Planetary Radio • Mar 27, 2019

Dunes, Walnut Shells, Alien Impostors and Other Worlds: A Visit with Sarah Hörst

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Sarah Hörst

Planetary Scientist for Johns Hopkins University

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Bruce Betts

Chief Scientist / LightSail Program Manager for The Planetary Society

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Mat Kaplan

Senior Communications Adviser and former Host of Planetary Radio for The Planetary Society

A very special, extended conversation with Johns Hopkins University planetary scientist Sarah Hörst is capped by a tour of her fascinating lab. That’s where Sarah and her team simulate decidedly un-Earthlike atmospheres and more. Emily Lakdawalla has returned from this year’s Lunar and Planetary Science Conference with news from around the solar system. Caffeine! It’s on Saturn’s moon Titan AND in the espresso made on the International Space Station! More about the latter in What’s Up.

Sarah Hörst demonstrates the glove box in her lab.
Sarah Hörst demonstrates the glove box in her lab. Image: Mat Kaplan
Giant Moon map at the 2019 Lunar and Planetary Science Conference
Giant Moon map at the 2019 Lunar and Planetary Science Conference Image: Lunar and Planetary Institute
Planetary scientist Sarah Hörst in her Johns Hopkins University lab.
Planetary scientist Sarah Hörst in her Johns Hopkins University lab. Image: Mat Kaplan
Tholins created by Sarah Hörst
Tholins created by Sarah Hörst Sample of the organic compounds named “tholins” decades ago by Carl Sagan. These were created by Sarah Hörst in her JHU lab.Image: Mat Kaplan
Peering inside Sarah Hörst’s PHAZER chamber with its plasma glow.
Peering inside Sarah Hörst’s PHAZER chamber with its plasma glow. Image: Mat Kaplan
Samples of simulated regolith in Sarah Hörst’s lab.
Samples of simulated regolith in Sarah Hörst’s lab. Image: Mat Kaplan

This week's question:

On what types of bodies have we landed spacecraft that have transmitted (survived) after landing? Hint: Planets are one type.

To submit your answer:

Complete the contest entry form at or write to us at [email protected] no later than Wednesday, April 3rd at 8am Pacific Time. Be sure to include your name and mailing address.

Last week's question:

Who was the second youngest person to orbit the Earth?


The answer will be revealed next week.

Question from the March 13th space trivia contest question:

What is the name of the espresso maker on the International Space Station?


The espresso maker on the International Space Station is the ISSpresso.


NOTE: This automated transcript is currently being edited by a human. Check back soon for updates.

[00:00:00] The dunes of Titan and the air of other worlds this week on planetary radio.

Welcome. I'm at Kaplan of the planetary Society with more of the Human Adventure across our solar system and beyond. I've enjoyed every interview I've done for this show some of them run long. It always makes me uneasy when an episode approaches the hour mark because your time is valuable. But now and then there's a conversation that makes a longer visit seem just right.

That's the case this week with Johns Hopkins University planetary scientist, Sarah Horst. Let me know if you agree. How does caffeine in space come up while talking to both Sarah and to planetary Society Chief scientist Bruce vets stay with us and you'll find out first up a report from our senior editor Emily locked Walla who just got back from a big meeting in, Texas.

The lunar and planetary science [00:01:00] conference. It's one of your favorite stops every year, isn't it Emily? It absolutely is. I've been going for 20 years. Now almost every year. I see all my friends from grad school and ever since we catch up on our families and on great science. It's just a fun meeting.

We're going to put a link up to the conference looking back at the conference partly just because the photos are such great are so great. It looks like everybody was having such a good time. Everybody has a great time when they get together and especially. There's a lot of great science going on.

There were new results first results from the Insight Lander on Mars from these two missions to asteroids. There was a celebration of the 50th anniversary of the Apollo 11 Landing with a whole day long session looking back and also looking forward. It was just fantastic. We're not going to get to go into much of this at all in any detail.

But but how about those asteroid missions? Yes, there are two asteroid Missions at near-earth asteroids getting ready to grab. Samples, one of them has already grabbed a sample. [00:02:00] I'm talking about Osiris Rex which is the NASA Mission at asteroid bennu and also about Hayabusa 2, which is a Japanese Mission at ryugu.

They both showed up at asteroids that look remarkably similar their these top shape asteroids with very Boulder resurfaces. The top shape has to do with them being Rubble pile asteroids there the boulder resurfaces probably go all the way through. Found that both of the asteroids have very low densities about 1,200 kilograms per cubic meter.

If you're interested what that means is that they're made more than 50% of empty space. So there they really are just jumbles of Boulders collected together the weirdest thing the weirdest fact that I enjoy repeating about results that were discussed at lpsc is the one about ryugu ryugu is probably the darkest object ever explored in.

Any Mission its Albedo that's its [00:03:00] reflectance is about 1.7 percent to put it in context like asphalt blacktop has a reflectance of eight percent. So this thing is like 5 times darker than asphalt it is so incredibly dark that their instruments actually had the laser altimeter had a hard time getting Reflections from the surface initially, but they figured out how to how to make everything work and of.

To successfully grabbed a sample and they release some new videos of that process and they're just amazing. You told me that there was also interesting news from Curiosity on Mars as well. Of course, I follow curiosity very closely. And so this was the first meeting where there were results from Curiosities exploration of the place called Vera Rubin Ridge, which was identified from way before the landing from the time of the landing site selection as being an interesting place for curiosity to visit because from orbit there.

Very strong signature of the mineral hematite, which is related to [00:04:00] liquid water. One of the interesting things about curiosity is that it's been finding hematite all the way along as it approached the ridge. It's just that it seems that the ridge either has a coarser grained kind of hematite that's easier to detect from orbit or it's just so Windswept that there isn't dust covering it.

So it turns out that hematite Ridge doesn't really have any more hematite then the rest of the rocks that Curiosity explored just a little bit more a little bit more but one of. Thus interesting things they've been looking at on the ridge is that the sum of the upper rocks on the ridge there?

Either gray or they're red. They're it's like has this patchy appearance to it there now pretty certain that the gray and red patchiness is not something that happened when the Rocks were laid down but is caused by ground water percolating through the Rocks after they were laid down and the gray stuff has had the iron leached out of it and deposited in these beautiful hexagonal crystals.

Of coarse grained gray hematite in veins that are inside the [00:05:00] Rock and so they're they're seeing evidence for all this kind of ground water interactions with the rock after the rocks formed which of course was long after the Rocks were sedimentary when they were first laid down. So water was involved in these rocks formation and evolution at multiple times throughout its history fascinating stuff.

What was your panel about you moderated one, right? I did every year at plant at the lunar and planetary science conference. There is a woman in planetary science. Event and I was very honored to be invited to moderate a panel of three women who had been involved in lunar exploration since nearly the beginning.

There are two women who have worked in the Astra materials curation facility at Johnson Space Center. That's where they preserve and handle the moon rocks and the Genesis samples and the Stardust solar wind samples and even some samples from Hayabusa the previous Japanese sample return Mission. And so those were Judy Alton and Andre Emoji who work at.

Be and then there was Curly Peters who is a planetary spectroscopy stand one [00:06:00] of my former professors at Brown University and it was just a lovely conversation. Those three women have absolute have great stories. They're very different stories and mostly very fond memories of working in planetary science Andre Emoji was just a delight to talk to she absolutely loves her job and they love being able to preserve these great rocks from or brought back by the astronauts and.

Kind of science that Carly does in her work she talked about how scary it is to get Apollo samples because she works with these Dusty samples and she said you're afraid to breathe. You're afraid you might sneeze. You don't want to drop it thing and everybody laughed but they were they were an absolute delight and it was a it was a great opportunity to interview them very timely conversation with that 50th Anniversary coming up speaking of the Moon.

Did you get to walk on it? If we did so there's a project they did Mars first and then it's. Out of ASU and they printed a very very large print out [00:07:00] of a lunar map. I think they're using the same material that they use now to wrap Billboards. And so they emptied out one of the conference Halls one of the ballrooms and they spread it out on the floor and invited people to walk on it in their socks.

And so people were finding all kinds of favorite spots on the moon either Landing sites or favorite craters that they'd researched. I went and found the landing site of the China for Mission and people. Just having great fun. And yes, indeed. Some people did attempt to moonwalk on the moon. Ha ha ha.

I love it my favorite shot and and maybe we'll steal it from the site and post it at planetary dot org slash radio on on this week's show page are all these people pointing with their sock enclosed toes and they're all space Socks by the way. At the lunar North Pole it it really did look like fun.

I was I was pretty envious looking at all those pictures. You got to come next year Matt. I'd love to thanks Emily for giving us this this virtual visit to this year's lpsc. [00:08:00] My pleasure. That's only locked Wallace senior editor for the planetary Society editor-in-chief of the planetary report that March Equinox addition.

You can now read online at planetary dot-org our planetary evangelist. Hey, Emily before I let you go. I'm going to be talking to Sarah Horst in a moment. And and I know she's one of your favorite people. I can't wait to listen to this conversation. She's fabulous. It is terrific.

I recorded so much great material when I visited the Johns Hopkins University Applied Physics lab back in January. You've heard all of it now except for a conversation recorded not at APL but at the University itself, it's on that beautiful campus that planetary scientist. Sarah Horst does her [00:09:00] work.

