Planetary Radio: Space Exploration, Astronomy and Science - More Moon Water and an Update from Venus on Our 18th Anniversary!

Episode Date: November 25, 2020

We celebrate 18 years of Planetary Radio with two great features and 10 personal questions for host Mat Kaplan from Planetary Society Chief Scientist Bruce Betts. Astronomer Jane Greaves is back with an update on the phosphine gas detected above Venus. Then we find water right out under the Sun on our own Moon. Research leader Casey Honnibal tells us how her team found it using the SOFIA telescope on a 747. Learn more at https://www.planetary.org/planetary-radio/1125-2020-greaves-phosphine-honnibal-lunar-waterSee omnystudio.com/listener for privacy information.See omnystudio.com/listener for privacy information.

Water all over the moon and an update from Venus 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. Happy anniversary, Planetary Radio. It has been 18 years to the day since our little show was first heard. It has been 18 years to the day since our little show was first heard. Stick around for a sweet yet understated celebration with Bruce Betts in this week's What's Up segment. In the meantime, we'll do what we love to do, and that's bringing you the passionate explorers who are revealing the wonders of our solar neighborhood and the farthest reaches of the cosmos. We'll start shortly with an update from Jane Greaves about her team's

discovery of phosphine gas in the atmosphere of Venus. There's news on that front. Then we'll go to the leader of work that has found water on the moon, this time not in those permanently shaded regions at the poles, but on the brightly sunlit surface as well. I think you'll enjoy hearing about this from Casey Honable. The big story in planetary science since our most recent issue of the downlink has to be China's successful launch of Chang'e 5, the first lunar sample return mission since the 1970s. Kudos and best wishes to the international team behind this effort. Topping our stories in that November 20th edition of the Downlink is approval of the European Space Agency's Ariel mission. Ariel will focus on about 1,000 exoplanets,

measuring the chemical makeup of their atmospheres, which sounds like a big step in the search for life elsewhere. You may also want to check out the new selfie captured by the Curiosity rover. It was snapped at a location called Mary Anning, named after the 19th century paleontologist whose discovery of marine reptile fossils was ignored for years. As always, there's much more at planetary.org. You can also have the downlink delivered for free every week.

Here's a little treasure found by my colleague Jason Davis. It's a young Carl Sagan's contribution to a 1963 NASA documentary about Mariner 2, the very first interplanetary spacecraft. Many theories of the Venus environment have been suggested. However, new information eliminates at least some of these theories. Measurements with radio telescopes show that there is a region on Venus

where temperatures are greater than 600 degrees Fahrenheit. It is just possible that the surface temperature could then be almost Earth-like and life as we know it could exist there. However, it is more likely that if there is life on Venus, it is probably of a type that we cannot now imagine. We've learned much more about Venus in the 57 years since Carl spoke those words,

but so many mysteries remain. Many of you heard Jane Greaves on our October 21st episode. Many of you heard Jane Greaves on our October 21st episode. Jane led the research that found evidence for phosphine gas in the Venusian atmosphere and found it at roughly the altitude where temperatures and pressures are Earth-like. I rarely bring a guest back on Planetary Radio after only a few weeks, but there have been further developments in this story. Jane generously agreed to return. She is a professor in the Cardiff University School of Physics and Astronomy.

She has led and participated in studies of planets and how planets form from protoplanetary disks around stars. She also studies the moons in our own solar system that may be able to support life. Jane was awarded the Institute of Physics Fred Hoyle Medal in 2017. Jane, welcome back to Planetary Radio. Thank you very much. Lovely to speak to you again. We first talked, of course, just over a month ago. Science has taken its course since then, with other researchers examining your data and conclusions, and I've read that your team has

done the same. What is the latest news? Well, the main thing we focused on is the discovery that there was a bit of a calibration issue, which broke down into several small issues with our original data from the Elmer telescopes. And the observatory there has been super helpful in sorting that out for us, as a result of which, in fact, observatory performance overall will be better for other observers. So yeah, that's been our main thing. Well, maybe we are witnessing once again science at its best. Does this mean that your feelings about the level of phosphine in the Venusian atmosphere, have you had to back off somewhat?

Not entirely. I think we've just adjusted the numbers. In a way, it's been the best of times and the worst of times, if I could quote, because we were very keen to use open science so people could look at exactly what we've done. And people have indeed done that. What's been slightly less open is they didn't get back to us and say, you know, here's how you think you could improve. Most of them just rushed something out, which left my team, which is really small, scrambling to try and come up with scientifically valid answers. But with the enormous help of the ALMA Observatory, particularly the European end run at the ESO Southern, sorry, the European Southern Observatory, ESO, they've really done a superb job on the

calibration. So now we could say in the ALMA observation, there is less phosphine than we originally thought, a few times less. But it does give us an exciting insight to parts of the planet where we think it peaks. And although that observation done in 2019 now doesn't look ideal, we can certainly go back and have another go. What about that wonderful graph that plotted the original ALMA results against the observations by the Maxwell Telescope in Hawaii? That matchup between those lines looks so conclusive. Is it still there? It's still a matchup. The lines are in the right place. But I guess as an astronomer that doesn't normally do planets planets I was thinking they ought to be kind of equally absorbing that I think is not the case it does what lines on Venus do is sometimes the line

