Planetary Radio: Space Exploration, Astronomy and Science - Leaving Behind a Life on Mars—Former Curiosity Project Scientist John Grotzinger

Episode Date: March 17, 2015

The Mars Science Laboratory rover has accomplished its primary goals on the Red Planet, and John Grotzinger has left his central role to become Chair of the Division of Geological and Planetary Sciences at the California Institute of Technology. He shares his thoughts about the ongoing mission and much more.Learn more about your ad choices. Visit megaphone.fm/adchoicesSee omnystudio.com/listener for privacy information.See omnystudio.com/listener for privacy information.

Greetings once again, Planetary Radio listeners in the online segment of our audience. Thank you for listening. Thank you also for all of you who take the trouble when you enter the contest or just send us a separate piece of email to tell us how much you enjoy the show. So here I am with a special request, not for money, not this time. I might do that again. But what I'm going to ask is something I have also asked for in the past, and that is that you make a comment, add your review or at least a rating to a podcast service,

an aggregator, as they're called, like iTunes or Stitcher or wherever you hear Planetary Radio. like iTunes or Stitcher or wherever you hear Planetary Radio. Now, I know a lot of you hear the show directly from our website at planetary.org. So this means a little bit more effort for you. You'd have to go into iTunes and actually click one of those little stars. Of course, we hope it'll be one of the high-end stars. We still have, as far as I know, the highest percentage of five-star ratings of any science program that I could find in the iTunes store.

Anyway, if you will help us out, that does an enormous amount to help get the word out. And I would hope that you'd want to share this, not just keep it to yourself, but share this little exploration of the final frontier that we bring you along on each week. And if you do find time to do that, we will be very, very grateful. Thanks again for listening, and I'll see you around the solar system.

Leaving behind a life 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, and I've got a terrific conversation for you today. It's with John Grotzinger, the former project scientist for Curiosity, the Mars Science Laboratory rover. Bill Nye has graciously given up his slot so that we can get a light sail update from Jason Davis, up his slot so that we can get a light sail update from Jason Davis. And we'll learn from Bruce Betts what a white dwarf star has in common with a can of tomato sauce. First though on location is senior editor Emily Lakdawalla. Welcome back, Emily. A time for a different kind of March Madness. It's absolutely crazy here in the woodlands, Texas, north of Houston,

for the Lunar and Planetary Science Conference. And that, of course, is why we're talking to Emily today on her cell phone. Did you just come out of some sessions? I did, and this Monday morning has been absolutely crazy. I began in the session on Rosetta, then I jumped to Mars to learn about Curiosity results, went over to the Moon to learn about its interior from the GRAIL mission, back to Mars for more Curiosity, back to the Moon for the Chagat-3 mission from China, and finally to a lunchtime press briefing on the MESSENGER mission. Wow.

Any big stories amidst all of those sessions? Well, scientific meetings like this are where scientists present the results of their work in progress to other scientists. So I wouldn't say that there are any earth-shattering announcements that I saw today, or moon or Mercury shattering. It's more like incremental updates on science that people are doing. For instance, we've learned that the mass spectrometer on the Celay lander worked and detected, maybe it detected some kind of complex organic material of a kind that was actually first seen at Halley's Comet by the Giotto mission,

something called polyoxalic acid, I think, if I got that right. And then over at Curiosity, they're also trying to figure out what kind of organic material may have been present in their samples, and they're thinking that maybe instead of carbonate minerals being there on Mars, they have a kind of an acid called an oxalate, which is another kind of carbon-containing compound. It's just, it's all a little complicated. I'm going to have to step back from it and try to look and figure out what the big picture is.

