby of the airport is the Lynx reusable space plane that's's X-Core. And they're all hot,

pun intended, for their 8H21 hydrogen liquid oxygen engine. This is really good because someday, from an environmental standpoint, we don't want to be burning fossil fuels. Don't want to be burning non-renewable fuels someday. So hydrogen and oxygen can be produced by separating water, H2O, into hydrogen and oxygen using electricity, and you presume you'd get electricity from the sun or from wind turbines. And so in the long or even the medium term, that's going to be the way to go. Meanwhile, SpaceX has, what, the Draco? Yes, yes, and the Merlin.

The Merlin. And the Merlin. The Merlin runs on your Falcon 9 and your Falcon Heavy. Sooner or later, people are going to use methane, natural gas. That's, they're working on one called the Raptor, which according to Wikipedia, is only for their Mars program because, as we all know, that's where Elon wants to go. We call him Elon because we're tight. But he was on the board of the Planetary Society for some time, and he had to recuse himself when they started doing all that business with NASA. But this is the future, everybody, is not to use kerosene.

You know, methane burns pretty cleanly. I mean, very cleanly compared to other stuff like kerosene. But ultimately, you want to use completely renewably produced fuels, sustainably produced fuels. It's very competitive, and that's good. And giving people, giving humankind access to space, I claim, will change the world. Thank you, Bill. Thank you, Matt. That's Bill Nye. He's the CEO of the Planetary Society and the author of that book we've been giving away, Unstoppable, which I recommend. Next, we are going to talk to the new, well, he's been there for a year now on the job, the new project scientist for Curiosity, the Mars Science Laboratory rover. Ashwin Vasavada is a senior scientist at the Jet Propulsion Lab near Pasadena, California. His old boss told us we should get him on planetary radio. That was

over a year ago. I've finally taken John Gratzinger's advice, and I'm sorry it took so long. As project scientist for Curiosity, the Mars Science Laboratory rover, Ashwin leads all science activity for the big rolling laboratory that continues to make its way up the slopes of Mount Sharp. One morning last week, Ashwin stopped by Planetary Society headquarters to join me for a conversation about his work and this exciting mission on the Red Planet. Ashwin, welcome to Planetary Radio, and thank you especially for joining us here at Planetary Society Headquarters, your first visit, I think.

It is. It's an impressive place, and it's great to be here. As we speak, Curiosity is nearing 1,300 sol souls, Martian days, on the surface. I personally find it so hard to believe that it has been now more than three and a half years since we endured that seven minutes of terror. It has gone incredibly quickly. It's amazing to me to think that it's been that long since we landed. But, you know, when you operate it every single day or, you know, as much as we can, time just kind of gets away from you, you know? Yeah. And we've gone through so much with the rover.

We've learned so much. And we've seen so many different terrains. But on the other hand, it doesn't seem like it's been that long. No. You have been on this mission for a long time. Yeah. Well before it left for the red planet. That's right.

It's almost a career, although you have worked on other missions before and during. Yeah, it just means I'm getting old. But yeah, I started in 2004 on Curiosity. I guess that would make it about seven years before it launched, and then another year for it to get to Mars, and then another three and a half years on the surface. So it's been the better part of my career. You came in as deputy project scientist, right? Yeah, I got lucky. You know, JPL was down a few Mars scientists at the time, a short a few, I should say, because there was an explosion of spacecraft there. Not a literal one. What I mean is we had the Mars

exploration rovers and Mars reconnaissance orbiter all going in the early 2000s. And so they were recruiting other people who were scientists who worked on Mars and got lucky to come in when Curiosity was just kind of scribbles on a napkin and got this cushy job early on. Your predecessor, John Grotzinger, he's been on the show several times. I guess the last time he was on was about a year ago when you had just taken over the job. He had the nicest things to say about you. Do you want to return the favor? Well, you know, I'll just put it this way.