is stronger than others so that's something I'm trying to do at the moment just see if we can get an idea of the behavior over time because our telescope observations done with the James Maxwell telescope actually took place over several mornings all the way back in 2017, but over a week. So we can look at time scales of variability as well. I was going to ask about that next, because I read that it seems more apparent now that the concentrations of phosphine vary over time and from place to place above Venus. Yeah, that really seems to be the case. So the ALMA data are really exciting for looking at different places,

which the JCMT data can't really do. The ALMA data are still not perfect in the sense there's kind of instrument gradients across the face of Venus. I think we can point at a few places and go, hmm, that looks like a bit more phosphine, but the significance of the features is maybe, you know, five times the noise anyway. So we don't want to get too bold in what we say now. But we're really looking forward to more rounds of observation.

I remember, at least I believe I remember a month ago, bringing up with you, comparing these findings of phosphine with those findings that seem to come and go of methane on Mars. Do you still see that as a pretty good analogy? Well, Mars has the advantage that some of the rovers can explore it in situ and in some way that raises bigger puzzles, because you're not quite sure what a waft of gas blowing past a rover turns into when it's seen from an orbiter, say, much higher up, looking at bigger scales. So it could be something like that. Venus

probably doesn't have quite such local effects because the really high speed winds in the clouds would kind of smooth everything out. But, you know, we're just finding we don't have quite enough information at the moment. Hasn't there been other recently found evidence of phosphine, or at least something that contains phosphorus in the atmosphere? And I think it was someone at a university not far from me, Rakesh Mogul at Cal Poly Pomona, who looked at very old data. I think he was inspired by your work. Yeah, that's really exciting because he's the

mass spectroscopy data from the NASA Pioneer Venus probe that went down through the clouds in 1978. And those results were mainly published in 1980. Not a technique I have any familiarity with, but they've done a very sophisticated reanalysis now to say the mass of some molecule that was detected really looks like phosphine and indeed kind of bits of phosphine if the molecule was then broken up. I think one of the most impressive things is somebody helping Rakesh with that work was an original member of the team in 1978. So they're getting the best possible advice. Oh, that must have been thrilling for that original member of the team to see science coming from this old data, which happens so often. It must. And I wonder if they, you know, had to look in the garage for a notebook.

Well, they're lucky that the data was still readable. I know that's been a problem with some other probes from when you go way back where they had to resurrect old computer drives to be able to read the data. Yeah, I don't know how much they've actually been able to do that yet. Fortunately, it was published in 1980 with the numbers describing the masses of the molecules they saw. I don't know if they've had to go back and look at, I don't know, punch cards or large magnetic tapes. It'll be exciting to find out. Absolutely. I think this is evidence of the continuing excitement that has been generated by your findings. There was this great quote from Sanjay Limay.

Maybe you know how to properly pronounce his name. He's a planetary scientist at the University of Wisconsin. He says, I've waited all my life for this. And the feeling that really this has reinvigorated the interest in examining Venus much more closely than we have recently. Yeah, I think interest has been bubbling away in some quarters for a few years now. And Sanjay's work's been really impressive to me. So they've put together some of the data about mysterious ultraviolet absorption in the

clouds of Venus, something that comes and goes and you can see in patches. And then a few days later, it's changed. And that's been suggested because the particles responsible floating in the clouds are thought to be a few micrometers in size, which is like the size of microbes. It's been suggested, I guess, this is actual microorganisms or perhaps the dead ones that don't make it coming and going in clouds or colonies. So I'm really excited by that parallel piece of evidence as well. Well, that's an exciting hypothesis. All of this means that no one should be any less interested

in sending a properly equipped spacecraft to Venus. No, I think that's correct. I mean, it may turn out to be we're very early in the hunt for life in the solar system, I think. It may turn out to be some pieces of the puzzle were a bit wobbly, didn't quite fit. Or in the case of phosphine, maybe there's some peculiar chemical source in the atmosphere that nobody's ever thought about because it doesn't happen on Earth. So, you know, it might turn out to be there have been some false trails or it might turn out to be everybody, the mass spectroscopy and the ultraviolet and us in the millimeter waves. Maybe we're really onto something.

So, yeah, certainly a really nice case to send a mission to what's, in any case, a fascinating planet with a climate so different to our own. So the hunt continues and hopefully expands. Before I let you go, I told listeners up front about some of your other work, but I left out a fascinating conclusion about protoplanetary disks that you and your colleagues there at Cardiff reached in 2018. One might say it's a real gem, if you know what I mean. Could you tell us about that? Let me make sure we're talking about the right one. Give me another hint here.