But in the Mercury session, there were some really big picture observations made from very low-altitude observations that the MESSENGER mission has been doing as it gets very close to the end. It's just about to crash into Mercury, And as it's flying lower and lower, it's getting these pictures with absolutely amazing resolutions. And we're seeing these beautiful structures on Mercury, some of which may have been made geologically very recently. And so we're learning on the Moon and Mercury and Mars and on comets that the geologic activity seems to be happening everywhere, even down to today on places that we thought were geologically dead. Sounds like a pretty good first morning to me, Emily,

and much more to come. You'll be writing about much of this? Oh, yes. I'll look for several blog entries, both from me and also from guest bloggers, various scientists that I'm roping into telling you all about the latest science news from Houston. All coming up this week, the week of the Lunar and Planetary Science Conference in Texas.

That's where we find Emily this time. Thanks for joining us. Have a great time. I will, Matt. She's our senior editor, the planetary evangelist for the Planetary Society, and a contributing editor to Sky and Telescope magazine. Up next, a special report from Jason Davis, our embedded reporter in the LightSail project, has some news. Jason, welcome back for this very brief update on what's going on with LightSail.

I guess there is some real news coming out of Florida. Yes, our spacecraft is in Florida, did a cross-country flight, and has arrived where they're getting ready to bolt it onto the side of the Atlas V rocket that it's going to ride this May. Speaking of May, we have a launch date. It's preliminary at this point, so it could change, but right now we're slated for May 6th. And big plans coming together around that. So everybody, we hope you'll stay tuned as we plan to both celebrate and cover that launch and the later deployment. Now, tell us a little bit more about what's going on right now. There are all these interesting

acronyms like ULTRASAT and PPOD. Yeah, the Air Force cleared us to release some of this nomenclature, and it is a little tricky. First is the name of the flight itself, the name of the mission, and that's AFSPC-5. That's just an acronym that stands for Air Force Space Command 5. I like to think of that acronym as none of your business, essentially. And the secondary payload is called ULTRASAT. And that's the one that we're on. So ULTRASAT is essentially just a little group of P-PODS. And that's the one that we're on. So Ultrasat is essentially just a little group of P-PODS. And that's another acronym there. P-PODS stands for Poly Pico Satellite Orbital Deployer.

Poly comes from the name Cal Poly, which has been great to us in helping us get light sail ready up in San Luis Obispo. There's eight P-PODS that will potentially deploy little spacecraft like ours out into space from the side of the rocket, and we're inside one of those. And I am looking at your March 9 blog entry at planetary.org. There is a picture of the Peapod in its little fancy mil-spec-looking carrier. It's a pretty cool-looking device. Yeah, yeah, it's pretty small, as these CubeSats are small. But, yeah, they've got it on a little hardware mount device. Yeah, yeah, it's pretty small as these CubeSats are small, but yeah, they've got it on a little hardware mount there with wheels, and they put that whole thing

inside a little shipping container and that rode on a plane to Cape Canaveral, and that's where they're going to install it to the side of the rocket. All right, before we end this brief report, let's look to the future. What's going on with the next LightSail? Yeah, LightSail B, as the team calls it. Yeah, so LightSail B actually has to be packaged and ready for launch around the same time that the first one is launching. So they're kind of on a deadline with that. And they're basically going through and applying all of the lessons learned from the first light sail. So things like the radio problems that we experienced, they're going through and making all of those changes.

There's a whole list of those. So they're taking the spacecraft apart. And they're working on it right here in Pasadena at Ecliptic Enterprises. So if all goes well, light sail B on top of a Falcon Heavy, piggybacking on that rocket sometime next year, right? Yes, that's still the plan as far as we know it, yes. All right, exciting stuff coming up, Jason. We'll be checking back with you as we get closer to the launch of LightSail A. Thanks very much.

