Book Club Edition: Planetary Society Chief Scientist Bruce Betts’ latest for kids

Mat Kaplan: Are we alone? And just how big is space? Planetary Society Chief Scientist Bruce Betts joins us with the answers on this month's Planetary Radio book club edition. Hello again. Planetary Radio listeners and lovers of books about our solar system and beyond.

I'm Mat Kaplan, senior communications advisor for The Planetary Society, the former host of Planetary Radio. Bruce Betts has completed his series of space books for young people. The size of space collects many of Bruce's successful and very entertaining attempts to reduce the vastness of the cosmos to human scale.

The other book, Are We Alone, borrows that greatest of questions that drives so much of science and is at the core of The Planetary Society's mission. Bruce is still the only human being who has been heard on every episode of the Weekly Planetary Radio series with me for the first 20 years and now with host Sarah Alakmed.

But he is done so very much more for us across his many years at the Society, including his brilliant management of the Light Sail Solar Sail Project. He's a planetary scientist whose PhD studies at Caltech were overseen by our co-founder, Dr. Bruce Murray.

Bruce Betts spent three years at NASA HQ and has crossed the globe in his work for us and others, including the Planetary Science Institute where he is an alumnus senior scientist. You're about to hear much more about my good friend in this recording of the live stream conversation we had in the Society's member community as 2026 gone underway.

We are here to talk about Bruce's latest books. You see a shelf full of them behind him there. Here are the two latest and as I understand it, last books in the series. Am I correct?

Bruce Betts: Yes, you are correct. It is a 15-book series if you count all of them going back to the Eclipse book and one for each planet and a few for other objects besides planets in our solar system. And then we finish off with a couple different topics measuring the size of space.

Basically, for those who may be aware, it's basically Random Space Fact with a little introduction to talk about scale models and things like that. I pulled out some of the coolest Random Space Facts, had the ARG department do some things, found some images and made a groovy book, and this was part of a Planetary Society partnership with Lerner Books who is particularly active in school libraries.

So feel free to tell your school library to check these out or you can order them for yourselves at Amazon or if they seem to have inventory weirdness sometimes. So first go to the Learner Books and check out all the books there.

Mat Kaplan: We'll talk about the books, but I also want to talk to Bruce about his job and how he ended up in this work and about The Planetary Society and our mission and how he contributes to it, how he has done that for many, many, many, many years. I think roughly almost as long as I've been around TPS.

But I started beginning with the books, which is a great place to start. How did this come about? How many of them are there? Why did the Society decide that we should make you the author of this whole series that lists The Planetary Society right up there at the top of the book?

Bruce Betts: I don't really know the answer other than they had made a mistake. I can mention that I had, as you can see on the shelves, six books before I started writing these separately with different publishers. And so there was a basis of, I've been writing children's space books at all levels from my first book of planets up to teens and adults, but yet to actually be willing to get a book that says it was for children, but I've had many adults enjoy them, particularly the high, and all the levels.

Anyway, our partner group and leadership team, including Ridge Chute and also Jennifer Vaughn and the gang made contact with Lerner and worked out this deal where basically, we would contribute a series with using our solar system planetary knowledge and they would publish and distribute it.

So you will see that most of these are nicely branded with Planetary Society and we're trying to work more with the educating children, kids, getting them excited about space, getting them involved and showing them all in, well, the beginning of all the need stuff with space. So that's where it's genesis and then we worked out, been working over multiple years working on coming up with what's included and how it's structured and the whole nine yards.

Mat Kaplan: I heard now and then from you and others how much work this was because it was this long stream of books and anybody who thinks that putting together a book like this, which is, it's fairly thin, it's fairly typical for what you do for kids that this would be an easy task. You put a lot of work into these.

Bruce Betts: I did. Hopefully, it shows in the product and wasn't just a foolish waste of time. No, every time one of these comes out I feel a great sense of accomplishment and then I pick it up and I realize it's fairly thin and I am not really sure how I spent that much time.

But trying to get the language appropriate for the age group, trying to figure out what you have to do, a lot of squeezing things down, figuring out what you throw out. So I love space. I've been studying it my whole life, so there's all sorts of things I want to put in there, but you need to fit fairly tight constraints in the process.

And then I'm obsessed with images and so finding images that are real, images when possible and art when not, and finding the best representative ones where again, you only have room for a few and trying to have a caption that although short gives you an idea of what you're looking at and whether, for example, you're looking at something your eyes could see or something in the infrared otherwise. So anyway, I found a way to spend a lot of time on them, so hopefully, people enjoy them. Some people do.

Mat Kaplan: I know my relatives, my grandson is going to, I haven't even shown them to him yet but I know, especially the size of space, I think he's going to love because he already knows everything about astrobiology, but this is-

Bruce Betts: How old is he now?

Mat Kaplan: He's nine. Nine and a half, yeah.

Bruce Betts: Okay, good enough.

Mat Kaplan: Two PhDs so far, but he's a slow learner.

Bruce Betts: He's published astrobiology papers?