He left giant shoes to fill. It was a real honor to work with someone of his stature. You know, he's known equally on his work on paleontology and geology on Earth, as he is on everything he's done when he kind of switched his career over to Mars in just the later part of his career. It was a privilege to work with him every day. And now to take over as the lead scientist, always thinking, you know, what would John have done in this situation? You have a wristband, what would John have done? Yeah, right. Exactly. Yeah. Let's talk about the mission. Has it accomplished what it went to Mars to do? It certainly has. You know, we went there to figure out if Mars ever hosted a habitable

environment, if there was ever a place on Mars that could have supported life, if all the conditions were right, the water, the chemical elements that life would require, organic molecules, perhaps, and sources of energy that life would need, too. There's kind of that recipe list of what makes a habitable environment. And before Curiosity went, we knew that there was liquid water and even sustained liquid water. That's what Opportunity had found, for example. But all those other factors, to answer those fairly detailed questions, you need to send laboratories to Mars, you know, or bring the samples back to Earth, which is a little far off. Still to come. Still to come, exactly. So we sent laboratories on wheels

to Mars. And within the first year of the mission, we found such a place. We now know that there was a long-lived lake in Gale Crater that had the key building blocks of life in terms of the chemistry. It had liquid water, fresh liquid water, and sources of energy for life. Everything that would have made a microbe a happy microbe. Finding that in the first year of the mission, of course, was a great, a wonderful thing for us, but also took a lot of the pressure off. And so now for three and a half years, you know, two and a half years after that discovery, we've been able to really just dive in deeper into what Gale Crater has to offer, see how habitable environments may have evolved over time. Very importantly, looking forward, another big question that the mission seeks, and it hasn't fully answered yet, is what conditions allow signatures

of life to be preserved over time? We and then 2020, other missions beyond that, they're looking for traces of life that may have been in the rocks for three and a half billion years. A lot can happen to them to destroy that evidence, and that's one thing we'll contribute going forward. Well, I was going to ask you this question later, but you've already touched on it. How is Curiosity acting as a sort of pathfinder, if you'll pardon the expression, for its sister rover in 2020? Yeah, in a number of ways. You know, one kind of very little way is that 2020 is largely designed off of Curiosity. The rover looks the same.

The payload will be different. So there's that way. We've pathfinding the landing system of landing a six-wheeled robot. We've learned so much about how to drive that vehicle on Mars and use its arm and sampling capabilities. But from a scientific standpoint, when you're looking for traces of ancient life, which is the mission of the 2020 rover, it's a tough thing to do. You need to go to the right place, and part of what makes the right place is a place that not only would have been a suitable environment for life three and a half billion years ago, but the conditions between then and now would not have erased the evidence in those rocks for us to find today. would not have erased the evidence in those rocks for us to find today.

And that is a whole area of science and paleontology on Earth. They call it taphonomy. Taphonomy is a study of how fossils are preserved. You know, it's fascinating that we're applying that to Mars now. You know, kind of mind-blowing. And that's one of the things that John Grossinger really brought to the whole Mars exploration program is this idea of taking everything we've learned on Earth. Why certain parts of Africa are where we find all the fossils, you know, that sort of thing.

And even more complex is how do you find evidence of life that may have never had hard skeletons? How do you find evidence of life that never got beyond gooey microbes? And you're now trying to find that a few billion years later. The trek continues. Yes. We're still, clarify for us, we've talked about this before on the show. Are we now on Mount Sharp, but still headed toward the real geologic and maybe biological gold? Well, you know, we landed on the plains next to the mountain. And then the whole goal of the mission since Gale Crater was selected as a landing site was to climb this mountain, which has this clearly layered structure from orbit, sedimentary rock.

So this mountain was built up over time. It's not a volcano. It's not the peak at the middle of the crater that formed when the crater formed. It was dirt that was progressively brought in over time by wind or water. And because of that, we think there's a record of time in these rocks. And by driving from the bottom to the top, we get to read that record of the ancient climate and suitability for life. So we crossed over onto what we can map out as the base of the mountain about a year and a half ago now, September 2014.