Oh, thanks for having me, anytime. Jason Davis, he's a digital editor for the Planetary Society and most prominently in this case our embedded reporter on the LightSail project. In its first two and a half years on Mars, the Curiosity rover has accomplished all of its primary goals. It did this with the most complex and comprehensive set of instruments ever sent to the Red Planet, with a gigantic team of scientists, engineers, and administrators, and with an entire world holding its breath as the big machine thundered down to the surface in 2012. project scientist. John Gratzinger has now departed that powerful and vital job to become chair of the Division of Geological and Planetary Sciences at the California Institute of Technology. As you'll hear, he hasn't left the exploration of Mars behind, but he does leave quite a legacy. I talked with John in his Caltech office a few weeks ago. John, thank you for coming back on

Planetary Radio and especially for welcoming me back into your office here his Caltech office a few weeks ago. John, thank you for coming back on Planetary Radio and especially for welcoming me back into your office here at Caltech. Well, thanks, Matt. It's always fun to do these things with you. I have lots of questions, mostly related to this transition that you've just completed a couple of months ago as we speak. If you will, pardon me first for asking you a question that may have an obvious answer, maybe not. What is your take on Curiosity's greatest accomplishment to date? It comes in a trio. First, we found evidence for water very quickly, but that was a necessary thing to do. Then we found evidence for a habitable environment, which was the reason the mission

was built. That happened roughly a year after we landed. And then two years after we landed, we had drilled enough holes to realize that, in fact, that first habitable environment that we discovered was also one that preserved organic carbon. So I think that's the answer that the public will be most interested in. But my personal favorite is that that first hole that we drilled was not an accident. And we had intended to go to Mount Sharp. We had selected it from orbit, but we made maps in advance. And those maps led us to a different location after we landed. Not far out of the way, but I feel in a personal way that that was really a turning point for Mars exploration, that we had turned the corner from exploration of a planet where you look from above and you kind of have an idea what's going on. And then when you land, everything changes.

And this time around, actually really nothing changed. And it sort of met our expectations based on the orbiter data and the hypotheses that we built. And this is powerful because the future of Mars exploration depends on looking down from orbit and coming up with models that other future rovers can go to to enhance their discovery rate. And so for us, we very efficiently and quickly accomplish the mission goals, and that mitigates the risk of mission failure prematurely. That, to me, is actually the best one, that we can make maps from orbit that have value on the ground.

I'm delighted you made that point. I actually wrote that down as one of the things I wanted to ask you about, because in an issue, Astrobiology Magazine interviewed you a while ago. You made the same point. It's not an accident that these things happen. It seems to be based on the fact that we are coming to know this planet. Yeah, that's important. And I think, you know, for some people in the tradition of planetary science, that may seem a bit boring. You know, let's go someplace where everything is different. You know, I call that the Star Trek mode.

You go out there to seek lands that nobody has seen before. Where no one has gone before, right. Right. And that is surely the domain of the outer solar system now. But for Mars, if you're really trying to purposely look for something, this also may seem a bit boring, but you're more like an oil company or a mining company. You're really trying to study the geology of a planet and be predictive. And for the sake of the shareholders, who on our case are the taxpayers, you'd like to get at that objective that you built the mission for as quickly as possible.

The discovery of things like organics and maybe possibly in the future biologic materials, this is tricky business even for the early Earth. And that's my favorite analog is that it took 100 years after Charles Darwin first made the prediction that there should be organisms to predate the evolution of trilobites on Earth. It took 100 years to find microfossils that really showed that his hypothesis was correct. So on Mars, you know, we don't have 100 years. We'd like to do it a little bit sooner. And you need these maps to guide you and to be successful. And so that's why I feel so good about that one. I'm going to come back to some of this science and where you hope that things are going. But first, before we started to record, we were talking about the fact that

unlike many of the people who are part of this mission and other missions exploring the Red Planet, you're a fairly recent addition to Mars exploration. You had been concentrating on this planet for a long time. When did you get into this? It was roughly 10 years ago. 2003, I wrote a proposal to become a participating scientist on the Mars Exploration Rover mission, and I spent most of my time subsequently working on the Opportunity Rover. But that was really the first chance that I had to get involved in Mars, and it seemed like my background was suitable for a proposal that if certain kinds of rocks got discovered on Mars, I'd have something