Mat Kaplan: Yeah, all the time. You haven't seen them? You've been too busy writing books. They're perfect. What age are they targeting?

Bruce Betts: Targeting second to fourth grade, talking Americans four, seven, eight. So it's in that range, but hopefully it target that you're interested. Even younger kids like it at some level and then older kids can digest it.

Mat Kaplan: It's full of your wonderful Random Space Fact analogies and demonstrations of scale. Let me bring up some of your examples, some of your Random Space Facts. Beginning with mouse earth and elephant sun.

Bruce Betts: Yeah, I like that one. The way it's expressed here is that it's the earth were the size of a mouse, then the sun would be the size of an elephant, and I took out all the part about what kind of elephant and what gender, but it's really an expression of masks to be perfectly honest.

But it roughly conveys to the size of the animals and indeed there's a lovely elephant picture that we found in there and a mouse, and that's about the difference because we're really tiny and the sun's really big and that's what I tried to convey, Mat, did you know that mouse elephant, small, big?

Mat Kaplan: I didn't until I saw that example, of course.

Bruce Betts: Oh, good.

Mat Kaplan: I'll tell you one that honestly did surprise me. Even though I have known many, many years that Olympus Mons, Mount Olympus on Mars is that much huger than Mount Everest. It was actually seeing them in the book laid out against each other Everest in front of this behemoth that is so impressive.

And I'd be showing more of these pictures, but people are going to be listening to this on Planetary Radio, so I decided not to, but get the book folks and you'll see it. It's a mother, it's a monster.

Bruce Betts: It is enormous. Both in height, it dwarfs Mount Everest and in breadth because it's a very broad shield volcano, more like a Mauna Kea or Mauna Loa with the very shallow angles as I've heard a phrase that it's the size of Arizona also, I went ahead and went international and it's the size of Poland.

Mat Kaplan: Poland is the size of Arizona?

Bruce Betts: That would be by the transitive property of geographical silliness, yes.

Mat Kaplan: Yes. A equals B, B equals C, therefore A equals C. I remember the transitive. It's about as far as I got in math. If the sun was at New York City and not huge and burning it up, take it from there.

Bruce Betts: And you put Neptune in LA, so sun, New York, Neptune, LA, then the earth would be orbiting roughly at the distance of Philadelphia. So we should graphically, the point is the earth is much closer to the sun than Neptune is.

Neptune is about 30 times farther away from the sun than the earth is, and it's a way to really see it, at least for those familiar with the United States contiguous geography. That really did it for me. I was pleased when I came up with a city comparison that was pretty accurate. Did you recognize my son in any of these pictures?

Mat Kaplan: No, not your S-U-N, but your S-O-N. I know you dedicated the book to your sons who both of whom I know find fellows and to the members of The Planetary Society.

Bruce Betts: I have a picture of Kevin, the younger, Daniel, the older, they're both fine men now in their 20s, but at this time Kevin was somewhere in the teen, pre-teen and there he is kicking the earth, getting ready to kick the earth where the Random Space Fact with some manipulation of the photo is if earth were the size of a soccer ball, professional soccer ball, then Jupiter would be about pretty darn close to the height of a soccer goal.

Mat Kaplan: So this reminds me of the brilliant stuff that you did for a long time with our brilliant video guy, Merk Bowen, the Random Space Facts series, which are still on our website if you check them out under the video, they're so entertaining. And my grandson, I already know, loves those. Even when he was four years old, he just loved lining those up on our website and got a-

Bruce Betts: Yeah, if you're not familiar with, we did work in with Merk Bowen, our video guy a few years ago. We did a number of random space fight videos where they're a minute or two long and have real science fact, gee whiz. And then usually I get hurt and it's funny, at least for kids.

Mat Kaplan: Yeah, either you get hurt or you get embarrassed somehow or you break your car somehow. There's one, I think, for you.

Bruce Betts: Well, my poor car, although my car suffered a fate very similar to, well, not really, kind of similar to it. It came in through the atmosphere representing a car-sized asteroid entering the atmosphere and burned up. This case, it just burned up in the Eden Fires that were about one year ago just melted most of it, and that's not important right now.

Mat Kaplan: Word of explanation, Bruce lived in the center of the Altadena fire, more or less, and that neighborhood is pretty much gone. But you're doing okay, right?

Bruce Betts: We're doing good. We got ourselves and the dogs out and plenty of time and thought we were just evacuating to be cautious and then everything no, wasn't caution, everything was cautious us and everything around it was wiped out. I'm sorry it was caution. I get a little distracted when I start talking about it.

But that's not important right now either. That's my theme for this is what's not important right now. That was very important in my life. But random space track videos, there's a playlist. I don't remember if that's linked easily from there or not, but on YouTube you can find all of them, but there's about 50 and we have fun and a couple of those made it into the book as well. Once they're similar. If our solar system out to Neptune where there's size of a quarter, then the Milky weight galaxy would be the size of North America.