Since then, we have been in the thick basal layer of the mountain as mapped from orbit. The thing that was interesting about that is the basal layer of the mountain doesn't reveal much about itself from orbit. We didn't really know what we'd find there. It looked a little bit of a jumbled mess. The higher layers were clearly, there were clear mineral signatures there. For example, an entire layer made out of, that had clay bearing minerals in it. Clay minerals is one of the things we're looking

forward to seeing in the next few years. When we get to that layer, that may be the best chance of finding another truly habitable environment. And clay minerals also are known to preserve organic molecules over time. So we're excited about that. But this basal layer turned out to be no slacker. It actually was a great discovery to find that that basal layer was actually formed of lake sediments. One of the mysteries or ways this mission really could have failed in a sense is to get to the mountain and figure out it was all formed by wind, you know, just a bunch of boring dust that came in from somewhere else. Instead, we're finding that every part of the mountain we've seen so far

is another layer that formed at the bottom of an ancient lake. So not only does that tell us that these are habitable environments, but it tells us something profound, actually, about the early climate of Mars. We're studying rocks that date from not the earliest period, when there's all this evidence of channels and valley networks and rivers, but a little later than that, when we had thought the planet was already well on its way to drying out. And yet, the more we study these basal rocks of Mount Sharp and Gale Crater, the more we find there was long-lived lakes that would have required a humid, warm climate. That's pretty exciting. It is. Everybody on the team is always very careful to say that this is not a life detection mission, but you do

have some pretty sophisticated spectrometers and other instruments on there, there's some possibility, isn't there? I mean, at least for the detection of the kinds of organic molecules, which would make people wonder? Yeah, I mean, yes and no. We do have very sophisticated laboratories, unlike anything that's flown in space before, and we love that. And with those, we can find organic molecules, even large organic molecules, even the kind of organic molecules that we're familiar with when we talk about life, amino acids, that sort of thing. We also can find isotopic variation. So life, you know, we're all familiar with carbon-14 dating and how life processes that life uses tend to favor certain isotopes of chemical elements over others and leave those traces. We can find those.

So that's the yes part of the answer. The more hedgy part of the answer is that even on Earth, convincing your scientific peers that that evidence leads to a conclusion about the presence of life is much more difficult. We know that. There are certain Mars meteorologists found on Earth. Just going to say. And there's that saying that I won't get right if I try to say it.

But, you know, the bar is very high for the evidence that when you're claiming detections of life. Our founder, actually. Extraordinary claims require extraordinary evidence, I think, along those lines. I think that's right. More of Ashwin Vasavada, project scientist for Curiosity. The Mars Science Laboratory rover is coming right 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 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. Welcome back to Planetary Radio. My guest is the project scientist for Curiosity, the Mars Science Laboratory.

Ashwin Vasavada served as deputy project scientist on the mission for 10 years before he got the top job in early 2015. With luck and careful driving, Curiosity will keep him and many other scientists and engineers busy for years to come. What else has surprised you about the data that what Curiosity has been able to tell us about Mars? I think from the scientific standpoint, I'd have to say it just turned out to be even more of a special place on Mars. I shouldn't even say special. Who knows? Maybe all of Mars was like this at the time, which would be fantastic. But I think the landing site has delivered more than we could have hoped, even more than we could

have hoped. You know, we knew we were, we chose a place that from the orbital data, we thought it would give us the best chance of finding evidence for flowing water. And then maybe all these other things, all the chemical elements that life requires, carbon, that sort of thing. But we've basically found everything. And now we're just looking for, now we're asking like, how long did it last? And how many times in Mars history did this habitable environment exist in that crater? That kind of blows me away. And this is now me more as just a human being rather than a planetary

scientist. I just love looking at these pictures every day with my lifetime of hiking in the Mojave Desert and going on family trips to Utah and just thinking, my goodness, you know, this world is so much like Earth, and Earth is so much like Mars. Wouldn't it be something if we discovered, I mean, maybe years down the road, yeah, Gale Crater, we thought it was so special, but really kind of boring compared to other parts of Mars. That would be truly mind-blowing, yeah. That would be truly mind-blowing. You and your team, just a couple of weeks ago as we speak, made a bunch of scientists very happy, some of them brand new to the mission.

