Planetary Radio: Space Exploration, Astronomy and Science - Where Do We Come From? – Exploring the Origins of Life Lab

Episode Date: November 7, 2018

They may be the most important questions in all of science: Where do we come from?  Are we alone? Researchers Ralph Pudritz and Maikel Rheinstadter are working on these puzzles with their new Planetary Simulator, possibly edging toward the natural creation of self-replicating molecules. Bruce Betts’ new book, Astronomy for Kids, is just one of the prizes offered in this week’s What’s Up space trivia contest. Learn more at: http://www.planetary.org/multimedia/planetary-radio/show/2018/1107-2018-pudritz-rheinstadter-origins.htmlLearn more about your ad choices. Visit megaphone.fm/adchoicesSee omnystudio.com/listener for privacy information.See omnystudio.com/listener for privacy information.

Where do we come from? 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. Where do we come from? Which is to say, how did life begin? And did it only happen here on Earth? Or do we live in a universe teeming with life? These are arguably the most important questions in science. Researchers at McMaster University in Hamilton, Ontario, have created the Origins of Life Lab to help provide the answers. We'll meet two of them in a moment. I hope you'll also join us for this week's What's Up with Bruce Betts. Work on the origin of life is taking place at institutions around our world. Ralph Pudritz, Michael Reinstatter, and Ying-Fu Lee are the partners who have created the Origins

of Life facility at McMaster. It contains a marvelous new device they call the Planetary Simulator. This stainless steel test chamber may reveal some of the vital steps that could have led billions of years ago to the natural development of self-replicating molecules and then living cells. Ralph is an astrophysicist while Michael is a biophysicist. They joined me from their offices a few days ago. Prepare yourself for a deep dive into what might be our own genesis. Michael, Ralph, gentlemen, thank you very much for joining us on Planetary Radio and congratulations on the creation of this new lab, the McMaster Origins of Life Lab, which we'll be talking about today. Great to be on your show.

Thank you very much for having us. It's quite exciting, actually. I was extremely intrigued when I read the press release that came from your university. When I read about this, I immediately thought of the justifiably famous Miller-Urey experiment 65 years ago. As I'm sure you guys know, it showed us that the building blocks of life, amino acids, can be generated when energy in the form of, in their case, an electric spark is produced in a flask containing simpler compounds that might have existed on a very young Earth.

Is this new lab that you guys have created and are working with, is it in any sense a 21st century descendant of that groundbreaking work, Ralph? In a sense it is, Matt. It's origins of life 2.0 in that context. So in our experiments and the view we're taking is that we're imagining that by some mechanism, we already have, in this case, since we're interested in genetic materials like RNA that is in all cells, all organisms, how it's built, how it's built out of building blocks called nucleotides. So for the first set of experiments, we're imagining that these are already delivered by meteorites or perhaps built through a planetaryinometry atmosphere process, and then asking the next question, what then? How did you build the genetic materials that are going to lead to that, if we're lucky, will demonstrate reproducibility and evolution onwards to life?

My boss, Bill Nye, the science guy, he says the two big questions that we want to answer in science are, where do we come from? And are we alone? And it would appear that you hope to answer both. Do you see it that way, Michael? The Miller-Urey experiment was indeed a very fundamental and exciting experiment. So what they found is that you can produce the building blocks of proteins and peptides and RNA and DNA on Earth through very basic chemistry. But the Miller-Urey experiment kind of failed to polymerize these building blocks into proteins, peptides, RNA, DNA. And that's what we want to do in our experiment.

So if we are successful in this one, this would indeed show how the first very basic cells could potentially have formed on the Earth and also on other planets. I'll just follow Michael's remark on that. The second part of the question, are we alone? In other words, that this occur beyond the Earth on other habitable terrestrial planets, we already have, through astronomy observations, we note that the existence of perhaps a couple of dozen of these rocky potential worlds, but around other kinds of stars. And so our simulator was very carefully designed that we can simulate, say, the radiation fields and other atmospheres that would be present on other habitable planets.