Mat Kaplan: Yeah, that's another one of the ones that I made note of, but here are two at least that got my LOL. One of them I was completely unfamiliar with.

Bruce Betts: Yeah, I was surprised that everyone went along with me, including the ones at the back, but.

Mat Kaplan: One in particular I bet was the one that was in question.

Bruce Betts: Yeah, go ahead.

Mat Kaplan: Yeah. Here's the first one, fingernail growth.

Bruce Betts: Oh, yeah.

Mat Kaplan: With illustrations.

Bruce Betts: The learner got the illustration made with my sharpest description. And so yes, if the moon gets farther from the earth in its orbit in one year, it's about the same distance as your fingernails grow in one year.

There's a lot of variability in fingernail growth, but at least an average fingernail growth, that's how. Turns out in one of the amazing things I didn't say, there's actually a third coincidence, which is that's also the approximate rate that the mid-ocean ridges are expanding outwards rift.

Mat Kaplan: Tectonics.

Bruce Betts: And what did I say? Do you have it? It's a few centimeters.

Mat Kaplan: I'd have to hold it up. Let me see here. I'll see if I can find it.

Bruce Betts: That's okay. I'm supposed to remember the number, but I just have those cool analogies and everyone knows how fast their fingernails grow.

Mat Kaplan: Oh yeah, and you have to see the camera to be able to do this properly, but there you go. There are the fingernails.

Bruce Betts: The cheeseburger looks good enough to eat?

Mat Kaplan: Yeah, it does actually.

Bruce Betts: This also has a Rover, the dog and Luna, the robotic cat and dog that participate in our membership program, Planetary Academy. And the content from that is somewhat is tied to the content in these books at some level. And in this particular one, the publisher wanted to use those creations of our designer and they're super funny and cool, fun and cool, fun, fun, fun and cool.

Mat Kaplan: So here's the other one, and you probably can guess which one it was that I cracked up.

Bruce Betts: Well, sure.

Mat Kaplan: However, it's right at the end of the book a couple of facts about Uranus. You would have to unroll more than 47 billion rolls of toilet paper to reach Uranus. Pardon me, Uranus from Earth.

Bruce Betts: Yes, you would.

Mat Kaplan: And then this cute little illustration that says if the sun were the top of your head and Pluto were the bottom of your feet, then Uranus would be right where you'd expect it to be. Really?

Bruce Betts: Yes. That is the most popular Random Space Fact I've ever come up with.

Mat Kaplan: How did you come up with this?

Bruce Betts: Sometimes for every successful calculation, there are a bunch that aren't successful, so I kind of hunt around and that one I was like, oh, well it'd be neat to do a human body type thing. Let's say, why don't we put the... And then I just calculated it's like, wait a second, and I'm standing up with measuring tapes and going, well, that's funny. That's very funny.

Mat Kaplan: I'd like to have seen that little proof.

Bruce Betts: Great moments in Random Space Fact history.

Mat Kaplan: Yeah, it does seem cosmic that it works out so well actually, at least to me.

Bruce Betts: You do have to use Pluto instead of Neptune, although bodies vary. It's like fingernail growth.

Mat Kaplan: Before we go on to the next book here in the book club, let me look over what we've got here. I saw that Timothy had a question quite a while ago and I hadn't been scrolling down. I see a whole bunch of, you have now, Timothy said, "How many Earth-crossing asteroids could there be?" And he says, "Explain the blind spot a little more." So an estimate isn't there for the number of near-earth asteroids, which is another thing that Bruce is quite expert on and represents us at such things as the Planetary Defense Conference when it happens every other year.

Bruce Betts: It is true. I was going to say I use Random Space Facts, but frankly, I have, because we did talk about how to convey do public education and outreach about the asteroid threat. And so to be very specific, I don't have a number in my head for current earth-crossing asteroids, by which I assume you mean crossing its orbit, but what the so-called Planetary defense community usually uses are a couple of defined things.

One of them is near-earth asteroids or NEOs or near-earth objects, NEOs, which includes the small handful of comets. And the NEOs come within 1.3 AU of the sun, AU being astronomical unit, the distance from the average distance earth to the sun. So they get close enough to the earth that even if they aren't crossing our orbit now, the concept is they that close a perturbation from Jupiter to gravity or something else within, I believe the modelers are like a thousand-year timeframe.

It's not unreasonable that they might be thrown into an earth-crossing orbit. So that's kind of the ones we want to pay attention to and find. We've found about approaching around 40,000 of those currently, and the estimate gets really big if you talk about NEOs that are big enough to do damage affecting people.

So the Chelyabinsk and above, so the 10-meter diameter asteroid type thing that's going to come down doesn't hit the surface. It's doing it. There's an air blast that can cause damage. And the estimate is there're about a million of those NEOs of which we've found 40,000 and we're doing great compared to where we were, which was almost none turn of the century.

And so those numbers are going up and up and you find the most dangerous, the biggest ones the easiest because they're the biggest and reflect more light, easier to see. So that's the good news. So we found almost we're probably over 95% estimate of the one kilometer and above the real global disaster, but the numbers get worse as you get smaller objects.