Tell us what happened. Oh, yeah. We chose our second round of participating scientists, and this is a program that NASA has. These missions are all competitive. Let me start back with how our existing team got selected. NASA decided that their goal was to send this rover to Mars, this big geochemical laboratory on wheels. And they put out a call to scientists around the world to propose instruments. With those proposals came teams. So we got about 120 scientists from around the world with our 10 instruments when they were selected.

And then there were, of course, all the people whose proposals didn't get selected. So you're leaving a lot of the brainpower of the community on the table. So then NASA opens up this competition to the rest of the community again. You might call them like walk-on scientists. They weren't selected with the instruments, but they now will be added based on their individual proposals. So we just welcomed another 28 scientists, and they'll be replacing the original crop of participating scientists that were selected in 2011. Are you hoping that there will still be scientists happily gathering data from this spacecraft, maybe even when its sister arrives in 2020? Yeah, you know, I think there's a good shot of that.

One thing that's interesting about Curiosity is we know somewhat definitively of how the mission will unfold. You know, there's always a chance of some catastrophic failure, and, you know, we keep our fingers crossed and drive safely and all those things. But we know that the power output from the radioisotope thermoelectric generator has a very well characterized rate of degradation. And at some point, not too far from now in the scheme of things, you know, five, six, seven years, we'll get to the point where we really will struggle to just keep the lights on. The rover is a very complex spacecraft,

and it requires quite a bit of the energy coming off of that RTG just to keep the pumps going that move the fluid around inside. It actually almost has a circulation system in it where it keeps itself warm and uses electronic heaters to keep other elements warm. So there's a good amount of overhead just to keep the rover going. And then on top of that, whatever energy is left over, you know, which currently is a good amount, we do all the science with. So over the next several years, that margin available for

science will slowly shrink. And then sometime, half a dozen years, we'll get to the point where we don't have any extra energy. And we even start dipping below what the rover needs just to keep going. Yeah, I don't want to make a direct comparison, of course, but you look at Voyager, which is still struggling along, still talking to us from all the way out there at the edge of the solar system, still doing science. Yeah. So that's a good example.

It does, and we'll do our best. We do have a little bit more of a challenge not being – Voyager has the benefit of sort of being in the womb of space, you know, where we have to take day and night, you know, freezing and hot temperatures and a lot more work Curiosity has to do to keep herself alive. Nasty place, Mars. Right, in some ways. And you don't have the benefit of dust devils cleaning off your solar cells every now and then. Yeah, who knew, right? I mean, we decided that if you want to live a long time, you need an RTG, you know, and an opportunity has shown otherwise. But on the other hand, you know, we're going to make the most of the next several years because of this.

Yeah, you don't have to hibernate in the winter either. No, you know, and we know we have these layers on the mountain we need to get to. And so it really helps us to know this rate of energy degradation because we can plot out. In fact, this is part of my job. We plot out we need to get to the highest layer on the mountain that is scientifically interesting, which is what we call the sulfate unit. And we need to be there in, you know, four years. And every day we have to look how we're making progress toward that eventual goal. And almost every one of those days, curiosity reveals something about that planet.

Yeah. John Grotzinger and I both are strong believers in doing a lot of advanced planning and proposing hypotheses that we'll test with the rover. There's different ways you can explore. There's kind of the Star Trek mode where you just kind of go out into the universe and see what you find. That's a very valid concept, and it's one that we did with previous missions. But because we very strategically chose Gale Crater and we have very specific things we're looking for, we also have laid out a very well thought out plan that proposes we need to get to this unit and this unit and ask this question and do this experiment. This is a long answer to your question. No, no, it's fine.

The point is what throws all that off are exactly the daily discoveries that you mentioned. off are exactly the daily discoveries that you mentioned. So this is the challenge that the team has almost every day, is that we all know as a team that we're on this well-defined path up the mountain. But every day, there's something else that we'd rather study instead. You and the engineers are the ones, right, who have to tell, sometimes have to tell other scientists, no, I know it looks like such an interesting rock, but we just can't make it over there right now. That's right. We found huge iron meteorites. You know, we weren't the first to find that.