In other words, other planets that would be present on other habitable planets. In other words, other planets that have liquid water on them. So that's the way we're going to attack the question, are we alone? Could it occur in other off-Earth environments? Why is RNA, ribonucleic acid, the kissing cousin of DNA, why is it so central? The way we work today is our bodies work based on proteins and DNA. But these are very complicated molecules. And once you have DNA, then you can use proteins and enzymes and such to cut and to replicate and duplicate RNA. The question that we ask is how did the entire thing start? So we want to do, we take a bottom-top approach,

and it is conceptually much easier to think of starting this process with RNA and then building up to DNA and proteins and such later. So this is why in our model, RNA is the central molecule for us. The DNA protein world that we have now at the heart of our genetic code is far too complicated to have been the first thing that appeared. I mean, most scientists working on this problem, I think, would all agree on this point. Whereas there was a breakthrough in the late 1980s that showed that RNA is a molecule that doesn't need all this elaborate machinery to reproduce itself. It can do this all on its own. It's a unique molecule that can, what we say, catalyze or engineer its own replication.

And that's why, and we see it in, as Michael said, all forms of life. So it seems to be the more fundamental molecule thing that may have been there first, as Michael has suggested. more fundamental molecule thing that may have been there first, as Michael has suggested. The question that then comes to mind, which we don't have to answer today, is, gee, I wonder why life moved on to DNA if RNA was capable of doing so much on its own. I don't know. Do you want to address that? That's pretty hard for us. I mean, that is a lofty goal, but I think we need a good, solid start on something that's simpler. I mean, both of us are physicists. I'm an astrophysicist, and Michael is a biophysicist. And I think starting on the most fundamental, simplest possible level on a problem is kind of a natural way to go, we think.

If we get this right or somewhere interesting, then that may lead to such other thoughts. But for the moment, that is just a very complicated machinery. Speaking of the foundation of this work, Ralph, could you tell us a little bit about the theoretical work that you and yet another McMaster colleague, Ben Pierce, published that led to the creation of this lab? Yeah, well, that's a very exciting project, Matt. My student, Ben Pierce, and myself, in collaboration with two colleagues at the Max Planck Institute for Astronomy in Heidelberg, joined forces to try to understand what would be the fate of nucleobases, that is, the basic building block that goes into these RNA nucleotides, that molecule, there's four of them. That is delivered in the early Earth by a vast influx

of meteorites. The Earth was built by meteorite and planetesimals, large bodies colliding here to build it up. But the meteorites, a class of them, also brought a huge amount of organic material. This was first pointed out in a great paper by Carl Sagan in the early 1990s. Enormous bombardment, we're talking bombardment rates of trillions of times greater than the Earth today, when the Earth formed. That huge influx of nuclear bases, what would be the fate of these if they were dropping into warm little ponds? Our paper calculated in a fair bit of detail what would be the rate at which you would have this

kind of infall of these molecules, what happens to them in their ponds, what kind of concentrations could they build to, how fast would they polymerize, you know, join up into these long molecules. would they polymerize, you know, join up into these long molecules in the face of destruction mechanisms like the very strong ultraviolet radiation field on the earth at that time. Remember, before life the earth has no oxygen. There's no screening ozone layer for us. So those early molecules might have had a tough time in a radiation field like that. So we looked at, as we call the sources and sinks, how these molecules build up to polymers and what can destroy them and the basic calculations in the environment of warm little ponds on the Earth. And that for us, at least for me, is really the kind of theoretical basis

of some experiments that we'd be very interested in pursuing. There are different models where and how life has formed on the Earth. Some people push forward the idea that life has formed in the ocean, in hydrothermal vents. Some people are looking for traces of life deep inside of ice, at high pressure, for instance. We follow with the new lab the idea that life has formed in these warm little ponds.