to offer. It worked out that way, and I got hooked. And I think that it's been tremendous for a change in a career, sort of mid-career, to do something so completely different. And it's not as if you've given up exploring Mars, even though you now have the time to explore a good deal more of this planet again. I mean, you're still very involved with this mission and others, right? Yeah, I'm still very much involved with Curiosity. I stay on as what's called the strategic path planner. So I help lead the discussion amongst the team of where the rover should be a month from now, six months from now, a year from now, and see how we can drive according to the hypotheses we're trying to test, stuff like that.

So I'll keep working on that. And then I work with my students who are involved in the mission. I keep a hand very remotely involved in the Opportunity mission, which is now going on 11 years. And that's always fun to see what that rover turns up. And I work with high-rise data from the Mars Reconnaissance Orbiter. That amazing camera in orbit. It really is. And although I don't have too much to do with that team on a regular basis,

the access to that data and the insights that the team brings are important in terms of trying to understand the geology where Curiosity is exploring. Tell us about the man who has stepped into your job as Curiosity's project scientist. Oh, Ashwin Vasavada. You know, he was just the perfect choice. He has so much experience. His technical background is extraordinarily strong, and he really understands the way projects work at JPL. And that is essential for this particular mission, which is an order of magnitude more complex than Opportunity was. For Opportunity, you had a single PI. For Curiosity, you have nine PIs. And the project scientist really sits at that interface.

And so Ashwin has been involved in the mission before I got involved and even before my predecessor got involved, Ed Stolper. And so he's been there from the very beginning. He's seen everything get made. He's seen us fly it all. And now he's really stepping up well to the task of leading the team and all the daily demands that this rover creates. It's not an entirely fair question because you're still really completing the transition, but how has life changed since you

moved back over here to become chair of this division at the college. Yeah, it's a bittersweet experience. You know, I don't think, I can't think of any other project scientist that stood down during an active part of the mission. And I did it for a couple of reasons. One was that I was asked to come back to Caltech and serve as a division chair, and I feel that at times like that you do have to step up and help. It's one of the reasons that I wanted to be the project scientist for Curiosity

is that I felt I benefited so much from being involved with Opportunity Rover. So I do think it's important citizenship to give back to the community. On the other hand, I also feel like for a mission this big, it's essential to have new blood come in. This is a very exhausting and tiring mission. You have to be up at JPL 100% of your time. You have to be aware of what all the engineering subsystems are doing at any time, what the science demands are. And if you're going to do the job right, you need to be 100% engaged. And I think for me, it was important to get out of the way and create an opportunity for, in this case, for Ashwin. And I also think that with so few of these Mars missions, it's important to have turnover.

On Earth, we have something called the Ocean Drilling Project, and there's a single spaceship. It's a ship, and it cruises the oceans. And scientists come and go for different legs of the journey. And I would like to believe that for these rare space missions that we have, that maybe you could do a crew change once in a while. NASA does that a little bit through the Participating Scientists Program, but I also think it's okay for the leadership to roll over. So those were the motivations for me to do it, but to be the division chair of geology, geological sciences, and planetary sciences, I'm still very

much engaged in training, helping to develop the next generation, and facilitating faculty through postdocs and students to work on missions like this. Caltech, not a bad place to be in that job, is it? It's pretty fun. It's, you know, Caltech is a special place in the history of planetary science. Bruce Murray, of course, everybody knows Bruce and Bob Sharp. Those guys were really the pioneers, and it was born here, and it was born here for a good reason, is that Caltech is right next door to JPL. There is some interesting history. When a lot of geology departments and geophysics departments were off doing plate tectonics,

Caltech instead embraced a different organization in JPL. And instead of exploring the oceans, they chose to explore the heavens. And instead of exploring the oceans, they chose to explore the heavens. And that set this division off in a very different direction than what other programs were doing. And cosmic chemistry was born here. When the samples were returned from the moon, they were studied in labs here. So there's a great tradition, and I'm very motivated to keep that great tradition going. That's former Curiosity Project scientist John Grotzinger. We'll continue our conversation in a minute.