So the most important thing in Planetary Defense is find them. But until you find them, track them and get some basic characterization and most importantly, whether they're orbit is targeting earth at the time, you can't do the next nifty parts like slamming something into them to change their orbit.

Anyway, that's my little pitch for, let's do it, and we're doing better and better with the ground-based work and we've got NEO Surveyor, which we keep pushing to make sure it doesn't drop out of the budget at some point, and that will be a space-based telescope that the community has been really wanting since the Planetary Defense Conference started 25 years ago.

This has been the big goal because... Oh, coming back because the blind spot, and I'm not exactly sure where you're referring to, but not surprisingly, it's very hard to find objects on earth coming out of the sun. And so some of these go inwards of the earth and then the sun is in the way. It's more complicated if you're on the surface of the earth.

And so NEO surveyor, even though it won't be that far from earth, it will pick up a much broader swath of sky that it can look at at any given time being towards the sun. It's designed, I believe they're still on the putting an earth, sun, Lagrange 0.1, which is about a million and a half kilometers towards the sun, and that will enable it to see a lot more of the sky without that pesky sun interfering.

It's also infrared-based, which turns out is more... You can do a lot better often with that than with visible. Depends. You want both, really. So that's the blind spot I think of which is anything where it's inwards, it really is an earth crosser and it's inwards towards the sun. It's extremely hard to pick up.

So, Chelly Vince came out of the sun in 2013 and was not picked up, not seen. Of course, they orbit farther out, so you are going to pick them up or have the option to pick them up later as long as they're not on their impact dive at the time.

Mat Kaplan: That was my guess as well about what he was probably referring to at the time. We got a useful note here once again from Ridge Chute who's really proving himself helpful tonight. He says, "RSF, Random Space Facts are also available in schools on the EPIC where they get hundreds of thousands of views every year." I did not know that.

Bruce Betts: Apparently you did. That is so cool. I did, and Ridge has been great about passing that information along and I have not publicized enough to you, Matt. It's really cool and very gratifying and there even, at least there were.

I haven't checked recently hospitals that use them, a couple of them at least as running on a channel on their internal system, especially for kids. But yeah, the school thing is very gratifying on the epic service that there are that many views and people checking them out. So it makes us feel good.

Mat Kaplan: I got to go back into it and see if my grandson is still as excited and entertained by them as he used to be. I bet.

Bruce Betts: Well, if he's not, don't tell me.

Mat Kaplan: Okay, let's see. Dave said, "Wait, the earth's orbit is growing in size?" And then was answered by Dian, "The Moon is moving away from the earth," which is what you were talking about with the fingernail thing, right?

Bruce Betts: Tidal effect. It's a tide of the earth. The earth's rotation in other length of our day is getting slower. That's what happens to the earth with this tidal effect. And the moon is getting farther away, and they're both very small from a human standpoint, but significant over geologic time, say the least.

Mat Kaplan: And Timothy just posted, "Don't worry, the moon isn't escaping anytime soon. It's actually moving away very slowly," which is what you were just talking about.

Bruce Betts: Right. No, we're good. We're good for a long time. It's not pulling the moon fall thing and almost crashing into the earth either. I don't think. No, I'm not worried. We're good.

Mat Kaplan: Do you remember the name? It was a short-lived Steven Spielberg TV series, which I think most of them have been, sadly, where they go in a time machine back into the past and they did a cool thing when they look up at the night sky, the moon is huge because the Moon is substantially closer to earth, but Terranova, thank you, William.

Bruce Betts: That was quick feedback. No, I do not remember it and I didn't know they did that and could have just been because they had the glasses on and they don't figure.

Mat Kaplan: I don't think so, but they had a time machine, which is much better than glasses. And we will talk about Are We Alone? The other of Bruce Betts' great new books for Young Space fans when Planetary Radio's book Club edition continues in moments.

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Mat Kaplan: Let's talk about this one, Are We Alone, Searching For Life Beyond Earth with The Planetary Society, Bruce Betts.

Bruce Betts: That was a great quote. I'm sorry they had a time machine that's better than glasses.

Mat Kaplan: Yeah. Again, fun book and a great introduction to the search for life elsewhere to astrobiology. You cover a lot here like what's happening in our solar system and looking at extra solar worlds and also eventually, SETI, which is all stuff that The Planetary Society has been deeply involved with, right?

Bruce Betts: Yes, yes, yes, we have. We've started funding SETI and within the first year or two, the organization started in 1980 and we're funding efforts we worked with. Steven Spielberg, or at least he made contributions to our program when he was making alien movies and he helped throw the pretend switch to fire up one of the searches that was run by Harvard University and Paul Horowitz there ran several going from radio astronomy even to optical looking for laser signals.