I spent a delightful afternoon with Sarah touring her lab and talking about the many topics that capture her Fascination. She primarily studies atmospheric chemistry and complex Organics. But those are just the start. You're about to hear her cover such varied topics as. Her efforts to simulate the atmospheres of other worlds and the dunes of Titan and how Walnut shells are helping to reveal their secrets about the wonders of life and where to look for it about alien imposters and about the thrill of scientific discovery that drives her settle in and then stay for a quick tour of her lab, including the stainless steel chamber.

She calls phaser Sarah welcome to planetary radio and thank you for making me welcome in. Great office with all of your toys your entire space collection, which you met you seemed a bit embarrassed by but I think I think it's just science [00:10:00] Disneyland in miniature in here. So I this is great fun to say nothing of your lab, which we will go back to in a minute.

You already showed me around a little bit. Thank you so much for for having me and it's nice to have you in my in my. Office that looks like it might belong to a twelve year olds and not a professor at a university. It would be a 12 year old who's in love with science. I yeah. Yeah, that's absolutely true particularly planetary science.

I mentioned your lab which is literally across the hall from where we are. Now, what would you give to have? Lab of some kind maybe like that on the surface of Titan a lot. I would I would I would I would give I would give more than I think I will ever possibly have although it's funny that you mention that because in fact the place that I would really like to have that lab is actually the moon really yeah, we were you know, when we were in the lab we were talking about some of the issues that we have with Earth's atmosphere it would help us with a lot of our experiments if we didn't have verse atmosphere to [00:11:00] contend with so I'm always kind of.

Cooking it would be lovely. If someone would build me my lab on the moon. Yeah, well because then we wouldn't have to draw their ass atmosphere. Of course, it turns out that Earth's atmosphere. Is a little bit important for those of us who you know need to breathe it. So, you know, it's kind of six of one half a dozen of the other either we are fine in the experiments are challenging or the experiments would be easier and then we would have some challenges.

So well, I was going to say don't hold your breath for that laugh and move it would actually be quite useful. Yes, you might just you might make maybe so maybe so maybe someday with the at least not yet ability to do this. Tighten much less the moon or maybe I should have said the moon much less tighten your trying to simulate it here.

I mean we were just looking at that gorgeous little stainless steel chamber. Yes. Yeah. It's true. We can send spacecraft places and we build these big beautiful telescopes and those missions have so much to tell [00:12:00] us and we can build computer models and. You know run all different kinds of cases and all these other things but I think one of the really important pieces of planetary science that people don't always think about is the fact that we you know, we have laboratories on Earth and we can build small versions of an atmosphere or an ocean or a volcano or all of these amazing things that people do in planetary science and very very tightly control the conditions and change one variable at a time and see what happens or we can use.

Who's these places to test material Properties or to make analog materials that we think might be similar to the particles in Titan's atmosphere or the composition of europa's ocean and use those things to test? Instruments test capabilities of instruments to taste test materials to test sampling systems all of these things and so having this ability to build these little these little planets and moons in Lads here on Earth is [00:13:00] really, you know, one of the crucial pieces of the puzzle to being able to figure out how planets work and so it's exciting to be able to have my own little lab just across the hall from my office where we can do these things ourselves.

So as exciting as that stainless steel chamber is all of the. That feeds into it which you said was built here on campus at JHU which allows you to mix these gases which we are which you are doing to simulate. The atmospheres of other worlds. Yeah, it's really cool. So we're the chamber that you saw the experiment that you saw is about 4 years old that actually makes it one of the newest of these experiments in existence on Earth.

And so when we built it, we had the advantage of already knowing a lot of the major results from Cassini, we had the advantage of not only knowing that extrasolar planets exist, but already already having some [00:14:00] idea of. Their temperatures would be like and what their atmospheres might be like and all these other things and so when we built that experiment we built it with the idea of being able to simulate any atmosphere in the solar system and a large chunk of the atmospheres of planets around other stars.

That means that we can basically make any atmosphere you could think of right now today if you wanted because we have all the different gases in the lab right now, we can mix them in whatever ratios you want. We can run at temperature. From the surface of Titan or almost Pluto atmosphere temperatures all the way up to the temperatures at the surface of Venus if we wanted to or some of these warmer exoplanets and so we can study whatever atmosphere we want and we've really been taking advantage of that.

So the experiment that's running today. You saw Titan, which is, you know, kind of our standard. It's my first love it's the it's the one that has the most work has been done on in these types of experiments, but we've done Venus Triton Pluto. [00:15:00] We've done a ton. Of extrasolar Planet experiments at this point for the past couple of years.

And so we really can do this huge range of atmospheres, which has been really really fun and just all kinds of exciting science has been done so far and will do in the future when we pick through the little window in that chamber. There was this lovely Violet glow because that's yet another factor that you can control talked about that.

Yeah. The other thing that we control is we can control the energy that goes into the experiment and of all of the things. That we have to worry about in terms of simulating an atmosphere in the lab on Earth the energy sources the hardest I'm constantly joking, but if somebody could build a little star for me to put in my lab.

I would really like a miniature Sun. But if you know if we're going to go to the trouble of building a miniature Sun would I would actually like is one that has a little dial so that I can change the Stellar type for the exoplanets. They're working on that. You know, it turns out to be a little bit more challenging and [00:16:00] and now.

Well, you can do that with LEDs and it's like yeah, you actually could do a pretty decent job at this point of simulating the spectrum using LEDs, but we need a fairly high flux of photons coming out of these things, but you can't really get from an LED. And so that's really one of our biggest challenges is to say okay, you know, we have gotten this perfect mixture of all the different gases.

It's at the right temperature. It's at the right pressure. Now we have to put energy into it to simulate the chemistry, which is what we're really interested in and that turns out to be one of the biggest challenges. So the way that we get around that is we use two very different energy sources in the.

The one that you saw running today is a plasma which is energetic electrons and they run into the methane or the nitrogen or whatever. They break it into pieces. Those pieces are very reactive. They start building new molecules. The other option is an UltraViolet lamp. So just a lamp that provides UV light and it's hooked up to the chamber in the same way.

And so then instead of using the energetic electrons were using energetic photons to [00:17:00] break up the molecules and start the chemistry. We use those two very different energy sources. Is to kind of help us see okay, how sensitive is this experiment to the energy source, some of the experiments are very sensitive to the energy source.

And so that means that we have to think really really hard about how to apply those results to a real planet because we can't yet at least have a star in my lab. And so we have to be very very careful some of the results that we see don't care. Either way, we run the experiment we get basically the same answer and so we take that to mean that the energy source is not the most important characteristic of that particular experiment that maybe the gas mixture matters more or the temperature matters more something else is really.

What happens in the experiment? That's one of the ways that we try to get around it and I would say that's you know, that's kind of a typical way to approach some of our scientific challenges. If we can't do something perfectly instead we try to do a range of things and see how sensitive it is to [00:18:00] the thing that we can't do correctly.

So that's that's what we do to try to try to make a star in the lab. We never provided the cute name of that chain. So it's phaser which stands for planetary Hayes research. I tried to crowd Source the name on Twitter at least four or five times and got a whole bunch of hilarious and snarky acronyms that were not at all useful to me.

And when we finally settled on phaser then we had a very very long debate about whether it should be phaser with a z. For Hayes, yeah or phaser with an S for Star Trek. It turns out that one of the things that's really nice about having your own lab is that you're the decider and so despite the fact that there were a number of votes for the S4 Star Trek rather than the Z4 Hayes.

I got to [00:19:00] decide what's the right way. It's I don't honors track it honors truck. And also I feel like zis are really amazing extremely underutilized letter and so it's quite pleasing to have. Have it involved in the in the chamber, but it was kind of this like last minute. So we have been talking about it forever ever since we very first started working on the chamber and then all of a sudden we were getting ready to submit a paper and I was like, oh no we have to name the chamber now because we have to put it in the first paper that talks about it.

And so there was at that point a whole bunch of options on the Whiteboard and we were brainstorming acronyms and finally settled on one. I'm trying to resist making references to a Purple Haze, of course. Yeah, everyone everyone sees that purple plasma and starts making references to purple. Hey, so you wouldn't be that you wouldn't be the first one the fact that it's creating a haze.

That's pretty key to all of this, right? Why are haze's so important? Yeah, that's a great question. You know, I mentioned that, you know, the [00:20:00] experiment we put energy in it breaks up the molecules. They make new molecules depending on what gases we put into the chamber and the temperature and the energy and all of these things.

Sometimes that chemistry keeps going until it makes a solid so in the Titan experiments. It always keeps going to make a solid the solid particles. We think are at least somewhat similar to the solid particles that we see in Titan's atmosphere. So one of the reasons why we can't see down to tighten surface is because Titan has this very thick Global Haze layer.

So it's kind of like the worst day you could possibly imagine in Los Angeles and it's very similar actually the the smog in LA or in other major cities. From photochemistry. It's yeah chemistry driven by the sun different molecules involved and different consequences. But the same basic process.

The reason that we care about Hayes for Titan or for any other planetary atmospheres is there's multiple reasons why so one of the first reasons is that particles interact with light differently than [00:21:00] gases do having particles in an atmosphere whether they're Haze or a cloud or done. Affects the way that light moves through the atmosphere.