Nano diamonds. The nano diamonds, not the one about Giminga or Jaminga, which is a whole different thing. You can talk about that one too. I don't think I read of that. The Jaminga one is the search to see if there is a planet-forming disk around a dead star, a pulsar, and that's a project that's ongoing in the background. It looks like maybe it's a null result, but still a gem of interest to me. So the nanodiamonds, yeah, is nanometer scale particles,

as you might imagine. And I managed to link some radio observations with some infrared spectra of these particles and suggested it's these spinning nanometer scale diamonds that are responsible for something called anomalous microwave emission around stars. So that was a really fun project. It's perhaps a smaller area of science,

but it's really nice to feel you've contributed something. I think I remember you saying something about when we spoke last time, that you like to have the freedom to do research, to go in directions that pique your interest. And this certainly sounds like that is evidence of that. Shiny objects in the sky, even if they are at the nanometer scale. Yes, I do get perhaps it's a mental disorder, which I don't mean in any disrespectful way. But you know, something like attention deficit disorder possibly is behind the going, oh,

look, a new shiny thing when I read the literature. But I think this is great, you know, because you can do science in a very long-term, careful way, building on something done by huge teams, like the discovery of gravitational waves would never have happened without huge teams. But there's also, I think, a role for a kind of, I don't know, like a jackdaw bird approach,

poking around in a heap of shiny stuff and going, I like this one. What does this one do? I think it was Isaac Asimov I've heard quoted saying that science is not so much. Aha, I have found it as, hmm, that's interesting. That's strange. Yeah, I think that's very valid. So particularly the one about the anomalous microwave emission really wasn't that strange. When you talk about big data and the difficulties of gigabytes, terabytes, petabytes of data, that particular one I counted up and although it was data taken by the really

large Green Bank telescope in the US, so that does actually handle huge data volumes, the numbers that I was scratching my head over was actually 81 bytes of data so possibly the only bit of data I've ever dealt with you could carry it around with you tattoos on your arm or something. Wonderful stuff. Thank you, Jane.

I'm very grateful. As I said up front don't often have guests return so soon but this work remains so exciting and so interesting. I'm really delighted that you were able to give us this brief update. Well, thank you very much. It's a pleasure. Astronomer Jane Greaves of Cardiff University. We'll move outward from Venus to our own moon and the new water discovered there. That'll be right after this break.

What a year it has been for space exploration. Hi, I'm Sarah, Digital Community Manager for the Planetary Society. Will you help us celebrate 2020's greatest accomplishments? You can cast your votes for the most stunning image, the most exciting mission, the most surprising discovery, and more at planetary.org slash best of 2020. We've also got special year-end content on our social media channels. Voting is open now at planetary.org slash best of 2020. Magnificent desolation.

That's how Buzz Aldrin famously described the moon when he and Neil Armstrong set foot on our big natural satellite. The assumption for many years was that you couldn't find a drier place in the solar system. We've now known for several years that there is water in the permanently shaded areas at the top and bottom of the moon, lots of water. And as you'll hear from Casey Honnebel, there was evidence of something that was at least a cousin to water out there on the brilliantly sunlit surface. Casey is a NASA postdoctoral program fellow at the agency's Goddard Space Flight Center. As you'll hear, her projects have brought her to some of our

planet's most remote regions. She's also lead author of the paper published a month ago by Nature Astronomy titled, Molecular Water Detected on the Sunlit Moon by SOFIA. SOFIA, of course, is the Stratospheric Observatory for Infrared Astronomy, that big telescope mounted inside a Boeing 747. I talked with Casey a few days ago. Casey, thanks very much for joining us on Planetary Radio and congratulations on your leadership of this team, which has found even more water on the moon. We've talked frequently about the water hiding up in those permanently shaded areas of the poles, but your work, your team's work has gone considerably beyond that. Welcome once again.

Thank you. Thank you for having me. So Paul Hertz, the head of NASA's astrophysics division, said, now we know it's there. Elsewhere, I assume, on the surface. Are you as confident as he is? Yeah. So the results that I show in my recent nature astronomy paper, which were part of the NASA press release conference, were actually showing definitively that molecular water, like we drink, is present on the sunlit surface of the moon. I want to come back and talk more about how you know this is water and not some other compound. But first, you know, I have a soft spot in my heart for SOFIA, since I also got to take

one flight on it, just as a passenger, I'm afraid. Got to take one flight on it, just as a passenger, I'm afraid. You use SOFIA and FORCAST, faint object infrared camera, to examine the moon. Why was SOFIA and FORCAST, why were these the right tools for this observation? Yeah, so that's actually a really interesting question. From a ground-based telescope, we can't observe this signature of water that we were looking for. And so in order to do that, you either need to be above the Earth's atmosphere as much as possible, or you need to have a spacecraft. Currently, there's no spacecraft available to make this type of measurement that we needed to look for the water. And SOFIA flies above 99.9% of the atmospheric water vapor,

which allowed us to make this measurement, which we couldn't have done from a ground-based telescope. Is this also why you've been a part of efforts that have sent telescopes up on balloons above most of the atmosphere? And you spent some time in the Atacama as well at very high altitudes. Yeah, that's partly the reason that we go to high altitudes is to get above the atmosphere and get above the water vapor that kind of plagues ground-based observatories. SOFIA was built to look across the galaxy and back toward the beginning of the universe, primarily. Was looking at something so close, I mean, we could almost reach out and touch it comparatively, was this a breeze or were there new challenges?