The answer, to skip ahead, is no, we didn't find anything. But the other part of the answer that I feel like people haven't been given enough information to appreciate, it's a really big haystack that we're looking through the needle. So I don't find that surprising at all, even if there's a lot of life out there, the distances, the powers involved, the fact that you have to be looking at the right place at the right time, see it multiple times to believe it, be looking at the right wavelength, be able to interpret the signal label to sort it out from other forms of human radio interference, which by the way, one of our recent step grant winners at UCLA has been using, developed a program that we help sponsor, which is using citizen scientists to go through and help them categorize the earth interference noise in the radio signal.

Because one of the hardest things about SETI is sorting out all those pesky human signals and figuring out what might be an actual intelligent alien signal. But as you say, in the book where I start more basic, which is life on earth and the three things life requires, well, four things, we count Mat's sonorous voice.

Mat Kaplan: Thank you. Thank you. Thank you very much.

Bruce Betts: Energy source, liquid water-

Mat Kaplan: Liquid?

Bruce Betts: Liquid water, which guides a lot of our searches. And then the right kind of atoms, molecules spilling blocks to fiddle with in a nutshell is at least what earth life requires. And so then we start there in the book and move into places in our solar system where we're most intrigued by the possibility of past or present life from Mars and the obvious lots of liquid water there in the past to Europa with its liquid water ocean, crazy.

And Enceladus was spewing out geysers. And then we go out and at least touch in the subjects of looking elsewhere and looking at exoplanets and the concept of the Goldilocks zone of the, where it's just right temperature to keep your liquid water oceans on the surface or the expanded Goldilocks where you have things like subsurface oceans, blah, blah, blah, blah, blah. It was fun.

That one was a challenge to write, I got to say, because taking the field of astrobiology and making it digestible, hopefully, I succeeded. But obviously, it's like anything else. You do a book on Mars, you're only scratching the surface. You do a book on astrobiology, you're only scratching the surface, but you're trying to do it in a way that gets kids excited and gets some of the basic gist so that hopefully, later on or even after they read that they go look for more information and dig deeper.

Mat Kaplan: Yeah, it's all about whetting their appetites. And by the way, you mentioned step grants, science and technology empowered by the public, right?

Bruce Betts: Nailed it.

Mat Kaplan: Nailed it this time. And also a program that Bruce is in charge of where we fund this great research by people all over the place.

Bruce Betts: So we've got four great projects in the few year histories so far, and so we're looking for probably a couple more to come.

Mat Kaplan: We'll see.

Bruce Betts: And it's open to pretty much anyone, but obviously you have to convince us that you're going to do a project and have the skill and the equipment and whatever, and it's a realistic budget and things like that. The usual for tech proposals.

Mat Kaplan: So far so good. Some really, really good stuff. In addition to our Shoemaker Neo book grant program for finding those rocks that are headed our way, which we won't go into today because we don't really have time, but check those out on the website as well. I'm going to give another gratuitous mention to Steven Spielberg. If you're watching Steven, call Rich-

Bruce Betts: We got a sponsorship that I missed. Ridge? Do we get money every time he mentioned Steven Spielberg?

Mat Kaplan: There's a picture of a much younger Steven Spielberg throwing that fake switch that Bruce mentioned. If you're ever lucky enough to get a tour of The Planetary Society office, which we don't do much anymore, not since the pandemic, but if you do, directly opposite that photo of him throwing that switch to figuratively start a SETI search.

But is another great example of our involvement with both the search for life, but also life's ability to, well, as Jeff Goldblum put it, life finds a way, is the life experiment. Say at least a couple of words about that. And a little tart words.

Bruce Betts: Life experiment.

Mat Kaplan: Right. That's two words.

Bruce Betts: Living interplanetary flight experiments where we developed a bio module, basically half a hockey puck, but made of titanium with all sorts of internal features to survive the anticipated 4,000 G impact when it came back to earth on the Russian Phobos sample return mission, which ended up going to space orbiting the earth a few times and then exploring the ocean of earth.

So the concept was to test the ability of life to survive. Life had been tested in space and life had been tested outside the magnetosphere a couple of times on the moon, but to actually do that for a few years was the goal. And so various everything from bacterial spores to archaea to the seeds, and at the other end, and your favorite tardigrades, otherwise known as water bears that tend to be very rugged and can survive vacuum of space at least when other people fly them.

Mat Kaplan: So I'm guessing that this book, you had it all locked up before the announcement of what happened on Mars Perseverance's finding in Jezero Crater.

Bruce Betts: Yes.

Mat Kaplan: So those leopard spots, am I right about that?

Bruce Betts: That is correct.

Mat Kaplan: It just says that we're still learning stuff pretty quickly, doesn't it?

Bruce Betts: Oh, yeah. And I think it's a strange field, not in a bad way necessarily. SETI is the ultimate example of a strange field because you can spend decades doing really legitimate science and not ever find what you aren't even sure is there. But it's one of those things that if we don't look, how do we know?

Broader astrobiology, they do everything from considering the origins of life and what's required and how it happens on earth to figuring out what might non-earth, other permutations of life look like. And most importantly, how do we look for it in, for example, we go to the surface of Mars and we drive a rover round, let's say we call it perseverance, and we look for things that might be evidence of past life, and then in a theoretical hopeful world, we return the samples to earth to use the big laboratory on.