So it affects the temperature structure of the atmosphere it can what photons get to the surface. And so, you know, if you think about the early Earth that would have an impact on what photons were available for plants and what photons especially the real energetic ones might be getting removed before they could do damage to DNA and RNA and things like that.

And so the kind of first reason we care is it really. We're in which photons end up in an atmosphere and on the surface and you could even Envision cases in which having a haze layer or not might determine whether or not there is the possibility of liquid water on a surface with our example. So that's one reason why we care another reason why we care especially in the case of Titan is that these molecules in the haze and Titan are very complex and they're organic.

So they have carbon in [00:22:00] them the molecules and Titan's atmosphere. We know also have nitrogen they have. Jen those atoms are part of a very small set of atoms that form the building blocks for all of life on Earth the building blocks of DNA and RNA which are called nucleobases the building blocks of proteins, which are called amino acids.

All of life on Earth is built on a very very very small set of molecules and that small set of molecules is has built on a very small set of atoms. So I'm less surprised that you get amino acids, but nucleobases nucleotides the the real blood. Building blocks of RNA and DNA. Yeah, so we have found in these experiments that we run that we make amino acids.

We make all the nucleobases that life on Earth is based on so adenine cytosine the atcg that we all learned. Yeah. Yeah. The question that we have at this point though is how much farther does that chemistry actually proceed and so we can run these experiments in the lab and we can [00:23:00] analyze the material that we make and look for things like amino acids nucleobases, but.

Really want to know not just are those molecules present in Titan's atmosphere, which I think they are whether they're present in Trace Amounts or whether they're present in larger amounts. We don't know yet, but I would at this point bet a lot of money on the fact that those molecules are present in Titan's atmosphere their present on the surface.

But how far did that chemistry proceed? And and that's one of the been one of the big driving questions of my career so far and I think going forward is how far can organic chemistry proceed in the absence of life and how far can a person the absence of life in an atmosphere? There's two reasons why we care about that question.

One reason is that this material that we share in common for all of life on Earth? It has to have been around at the beginning for some reason there's some reason why that became the fundamental set of molecules that all of life on Earth is based on but we don't know where [00:24:00] it came from. We find these molecules in meteorites and comets you can make them in hydrothermal vents in the lab people do hydrothermal vent experiments and you see them made there.

And so we see that they get made. Everywhere, but we don't know what the source was, but there must have been a source. That's one reason why we want to know how far the chemistry proceeds. We also need to know. Where did it stop? Without life at what point did life have to have existed to make the processes keep going?

Yeah, and that's going to help us understand a lot of questions about the origin of Life the other reason why we care about answering that question. We're thinking about Europa Lander. We're thinking about using James Webb to look for life on planets outside of our solar system. We're talking about dragonfly to go to Titan to see if Titan is or was or could be habitable or inhabited dragonfly.

Is that that little draw. Quadcopter that proposed yeah right has been fun to go propose to go to [00:25:00] Titan. But to do all of those things all of the ways that we're talking about doing life detection. We're not assuming we're going to get lucky and have some elephant go tramping in front of a camera or do whatever.

I mean that would be much easier. We're assuming that we're going to have to look for chemical signatures, right? We get a sample of the surface at Europa and we put it through, you know, really sophisticated. Instruments or dragonfly or you know looking at the Spectra of these exoplanet atmospheres.

Our idea is that we're going to be looking at molecules to look for life. And so to do that. We really have to have an understanding of what molecules can only exist if there's life. And what molecules exist on their own in nature on the surface of Europa or in the atmosphere of one of the Trappist one planet, we have to start to really get a robust understanding of where the line is between molecules that get made by processes that occur on whatever Planet you want to [00:26:00] talk about and molecules that only exist if there's life on that planet and so that's one of the things that we're interested in studying and trying to understand we know there's complex Organics on tight.

But what does that actually tell us about the possibility of Life on Titan? That's one of the things that's really beautiful about doing these lab experiments because we can take this material that we make and run it through any instrument you want on Earth and we've run it through a lot of them to try to figure out what's in there and that also helps us figure out what instruments we need to send two.

Mmm-hmm to say okay. Well, if we run it through this instrument, we don't learn very much. But if we run it through this instrument that tells us a whole lot about the chemical composition and this was the it wasn't a mistake because we just didn't know any better and it was they were wonderful spacecraft, but this is what happened with Viking on Mars, right?

We didn't know enough about Mars and so we got back these ambiguous at best results. From the life [00:27:00] detection. Well, absolutely. So people tend to talk about the life detection experiments on Viking as if they were a failure, you know, a lot of people don't realize that Viking was really the first and last time we ever sent a life detection experiment anywhere.

Hopefully that'll be remedy that will be remedied soon the lesson that we took from Viking or at least some fraction the community took from Viking I think is maybe not the right lesson Kevin hand. He's at JPL who's done a lot of really amazing work on Europa a great God about right? He always says the Viking Life detection experiments would have been a failure if we had found life on Mars.

All right, if the next time we went tomorrow's there were bacteria everywhere and all of these things if we had all of this evidence of Life on Mars now, then we would look back at Viking and say whoops like we did it wrong, but the fact of the matter is we haven't found evidence of Life on Mars yet.

And so the thing that happened with Viking is that we didn't know. The composition of the surface hmm which makes [00:28:00] sense because we hadn't spent 30 or 40 years exploring Mars at that point. And so we didn't know that there were these molecules called perchlorates which were discovered by Phoenix have been confirmed by curiosity and some other Mars missions when you put perchlorates and organic.

Into an instrument and heat them to very high temperatures, which is what Viking did you destroy all of the organic molecules in your sample? So we learned a lesson Curiosity has a different way of analyzing the Organics that doesn't require heating them to such high temperatures because we know about the perchlorates.

It's one of the things that's really frustrating about Planetary Exploration. Is that every time we go somewhere we learn something new and one of the things that we learn from going somewhere is. We probably should have sent a slightly different spacecraft. And so we learn and we try to you know, build on our discoveries and send different spacecraft.

But sometimes that means the pace of exploration can be frustratingly slow, especially [00:29:00] when you're talking about studying the outer solar system where you're not necessarily getting to launch a spacecraft every couple years to go explore and so it took us a long time to be able to actually use the the discoveries from Voyager.

To actually learn more about the Saturn system with Cassini and it will again take a long time to be able to leverage the things that we learned from Cassini to explore the Saturn system further, but every time we go somewhere we learn something new. Yeah, and the thing that's actually really neat about that is that then we can go back and actually look at the old data again.

And so there's been a ton of Rhea. Reanalysis of the Voyager data now with our understanding my condition no Voyager. Oh with our understanding from Cassini. No kid. There's been a ton of real analysis of the Viking data with the understanding that's come from further Mars exploration. And so those data are so so precious.

We try and we're trying to do better now than we have in the past it. Really good care, you might think how could the Viking data be useful useful to us. Now that we've had all of these [00:30:00] much more technologically advanced spacecraft at Mars and we've been to more so many more times now, how could those data be important?

But every single data every single piece of data that we take in Planetary Exploration is so precious. It's a moment in place in time that will never exist again. An instrument that we may never fly again. Mmm every single time we get more information it provides this opportunity to go back and look at the data that we had before with a different understanding and see if there's more things in there that we didn't know at the time and it's you know, it's been done with all the Mars data.

There's been some really beautiful results looking at the Voyager data being reanalyzed with both with our Cassini understanding new technical tools new lab experiments that have been performed. Bowl of members of my group with some people at Nasa Goddard were reanalyzing the data taken by the gas chromatograph Mass spectrometer on the Huygens probe.

So this data were taken in 2005, but we have new computer [00:31:00] tools new understanding of Titan's atmosphere from Cassini. And so we asked NASA. What do you think? Can we take another shot at this beautiful dataset? Because we still think there's more information in there that we couldn't get at the time because we just didn't have all of the pieces that we needed and NASA said sure and so now we're working on, you know re analyzing those data to important lesson in all of that.

I want to go back to the earlier theme one of those two things you say that we should have learned because it resulted in this paper, which we'd already arranged to to talk during this trip that I've made to Baltimore and APL but since then you had this announcement. From one of your Associates in your lab.

It had this great title alien imposters, which is kind of a warning. I mean, it's like you said we'd better know what we're looking for if we're going to take these things as evidence for life. Yeah. So exoplanets are so [00:32:00] so hard there's lots of different flavors of planetary. I am the planetary scientist flavor of planetary scientist, which is actually quite rare.

So all of my training is in planetary science. My undergraduate degree is in planetary science. My PhD is in planetary science. I tell people I was planetary scientist born and raised what that means is I really love the solar system. I love. The planets and moons in the solar system. I love the way that we can turn these points of light in Two Worlds.

That is why I got into studying planets exoplanets are interesting to me. We're just starting to turn these points of light in Two Worlds and it's going to be a really really long time before we can do it the way we've done it in the solar system. For me, I'm still kind of more interested in what we can learn about the solar system by studying exoplanets.

But one of the things that people are really thinking about and talking about now, especially with the hopefully impending launch of James Webb, [00:33:00] if you only have a spectrum of a planetary atmosphere if you only know how light interacts with gases in a planetary atmosphere. How do you know if there's life there or not?