There were actually quite a few challenges observing the moon with SOFIA. It had never been done before. And so it was definitely a test run that we had done in August 2018 to see if SOFIA and FORECAST itself could look at the moon, find the moon, not saturate, and actually acquire good data that would tell us something about the components on the moon, not saturate, and actually acquire good data that would tell us something about the components on the moon. So by saturate, you mean just the moon being so much brighter than most of what SOFIA looks at? Exactly, because the moon is so big and so bright compared to these faint galaxies that were molecular clouds that SOFIA looks at, we had no idea if forecast could handle the amount of signal it would measure. You know, I got something that you just reminded me of from

the briefing and from the press release, that this was a fortunate accident, serendipity, that this was really just a test of a forecast. Yeah, it was a test. We only had about 20 minutes of actual observing time on the moon to see if this would work. And 10 of those minutes were actually looking at the lunar surface, trying to see if we could see this molecular water signature. So it was quite exciting when the test turned out to provide such an exciting discovery. Really, I'm not sure when such a short observation resulted in so significant a find, at least in recent years. Back to the water that we're following, as NASA likes to do. It really is water. It's not some similar compound because that was some of the confusion in the past, right, where there were hints, but it couldn't be confirmed? Yeah, that's exactly what it was. Prior to these observations with Sophia, we had been looking at a spectral range at three microns, so a little bit further than the visible in the infrared. And what they see at three microns is an absorption band, but this band

is actually due to hydroxyl, which is just an oxygen and a hydrogen, or possibly molecular water, which is H2O. So at this three micron band, they couldn't distinguish between the two. And which one is present is very important for processes occurring on the moon and also for potential resource utilization, because you don't want to drink hydroxyl because that's the main factor in grain cleaners. Yeah, quite a different compound. When you talk about the presence of this stuff, how much of it is there? So there's actually not that much that we measured at this time. So we looked at the Clavius crater at high southern latitudes. And what we estimate is that there's an abundance of 100 to 400 parts per

million of water present. To make some kind of comparison, if you think about the Sahara Desert, the Sahara Desert is 100 times more wet than the soil that we observed on the moon. Wow. All right. Another comparison I heard was something like your standard 12-ounce bottle of water per cubic meter of lunar regolith. Does that sound right? Yeah, that's correct. But instead of being at depth, that cubic meter would be spread across the surface. Ah, okay.

So where did this come from? Or is it actually being produced on the surface of the moon? There's actually two ways that we think water got to the moon. So one way is solar wind is constantly bombarding the lunar surface with hydrogen. This hydrogen interacts with oxygen on the surface to form this hydroxyl compound that confuses water. Well, if high temperatures occur on the moon, like at lunar noontime temperatures, then this hydroxyl can combine

to form molecular water. But another way is that when a micrometeorite impacts the moon, it can create a high temperature environment, allowing pre-existing hydroxyl that was formed from the solar wind to combine and form molecular water. Or the micrometeorite could have even brought in the water itself. How does it manage to survive? I mean, one thing that I thought of was, well, what if a comet had hit the moon? But was that considered or is the water just too volatile? Because since we haven't seen a comet hit the moon, at least in the time we've been studying it. A comet could have impacted the moon and brought some water to the surface of the moon.

But like you said, we haven't seen one hit the moon in a very long time. This would have happened when the surface of the moon, the lunar crust was still forming. And so it would have implanted water into the lunar interior. And then while this lunar interior was still molten and magma, it could have erupted magma onto the surface of the moon, exposing some water to this, bringing some water up to the surface. But one thing that we think is happening is that the reason we're seeing the water on the surface of the moon under these harsh lunar environment conditions is because the water is actually being sheltered inside impact glasses that are formed during the micrometeorite impacts. Are you talking about what, little spheres of essentially glass?

The image that first came to me where you may have seen these little sealed aquaria or terrariums, they're actually little microbiomes with water and plants and brine shrimp or something like that, except at the microscopic level, I am not suggesting that there are brine shrimp alive on the moon. So what's actually really interesting is that these glass beads that we're hypothesizing are holding the water is actually this very rugged, not so sphere-like grain or glob of lunar regolith. Nasty stuff. Yeah. And of course, this is one of the big challenges that past visitors to the moon, human visitors have had, and that folks are trying to figure out how to deal with when humans return to the moon. So it's the same kind of razor sharp

regolith, and yet it may have water hiding inside it? Maybe. Yes, that's exactly it. It might have water hiding inside of these little glass shard beads that are formed all over the moon. I imagine they'd be gone pretty quickly if these things exposed the water to the sun and hard vacuum. But how long is it expected that they could survive in these tiny particles? So as long as the glass particles or glass beads are not disturbed or destroyed themselves, then the water could last for decades to thousands of years. The only way that we think that the water could be released from these glasses is if another impact hit these

glass and released the water out to the harsh lunar environment. Okay, that brings up another thought. We've already had an impact or two on the moon and some that we've watched carefully to see what gets thrown up. Is there enough water in this find that an impactor would be? You know what? I would guess that that's probably not the best avenue to follow. I'm thinking maybe you'd like to see a rover look for this stuff. Yes, definitely a rover. That would be the most comprehensive study to see what is there, how the water is being stored on the surface.