The Spirit of Opportunity did also. But they were just over there, you know. And yet we had to have this kind of tough discussion among our team, which we do every day at noon, in fact. We have a team science discussion where we rehash these issues. And we have to basically say, well, iron meteorites are awesome, but is that what this particular mission is about? And unfortunately, no. For another day. They're not going anywhere. They're not going anywhere. Well said, yeah. I assume you are comfortable being called a science geek. Yeah, sure. Why not? But I also read that maybe we could also call you a bit of a policy wonk. This stuff is important to you. It is. Just before I

took this role on Curiosity, I did spend a year in Washington, D.C. as a science fellow, which meant that I was attached to a member of Congress. I was in my early, late 20s, early 30s, so I wouldn't call myself an advisor at that point, but at least someone knowledgeable who was a scientist who could work with the congressperson on their involvement. I worked with a member of the House Science Committee, for example, who worked on environmental issues and space and other things. the House Science Committee, for example, who worked on environmental issues and space and other things. So that's a great experience that fulfilled this other, like you said, this other part of my professional life, which is caring deeply about science literacy in the country and having our country make decisions based on everything we've learned about the world through science and not for other reasons.

everything we've learned about the world through science and not for other reasons. This mission of advocacy and just providing information, it's an ongoing challenge, just like doing science around the solar system. It really is. I think one of the most rewarding parts about Curiosity that ranks up there, to me personally, with all the successes we've had scientifically, is how much the world has cared about the mission and how being able to draw so many young kids but you know frankly it's not just we love talking about how we're inspiring younger people but adults and older

people need just as much inspiration and just as much outreach from us, you know, they're voters too, and they're citizens too. And we all need to understand the benefits that we get from science and understanding the world through science. Well put. Thank you. You've been very generous with your time. Very happy to have hosted you here at Planetary Society headquarters. Headed to work now? Yeah, we got a rover to run. It's been a pleasure. Thank you. We've been talking with Ashwin Vasavada. He is the project scientist for the Mars Science Laboratory. Curiosity, three and a half years on the surface of Mars, but he started and spent a good 10 years as the deputy project scientist on that mission. But he's kept his hand in several other missions as well,

notably the Lunar Reconnaissance Orbiter, Galileo, Cassini, even Mars Odyssey. So you've been at this for a while. He received NASA's Exceptional Achievement Medal about three years ago. But one I've got to ask you about, Group Achievement Award from NASA for Angry Birds Space. What was that about? Yeah, that was the most unexpected award I've ever had. JPL contributed to Angry Birds Space Edition.

We talked about education a bit. But what was really cool is that they asked me to contribute some words on what, about Mars exploration and space exploration, so that when kids are playing the game and they click on a little icon, you know, read more about space, my words will be there. And that was cool. Nice. Teachable moment.

That's right. Angry birds on Mars. Thanks again very much. Thank you. We go now to Bruce Betts for this week's edition of What's Up. Still in the studio at headquarters, ready to talk to Bruce Betts, the Director of Science and Technology for the Planetary Society. It is time for What's Up.

I open with this message from a question, actually, from Mark Little in Ireland. He says, is there truth to the rumor that Bruce is himself a random space fact? I can neither confirm nor deny that. That's pretty random. Welcome. Tell us about the night sky. Okay, evening. Got Jupiter over in the east in the early evening. And then Mars will be intriguing to watch over the coming weeks.

It is coming up now around 11 p.m. in the east, looking reddish as it will do. But it will actually quadruple in brightness by the end of May as Earth and Mars grow closer together. And it approaches opposition on May 22nd. Saturn coming up not too long after Mars and can be seen in the east around midnight. We move on to this week in space history. It was 1974 that Mariner 10 did its first Mercury flyby, introducing us to that world for the first time up close and personal. And in 1966, 50 years ago, there was the first lunar orbiting spacecraft. We'll come back to what that was. Ah. Ah.

On to... Old radio technique there. You turn away from the microphone. It sounds like, I'll just walk over here across the street. Works really well. So as of now, when we're recording this, there are 67 known moons of Jupiter. But almost... I'm sorry.