And so yes, indeed, the book was finished before they found that particular sample. And the interesting leopard spots, which by the way, not caused by leopards, just a simple similarity through me for a while. There's amazingly a lot of great work going on in Astrobiology and the planetary side, even hosted a small workshop with some of the leaders in the field trying to look at what's next and where we could fulfill roles in helping to advance the search for life, which, along the planetary defense and planetary exploration, one of our core enterprises of what we do.

Mat Kaplan: And that Search for Life workshop, I was my honor to be involved with that. It was an amazing collection of folks, and I'm sure that kind of work will continue. Doesn't it just kill you? It's killing my dog downstairs, apparently. Does it just kill you to...

No, no, no. He's very concerned. He's concerned that we've left all those wonderful sample tubes on Mars and inside perseverance, and we can't get the things back home. It just kills me. I don't know if it kills you.

Bruce Betts: Apparently, you swore-

Mat Kaplan: That's about as far as I'll go.

Bruce Betts: I know, I know. But you don't go that far very often.

Mat Kaplan: Wait till you hear me when if the dog keeps barking.

Bruce Betts: He's an example of life on earth.

Mat Kaplan: Well, I bet. Are you any more optimistic about the search for life than you were 10 or 20 years ago that we might find somewhere-

Bruce Betts: In what way? That there are?

Mat Kaplan: Yeah, that something's out there waiting to be discovered.

Bruce Betts: Am I more optimistic now than 10 or 20 years ago? Certainly if you win 25 or 30.

Mat Kaplan: Okay, 25 or 30, do your call.

Bruce Betts: Yeah, I am. But generally no, because my assumption has been for, there's so much stuff out there that it's just hard to imagine life not evolving elsewhere. It gets much harder when you start saying, how about on Mars? Well, we have one laboratory right now that has where we study life and it's called earth, and we know what happened there.

We know really pretty darn well, but it gets old fuzzy when you go back 4 billion years, although they do an amazing job. And so studying one laboratory, we see life pops up fairly early on a geologic planet's timescale in earth's history, and it's pretty rugged and it finds a way, but we don't have any other laboratory. We have no other place where we've done the experiment to live thoroughly enough to know whether that's generally true or not true.

Was there life on Mars? No idea. Neither does anyone else life on Europa and the subsurface ocean, that's a really exotic one. No idea. Life on a star within 10 light years, probably not. Maybe. Proxima Centauri. Life around M-class red dwarf stars that are friendly and cool, but really hostile with spitting out nasty ultraviolet and particles, we don't know.

That's part of what makes it interesting, but it's one of those things where people are learning a lot all the time. But since we don't know what we're looking for at some level, but we certainly don't know how prevalent it is. So even though within space in general, I'd say you must've had life lots of times, especially now that we've found there's on average, one planet or more per star in our galaxy, there are two to 400 billion stars.

So therefore, that many planets in our galaxy, not just our galaxy. Then you get to the ridiculous, there are another 200 to 400 billion galaxies. So the statistics, if life is anything other than just a miracle, then it's out there. But whether it's out there close enough and we know how to look for it, I don't know. That's why it's cool. And the fact that it's rather profound.

Mat Kaplan: We are going to get to some more of your questions and comments here. As I turn with Bruce away from his books, which I do highly recommend, it is a terrific introduction to the search for life, I think, and one that the kids, particularly in that age group, but that are going to get a lot out of, I did as well. A lot of the stuff he's just talked about, that world circling Proxima Centauri, it's in the book. I don't know how he got this much stuff into it.

Bruce Betts: Let me ask a quick question to those people, if you get the books, consider doing a review on Amazon.

Mat Kaplan: Oh yeah, sure.

Bruce Betts: Especially this series. It wasn't as actively encouraged and pushed, and that's what helps get them out there more. Learner's doing a great job of getting out in libraries all over, and that's wonderful. And as they point out, that means you get for every book you get 10, 20 people kids interacting with that one book or whatever the multiplication factor is that I've forgotten.

But reviews would be helpful, especially because if one person comes in and they had to think, I look like a bad person, and so they say it's terrible. You need a couple of people to say, well, he looks like a bad person, but it's a good book, if that's what you think.

Mat Kaplan: He's a good person. We're almost into bonus time here as we frequently on this book club series, and so we're going to do that. I know Bruce is able to stick around for a few minutes because I got more that I want to talk to him about. But first Qua says, "How long before we are no longer able to enjoy a full solar eclipse?"

Bruce Betts: So right now, we have this amazingly wonderful weird coincidence that the moon and the sun subtend roughly the same angle in the sky. And so you get total solar eclipses and also annular because of the elliptical nature of the orbits. But as it moves away, eventually, you will not get that, and I don't remember the exact estimate, but none of us have to worry about it for our few gazillion generations because it's millions of years off.