Because with the rover, you could take ground-based remote sensing of the surface. You could understand how much is there prior to collecting the sample. And then you could collect a sample and then you could look at the glass beads that are there and you could melt them and find out exactly how much water was there. And you could even do a drill core, which would go down to depths, so you could understand the distribution of water with depth. The missions that I know of that are planned for the next few coming years, I think are mostly focused on the poles,

where we know there's probably, almost certainly now, a great deal more water than you may have found elsewhere on the surface. Do you know of any, is there any talk about sending a mission that might be able to make these examinations? So there's quite a few ongoing things. One particular one that I think is going to be able to answer some of the questions that have been raised is the Viper rover, which is scheduled to go to the South Pole in the next coming years. They're looking to understand the water distribution around the poles, and they have a drill. And so I think that they're the most comprehensive or going to be the most comprehensive rover in the coming years. Is there a chance then that Viper, when it is out there in the sun, that there might be a decision,

or would you hope that there would be a decision to drill down there as well as in those permanently shattered areas? Oh, I definitely think that they will do multiple drill cores in the sun and also in shadow. I think that if they decided not to, they would be losing out on quite a bit of science. Slight change of subject here. I noted that your examinations focused on Clavius crater. I'll bet you know that Clavius is not just any crater, at least not in science fiction. Yes, definitely knew that. Yeah, Clavius base. It's all hiding there. I guess we just haven't been told about it, that subterranean base that most of us have seen in 2001

in Space Odyssey. Was there any particular reason you chose Clavius? So I actually hadn't seen 2001 Space Odyssey prior to choosing. So we actually chose the Clavius crater because it is one of the largest craters in the southern hemisphere that is very noticeable in guider images from the telescope. So because it was a test, we weren't sure that we were going to be able to find the moon. So we wanted a target on the moon that was going to be easily identifiable. And Clavius was one of those craters in the southern latitudes. And then we also chose the southern latitudes because, well, there's a lot of focus to go down there. And also because in Moon Mineralogy Mapper from the Chandran-1 spacecraft, they show higher water abundances in the southern hemisphere than in the northern hemisphere. So we wanted to make

sure that we got somewhere that might have the high potential of having molecular water present. China is about to launch, actually, as we speak, it will probably already have launched the first lunar sample return mission in a lot of years back since the Apollo era when it was accomplished by the old Soviet Union. Would you like to get your hands or are there people that you know on your team who would like to get your hands on some lunar ragged lift? Oh, I'm sure that there's a lot of people on my team that would love to get the lunar samples from the Chinese mission. I personally do not work on the lunar samples.

I'm more of a remote sensing person than a lab person. But if I got the opportunity, I would most definitely love to work with them and try and understand how the six micron emission band for molecular water changes with the three micron band that confuses hydroxyl and water. Something else that has occurred to me, there may be people out there who are thinking that not much difference between three and six microns, but actually you're talking about a 100% change in frequency, right? Since you're talking about wavelength there. Do I have that right? Yes, that's correct. It seems a very small change, but it's actually quite a big change.

Let's turn to more of your personal experiences with this. As you said, you're a remote sensing person. Were you on that test flight on SOFIA? I was. I actually was invited along with my advisor, Paul Lucy, to go onto SOFIA to help aid the observations and direct them where we were on the moon if we were able to find the moon. It's an impressive operation, isn't it? It is very impressive. Hardly the first time that you have done something a little bit exotic. I'm thinking of the work that I read about that you did in the Antarctic

with some of those balloons that we've talked about, specifically STO-2. Could you talk a little bit about that and why you needed to go basically to the South Pole? STO2 is the Stratospheric Terahertz Observatory, and it is a balloon-borne telescope. And so what I did is I helped build, test, and deploy the actual payload telescope that went onto the balloon. So what is interesting about STO2 is it's similar to SOFIA in that it looks at molecular clouds and the Milky Way galaxy, and it tries to understand the life cycle of star-forming regions. The reason that we put it on a balloon is because the terahertz region, where you might want to look for water or other hydrogen-bearing compounds,

you also need to get above as much of the atmosphere as possible. The balloon-borne telescopes actually put us above more atmosphere than the SOFIA telescope does. SOFIA flies above 99.9%, so how much more can you get above? But you can get quite high into the atmosphere with a balloon. And these balloons are huge. They're the size of a football stadium. Wow. This was a big telescope too. This was no small instrument. No, it was definitely a big telescope. I think the whole thing was probably, I want to say like 20 feet high. I'm estimating. Must have been fun to work on.