And the lab, this idea was also highly inspired by David Deamer from University of Santa Cruz, who is pushing forward this idea for many, many years now and who kind of infected us a few years ago, the discussions with him and collaborations with him eventually led to the application to the idea of such a lab and eventually to building this lab. I was also fascinated to read about another element of this work, which apparently you will be attempting to simulate in the planetary simulator, which we'll talk about in a moment. But it is this idea of wet and dry cycles, which I guess somewhat intuitively I would have thought would not be very good for the progenitors of early life. But maybe I'm wrong about that. The cycles have indeed turned out to be one of the key points in the process of polymerizing RNA from the basic nucleotides.

Because if you just mix these nucleotides in water or in these ponds, then with time, not much happens. But if you dry them out, if you have your pond and the pond dries out at the beginning of the summer, then all these molecules get dried out at a very thin layer at the bottom, and you reach extremely high concentrations of these molecules, and you suppress the mobility of these molecules. And this is the time when they can react with each other and start forming dimers and trimers and longer and longer RNA chains with time. So you need the cycles of hot and cold temperatures, and you need the cycles of wet and dry to make this process happen. Imagine you're trying to build a long train, and you've

got a bunch of boxcars lined up on the track, but you need to link them up to form the train. The boxcars are the nucleotides, and the long train will be your RNA molecule. In order to get the hooks to form, to latch together, the links between the boxcars, that is what we call a bond. And forming that chemical bond requires that you get rid of water. So that's what happens when you dry these systems out. So then you get a few boxcars at a time, you know, forming these chains. And as this goes on now, if you have two linked, if you throw down, you wet again, things move around, you dry. Now, a couple of boxcars together find another two, and they link together, and so on and so on. Another important part, actually, it came out in Michael's own experiments with David Diemer, with David Diemer was that this can be probably facilitated very much if you have a surface like a fatty acid, like a lipid, as we call it, like soap films on which these molecules rest.

That is an ideal surface to help this process of what we call polarization. And that's very interesting. You know, that goes in a direction that I was going to ask you about, because I have read that the formation of membranes is probably also key to understanding the formation of the first living cells. I mean, Michael, is that kind of where this might be headed, talking about lipid layers? Exactly. So the fundamental difference between what we are proposing in the new lab and the Miller-Urey experiment is that the Miller-Urey experiment happened in an isolated environment, in a glass flask, basically. But we think that the environment is extremely important. So the presence of porous rocks, the presence of inorganic salts, the presence of other organic molecules like the lipid molecules is extremely important for the polymerization of these nucleotides eventually.

Let's talk about that lab and in particular, this beautiful piece of hardware, which we will link to information about the lab and our audience can take a look at what you're calling the planetary simulator. Please, maybe Ralph, you could tell us a little bit about really what would be the focus of your work. Yes. So the planetary simulator is well named because what it attempts to do, what it will do is allow us to control in a very controlled way, kind of dial up, if you will, different kinds of planetary environments. What we're doing is breaking away from kind of clean test tube chemistry in an Earth environment in a clean lab,

but we're recreating the somewhat complicated geological environments on different kinds of planets. Your viewers will see there's a very interesting set of cylinder-like looking objects on this outer part of our simulator. Those contain a series of lighting devices, LEDs and various other kinds of things, that go from infrared wavelengths, very long wavelengths, all the way to the ultraviolet wavelengths. And we can dial up, if you like, the fingerprint, the radiation fingerprint that we call a spectrum of any star. So our sun is rather yellow. It will have a lot of UV in its early life. We know that the most dominant kind of star in the universe in our galaxy is a dwarf star. It's actually red. It's maybe a tenth the mass of the sun. And a habitable planet there would be inside the orbit of Mercury.

So their days are very much shorter, obviously. A year would be maybe 15, 20 Earth days or something like this. There's a different kind of radiation. Those so-called red dwarf stars, M stars in astronomy parlance, have lots of UV. They're very dangerous in that way. But their radiation is more skewed to red optical light. So by that, we can control the radiation that will affect the kind of chemistry. As Michael mentioned, we control the humidity, the dry-wet cycles, the temperatures that we can tune to whatever we think we want for planetary

conditions. We're looking at habitable conditions on all of these planets. So in those conditions, water will always be liquid. But there's still a huge number of parameters that we have to alter the physical and kind of planetary environments we're talking about. It was deliberately done that way to allow us to address this question, are we alone? In other words, if we found that we could get these RNA molecules to be made in an Earth-like simulation, could we find similar sequences in another planetary environment or not? Would that be prohibitive? And if so, why would that be? That's really what we'd be driving at with this. Very exciting.