And I'm sorry, I stopped being really attentive when it passed a hundred years, but it's millions and I don't remember whether that's one or 10 or a hundred, but it's off the waves longer than you might expect.

Mat Kaplan: Got a great question from Diana. I'll get to Dave in a moment. "Wouldn't putting SETI searches on the far side of the moon make for less or fewer interference problems?" Well, there've been a lot of talk, right? About putting radio telescopes on the far side.

Bruce Betts: Yes.

Mat Kaplan: Okay, next question.

Bruce Betts: Let me quickly mention, obviously, you have some serious challenges to deal with. You're never, well, I won't say never. You're not in the near future, even if you can manage that and manage the setup, the pointing, the communications, which by the way, it can't see earth, so you have to communicate with an orbiter to get back to earth.

Even when you get those things done, you're not going to end up with a big, giant a hundred-meter telescope, like the UCLA group is using the West Virginia Green Bank Telescope. So you're not going to get as much coming in. But yes, the really good news is that you take care of the the radio interference. So it's a very good idea, but the implementation is hard and expensive and has other issues. But someday. It's a good point.

Mat Kaplan: Here's that question from Dave, and it's a good one, "Do you have any advice for someone thinking about writing a children's science picture book other than don't do it?"

Bruce Betts: No, that's just when I'm pushing the deadline and it's one in the morning, then it's like, "Oh, don't do this. Don't do it." Never again. No, but on the flip side, what I'm not sleep-deprived. And when I look at the books and I hear cute stories of kids who want the books read at night, and it's very, very rewarding. I lose track of that when I'm on a deadline. But then I remember, again.

Advice. I'm a big fan of real images, and so if you can use real images, use real images, because in the space business, it's been a lot of effort and amazing technology that gets us what these things actually look like. Whereas you often end up with cartoony versions of that, and that's my pet peeve.

And sometimes if you're wondering what exoplanets look like, you have to use art because you put the pictures in, but it's like a dot. And it's not very exciting when you see a planet as a dot or don't see the planet at all, which is what's true of most exoplanet hunting that we do. So that's one specific thing.

Writing and then rewriting or to try to get to the right age range and keep it limited and focus on what are the kids going to get the most out of? What's the fundamental concept? What you only have this many words? What do you need to convey and what can they get later on? And even though you want to tell them that now, it's not part of the core. That's my thought. But thank you for asking. No one's ever asked before, so I didn't have a good answer.

Mat Kaplan: Dave, thanks for asking and good luck. Go for it. Timothy is keeping us busy. Here's a statement, "This abundance diversity and sheer density of life forms sets earth apart within our known solar system. The presence of such a vast array of complex ecosystems and species would represent a unique finding in the search for extraterrestrial life. Damn shame if we humans mess things up with these wars and pollution, we must find the balance." I'm with you, Timothy. There was another one here I want to catch. Where did that go? Ah, William said, "There are those who believe that life here began out there. Tell us about Panspermia."

Bruce Betts: Okay, that's the second time he's sworn. Sweared. No, not really. Just the expression for life, what you just described, life gone, originating elsewhere. Well, that was actually part of what was being explored in a way with the Phobos life Capsule if it had worked, which was the concept of it would've only addressed one piece, but one tiny piece of... Can you have something kicked off Mars? Well, yes, you can.

Can you have something survive as makes in the space? Valid question. But we did nothing would've done nothing to answer that. Can you have it survive on the shortest trips that are orbitally possible? And that we were a test for, if you, basically, the biomodule was a simulated asteroid, and so they weren't sitting on the outside, just they're simulating organisms, spores, microorganisms that are hanging out inside a rock, and then suddenly they feel a big shock. And then they're cruising through space, chilling hard, figuratively and literally endlessly. And then will they survive? And obviously you have the re-entry and stuff.

So there are thoughts that, for example, Mars was we think was warmer, much warmer and much wetter and a better place for life back four billion years ish. And so what if life evolved then and then you had a big impact that threw rocks off, that actually kept organisms, hibernating, whatever inside the rock re-entered, were big enough that they didn't melt and die. And so in that respect, you start life on earth. You started on Mars, but then it came to earth.

And so to quote in a totally different context, then you end up with we are the Martians, not the Earthlings. So do we know if that happened? Could have happened? We think it's plausible but challenging. And it's one of those, I don't know, but it's an intriguing possibility that a lot of people have pondered and think about, well, maybe not a lot of people, but a few people like you. Good job.

Mat Kaplan: So enough of this speculation and wonder about the possibility of life across-

Bruce Betts: Somebody say wonder.

Mat Kaplan: Let's talk about us. Let me show everybody something that is one of my happiest and most prized possessions. It's right here. It's hanging inside this room where I'm speaking. And yes, it made Bruce smile warmly as I hoped it would. You see this collage? This was presented to me by the chief scientist who assembled it and took most of these photos.

I think when I backed off from hosting Planetary Radio, turned it over to our colleague, Sarah, and there's so much fun stuff here. I just love this. I got stuff all over my walls. Most of it I totally ignore. This one makes me happy. Every time I look at it.