Yes, it was fun. It was definitely fun to go down to the McMurdo Basin, Antarctica. I spent about a month down in McMurdo for two summer seasons to launch STO2. Along with all the other links we'll provide on this week's show page at planetary.org slash radio, there's some good stuff, including video of this work with STO2. And the other interesting thing that I read about that makes it nice to do this at the South Pole is that a balloon can kind of fly in circles for days and days. Yeah. So the balloons that we use fly around the South Pole for onwards of 20 to 100 days. That's part of the reason that we go down to Antarctica is because the polar vortex takes the balloon in circles around the pole,

which if you were to do it above like the United States, that could be very hazardous if something went wrong and when the balloon came down. So Antarctica is a really good place. It's a safe place. And it also allows us to recover the balloon because it goes in the circular motion around the pole. So what are the results from STO2 and what's ahead in that line of research? I actually never worked on data for STO2. I was mainly an instrumentation person

where I tested and built the detector that the telescope was made of. But I do know what came out of STO2 was that they got additional funding to do another telescope, which is called Gusto. Well, they must have gotten some decent or at least promising results out of STO2. I did see one mention of Gusto, and I was wondering how to properly pronounce that. We already mentioned that you spent some time down in the Atacama as well. What were you doing there? In the Atacama, I was also working on a terahertz instrument. This one was the largest 64-pixel terahertz array that has ever been built. It also looks at the Milky Way and molecular clouds.

And this one, instead of being put onto a balloon, this one's put onto ground-based telescopes, ground-based radio telescopes. So the Atacama has the APEX telescope on Mount Tronjantor, and that is where I built and tested that instrument and deployed it to the Atacama Desert and installed it onto the APEX telescope, which is actually right next door to ALMA. And you told me that because it was a next door neighbor that you got to make a side trip over to ALMA. Where'd you go? Did they let you go up to the high side? So I didn't have a lot of time because I was still trying to, you know, install the instrument on the telescope and make everything run properly, or we were observing. And so I just kind of got to wander over there, look at the visitor center,

and wander up to one of the lower ways and look inside of it. All right. Well, you've still got something to go back there for then, I guess. It is a starkly beautiful area, isn't it? Yes, it is Mars-like to me. Oh, yes. Yeah. And it stood in for Mars on occasion. I'm wondering about this whole professional direction that you've taken. What do you think made you so interested in helping to build these instruments that are helping to reveal the cosmos? I've always been a hands-on person. I don't learn through reading books. I learned through doing. And so when I was an undergrad, I was accepted into a job position

where I was working on building and testing PCB board components. So I would solder the computer boards together and then I would test them and make sure that they worked. So I would solder the computer boards together and then I would test them and make sure that they worked. And this was at a physics lab at the University of Hawaii. And that kindixel array, and STO2, I was like, yes, this is what I want to do. I want to work on these instruments. I want to build them and test them because that's the way I learn. And so I learned about radio astronomy through building and testing them. Through that experience, I was actually accepted into graduate school at the University of Hawaii to build an instrument to look at volcanic gases from the Kilauea Hale Ma'uma'u lava lake. That kind of all steered me in instrumentation. And then my graduate advisor, Paul Lucey, at the University of Hawaii realized that I had this astronomy, radio astronomy observing background. And he's like, hey, I want to get back into astronomy and I want to get back into observing. Let's observe the moon.

So yeah, that was kind of my career path. That's so cool. If science and engineering are, you know, independent circles that overlap on a Venn diagram, are you in that intersecting area between the two of those? I am now. I used to be very much so on the engineering side, but now I'm getting more and more so into the research side. And that sets me up to be very unique because I can understand when engineers talk, but I can also understand when a client talks. That is such a valuable talent. Yes. Tell me about your current position there at Goddard. So at Goddard, I am a NASA postdoctoral program fellow, and I am working on a project that uses the SOFIA telescope, but also the Infrared Telescope Facility on Mauna Kea to look at

the moon at three and six microns to understand how these two bands vary with each other and to understand the cycle of water on the lunar surface and how it might migrate across the surface and be a source of water ice to the poles or if there's locations on the moon like volcanic deposits that may be concentrating the water. So cool. I'll just leave you with this. Do you have any advice for anybody else out there, might be an undergraduate, knowing that they like to work with their hands, maybe not even in college yet? I mean, what would you tell someone like that who maybe feels like you that they learn better by doing? I think what's important is that you need to find what you like to work on. If you like to

work with your hands, then it is important to find a school that has labs that you need to find what you like to work on. If you like to work with your hands, then it is important to find a school that has labs that you can apply to for a job to work in. You got to put yourself out there. If you don't put yourself out there, you're never going to, the answer is always going to be no. So I, you know, for me, I walked up to the professor that was the head of the radio astronomy lab. And I was like, Hey, I want a job. This is my experience. And he was like, great, let's put you to work. You know, you got to put yourself out there. You got to work hard. You have to know what you want to do, because if you don't know what you want to do, then that's going to be hard, right? So find your passion. I'm just fascinated. It's a wonderful story and great advice. Casey, thank you. I look forward to hearing more great results from instruments that you have contributed to.