Michael, I wanted to go back to what you were saying about getting away from the sterile lab glass and putting in other kinds of stuff. We've heard from Ralph about the different kinds of environmental factors you'll be able to control. But are you talking about basically getting, if not your hands, at least your samples dirty in a sense, having all kinds of stuff in there like clay? That's right. Dirty in a very controlled way. So what our students are doing in the lab is they try to recreate these warm little ponds and they recreate them in different environments. And in these ponds, there would be salts, there would be clay. So often you have like a muddy layer at the bottom of a pond, which is made out of different types of clay. And we think that these environments are extremely important, not only for the formation of RNA, but they may also be very important for the sequence that the nucleotides may form on these particular pieces of RNA. So in some ponds,

even if you can produce RNA, this piece of RNA may not carry any biologically relevant information, while in other ponds, which exist on different parts on the earth in different environments, have different ingredients, they may produce RNA which is highly functional and biologically relevant. It's very advanced chemistry that we play, but we try to play it in a dirty way by mixing things together and get away from the controlled, clean chemistry environment that you usually have. I love that learning about the origin of life may require us to get our hands dirty. Exactly. An interesting point that bears on the theoretical ideas

is would salt be important? You know, if you form life in salty oceans, salt is a problem for making these such large molecules. That's well known. So we can control that very well by experiments in which we would vary the salt concentration, as an example, from freshwater, perhaps, to more something like seawater, and just check what happens. We think that that's why, in our view, it's more plausible to think that life began in freshwater, warm little ponds, and not in an ocean, just for that simple fact of what

salt does to inhibit this kind of formation of molecules, which is a topic that's pretty well known. So I think the other thing that intrigues me looking at the way Michael has set up the experiments, basically Michael sets up mini ponds. They're very small things on small little wafers. We can put in maybe 90 such mini ponds in the're very small things on small little wafers. We can put in, you know, maybe 90 such mini ponds in the simulator at the same time. Yeah, that's exactly what we do. So we call them mini or micro ponds. So depending on where we think these ponds would have been formed, would have formed on the earth, they would have slightly different compositions. So the compositions on the one hand, and also the type of cycles that you run,

they may play an important role for not only for the formation, but also eventually for the sequences that you get. So while some regions on the Earth may still produce, you know, have produced RNA in their ponds, this RNA may not have been functional in a biological sense. While in other areas on Earth, there might be ponds, this RNA may not have been functional in a biological sense, while in other areas on Earth, there might be ponds with different compositions, and they may have produced the RNA that was needed to form life and eventually form more complex cells as well.

There is a video that listeners can check out. It's in the article that we will link to, and I'm going to guess that what I'm looking at in a portion of that video are some of your students creating these little mini ponds. Exactly, exactly. So because we know, we assume that we know what was in these ponds, and we have all these ingredients in our fridges and freezers and such. So it's relatively easy for us to mix these things together, form these ponds, and eventually dry these ponds out on these little chips. And because they are teeny, that's very small, one by one centimeter,

we can run about, as Raul said, about 90 of them at the same time in the simulator. So it's a very efficient way of testing a lot of parameters at the same time and see which one eventually is successful in producing RNA. So you have begun to expose these mini-ponds, subject them to the planetary underway. Everything worked actually much better than expected. And after the machine was installed back in July this summer, after a few days, we were up and running simulations already. And we were extremely excited to see the first results already after a couple of days. So if we're lucky, there may be some more publications ahead. What if you're successful in showing how RNA may have formed on the early Earth? That will be not an earth shattering, perhaps, but a very important development in the history of science, I think. I tend to agree. So I'm cautious. to agree. So I'm cautious. So I would say that if we find out a process by which RNA can form under these conditions, we have a very solid proposal how life can possibly have formed on the early Earth and also on potentially habitable planets out there. I agree. This is tremendously