Because you find twenty percent oxygen in the atmosphere right? So maybe maybe you find oxygen. Maybe you find methane maybe but again this goes back to what we were talking about earlier you mentioned. What molecule do you see and sake got it. That's it. Yeah or what set of molecules. Do you see one of the lessons that I think the planetary science Community has learned from the solar system that I'm trying to remind the exoplanet community of whenever I have the opportunity is that.

Sometimes we look at an atmosphere Titan's atmosphere is a great example Titan's atmosphere the example. I always use sometimes we look at it atmosphere as we did from. Ground-based telescopes and from Voyager. We look at the molecules in the atmosphere and we say. huh and you build this super sophisticated computer model of all of the chemistry in the atmosphere trying to explain why this molecules there and why [00:34:00] that molecule is there and you think about it really hard and you have all these observations all these measurements are you looking at?

Huff and so the example for Titan is a very very simple molecule carbon monoxide Co discovered during the voyage or era. Nobody could explain it. Hmm. So you make this model of Titan's atmosphere with all of the things that we know about tighten all of the measurements that we have of the composition and the temperature and.

Snow the spectrum of the Sun and all of these things you make these beautiful chemical models and they can explain perfectly the abundance of acetylene and perfectly the abundance of ethane and all of these other molecules in Titan's atmosphere and no one could reproduce the abundance of carbon monoxide and people tried lots of different groups tried.

They tried from shortly after it was discovered in the early 1980s all the way through, you know, launch of Cassini arrival of Cassini. Nothing. Nobody could explain it. Maybe there was a comment that crashed into Titan relatively recently in solar system history that [00:35:00] dumped a bunch of CEO in but that didn't really make any sense with some of the other molecules.

Nobody knows it. There's this temptation at some point to say CEO of is that a biomarker is there life on Titan? Um, you know, and you don't you don't see that? Temptation necessarily published a lot in planetary science, but you know that the conversation happened about is the only possible way to explain this life.

It's not life. I mean there might be life on Titan. Don't get me wrong, but the carbon monoxide is not signature of Life carbon monoxide is the signature. Of Enceladus. So the thing that we didn't know from Voyager, the piece of information that was missing when people were putting together all of those models of the atmosphere at chemistry of tighten.

The thing that was missing was Enceladus which sounds ridiculous but in solidus is shooting a bunch of water out into the Saturn system some of that water ends up in Titan's atmosphere and through photochemistry processes produces carbon monoxide fascinating. So this was the first paper I wrote as a graduate student.

[00:36:00] That's the one that's hanging on the wall above the door. Yeah, bright. We took this model of Titans chemistry, which had been, you know used for years. And we said what happens if you put the water from Enceladus and to the top of the model and when you do that you get. Titan's atmosphere carbon monoxide included wasn't life.

The reason why I tell that story in the reason that this is relevant to the question that you tried to ask that I've been avoiding answer that far because that's my style is that we are not going to know if any of these exoplanets have it in solidus not for a long long long long time just too small to detect too small to detect and you know in solidus is just kind of an example of of the problem, which is that.

For exoplanet atmospheres. We are not going to know our boundary conditions. We're not going to know if there's anything coming in from the top of the atmosphere whether it's Enceladus or comments or dust coming in from, you know, the remnants of a asteroid belt or a moon that's been [00:37:00] disrupted or ring.

We are going to have a real real hard time knowing what the boundary condition is at the bottom of the atmosphere. Is there an ocean is it volcanically active? Is it ice? Is it carbonates? Like what is the surface boundary condition? We will be able to measure the composition of the atmosphere pretty well, but when we are going to take our models.

To try to figure out if we understand the chemistry, which is what we're going to have to do to try to figure out if there might be life. They're not we don't have the bunt boundary condition of the top or the bottom of the atmosphere. Which is really important this kind of got us thinking about this problem.

You know, you have this beautiful Spectrum from James Webb, and it tells you I'm going to make something up that might be physically impossible. But okay tells you that there's 10 percent methane and 15 percent oxygen and 20 percent nitrogen. Whatever right? It's not going to tell you that there are amino acids because it's not going to be able to detect them even if they're.

It's not going to tell you anything about complex molecules. It's too hard to [00:38:00] measure those from remote sensing. It's going to tell you are kind of bread and butter molecules of an atmosphere. It's going to tell us the ratios and then we're going to have to figure out. If those ratios are possible on their own without life without life or whether the only explanation.

Or the most plausible to the point that you would be willing to have the president of the United States stand in front of the world and say we have found life on another planet is that the only explanation and so one of the things that we started doing is running a bunch of experiments. So people have done a lot of this work with chemistry models and I say this is a person who does chemistry.

Those models are only as good as the information that you put into them for places where we have a lot of information like Titan or Mars. We can do a pretty good job of reproducing the chemistry, but there's a bunch of choices. You have to make when you run those models and so if you don't have information about the place.

It's not clear what the result [00:39:00] is garbage in garbage out. Yeah, I mean, I wouldn't go I don't want to go that far because I don't know salt insult my colleagues, but but you know, the information that you get out is is only going to be as good as the information that you put in and so the there are limitations on what you get out if there are limitations.

What you put in you were more diplomatic. I try occasionally, but I definitely have used that phrase in reference to the atmospheric chemistry models, including our own at various points in time. And so we thought one thing that we could do instead of running the models and there's a bunch of really great people who are doing a lot of really amazing work on an exoplanet atmospheres with these models.

We said, let's run some experiments instead. So instead of saying okay. Well do we have all the reaction rates in there and are the cross-sections correct? And like what happens if you change the temperature like we're going to put a bunch of gases in there and put energy into them and see what happens.

And so we ran this whole set of different composition different temperature exoplanet potential exoplanet atmospheres right now. We don't have [00:40:00] measurements of any exoplanet atmosphere. That's good enough to do what we do here from a real atmosphere. So we can do tighten we can do Pluto we can do Mars Venus Saturn Jupiter, whatever you want, but we can't do a specific exoplanet right now because there isn't enough information.

There will be with web. We hope yeah, but right now we don't have it. And so we did this big range and one of the things that we found is that we make molecular oxygen. In the presence of methane or in the presence of other organic molecules, the combination of those two things is often mentioned as a bio signature because those sets of molecules are out of equilibrium.

Mhm. So if you left them alone in the chamber long enough they would cease to exist. They would either convert all the way one way or all the way the other way because they're out of equilibrium the thing about atmospheres. It's really frustrating. Is there perfectly content to be in disequilibrium for a lot [00:41:00] of reasons Titan's atmosphere isn't disequilibrium because of the Sun and because of him selling this Earth's atmosphere is in disequilibrium because of life.

We have to figure out how to tell the difference between those two things and it's going to be really hard. And so that was one of the things that our experiments showed was like look, I'm 99.9% Sure there is no life that we have created in this chamber if we have I'm very much looking forward to picking up our Nobel Prize.

Yes. Yes, that's relations. But I am I don't think that's what hat was happened. And so what that means is we need to think more carefully about what combinations of molecules were thinking about. Biosignatures because some of the ones that people talk about a lot we can make right there across the hallway together and it's not the sign of anything other than some really interesting chemistry.

So this is sobering stuff should be such a downer yellow dot has to be a little bit of a downer to some astrobiologist out there and people who thought it was going to be easy to find Signs of Life. Before [00:42:00] we move on from this though. It's one of your Associates right an associate of yours in your lab.

It's a research scientist. Yeah, let this work. What do you think of work that is underway elsewhere. I mean I had mentioned to you that not long ago we had. I talked to a couple of members of a team at McMaster University up in Canada. Yeah, and they are doing some of the stuff that you're doing but going a little bit further in one way at least where they're putting little samples of stuff in a little little on slides basically in there and watching to see what happens if they get membranes if they get the same kinds of complex molecules that that you're seeing.

Yeah, there's a number of different groups in the world that do, you know work like this or related work one of the things that's interesting is that all of these experiments have different things that are good and bad about them. And so I think it's one of the things that's so exciting about having lots of different groups working on kind of similar problem sure, you know, there's things that our experiment is [00:43:00] probably and it's going to come maybe come across a little bit as a little cocky or conceited but there, you know, there are things that we do with our.

That is you know better than what anybody else could do but there are things that we do that's not great. There are conditions that we can't simulate there are questions that we can't really shed any insight on and so we don't try and so then there's you know groups other places in the world where certain questions or maybe not really in their wheelhouse but there are things that we can't touch that they you know where the world's experts at.

And so we have lots of different groups. All over the world trying to tackle the same big picture questions, but from lots of different points of view and I think that's really important because at the end of the day, the only way that we're actually going to answer any of these questions is going to be a combination of not just different people, you know working on on lab experiments, but the, you know, the combination of these beautiful observations and the computer models and the lab [00:44:00] experiments and lots of different people thinking.

Way too hard about all of these things until we understand more about how planets work many paths that perhaps must be taken toward the truth. Yes. That's that's absolutely true lots and lots of dead ends, but you learn something every time you go down. The wrong path and that's one of the reasons why we just, you know, get up again the next morning and and go down this one instead.

What's down this one? Nope wrong? Okay, turn around come back science. Yeah. I don't want to leave your first. Okay, because there are other things we talked about this a little bit when we were in the lab that fascinates you about this world, which of course we and so many others often talk about is being so similar to our own other than the fact that it's frigid and but I mean with all the systems that we share [00:45:00] hydrological systems.