Bruce Betts: That makes me happy. I haven't looked at it in a while or looked at those pictures in a while. Do a lot of goofy fun stuff over the 20 years. You're Planetary Radio guy, you.

Mat Kaplan: Yeah. And that's why you think I'm wearing the sweater just because it's a cute sweater? I'm wearing it because I could lift it up and show off the first generation Planetary Radio T-shirt. Give us 30 minutes. We'll give you the universe.

Bruce Betts: Well, I'm going to claim that I came up with that.

Mat Kaplan: Did you? Maybe you did. I have no idea. It wasn't me. I know.

Bruce Betts: Obviously I stole it from the radio station. 30 minutes, we'll give you the world, but I figure we go beyond that.

Mat Kaplan: Well, one of the greatest pleasures for me of being a part of The Planetary Society other than supporting our wonderful mission in all of its facets has been all the fun stuff that we've been able to do together. For 20 years, I can't say it anymore. You are the only person who has been heard on every single episode of Planetary Radio.

Bruce Betts: It's a lot of pressures.

Mat Kaplan: [inaudible 00:51:21] of your segment of the show. What's up?

Bruce Betts: Yeah. And I think people actually listen to it.

Mat Kaplan: I think so.

Bruce Betts: I enjoy doing it. I enjoy doing it with you. I enjoy doing it with Sarah. And we do different modified version, but still hopefully fun stuff. And then there were all those crazy things we did back in our youth when we were getting run over by rovers and crazy, crazy, crazy fun stuff.

Mat Kaplan: So you are a scientist.

Bruce Betts: Well, supposedly.

Mat Kaplan: Did a bunch of stuff for NASA and other agencies. What was that group that you were part of for years? [inaudible 00:52:00] Institute plan.

Bruce Betts: PSI.

Mat Kaplan: Planetary Sciences Research Scientist. Spent some time in DC learning about that stuff. Went to Moscow, right? Did stuff with the Russians or the Soviets.

Bruce Betts: Three times. I participated in six failed Soviet or Russian missions.

Mat Kaplan: So what is it about your job here and the mission of this organization that has kept you around all these years, have kept you being creative and fun?

Bruce Betts: Partly the ability to at least occasionally be creative and fun, which when you're buried deep in a scientific paper trying to figure out every single detail that someone will call you on, and you have more of those moments where you wonder, like the one I talked about for writing these books where you go, oh my gosh, I'm so deep in the details.

Mars isn't important. What's important is this little channel here that's got something going on in the thermal. Anyway, that's not important. What is important is I get a lot, so much out of working for an organization where I get to do different things like this, science related things, technology management. But we're working with a lot of people who are very excited about space and the ability to reach out with things like this, with you Mat, with Planetary Radio, with the books we produce, with just every project we do in SciTech as well as other aspects of the organization.

We're communicating it out to the world, and particularly with the help of our members and to our members. So it's fun for me. And I enjoyed science and I still do some science once in a while, certainly review a lot of science, but it's different. And there's a fun aspect that I've been able to cultivate that it was more than I probably could have otherwise. And you know what's really made it, Mat? The people, mostly you, the people.

Mat Kaplan: I do agree with you broadly there that it is a great group of people. It is such a wonderful staff. You and I have worked with a whole lot of people who've come and gone at the society, and they've all contributed in their way, many of them, brilliantly. We have, I think right now, the best group we've ever had. And they are great fun to work with.

Bruce Betts: They are. They are. And don't tell them I said that.

Mat Kaplan: We're going to make that a little clip. We'll post it across all of us.

Bruce Betts: No, no. They have to know. I disapprove of all of them.

Mat Kaplan: So that's it, folks. I think we're pretty much at the end here. Bruce, I'll probably say it more than once, but thank you for many, many years of being my colleague and friend and for all the great stuff that you have done for us and our members, and also for these terrific books which have closed out this long era in your life of turning out these books for Lerner and The Plant Society.

Bruce Betts: Something I never thought I'd end up doing, but I've gotten a lot out of it, and mostly I've gotten a background for my web calls.

Mat Kaplan: Thank you everybody for joining us this evening. It has been a great pleasure to have you and stick with us in the member community and in the book club. As you can tell, lots more still to come. Once again, Bruce Betts, chief scientist of The Planetary Society. Thank you so much my friend.

Bruce Betts: Thank you, Sir Mat Kaplan.

Mat Kaplan: Are We Alone and the size of space published by Lerner and authored on behalf of The Planetary Society by our chief scientist, Bruce Betts. I'll be back with the next Plan Rad Book Club Edition on March 14 with astronomer and astrobiologist, Caleb Scharf, author of The Giant Leap.

Planetary Radio is production of The Planetary Society. Our associate producers are Rae Paoletta and Mark Hilverda. Post-production is by Andy Lucas, the Society's member community is led by Ambre Trujillo. The producer and host of Planetary Radio is Sarah. I'm Mat Kaplan. Ad astra.