exciting. I would probably take it one more point in the way we're thinking of the experiments. It'll be one thing to show that we could maybe build RNA molecules, like trains that have got 60 cars long, RNAs with 60 of these nucleotides linked together. We know in biology that these are already functional. They have functional purpose. But what we don't know in the lab, and the really big unknown, is supposing we get our polymers that long to form, which of them, if any, would be successful in replicating themselves? That is completely unknown to us at the moment. Here we're really on our own. And no doubt that why we're varying the environments, no doubt, you know, an RNA molecule will be successful somehow

within its own environment. It is the best kind of molecule to be able to replicate in that environment, if you know what I mean. And that basically brings in the idea of how molecular evolution would occur. We have no idea of how successful we will be yet in finding whether there are any of these molecules that form that would have this ability to self-replicate. Only if they do that could we really say that, yes, we've taken the first step towards something that, you know, one day we could think of as living. And I would say the other part of this that you mentioned before, Matt, is that it's this association between the RNA and the lipids. The fact that the experiments, when you drop a meteorite into a pond, it's full of these lipid molecules. They quickly form these little bags in which these nucleotides get trapped.

So automatically, you're in a situation in which the RNA is actually building itself in some kind of a membrane. With that, since that's a natural thing that happens in the physics and chemistry, we're very interested to see if that is going to play an important role in this whole thing of selection and ultimately reproducibility. A lot of unknowns here. Very exciting. RNA in little bags, courtesy of meteorites. I mean, these sound like protocells. Indeed. That's exactly what we are after. And I think after our first preliminary experiments that we have run over

the summer, we have seen evidence for the formation of these protocells already, much faster than we expected, actually. But Ralph is absolutely right. The critical question that we ask here is, even if you can synthesize RNA, and even if you can put them into these very simple protocells, will they at some point start acting as a biological system? So the question is, even if you can still make RNA using some chemistry, we still have to make the transition into a biological system which is able to self-replicate and show some sort of metabolism. And that's the big mystery there. So a long ways to go still, but

it sure sounds like a very important step that you're taking. You know, saying that this effort is multidisciplinary seems like an understatement. Ralph, I bet you'd agree with that. And I'm wondering if you could say something about your other colleague who isn't online with us today. That's biochemist Ying-Fu Lee, another colleague of yours at McMaster. Yes, indeed. This is one of the greatest examples, I think, of interdisciplinary science at its best. As an astrophysicist, I can bring certain ideas and knowledge to the table. As an example, the way that these molecules could have been made in space, brought to the earth, the conditions of young planets and their atmospheres.

I would have no background in the biophysical setup, the kind of experiments that Michael is trained to do, analyzing membranes, their physical properties, looking for evidence about how polymers would form. And the third person in our trio, Ying-Fu Li, is a leading biochemist. His own research is on molecular evolution. In fact, finding DNA sequences that are very successful in performing certain kinds of functions. So I think a success in this project needs, absolutely requires, all three of this kinds of expertise together. And this effort came about, the Origins Institute at McMaster, which I was the founding director of, was a very deliberate effort to create a program. Actually, we even have a graduate program that students can come and work on these types of things

in what we call a collaborative graduate program at McMaster that's unique in Canada and one of the few in the world, joining a few in such places in the United States, in which we can really bring together not only faculty but students to be trained very deliberately in this interdisciplinary kind of a way. If I was a student with an opportunity at McMaster to participate in this kind of work, I think I would consider myself very, very fortunate. I'm going to take a shot in the dark here to end our conversation. Have either of you ever read the classic science fiction story?