This is Planetary Radio. Greetings, Planetary Radio listeners. Bill Nye the Science Guy here. The Planetary Society's remarkable LightSail spacecraft is headed for space. We want you to come along. LightSail is a small spacecraft propelled by photons from the sun. The excitement is building as we count down to our launch in May. Follow every aspect of the mission at sail.planetary.org.

Let's change the world. Random Space Fact! Nothing new about that for you, Planetary Radio fans, right? Wrong! Random Space Fact is now a video series, too. And it's brilliant, isn't it, Matt? I hate to say it, folks, but it really is. And hilarious. See? Matt would never lie to you, would he? I really wouldn't.

A new Random Space Fact video is released each Friday at youtube.com slash planetarysociety. You can subscribe to join our growing community and you'll never miss a fact. Can I go back to my radio now? Welcome back to Planetary Radio. I'm Matt Kaplan. In January, John Grotzinger left his job as Mars Science Laboratory Project Scientist for Caltech, where he leads an initiative that will create a program in comparative planetary evolution, a field that he has already done much to advance. But that's hardly all he's up to these days.

As you've heard, he is still exploring Mars and exploring this planet, sometimes with shoe leather and a geologist's hammer. When I first called you about coming back on the show to have this conversation, we had to delay it for a while because you were headed off to, I think, West Texas to break some rocks. Do you like doing field work? I do. I love doing field work. It's my lifeline, really.

I got into geology to be able to work outdoors. I enjoy mapping in particular. It's like solving a jigsaw puzzle. You don't have to know a lot of geology to understand what mapping is about if you just think of a jigsaw puzzle. The question is where are the corners, where are the edges, and how do you get started on that? And that's, of course, what we try to bring to Mars and selecting landing sites and choosing where to drill and things like that. What I was doing in January was teaching a course for a mixture of graduate students, postdocs. Occasionally we get first-year young professors.

And it's in geobiology. And it teaches what it's really trying to do is to reveal the record of life and the evolution of life on Earth by studying very ancient rocks. Usually they're billions of years old. These rocks in Texas are about 1.2 billion years old. And from that the students get training into how to approach this sea of rocks, which in the beginning seems completely untractable, and how do you go about exploring for those rocks which are likely to give you the most biological content. So it relates to the Earth.

It's all about the Earth. But we increasingly get students with planetary backgrounds that want this training so they can apply it to a future rover mission. We've kind of headed back in the science direction, which is great, because I wanted to ask you, what do you hope the 2020 rover will accomplish that Curiosity may not be able to do? Well, of course, 2020 is really designed to be the beginning of sample return. And it is the same vehicle with some minor modifications to it. That's the way that you do it for a lower amount of money than what we did for Curiosity.

And instead of drilling holes, it will collect cores. And many of the things that we did with Curiosity will be the same for 2020, which is find an interesting place to land where you think there's going to be good stuff to return to Earth, and then using those maps, drive around and try to figure out where the best samples are to collect to hopefully someday be returned. And so I'm excited about that mission because it will leverage even more the background of geology and geochemistry that is necessary to understand how to collect the best materials. And that increasingly depends on having good training in those disciplines

as much as traditional planetary science. So it's a new fusion that's going on right now in the community for Mars. As in most scientific exploration, I think I see, and I assume you do as well, a sort of arc of discovery on the surface of Mars. If that's true, where do you hope that this arc is taking us? Well, the arc hopefully takes us in the direction of exploring for life in the solar system. You know, that is what underwrites, that ambition is what underwrites all these missions. That is what underwrites, that ambition is what underwrites all these missions.