I don't know that they'll all attract the attention that discovering really confirming the presence of water all over the moon, not just at the poles. That may not be quite as media present as that discovery, but I wouldn't be surprised if something else comes up like that again. Thanks so much for doing this again. And it's been great talking with you. Thank you so much for having me. Casey Honnable, lead author of the work that has confirmed the existence of water

in the moon's Clavius crater. We'll celebrate our 18th anniversary with Bruce right after this. Season's greetings. Bill Nye here. The holidays are racing toward us. We've got the perfect present for the space enthusiast in your life.

A gift membership to the Planetary Society will make her or him part of everything we do, like flying our own light sail spacecraft, two of them, advocating for space exploration, keeping our planet from getting hit by an asteroid, and this show. Sure, you'd like to give them a ticket to the moon or Mars, but I promise you this is the next best

thing. Memberships start at $50 a year or just $4 a month. We've got discounts for students, educators, and seniors. Visit us at planetary.org slash gift to learn about the benefits of membership and how easy it is to give someone special the passion, beauty, and joy of space. That's planetary.org slash gift. Thank you and happy holidays. Time for the 18th anniversary edition of What's Up on Planetary Radio. Here is my partner in this segment for all of those years, whatever, 900 something episodes, I think. It's Bruce Betts, the chief scientist of the Planetary Society. Happy anniversary. Happy anniversary, Matt. I am very excited about this and you should be very,

very proud. You've created an amazing thing for an amazing number of years. It, of course, doesn't feel like it should be 18 years, but it's been fun all the way along. It has been. Thank you. Thank you for being part of it all the way along. I certainly didn't do it alone. Now, to celebrate the 18th anniversary, I've got 10 questions for you to help the listeners get to know you. Matt has not heard these yet. So go through these and you can give me quick answers for most of them anyway. Where did you grow up? Los Angeles, California. I'm telling you, most of them are. Now you were a swimmer like in high school and such. What was

your favorite stroke? Well, once I mastered it, butterfly. I had a lot of trouble getting it down, but once I mastered it, that was my claim to fame at Narbonne High School and elsewhere. I mean, I wasn't great. You were probably a better swimmer. Oh, not necessarily. Bonus question. I'm throwing in what was the mascot of Narbonne High School? The gaucho. Oh, nice. All right. Now, a character you enjoyed playing as an actor? Oh, gosh. It's not like I was any good at this or did it very often. How about Mayor Shin in The Music Man?

Nice. All right. Where did you go to college? I went to USC, the University of Southern California, and I wasn't really happy there, I have to say, so I transferred to UC Irvine, where I was much, much happier and did college radio. Zot, zot, zot. Yeah, you got it. First job. Oh, first job.

Very first job. When I was 16, I was a courtesy clerk at a Safeway supermarket. Nice. First radio show. No, it wasn't. No, no, you weren't. All right. First radio show that you did.

These could have all been short answers, but the first radio show I ever worked on wasn't my show. I ran the mixer board for a guy who did a public affairs show at KUSC. First radio show I ever did? Okay, I take it back. It was on the intercom system at our high school, at our own high school, at lunchtime. We would play records and do silly stuff over the intercom system. Nice. All right.

This one requires a little more thought. Someone you met and were starstruck by. Well, Bruce Betts. There's that. That was the right answer. I'll leave it at that. All right. Most common noise or noises that interrupt your recording of this show?

Gosh, there are so many to choose from. Navy helicopters, because I live under that flight path in San Diego. Our dog, Dennis, Dennis the First. We didn't give him the name. Those are the two biggies right there. All right, favorite radio host besides yourself? Oh, gosh.

Of all time, there are two, Lohman and Barkley, who anybody who grew up in LA at the time that I was growing up in LA probably knows who I'm talking about. They owned the Morning Drive in Los Angeles for many years. They were wonderful men. I met them several times and even did a little bit of TV. They were just, they were just great. And Roger Barkley had a restaurant for many years near Pasadena. Named Barclays? Yes. I've been there. Oh, I've never been. Is it still there? Is it still open? Cause I knew he passed away. I don't know. I never leave my house. All right. Well, we're going to have lunch there. Someday. Okay. Bonus question. Favorite daughter. Okay, bonus question.

Favorite daughter? She's trying to trick you. Nice try. No, love them both. Absolutely equal. And most importantly, favorite person to end Planetary Radio episodes with? Is this a trick question? This isn't supposed to be hard.

Bruce Betts. Thank goodness. My ego needed that. Okay, now we can go on to normal stuff. Happy anniversary. Thank you. My ego needed that. Okay, now we can go on to normal stuff. Happy anniversary. Thank you. Thank you for those. Happy anniversary to you once again.

Let's talk about the night sky. We'll do a quick rundown. We got Jupiter looking really bright near Saturn looking yellowish in the evening in the southwest, and also in the evening sky. You've got Mars high overhead, looking still really bright and reddish, although it is dimming over time. And in the pre-dawn, east, Venus still there, still dominating. Preview, Geminids meteor shower peaks December 13th and 14th. We'll talk more about it next week. We move on to this week in space history.

2011, Curiosity launched for Mars. Still going. Still driving. On to random space fact for Matt Kaplan. Happy anniversary. Oh, that was wonderful. That was the best anniversary present yet. What a terrible anniversary you've had.