There was a snort in reaction to 67 moons. When is that planet going to give up? I don't think it is going to give up. But here's the real fact, which is almost all of the mass of those orbiting objects is in the four Gal-Land satellites, the four big moons, Io, Europa, Ganymede, and Callisto have more than 99.99% of the mass orbiting Jupiter, including all the other moons and the rings. So they kind of take after dad, right? Because what's the other random space fact Jupiter has? What percentage of the mass of all of the objects in the solar system? Am I making that up? No, you're not. It has more than, if you take all the other objects besides the sun and you put them together, it's got more mass than any of them.

That's what I wanted to hear. Okay. Well, good. I'm glad I can make you happy. Yeah, it takes after dear old dad. We move on to the trivia contest. In an effort to be confusing, once again, I asked you, how many science instruments, not counting radio relay, does the ExoMars trace gas orbiter carry that is currently on its way to Mars? And I kind of know how we did. How did we do, Matt? Yeah, we went through this ahead of time because I had to clear the winner, the supposed winner, chosen by planetary.org, with Bruce. Because a number of people did this. We were willing to accept either of two answers, four instruments, or as our, I believe, winner said, Susan Kurtik,

a first-time winner in Encinitas, California, a little bit south from where we are. She said eight instruments. Can you explain? Yeah, there are four instrument suites. And so some of the spectrometers are actually three spectrometers, depending on how you count them. One person's instrument is another person's instrument suite. So there are four suites of instruments that can be concluded to have eight instruments. And so we'll take either because of the confusion. All right, Susan, you made it through. And that means we're going to send you a Planetary Radio t-shirt, one of those OK Go t-shirts signed by Damian Kulash and Tim Nordwin, two of the founders of the band, and a 200-point itelescope.net account.

That, of course, the nonprofit network of telescopes all around the world. They're based in Australia, and they're fun to talk to down there every week when I send them the name of the winner. We did actually have one person who put it the way you just did, Mukesh Varsani in Salisbury in the UK, who said eight instruments in four suites. The instrument names anyway, Nomad, ACS, Cassis, and Friend, F-R-E-N-D. It helps to name your instrument friend because then you feel closer to it, even when it frustrates you. You really want help in remembering these?

Our friend, the poet, Dave Fairchild in Shawnee, Kansas. Here we go. The orbiter carries a payload of four called Nomad and Cassis and ACS for an infrared scan of the atmosphere, plus a friend that is hydrogen searching for us. Wow. It's good.

It's not his best work. Dave, you know, it's okay. We're paying you for the best work, but wait a minute, we're not paying him, are we? No, no, I think we need to accept whatever he gives us. Okay. We can go on to whatever you have in mind, that mystery you hinted at. I know it's hard to guess that my question would be, what was the first spacecraft to orbit the moon? First spacecraft to orbit the moon, go to planetary.org slash radiocontest.

You have until the 5th. That would be Tuesday, April 5th at 8 a.m. Pacific time to get us this answer. And if you're lucky enough to get it right and be chosen by random.org, we will send you another one of those 200-point itelescope.net accounts, a Planetary Radio t-shirt, and how about an extremely cool Planetary Society rubber asteroid? Those are some of my favorite things. You kind of started the asteroid war at the last Planetary Defense Conference. Yeah, I kind of did.

All right. I have one more message for you before we go. I just was touched by this. Kaz Moran, who listens to the show every week in Sendai, Japan, says he listens with his four-year-old who wants to be an astronaut slash scientist slash ninja. Wonderful and inspiring show and society. Very cool. A ninja astronaut. Those are good.

They get around the space station more easily and very quietly. We're done. All right, everybody, go out there, look up at the night sky, and imagine what the Planetary Society studio looks like on the inside. Thank you. Good night. It's beyond cool. And he's Bruce Betts, the director of science and technology,

who is just cool enough. He joins us every week here on What's Up. I'm super cool. Yeah, but you're not a ninja. That's true. Planetary Radio is produced by the Planetary Society in Pasadena, California, and is made possible by its roving members. Josh Doyle created the theme music.

I'm Matt Kaplan. Clear skies.