It was written way back in 1941 by Theodore Sturgeon called Microcosmic God. No, I haven't. Very unfortunately, I know that name very well, but I didn't. I highly recommend you take a look. It is a very far cry from what you are hoping to do with the planetary simulator, what you're hoping to achieve. But I recommend it highly, and we'll put a link up to that if we can find the story online. It's actually about a scientist who sort of develops a little microcosmic world in a sort of planetary simulator and eventually comes up with a very fast-living, intelligent life within his simulator. I suspect you'll be satisfied if you achieve quite a bit less than that. Fascinating. Once again, art leads. Gentlemen, thank you very much. And I absolutely wish you the greatest of success with this work.

Even if it is unsuccessful in creating more of the more complex building blocks of life, including RNA, that will be very valuable in itself, of course. But boy, will it be exciting if you start getting molecules that seem to know how to replicate themselves out of this little device that now lives in your lab up there at McMaster University, the planetary simulator. Absolutely. Thank you very much. Thank you so much, Matt, for your interest in that of your audience. Time for What's Up on this post-election day of Planetary Radio. Bruce Betts is the chief scientist for the Planetary Society. He joins us. As we speak, it is still election day, so

nobody can tell from how we sound what we think of the results, because there aren't any yet. That is correct, Matt. He said in a most somber fashion. I think it's only U.S. Election Day. You're absolutely right. I don't know. Maybe it's Election Day somewhere else in the universe. They should elect us president and vice president of the universe.

We'd have to fight over who was anyone. Oh, goodness. So we've got in the evening sky, Jupiter pretty much gone. Really tough. Maybe right after sunset, low in the west. But we've got Saturn in the southwest in the early evening. And then Mars still bright in the south. And you can use Mars to help you find the star Fomalhaut or Fomalhaut, which is the only

bright star in the autumn sky. Again, for Northern observers, Northern Latitudes, only bright star in the autumn south. But right now you got bright reddish Mars, and if you look to the lower left of that, about two fist widths held at arm's length, you'll find Fomalhaut, which is part of the constellation Piscis astrinus. The southern fish in Fomalhaut vaguely means the fish's mouth. And I've always wondered how to pronounce that star's name, and I'm proud to say that you haven't helped me a bit. Nope, not a bit, Fomalhaut. And if you're up in the pre-dawn, one, I'm sorry. And two, check out Venus

looking super bright low in the east near the bluish star Spica. Or Spike. Or Spica. Alright, we move on to this week in space history. It was 2014. Rosetta's Philae lander became the first spacecraft to land on a comet. 1971, Mariner 9 became the first Mars orbiter. All right, we move on to random space fact. I love it.

The Dawn mission was just recently retired as it ran out of fuel after all those years. Let's reflect. It was the first spacecraft to orbit two extraterrestrial bodies, Vesta and Ceres, and the first to visit a dwarf planet, Ceres. Also a little tidbit that with all the glorious successes one can easily forget, Dawn was canceled at least a couple times due to cost overruns and technical concerns before being scheduled for launch and what turned into a very successful mission. And we'll get Mark Raymond, perhaps others back on the show soon to give us a little bit of a wrap-up report on that mission. Although I am sure, like all

these missions, planetary science missions, the data will be entertaining scientists and the rest of us for years to come. Oh yes, they gathered a lot. All right, we better move on to the trivia contest because it was weird and I'm curious what people thought of it. So my question was, in an unrelated coincidence, what sequence of events that will occur for the BepiColombo mission can be characterized by the first three primorials, one, two, and six? How'd we do? Let me get the winner out of the way quickly so we can go on to some other really fun stuff. Mitch Roberts, I believe a first time winner in Mankato, Minnesota. Go Vikings! Of course. That series that you proposed, it stands for one flyby of Earth, two of Venus, and finally,

six of Mercury before BepiColombo goes into orbit around that rock that is so close to the sun. That was exactly what I thought was the intuitively obvious answer. Congratulations, therefore, Mitch, who says he loves the show. He joined the Planetary Society less than a year ago. He says he's listened to every episode. I don't know if he's one of those crazies who's gone back to the beginning of time and listened to our entire 16-year history. But Mitch, whether you have or not, welcome, and we're glad to have you on board as a member.