I haven't gotten any others. I really should have themed it on you or the show. I'm sorry. It's just a random. It's truly just a random space fact. Some binary stars, so star systems with two stars, orbit each other with periods of less than an hour. Wow. For example, AM Canum Benaticorum consists of a white dwarf and a semi-degenerate or white dwarf companion.

They are so close, they're orbiting about every 20 minutes. And one of the white dwarfs is gaining matter from an accretion disk from the other. First of all, that's just wonderful. What a terrific random space fact. Second, I, of course, immediately thought of the great line from the movie The Graduate. And I wonder if anybody's ever called that, said to that star, said to that star, you are a degenerate. Physics degeneracy is just really very different. Maybe that's what they meant in The Graduate. I doubt it. I doubt it. He did become a star, of course, Dustin Hoffman.

Yes, he did. Speaking of stars, actually not, we move on to the trivia contest and we'll get to stars, but we're going to start with the moon. I asked you who named most of the lunar maria with the names that are used today by the IAU. And how do we do, Matt? Well, here it comes. It's provided by the poet laureate of Planetary Radio, Dave Fertile. If you check the maria that dot the lunar face, most of them have labels that the IAU embrace.

Riccioli. Wait, nope, see, I got it wrong. I checked this with my Italian wife. Riccioli. No. Riccioli is the man who earned his everlasting fame since 1651. We've used his nomenclature name. That was a really good poem,

except it was kind of weird in the middle with all the pronunciation stuff. Yeah, you can't blame Dave for that. Oh, okay. Was he right? I mean, I have it. Here it is from Norman Kassoon in the UK, Giovanni Battista Riccioli. Yes, that is correct. You want to tell us any more about him?

I've got stuff here from some of our listeners. Why don't you tell us stuff from listeners listeners and I'll fill things in. Sure. 17th century Italian astronomer and Catholic priest, a Jesuit, known among other things for his experiments with pendulums and falling bodies, made arguments regarding the motion of the earth, widely known for discovering, well, here it is again, the first binary star. Marcel-Jean Kriegsman in the Netherlands added, he also did the first precise measurement of G, the force of gravity on Earth. I haven't told you who the winner is yet.

Jason Hensley in California. This is going to drive some people out there crazy. It's the first time Jason has entered. Oh, my gosh. And Giovanni Battista Riccioli. Riccioli. Emphasis on the first syllable, I am told. Jason, congratulations.

You have won a copy of Bill Nye's Great Big World of Science by Bill Nye and Gregory Moan from Abrams Publishing. And we will make sure that gets out in the mail soon. We'll even have the science guy sign it for you if you like. Mark Little in the UK says, when Riccioli's enthusiasm for astronomy

rose, he actually said this, rose within him, he could never extinguish it. So he became more committed to astronomy than theology. Here's one I love from Laura Dodd in California, who says, yes, he was a priest, and this was at the time, of course, that Galileo had gotten himself in hot water for talking about Copernicus. Riccioli couldn't officially endorse Copernican theory, but instead he put Copernicus's name on a crater along with Galileo and Kepler. Subtle fellows, says Laura. Finally, this from Devin O'Rourke in Colorado. Apparently, if you name hundreds of things at once, you can get away with naming something after yourself.

It's true. I bet you knew. Riccioli named a crater on the western or left edge of the moon after himself. Cool. Although, you know, to his credit, he didn't pick one of the brightest ones. Yeah, I guess not. He did give those to other people. Even gave one that's bigger to his partner in all of this. I guess the guy who drew the pictures that they made of the moon. That's it from this end. You got something new for us? I do. Here's your question. How many of the IAU-defined 88 modern constellations have dog in their name? And of course, it will be dog in Latin.

And just to be clear, we're talking domestic dog. Things like wolves and foxes don't count. Go to planetary.org slash radio contest. Wow, that's cool. You have until the first Wednesday in December, December 2nd at 8 a.m. Pacific time to get us the answer. Here's the prize. A brand new book published just two weeks ago, The Last American Hero, about John Glenn. It's by Alice George. It's from Chicago Review Press. I have read a good piece of it. I haven't finished it yet. Very well researched.

He really was a hero. Absolutely fascinating man. Deserved all of the attention that he got throughout his life, finishing as still today the oldest man or woman to go into space. That may change sometime soon, but there you go. It's the last American hero. You're still planning your space trip, aren't you? Yeah, but at the rate I'm going, I might take John Glenn's record. All right, everybody, go out there, look up the night sky, and think about how Matt Kaplan hasn't changed in 18 years. Thank you. Good night.

Oh, if only it were so. Of course, it's Bruce who still looks exactly the same. Full head of hair. I will assure people of that. He joins me every week, he and his hair. But what's up? Planetary Radio is produced by the Planetary Society in Pasadena, California, and is made possible by its members, some of whom have been supporting Planetary Radio right from the start. Help us celebrate by visiting planetary.org slash membership. Mark Hilverdis, our associate producer, Josh Doyle composed our theme, which is arranged and performed by Peter Schlosser. Ad Astra.