We do try to figure out, as we're doing that arc, how to bootleg other science. That doesn't directly relate to that goal. But I think what all of us really want to know, and I would have never agreed to have been the project scientist unless I thought there was a reasonable chance that life could have originated on Mars and that someday somebody might discover something. So I'd like to pursue that goal. You know, these missions don't happen that commonly. And you have to use all of your acumen, all of your training, all of your instincts to try to figure out where are those handful of rocks that might exist somewhere on this enormous planet that you're then going to bring back to Earth and hope to strike pay dirt with.

So I used to always tell the reporters in the media that I would work with, be patient. We have to be patient. Curiosity's middle name is patience. And we need to do that as a community. This is tough business. It took 100 years. a hundred years. It was 1958 when Tyler and Barghorn published the paper on the discovery of the first microfossils up on the shores of Lake Superior after Darwin made the prediction it should be there. A hundred years is a long time. So I'm not going to be disappointed if we

don't find anything the first time around. I will be disappointed if we don't follow a plan for the exploration. So that's the arc. The arc is derived by having a plan about how to leverage what you have learned from previous missions, including orbiters and rovers, acting synergistically. That's what's special about Mars. That's why it's called a program. And so these rovers and orbiters, they alternate with each other. And the success of that really is measured in how quickly Curiosity got to the good stuff.

So I'm optimistic that I think we will find some rocks that would be prospective in the language of a prospector. And what's in there remains to be seen, but I think we're doing it the right way so far. I'm really encouraged by it all. seen, but I think we're doing it the right way so far. I'm really encouraged by it all. You have reminded me, John, of why it has always been such a pleasure to have these conversations with you, whether we're in front of a live audience or sitting in your office at Caltech. Thanks for doing this. Thanks, Matt. It's always fun. John Gratzinger served as project scientist for Curiosity, the Mars Science Laboratory rover. In January, he left that job to become chair of the Division of Geological

and Planetary Sciences at the California Institute of Technology, where he has been Fletcher Jones Professor of Geology since 2005. He is the lead author of Understanding Earth, now in its sixth edition. We're going to go to another product of this place called Caltech. That's Bruce Betts for this week's edition of What's Up. Time for What's Up on Planetary Radio. Bruce Betts is on Skype. He is the Director of Science and Technology for the Planetary Society and is ready to tell us about the night sky. And then we'll learn about Ceres, which got an extraordinary

response for the trivia question that you posed two weeks ago. Welcome back. Excellent. You know, Matt, it's eclipse season. And I forgot to get you a gift. There's still time. You can either time it for the March 20th total solar eclipse or the April 4th total lunar eclipse. Now, March 20th, the totality will be crossing some pretty sparsely populated areas, Greenland, parts of Siberia. But the partial solar eclipse will be visible throughout Europe, northern Africa, and Central Asia. Not us, my friend. Sorry.

visible throughout Europe, Northern Africa, and Central Asia. Not us, my friend. Sorry. But we and everyone else in North America, South America, and Eastern Asia and Australia will get to see a total lunar eclipse on April 4th. So I'll get some more information on that next week, but it's a coming. Totally, dude. Totally, dude. We also, of course, still have super bright Venus low in the west shortly after sunset and very bright Jupiter over in the east-southeast.

Also in the early evening, Venus will be looking lovely near the crescent moon on March 22nd. And then Saturn coming up in the middle of the night and Mars getting tougher and tougher to see as it gets lower, lost in the wash of sunset, but still visible below Venus. We move on to this week in space history. Mercury, Mercury, Mercury. 1975, Mariner 10 completed its third Mercury flyby, the last. And then in 2011, Messenger went into orbit, becoming the first Mercury orbiter. They're still announcing science results, almost even as we speak. Yeah, we heard about some of those great results from Emily at the beginning of today's show.