Just a little tip. You may not want to call our listeners crazy. Especially the members. Oh, they know I'm muted affectionately, like I do about Christopher Dangler, who also says, he says he's listened to Planetary Radio for several years, recently became a member. He says, this week's question was great fun. I vote for more unrelated coincidences. Okay, I will take that to heart. By the way, did you know that there is a Reno,

New York? Sure. No, you didn't. That's where Christopher is from. Edward Smith. It's the biggest little city in New York. Mark Smith. Here in my hometown, San Diego, California. He says, I hate numerology. This is the astrology of trivia questions. Oh, oh, oh, that hurt.

Howard Medlock in Lubbock, Texas. We hear from him a lot. He came up with an entirely different set of answers. Almost what you were looking for. No, it's not at all what you were looking for, but it's pretty good. One, Mercury transfer module. Two, MPO and the MMO, the two major portions of that spacecraft are joined together. Six objectives for the mission.

of that spacecraft are joined together. Six objectives for the mission. Origin and evolution, study form, interior geology, structure, composition, craters. That's all number two. Exosphere, magnetosphere, magnetic field, and number six, verify relativity. Good try. Not what I was thinking, but sure.

All right, this one, prepare to have your mind blown. Stephen Donaldson. Wait, wait. Are you ready? Okay. Okay. Stephen Donaldson in Hagerstown, Maryland. He got it right. And he says, it turns out there are a lot of other examples of this series, one, two, six. And you know how he knows this? There is such a thing as the Online Encyclopedia of Integer Sequences. Awesome. Isn't it? Check it out.

It is absolutely legit. It is at oeis.org, the Online Encyclopedia of Integer Sequences. And finally, this from Caleb Grove in Frederick, Maryland. And finally, this from Caleb Grove in Frederick, Maryland. Third baseman Brooks Robinson, who wore number five, is definitely one of my favorite primorials. Mitch Roberts, our winner this week, he's going to get a Planetary Radio t-shirt, a 200.iTelescope.net astronomy account, and a signed copy of Bruce Bett's new book, Astronomy for Kids, which is fully available now, I'm not sure. Is it just the e-book version?

E-book version is available. The paperback is available November 13th. You can pre-order now. It's a signed copy of the book, right? That is indeed true. It is signed by me, so that's kind of a bummer. But yeah, signed copy. All right. So what have you got for next time?

Backing off the unrelated coincidences theme for a moment. So Dawn very successfully employed ion thrusters for propulsion on its many-year mission. What was the first spacecraft to employ ion thrusters beyond Earth orbit? Go to planetary.org slash radio contest. It's about time I knew one off the top of my head once again. You have until Wednesday, November 14, at 8 a.m. Pacific time to get us this answer. And you might win a Planetary Radio t-shirt. Take a look at it. It's in the Chop Shop store, actually the Planetary Society store at chopshopstore.com.

A 200-point itelescope.net account. By the way, we have had five winners donate their 200-point accounts on iTelescope to Astronomers Without Borders. And so 1,000 points, that's about 1,000 bucks worth, is going to go to a school with a lot of underprivileged kids in Puerto Rico. And we are very proud to be able to facilitate that as are our five winners. And finally, another copy, a signed copy of Bruce Bett's new Astronomy for Kids, which is a great book. All right, everybody, go out there, look up at the night sky, and think about your favorite integer series.

Thank you, and good night. Two, four, six, eight. Who do we appreciate? Chief Scientist. Chief Scientist. Yay. He's Bruce Betts, the Chief Scientist of the Planetary Society, who joins us every week here for What's Up.

Don't forget that we're now posting complete transcripts at planetary.org slash radio on the individual show pages. It may take a few hours after a new episode is published before the print version appears there. Planetary Radio is produced by the Planetary Society in Pasadena, California, and is made possible by its original members. Mary Liz Bender is our associate producer. Josh Doyle composed our theme, which was arranged and performed by Peter Schlosser. I'm Matt Kaplan, Ad Astra.