Yeah, we were talking about Dunes which is something that your lab is also worked on quite a. Because we we know we've seen them down there on the surface. Yeah, frustratingly. They seem to exist despite all of our best efforts to make them disappear. As I was mentioning to you earlier. Titan is amazing.

Titan has all of these Earth-like processes and one of the things that's so beautiful about Titan, you know at the end of the day it may turn out there is not life on Titan there has never been life on Titan there never will be life on Titan there. Can't be life on Titan that maybe the thing we eventually come to learn about it.

A little bummed out. But yeah seems pretty plausible. Even if that turns out to be the case Titan has so much to teach us about Earth and about conditions for habitability about how planets work because it has all of these processes that you just mentioned. It has a hydrological cycle. It rains there are rivers there must be [00:46:00] water falls and rainbows and all of these things that we think about is almost being uniquely characteristic of.

But the materials are different the liquids are different the solids are different. And so that gives us the best chance we have I think. I think that's really a true statement to test our understanding of how all these processes work because we have all these equations that govern how dunes form.

We have all these equations that tell you you know, how is a river Channel going to form and why does it Branch this way and how much fluid can it move? We have studied those processes on Earth for so long. We think we understand the physics and the best way to test that. Is to take those equations that supposedly are fundamental to these processes.

And say great how do they work on Titan and I can tell you right now the answer is they don't or at least they don't always and so one of the things that's really exciting about that is that tells us [00:47:00] somewhere in the equations and and you know, the people who study these things can point probably to where the issues are.

There are things numbers. Maybe some constants things that we have derived from studying these processes for very long on Earth that have within them something that is only on Earth and not on Titan something to do with the material properties something to do with gravity something to do with the atmospheric pressure something that's different and we don't know that it's there.

Because the equations work on Earth. We never had to figure out what was in that constant. You just use it and you get for an answer by using these same processes on tightened Dune formations. The rainstorms the clouds all of these things. They're going to help us really dive into all of these equations and figure out what things are trapped inside of them that we don't know about.

And then we can pull them out and we can say okay. Well, if you know that, you know, you're using these equations on Mars and on [00:48:00] Mars at silicates and it's this and it's that and whatever the equations will work perfectly because knowing you want to take them to Venus, here's how they work on Venus.

Here's how they work on. Here's how they work on Pluto. That's what we're trying to do the end of the day like. It might seem like we're you know obsessed with these details of exactly how this one Lake formed on mars or how this one process is working on Titan, but we're trying to figure out how planets work period so that the more you know, when we're starting to look at these exoplanets, we're not starting from scratch every time trying to figure out how the planet works the longer we do.

The easier it's going to get because we already know the equations we can already predict what will happen. We've been particularly trying to understand the dunes on Titan. I mentioned this to you earlier because features that are formed by wind on the surface of a planet and I am sure someone who is listening to this is going Sarah Titans not a planet.

It's a moon. Sorry Titan does Planet things I'm gonna call it a planet. My apologies. We really want to understand things like [00:49:00] wins. They're important for understanding how the atmosphere moves that tells us a lot about climate. Where is it going to rain and how much and how do things get, you know moved around on the surface and wind speeds are very hard to measure I know that sounds weird to people who live on Earth because you can just go outside and measure the wind speed.

It's not that hard but to do it on another planet. Okay, so you send a spacecraft that has a wind sensor. Curiosity has been censored. Yeah one place one place on Mars. You have the wind speeds. Congratulations you did it you have the wind speeds one place on Mars and only as long as curiosity is operating when you have a planet that has an atmosphere that has a lot of clouds.

You can track how fast they move. So that's how we measure the wind speeds on Jupiter and Saturn Uranus Neptune. We're looking at how fast the clouds move that helps you because especially Jupiter for example as clouds everywhere. And so you can get really good idea of the wind speeds from from looking at the clouds.

Titan doesn't have [00:50:00] that so much Titan does have storms it has. They tend to be seasonal and so they move location with season and they don't happen super often. And so to measure the wind speeds on Titan using clouds as hard and so we were really excited about having all these features that were clearly created by wind on the surface because that is a record of what the atmosphere has been doing in a way that we can't get from anything else and Severance.

I God's great. We're going to figure out you know how fast the wind speeds are in which direction and all of these things that's recorded in the dunes. And then everyone was like wait a minute. We think the winds blow the other way the opposite of what forms the same that is what informs the dunes.

I mean, like literally the opposite and then you start thinking like do we have a sign error? Like what is happening right now? It was immediately obvious. Something had gone horribly wrong and it wasn't clear what the something was. And so however many people know this but there's a facility at NASA Ames called the planetary [00:51:00] aeolian laboratory.

There's a number of wind tunnels there where they. Sediment transport sand transport June formation on other planets. So there's a Mars wind tunnel, which is called Mars with the Titan wind tunnel used to actually be a Venus wind tunnel and got repurposed when we got interested in tightened information.

And so we simulate the wind transport of. In this wind tunnel at NASA Ames and so people started working on these experiments at NASA Ames because the dunes on Titan and make any sense. They were clearly there. They didn't care that they didn't make any sense to us, but we were kind of mad about the whole thing.

And so people started doing these experiments to try to understand how fast does the wind have to blow? To move sediment on Titan and then what does that tell us about these constraints that we've been getting from these models what we see on the surface, whatever else and different sediments to as you demonstrated to me because you have that neat little display case.

Yeah, it has the little vials of all these [00:52:00] different potential sediments. Right? So the so the thing with these wind tunnels is that to simulate the movement of sediment on Mars are on Titan. We address the pressure inside of the chamber and the speed of the air moving inside of the chamber and there's a way in which you can do that so that you can mimic the conditions on the surface of Titan or on the surface of Mars that are important in terms of the physics removing the sand.

The one thing that you cannot change in those wind tunnels that governs the physics of moving sand is gravity unless someone has figured out how to adjust the gravity of Earth we run into problems. And so the way that that people account for this in the wind tunnels is by using different types of sand.

So instead of using the kinds of sand that we see on Earth silicates Sans, you know, we have these beautiful black Sands basalts all these different stance that we use on Earth. They use things that have a lower density because we don't actually care about the mass of the particle [00:53:00] in terms of transporting it we care about its weight.

Hmm and so by changing the density without changing gravity we can change the weight of the. So the thing that people have been using for now very very very many years in the Mars wind tunnel. And now in the Titan wind tunnel that has lower density can come in a large variety of sizes, which we care about also has to be not toxic and relatively cheap to purchase in bulk because once you use an experiment once you run an experiment, you lose your.

Sand are Walnut shells of course a here comes the punchline. Oh, well Michelle, it's so funny to me because the first couple of papers that really came out of my lab. When I started Hawkins were about Walnut shells of all things. I have to tell you never in a million years did I think that my research group was going to be writing a whole bunch of papers about Walnut shells, but here we are so they have lower density.

And so we use Walnut shells to simulate sediment transport on Mars sediment transport on Titan. [00:54:00] This is and you know, we talked about this a little bit before but this was where we came in and I said, hold on a minute. You got the pressure, right and you have the wind speed right to do that part of the physics of sediment transport on Titan or Mars or whatever you have adjusted the particle density so that your gravity is right.

So we're you know, everyone's sitting around here congratulating themselves about having done the physics correctly, but you're using Walnut shells. And the dunes on Mars are not made out of Walnut shells not that we know of that we know of I'm 99% sure that Dunes on Titan or not made out of Walnut shells that we know of.

How does that matter? How did the interactions between the Walnut shells that are determined by the by their composition matter and and does it matter because it might not and if it doesn't matter then great we can use Walnut shells for the rest of forever to simulate these processes and it won't matter but this was something that people had not done a lot of work on and so my senior grad student shouldn't in got very very interested in Material [00:55:00] Science and started looking at a lot of the properties.

And so what she's been doing for the last. Four and a half years now has been taking all these materials that we use in the in the wind tunnels here on Earth the Walnut shells some of the other things I showed you were different types of sand which are also used because we understand. Vaguely house and transport works on Earth.

I shouldn't point out to you some of the other ridiculous things that we have in there one of the materials that we were interested in looking at our class bubbles. They're very very low density because they're Hollow. Yeah, but then the material properties are better known and they're also more similar to courts and and glass are.

The same thing that's what we make glass out of at least the composition would be the same and so we have all of those different things. So chanting has been looking at density and she's been looking at things like fracture toughness and elastic modulus and all of these different [00:56:00] mechanical properties.

She's also been looking at interparticle forces. So if you were to take to Walnut shells and she's done this which I. Still it just wasn't what I thought. I was going to be doing with this period of my scientific career, but if you take two Walnut shells and you move them very very close together.

Is there any kind of electrostatic? Is there a force that pulls them together if you get them together, is there a forces that are cohesion force and adhesion force that keeps them together because this matters because you have this wind that's blowing along the surface of these particles and one of the forces that it has to overcome.

Is the force between the particles themselves? Yeah, and so something has been using these these, you know, nanotechniques to take one tiny walnut shell attached to this thing and one other tiny walnut shell in look and measure these very specific things. So she's used all the Titan WindTunnel materials, but then she's also been looking at a bunch of different Organics a big range of them and then also, The material that we make in our Titan [00:57:00] experiment.