Good stuff. On to... Random Space React. Stifle yourself, Edith. We were kids. We were tiny kids. All in the family reference there. All right. In approximate terms, a white dwarf, the end state of many stars, including what will be the end state of our sun,

a white dwarf has about the mass of the sun squeezed into about the volume of the earth, meaning they are very, very, very, very dense. Reminds me of a company that, I don't know if they still do, used to sell tomato sauce and crammed a lot of tomatoes into a nitty-bitty can or so they claimed. Yeah, it reminded me of tomato sauce too. All right, moving on to the trivia contest that was oh so popular uh we asked you who discovered series and in what year how'd we do matt apparently great not just apparently this may have been the biggest response of all time and i think it's because so many people wanted that jim bell book the interstellar age inside the 40-year voyager mission. So stay tuned, because you might just get another chance.

Random.org selected, and I was shocked, because we have quoted him many times on the show because of his comments that he gives us. Albert Einstein? No. Oh, sorry, I didn't mean to jump on. No, Albert's a past winner, but no. Mark Smith of San Diego, California was chosen by Random.org. But no, Mark Smith of San Diego, California was chosen by Random.org. He said, series discovered on January 1st, 1801 by Giuseppe Piazzi.

What did he do? Immediately after inventing the pepperoni pizza, he added. I don't think that's actually true. So Mark, you won, not for the pizza joke, which was, you know, middling, but for giving us the right answer this time around. And you have won that signed copy of Jim Bell's The Interstellar Age, a fine, fine book that we talked about just a couple of weeks ago. I got a few more.

Here's one from Jim Sosby. Interesting note, other astronomers wanted to find Ceres after Giuseppe announced it, but its orbit was by that time too close to the sun. So Gauss, the great mathematician, he developed a method for determining the orbit to help find Ceres later, and it worked. So I guess that was quite a thing in the world of orbital mechanics. But I like this one from Daniel Sorkin. Wouldn't Piazzi be thrilled by the Dawn spacecraft approaching the small world he discovered?

Could he even have conceived of such a thing? We are fortunate to live in an age when such things first became possible. Yeah, amen to that, Daniel. Thank you very much. Finally, this from Mark Schindler. Since Ceres was originally classified as a planet, that was true until the 1850s. It was the first World Series. Ha ha ha ha. Delayed reaction there.

I guess you... I got the feeling you didn't quite care for it as much as I did. I thought that was pretty clever of myself. No, I was just too dense to get it from. Ha ha ha ha. All right. Dense like a white dwarf. Or a bunch of tomatoes crammed into a little tiny can.

But seriously, folks, tell us what's up for next time. What is the closest known can of tomatoes? No. No. What is the closest known white dwarf? And we're looking for white dwarf, the stellar remnant. Gimli will not be considered a correct answer. Go to planetary.org slash radio contest and get us your entry. All right.

This time you have until the 24th. That would be March 24, Tuesday at 8 a.m. Pacific time to get us the answer. And the prize will be, just to see if we can repeat that response another signed copy i think it'll be signed we'll have to ask him to sign it and before they send it to us of jim bell's interstellar age inside the 40-year voyager mission anyway it'll be a copy of the book i hope it'll be signed how's that you can sign it if Jim does. Yeah, we'll sign it. We'll sign it. Bruce and I will sign it.

Watch the entries drop precipitously. All right, everybody, go out there, look up in the night sky, and think about mandolins. Thank you, and good night. Love the mandolin. Love the mandolin. Got a son-in-law who plays a mean one. I don't know what that means, actually. But anyway, he's Bruce Betts, the Director of Science and Technology for the Planetary Society, who serenades us every week here on What's Up.

It's coming soon to a device near you. Planetary TV premieres on Friday, March 20th at planetary.org. More about that next week. Planetary Radio is produced by the Planetary Society in Pasadena, California. And yes, that's a whole lot of planetary going on, thanks to its ever-loving members. The associate producer of Planetary Radio is Danielle Gunn. Our theme was created by Josh Doyle. I'm Matt Kaplan.

Clear skies.