So the experiment that's running right now is for shin tang. And so we take this analog material that we make and she's been looking at fracture toughness and electrostatic forces. And these are the foal ins the way you also had a little vial of the we looked at in there and we'll put a pictures of some of this stuff.

Yeah on the show page of planetary dot org slash radio. Yeah, so she's been looking at all of those things, too. One of the big things that she has found and I forgot to mention this when I started fell down this, you know, Titan Dune hole that we've been talking about but the dunes we think are made out of Organics.

We don't know how the particles get made. The Dune particles must be bigger than the haze particles that fall out of the atmosphere. We know that and so if the dunes are made out of haze there must be a way to build those particles bigger. Mmm alternatively. We could have some organic kind of Bedrock on Titan from all of this material having rained out of the atmosphere for so many years that then gets broken down.

Yeah into [00:58:00] smaller particles, so. The particle size we don't think exists naturally and so it's either getting made by building things up. From the particles that come from the atmosphere or breaking them down from the tear on the surface. But in either case that material is organic because it's made by organic chemistry that happens in the atmosphere.

This has been a question that we've now had for a long time. So the dunes have been striving us in a number of ways. Why are they the wrong direction? We're in the world of these particles come from those questions might seem a little silly but they really matter because they're telling us something really fundamental about the atmosphere and about the way the atmosphere interacts with the surface.

Something bigger picture about Titan is hiding in these question chanting started looking at this and one of the things that she has found. I think it's probably one of the biggest results from the work that she's done these materials that we think make up the Titan Dunes are not very strong. They don't want to be transported very far on Earth that you know, the extent of a [00:59:00] dune field how far the material can get transported really depends on what it's made out of because every time the the sand particle hops, it experiences a little force.

It gets a little bit rounder. It loses a little bit of its material and that's defined by how strong it is. And so the weaker it is the less it can travel right? You could Envision just having a suitcase right? If you have this like big strong suitcase that can handle every airport you take it through on a number of trips.

But if you have this suitcase, that isn't very strong one time through baggage claim and it's done. Yeah doesn't get to go on any more trips. It's never gonna end up in Paris. It only gets, you know through LaGuardia once or something and then you're done. That's one of the big things that that shouldn't thing has found.

Is that probably. The sand whatever process it is that's making it must happen where we see the dunes because it's very hard to transport it long distances. And the thing that's really interesting about that is we see the dunes everywhere on Titan. So they're centered around the equator, but they [01:00:00] go to mid-latitudes in both directions and encircle the globe.

And so if we can't transports and very far on Titan, that means that the process that makes this and must be happening. Basically globally that screams that it's not my spirit process because that's one of the main things that's Global on Titan, but we're still trying to figure out what the process is and what that means for for all of these questions the other thing that we found out from doing these wind tunnel experiments and and.

This was a result that we weren't originally involved with but I've done some subsequent work. The wind speeds have to be pretty high to move particles on Titan much higher than what we normally see and so that actually turns out to maybe be the solution to this issue that we had of the Winds going the wrong way because there is one time sorry two times of year at solstice.

Or sorry an equinox when the winds reverse at the equator and it's a very tumultuous time on Titan. We have big [01:01:00] storms the winds get much much higher. It's a very short period of time relative to the rest of the Titan year, but it does happen. And so we think that the dunes are probably not actually recording.

The average conditioner conditions on Titan, but rather the orientations of the dunes are recording these very tumultuous conditions that happen during this just very short period of Titans year when the wind speeds are higher and when they're the other direction. Yeah, and so there was something hiding in that information.

It wasn't that we were wrong. Yeah our model we were missing something big relief for our models are so I think I think everyone is quite pleased now that it's not it doesn't seem like we've completely. I said how do you information works but we still have a lot of outstanding questions about it.

Hang on one more about type. Yeah, which you've kind of nibbled at the edges of and that is getting your thoughts about what you have seen of the models for life on Titan [01:02:00] that some people have been playing with some people have been coming up with. Yes. It's a good question, I guess and I should have said this when we were talking about amino acids and nucleobases before.

If there is life on Titan, it almost certainly does not use the same set of molecules that life on Earth uses for a lot of reasons. Why wouldn't I guess since the first question you might have but because it's so cold. There's no liquid water at the surface water is like a rock part of the reason why life on Earth has the specific biochemistry is because we're based on water and so because of the low temperature.

If there's life on Titan, the chemistry will be very very different presumably it would still be organic. There's lots of reasons why life is carbon-based. We don't necessarily want to throw the baby out with the bathwater in terms of you know, thinking about what the chemistry might be. And so people have been doing a lot of work to say.

Okay fine. It's not water. So it's not going to be [01:03:00] DNA. It's not going to be lipids fatty acids the way that we think of them here, but we think that some things are going to be fundamental to life. We need to be able to build little boxes that we use to transport stuff around so cell membranes.

Yeah, things like that because there's reasons why we use those things, right? We keep those things out. We keep these things in so that we can move them to this other place. And so. One of the immediate questions that people had was okay. Well, how do you build a membrane? If you are not looking at liquid water your thing about liquid methane and ethane instead are their molecules are there organic molecules that we think are present on Titan that you could use to build a cell membrane.

That's a great question to ask and so people who you know are much better organic chemists than I am because I only play one on TV or on the radio started, you know thinking about this and the obvious thing to do is to take molecules that are somewhat abundant. We think on Titan and to see like to Jamaica membrane out of that and so people have been doing that.

And [01:04:00] so at first people were using some really sophisticated computer models to just see like okay if you had these molecules arranged this way and they have this. Pretty and whatever like would that make a membrane or whatever thing just kind of fall apart and they found some this group at Cornell found a couple of of molecules that seem like they would happily make a cell membrane in the lake on Titan.

There's people who've been doing lab experiments. What happens if we take the stolen material or some organic that we think is in Titan's atmosphere and on its surface and put it in liquid. Methane. Does it make itself into spherical membrane? Does it self assemble and the answer seems to be yes.

Wow, that's a big deal. It is a big deal. And so, you know, I think the thing that's interesting there is that that means there is a solution to the question of a cell membrane. It doesn't mean that's the solution because I think one of the most important things you learn as a planetary scientist is that nature is far more creative than we could ever possibly dream of being [01:05:00] but it means there is one way to make a cell membrane on Titan to that question at least has one solution.

Now, how would you make an information containing molecules? Because DNA and RNA are not going to be useful in this particular situation because they're not going to fold correctly because of the temperatures and so there's a group in Florida that's been thinking about how would you make an information containing molecule out?

The things we think are present on Titan. It results in some of them were entertaining conversations. I've had over the past. I don't know decade at this point because you know, the people who are doing these this computational chemistry. They want to know what starting materials they have. And so they'll come to me and say Sarah what's in Solon and I repeatedly say to them.

Well, what do you want? Because one of the things that we've learned from from studying this material now for 40 years is that it's very complicated. There are a lot of molecules in there. And in fact, one of the founders of the planetary site Carl Sagan who [01:06:00] coined the term in the first place and the reason he made up the word if you read the paper that he ambition Kerry wrote in 1979.

The reason for this word Solan. Is that they couldn't figure out what it was they knew it wasn't just a polymer. So something that just has the same repeating chemical unit. And so they didn't want to call her polymer because that's not what it was. And so they wanted a word for this thing that they didn't know and the quote is hilarious because in the paper because it talks about how it's this is an intractable polymer has been resistant to our attempts to try to understand what it's made out of back.

Back then and I and and if Carl was alive today, he would he would learn that it still has resisted many of our attempts to understand it. And so when these computational chemist come to me and say well what's in it I ask them what they want and they're like why don't know what do you got and so we just sit there and going back and forth, you know, not really really getting anywhere because there are so many different molecules in this material and so it's hard for me to just say, oh, well, you can only have [01:07:00] this because that's not the answer.

It's a fun game and I should I saw while we were in the lab. He tagged me on Twitter because this has become a game that we know sometimes play where someone for some reason will be interested in a molecule and they'll say hey is that in follin and I'll go pull up a chemical analysis recently guys.

Yeah. Looks like it's nothing. What a my collaborators messaged me. I don't know maybe a month ago and said to me. Hey, did you know there's caffeine in the Fallen ha ha and I messaged him back in this is this is a good life lesson because I messaged him back in full-blown skeptical scientist known as I said are using caffeine to calibrate your mass spectrometer because it turns out that caffeine is an excellent molecule to use to calibrate your mass spectrometer.

And so I have seen caffeine and many many many of our data sets. But because we use it to calibrate the instrument could be a contender. Contaminant and so I would never say oh, yeah, there's caffeine says we don't use caffeine the calibrator instrument. There's caffeine and Solan Casanova. So we you know, somebody at some point I think how we first.

[01:08:00] You know started doing this on Twitter was you know, when breaking bad was very popular and at some point somebody tweets at me and says Hey, sir, is there methamphetamine in Solon ha ha. Oh jeez. Some politics looks like there might be some little bit. So there's all kinds of stuff in this in this material at that means that at the surface of Titan.

There's a very robust organic chemistry. There is the opportunity to have a whole bunch of different options in terms of how you might build a cell membrane or how you might build an information containing structure. The question is. Has anything figured out how to take advantage of that. This is certainly enticing it is enticing you have given me a tremendous amount of your time and it has been delightful not just because.

Of the content of what you've talked about but because of the passion that you bring to it, we think as you know, that's a big deal to us on this [01:09:00] show and planetary society and to our boss Bill Nighy and and to Carl Sagan for that matter our founder one of our Founders. I know from your past that you worked with some great scientists several of whom have been on this show more than one.

It's a Schwinn bus of ADA and Mike Brown. What are you sure in common with them and and with other? Who bring so much passion to this work? Other than that passion? I think if you talk to most of the people in this field, what you find is a whole bunch of people who when they look at the night sky get really overwhelmed by wondering what's out there.

It's not always about you know, are there aliens there? Is there life in the solar system or their creatures on Mars that those questions the bat question. Maybe the question are we alone is something that a lot of the people in the field are interested in but not everybody but I think the thing that everybody has in common is that at some point in their life, they looked [01:10:00] up at the night sky, and we're so overwhelmed by the questions.

That they had which I think are common among a lot of people who look up at night, but they were so overwhelmed by the question that they had to do something to try to answer it that they weren't content to read about the things that other people were finding out that they had to that they themselves had to.

Get a bigger telescope and you know use the example of Mike Brown and I feel like if you were to track Mike's career at some point, it was just a process of getting access to bigger and bigger and bigger telescopes because the questions that he desperately wanted to know the answer to rip required a bigger telescope.

You know, you mentioned Ashwin who you know is that this project scientist for for curiosity now, I'm and former director of JPL. So I work when I work for Ashwin curiosity was a napkin drawing [01:11:00] effectively. I mean it was slightly more than that. That's that's a little bit unfair but you know, I was working for him curiosity was just kind of almost like a twinkle in the eye of the of the people who were building it and so it's been amazing watching.

The the process of that'll happening and I think I think Austin would say the same thing, you know, we just we just want to know how planets work. We just want to understand more about how our own Planet works and we want to know what else is out there. What are what are the weird options? What are the possibilities for Life?

What does what does this mean for the past in the present in the future of our own planet? And what does it mean for all of these other worlds all over the universe and we know now from Kepler. That there are at least in our galaxy and probably in the universe more planets than there are stars. And I try not to think about that very often because that's it's just a lot of work.

I vividly remember we had a happy hour of planetary [01:12:00] scientists that happened the day that they had made this announcement from Kepler that they could now statistically say that there are probably more planets than stars in the universe and everyone's kind of giddy. I mean, this is exciting right that the possibility for for life.

The types of planets that are going to exist like this is exciting as a planetary scientist and there's one person sitting in the middle of the table and I cannot for the life of me remember who this person was and they're just sitting there just crestfallen. You know, everyone else is like, oh this is exciting.

It's cheers. Let's have a beer. Let's just one person just sitting there and finally somebody just looks at it says what's wrong. Are you? Okay person goes. Hi started out in astronomy. And the reason that I started studying planets is that there were too many stars. Hahaha. What are we going to do?

And it was just this funny moment because I think my first thought was well, we're just gonna have to figure him out. [01:13:00] Isn't this a beautiful time to be here? Because not only are we to the point where we can look up at the night sky and ask these questions. How many planets are there in the universe?

What kind are they are there is there life there, but we're getting to the point where we can start to answer those questions where we can have looked up in the night sky with a spacecraft that we built. As humankind and we can say there are more planets than Stars we can do that. We know the answer that now we don't have to look up at night and wonder because we can answer that question.

So what's the next question in the question after that and I think that means that this is a very unique time in human history. We don't just ask the questions. We can start answering them now. I think that's the thing that we all share in common that we. Are not just excited about the questions but that we are excited now about the ability to actually start working on the answers and to push that [01:14:00] envelope and to think about how do we figure out if there's life on Europa or it and you know in an exoplanet or how do we look for for planet nine?

Is there another big planet in the outer solar system was there life on Mars? Is there life on Mars today like those questions? I haven't asked for a while at least some of them some of them. We didn't know to ask we didn't know to ask the question about planet night until relatively recently. We didn't know to ask what an exoplanet atmosphere looked like until relatively recently, especially on the scale of Jesus solar system.

History is a brand new question. But now we can start answering them and I think that's the thing that we all share and I think that's the thing that scientists in general share. It's just the thing that we are so compelled to try to understand is just different but I think at the end of the day for all of us, it's just I just really have to know the answer to this question.

Exciting time so they are exciting times. I want to say thank you. You're very welcome. But I [01:15:00] also want to take another quick look for the benefit of the radio audience that will only be able to see it and maybe a few more still photos. Yeah. Go back to your lab. Absolutely. Absolutely. We'll go get some pictures.

Let's go ahead over there. Okay, there it is. There's the the sort of Heart of this. Yeah, that's at least at least the mechanical heart of the lab. For sure. I think we have it. We have at least a few lovely beating Hearts around this joint, but that's certainly the mechanical heart of the lab. So that's the phaser chamber you put me to shame because of course, it's the people who bring the heart to the lab.

But yeah, this is it. It's we'll put a picture of it. Maybe with you in it for scale. So the people can see what we've been talking about. But it's a beautiful piece of Hardware. Oh, thank you. It's represents a lot of hard work on the on the part of the people that work in this research group. And right now it's running.

This is my favorite plasma color. So we're running a Titan experiment right now, which is you mentioned before is this beautiful violet color and it's just. It always makes me feel a little something deep down inside [01:16:00] when I see it running because I know that there's science happening right now and it's science that we made happen.

So alright now what is this whole panel of stuff that you told me was also fabricated here? Yeah. So the the chamber itself, which is about the size of a two liter bottle is where all the chemistry and all the interesting stuff happens. But as you'll be able to see in the pictures, I guess that you'll post there's this whole apparatus connected to it that is almost entirely to do.

Making the atmosphere very precisely. So all of these valves and tubing and stuff is to get the right mixture of gases. So whatever our gas recipe is and then the final step is getting it to temperature. So we're running a Titan experiment right now. So that means getting it cold. So the gases flow through this kind of vat of liquid nitrogen to get them nice and chilly before they flow into the chamber.

And so that's really what this whole setup is about is just making sure that inside of the chamber inside the phaser. The conditions are precisely what we want them to be and then they'll stay stable for the duration of [01:17:00] the experiment which will be three continuous days and you can simulate the composition you were telling us earlier of pretty much any atmosphere that we know about at least or maybe some we don't know about.

Yeah, I mean at this point just because we've been doing so many different experiments and especially with the exoplanets where we did this big range. We have all of the major atmospheric gases currently in the lab. In fact, they're in a bunch of cylinders behind you right now. Yeah, so we could do and have been doing Venus Pluto Titan Triton a bunch of extrasolar planets.

I've been contemplating some Saturn experiments recently. So we can basically do whatever atmosphere we want at this point, which is exciting and also sometimes a little overwhelming planetary atmospheres are us I mean and looking at this my two and a half year old grandson. Would go nuts with all these valves he would have the best time turning all of these.

So one of my favorite things actually and we don't it doesn't happen very often but it's always really exciting when it does happen and I could let you [01:18:00] do it. If you want, you know this whole thing which looks all very very complicated. Actually the way the experiment gets turned off and on is just that little red button right there.

And so one of my favorite things to do we have a step stool. Actually. It's right there is to have kids come visit the lab. And we'll just let them turn the button off and on a bunch of times and they're like, oh like like it true that because it turns the plasma off and on instantaneously so they can stand on little step stool and look in there and push the button or their sibling will push the button or their mom and dad will push the button and then they can watch it go off and on and so seriously, he would go nuts and II course.

I'm just hiding my own enthusiasm here because I can barely resist. I don't think you're actually hiding it. The cylinder down here that has ice forming on it. Yeah, that's a beer brewing equipment. So anybody who does Homebrew would very very much recognize that piece of equipment because we actually bought it from a home brewing company program because it was a much better solution to [01:19:00] our problem than we were able to come up with on our own and so we thought well.

They already make this then luckily so far. We haven't had any Auditors come by and be like, why are you using grant money to buy beer brewing equipment for very good reason is it turns out then you can you can show the photographic evidence that we are in fact not brewing beer with it. We are Brewing planetary atmospheres in the phaser chamber.

Some micro Brewery is going to be love to hear about this love is anybody wants to sponsor us we would happily take some free Homebrew equipment off of your hands to to do some science with science needs to go where it must the other thing that is in here, which you said is one of your loves I looked at it and I thought oh, this is just your typical glovebox.

Not really. Yeah. It's a little weird to describe a piece of equipment is your love, but we have a dry nitrogen. Oxygen-free glove box which is where we remove all of our samples from the experiments. And also where we [01:20:00] keep them. And so in that box, they're protected from Earth's atmosphere any subsequent chemistry.

It would do anything it would do to try to ruin. All of the work that we put into it it was something that I didn't have access to when I was working on experiments as a grad student or as a postdoc and so when I got the chance to build my own lab my very first thought was I need a glove box and so as I demonstrated for you earlier when I showed you people I tend to give it a little hug because it's just so nice to have it here and just.

One last thing that we have to worry about when we're trying to understand what we've done in our experiments. It's also nice. If you need a high five or a hug the arms that are sticking out which I guess you can take a picture of and show people so you just come in and give a little high five you're having a hard day just come give a little hug.

So it's nice to have these little creepy arms kind of sticking out of it can be used for good instead of evil. If you want to the reasoning behind this you basically said, but it's the same as when we heard Vicki Hamilton on this. Program talking about why she's so [01:21:00] excited about getting that pristine bit of asteroid bennu because as soon as something touches are nasty oxygen-rich atmosphere it it ain't the same anymore.

Yeah Earth is really challenging place to try to study not Earth's things. Um, so as we as we were measuring time that I would really want a lab on the Moon, I mean this is why and so instead I have this glove box. And so it's actually it's kind of funny because like you can think of it as a reverse Space Walk.

You have to make sure you have everything in there that you need before you start doing stuff because once you're set up you can't like open the airlock and let things in which it has on the side. There is an airlock for obvious reasons. Yes, you're offsides bigger lacrimal airlock the little air lock by the way is for when you forgot something.

So then you don't have to put them down the huge air lock before you can open it like you're like, oh shoot I needed that. Darn it you can pump down the little airlock and just get the wrench in that way. It doesn't take nearly as much time as if you had to do it through the Big Air lock. But yeah, that's one of my favorite pieces of equipment in this lab for sure.

[01:22:00] This is one of the reasons I love going to people's Labs because they are basically adult playgrounds of science. Yeah. It's definitely for sure. It's we have a lot of things that we frequently refer to as toys all. You know when something costs more than your house you don't really want to think about it necessarily as a toy, but I will say in this is just as really cheesy, but maybe everybody already knows that I'm kind of a ball of cheese.

I mean there are times when it's quiet sometimes if I'm here on the weekend. Nobody else is here and I'll just pop in your lab to grab something. I forgot a pair of scissors. I just need to check on this experiment real quick. And you know, I'm not sure what triggers the thought in my head. But all of a sudden I just get overwhelmed realizing like this is mine.

This exists because I came here and I dealt it and and I get to decide what we do with it and that you don't get that with a lot of other things in planetary science, you know, the Mars rover isn't anyone's it's you know, it's a team of five hundred scientists who are all wanting to do science in different directions and different instruments and whatever else [01:23:00] and so in this one little space in planetary science, I can say hey like let's do this experiment or what if we change this thing and and and that's really nice.

It's excited. You've earned that. Keep up the great work. Thank you so much. It's time for a very special caffeinated edition of what's up on planetary radio. I am joined by the chief scientist of the planetary Society. Dr. Bruce Betts and boy did your question about the ISS coffee maker generate a lot of a lot of action now nothing makes people more passionate than their source of caffeine.

Oh, man, you can say that again. I can't wait to get to answering that contest because we got some really good stuff, but I can wait. If you tell me about great stuff in the night sky, I will there's like really neat stuff going on with things lining up in the pre-dawn in the East. We've got four planets lined up and I'll even throw in the moon as a bonus.

So Gone [01:24:00] from upper right to lower left in the Eastern Horizon up pretty high. You got bright Jupiter and then yellow. Saturn and then super bright Venus and then the challenge which will be to see Mercury which is along the line to the lower left of Venus looking bright, but down buried in the light of dawn.

It will actually get better over the next week or two get a little bit higher in the sky. And then the Moon the Moon is going to be moving through this line over the next several days until it's hanging out near Venus on the 2nd of April. It's cool, but wait, don't worry yet man. I know you want to but.

Evening Sky we have Mars, which is looking like a bright but not that bright reddish star, but it's hanging out in an interesting area of the sky. It's near the Pleiades over the next several days and then it'll be lined up. So you'll have aldebaran a bright reddish star and then Mars to it's right in this is in the southwest in the evening Mars.

I'll Deb. I'm sorry aldebaran [01:25:00] Mars. And then the Pleiades all lined up particularly around the 8th of April and aldebaran is the brighter of the two right at the moment. That's all great. But I want to go back and compliment you on a turn of phrase buried in the light of dawn. It's gonna be my Epic book that I right.

I love it speaking of Epic this week in space history 45 years ago 1974. We got our first up-close. Look at Mercury Mariner tended its first Mercury fly by moving on. We're Fresh Fire. How authoritative try the Soviets named spacecraft or after where they were going so Mars One the narrow one for Venus.

But what about when the spacecraft went to places the Vegas spacecraft were named ve g a a contraction of Venera because it was they were [01:26:00] going to Venus and Galley which for reasons that are unclear to me was how they said Hallie for Halley's. In Russian, so is the narrow plus Galley and again, I don't know why the name got trance and translated with a G.

But that's where Vega came from. I did not know that until recently. So I thought I would share I didn't know that until just now thank you how knowledge knowledge we move on to the trivia question that got you and our audience. So very excited. What is the name of the expresso maker on the International Space Station had we do mad apparently great.

Wow, did we ever do great both in quantity and quality first? Let me I think I have to eliminate one up front. You're probably not willing to accept fictional coffee makers. Are you no, no, I'm okay. Well then very sorry John Morgan of Anacortes Washington who said it was how of Hal 9000 Fame [01:27:00] International Space Station.

It's a different place is the red light mean is it done? Here's our actual winner Eric Fox first-time winner, Boise, Idaho. He loves the show. He says that that coffee maker is called the is espresso. Yes, indeed espresso. Congratulations, Eric nice work and we did get the correct answer from. A tremendous number of people but it's Eric who is going to be getting a planetary Society kick asteroid rubber asteroid along with the 200-point.

I telescope dotnet astronomy account and. Michael walls out there a scientific guide to alien life antimatter and human space travel at a very great book with with Michaels own little hand-drawn cartoons in it. So congratulations Eric a whole [01:28:00] bunch of people who wanted to. One of my favorite astronauts probably because I met her and she was so nice Samantha cristoforetti how appropriate the Italian astronaut was the first to drink an espresso while she was wearing a Starfleet uniform and she get this she drank it from a special cup a special capillary action microgravity coffee cup designed by Don Pettit and isn't that interesting because she.

Have to drink it out of a bag. Anyway, she was the first on the ISS to drink the product that came out of that machine which makes sense because I believe and I may be going beyond my knowledge here that the Italian space agency provided espresso. You are absolutely right and they did it in cooperation with a company Lavazza.

I think that's how it would be an Italian Lavazza Coffee. There were a whole bunch of people more than I can mention who pointed out that Samantha [01:29:00] was the first to enjoy that first cup of java made on the ISS. We got this from Brenton Rashid in Australia. He says talk about your giant leaps for mankind Kevin Sullivan.

This one cracked me up Kevin Sullivan and Clayton, California with Sunrise every 90 minutes. I would wear this puppy out. All the friends in in Sweden. So if Canada invented a desert machine for the ISS, would it be the canid ice cream maker?

Calloway me maybe there's another Australian Callum in Australia. He's just 10. So he says I don't drink coffee, but my mom now doesn't want to be an astronaut because she likes a flat wider a lot a she wants milk in her espresso. Well, we'll work on it Callum [01:30:00] on the other. They send a counter space will be good.

How about a barista Edith Wilson engulf on? Rio she's worked in a whole bunch of coffee shops. She says she wants to be that first Barista on the ISS probably have to give a heck of a tip. Yeah, I would think and the and the commute to the station to back for the work shift would be very expensive.

Finally Dave Fairchild our Poet Laureate. If you need your coffee while you're up in space today, just turn to the ISS espresso, which I'm very glad to say was built by the. It's their caffeine don't mess around. Just take a sip and soon your feet will float up off the ground. That's it. Thank you, everybody, including all the folks.

I wish we had time to read. We're ready for another contest. I feel badly. It's not about caffeinated beverages. Maybe next time every other [01:31:00] week. I think should be a coffee related question. All right on what types of bodies and I'm going to give you one example, which. Should include planets on what types of bodies have we landed spacecraft that have transmitted after landed Landing.

So they survive Landing they transmitted what types of bodies with categories have. We as humans been awesome and landed on and transmitted go to planetary dot org slash radio contest. That's great. You have until Wednesday. That's Wednesday April 3rd at 8 a.m. Pacific time to get us this answer and.

Your self a planetary Society kick asteroid rubber asteroid and 200-point. I telescope dotnet account from I telescope with its worldwide network of Scopes that you can use remotely and image things all over the universe. Guess what I just remembered. When did you just remember man? This week's guest [01:32:00] this is so perfect Sarah Horst the researcher that we spoke to people call her all the time and ask.

The constituents of those materials called, 'The ohlins that you find here and there around the solar system including on Titan the moon of Saturn guess what one of those constituents is coffee. Caffeine. Oh, wake up and smell the saturnian coffee.

Thank you, sir. I think we're done. All right, everybody got their look up for the night sky and think about what you would name your expresso maker or soda machine or just your tap water. Thank you and good night. That's Bruce Betts the chief scientist of the planetary Society a man who proves that you can live by coffee alone.

He joins us every week here for what's up?

[01:33:00] I've heard about my new planetary radio monthly newsletter. It's great fun. You can subscribe for free at planetary dot org slash radio. The link is right below the Freeman Dyson video. Planetary radio is produced by the planetary Society in Pasadena, California and is made possible by its fired up members.

Marylou's vendor is our associate producer Josh Doyle composed our theme which was arranged and performed by Peter Schlosser. I'm at

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