 Okay, so good afternoon everyone and welcome to this afternoon's webinar, Past Life on Mars. My name is Chloe Hill and I am the EGUs Policy Manager and today I'm billing in for Simon Clarke who is usually running this webinar series. So today we are joined by Dr. Joby Resil-Hollis, a planetary scientist at NASA Jet Propulsion Laboratories who contributed to the development of Sherlock. The instrument on the Mars 2020 Perseverance Rover seeking chemical signatures of ancient Martian life. During the webinar today we'll be asking our expert how we might detect Martian life, what we might expect life to be, why should us terrestrial care and how may those interested in this type of research engage with it. So the webinar today will go for about 45 minutes. I'm going to kick the webinar off by asking some of my own questions and then we'll turn over to you so you can ask some of your own. Now to ask these questions you can do it at any time throughout the webinar today. You can just click on the little Q&A box and ask away and if you see a question that you particularly like you can also upvote that as well. Now do keep in mind that this webinar will be recorded and it will also be uploaded onto the EGUs YouTube channel. So if you like it, want to re-watch it, want to share it with anyone that you know you can do that and it should be uploaded about a week from today. Now if you do like this webinar you'll probably also like other EGU webinars we do run them relatively often and you can find the upcoming webinars on the EGUs webinar page. But without further ado I am actually going to turn over to today's expert and actually ask him to introduce himself. So, Dobie, can you tell us a little bit more about who you are and what your expertise is? Yes of course, well first of all just thank you for having me, this is really exciting. Yeah so I am Dobie Rizel Hollis, I'm a postdoc at the NASA Jet Propulsion Laboratory and I am a planetary scientist and astrobiologist. A little bit about me, well I didn't train to be a planetary scientist or astrobiologist, in fact I didn't train in astronomy or biology at all. I actually did a degree in chemistry and then a PhD in materials science looking at organic molecules that can be used to make solar panels. But it turns out that the techniques that we were using to study those molecules in these panels are very similar to the techniques that are being used on Mars to look for organic molecules that could be the building blocks of life. So my contribution to the project so far has been kind of that experience, that knowledge of how those techniques work, so how can we use light to detect and identify molecules in rocks. I've been doing it for about four years now and it's been an incredibly exciting experience living in California, working at a NASA center, getting to take part in an ongoing mission that's currently on the surface of Mars. And yeah, I'm really looking forward to seeing where the mission goes next. We're expecting to get several years out of this rover and I can't wait to see the kinds of data that we're going to collect in that time. A little bit about me outside of my work, I am a proud biosexual scientist, I'm actually a trustee of a charity known as Pride in Sten in the United Kingdom. And part of the work we do is kind of celebrating and promoting LGBT plus scientists in science, technology, engineering and mathematics, trying to make sure that our universities and industry are as kind of welcoming places for LGBT plus scientists as possible. So that's something I'm very proud of the work we do and I think it's very, very important that we try to foster that kind of sense of diversity and creating a welcoming, supporting environment for anyone regardless of who they are. Great. So I do have one more question about the sort of work that you do in the field that you work in. And you're an astrobiologist, now can a lot of the people watching us today, they probably IG members, they're probably scientists, but they might not know what an astrobiologist is or the range of things that astrobiologists actually study. Can you give us a bit of insight into that? Well, so it's very interesting. So astrobiology is part of planetary science. And planetary science is basically any science that you're doing where your focus, your field site is another world outside of Earth. So astrobiology is basically the study of biological systems and the theoretical kind of what alien life could be on other worlds. So it is fundamentally a very theoretical study at the moment, because we have yet to find conclusive evidence of life on other worlds. But it really ties back to big questions about life on Earth. Because we're still not entirely sure how life evolved for the first time on Earth. And if we can find, the more that we look at other worlds, whether they are living or dead, we're starting to narrow down what is possible, what conditions were required and how unlikely or likely was that to occur. So astrobiology, while theoretical, I think it's an incredibly important part of almost introspective, you know, we are studying life on Earth as much as we are studying life on other worlds. We want to find our place in the universe. This is very much how we do it. Yeah. So what exactly makes scientists think that Mars is a possible home of life or past life? Well, I mean, so we've been looking, kind of, at least gazing at the surface of Mars through telescopes for over a hundred years and desperately interpreting it as though, you know, at one point, you know, in the 19th century, the Scaparelli identified what he called canali on the surface of Mars. And that was, you know, through a mistranslation interpreted to mean canals. And so suddenly that created this whole idea of, you know, the civilization that was irrigating the surface of Mars, because we desperately wanted this to be true. Mars has always been viewed as very much like the sister planet to Earth. We can see, unlike Venus, we can see the surface of Mars from Earth. We can see mountains, canyons, dunes. We can see evidence that there was liquid water on the surface at some point. So, you know, it is very easy to kind of imagine and associate those features with what we see on Earth. So we've always, like, kind of looked optimistically at Mars as a planet that's similar to Earth, but just perhaps colder and drier now than Earth is today. And we want to, you know, we've wanted to find evidence of life we've been. So looking, you know, as soon as we could send the first orbiters and we started getting really detailed images of the surface, we started seeing these, you know, what looked like drive up, dried up riverbeds and lakes. We can see, we can detect minerals that were deposited by water as it evaporated. So we know that there was liquid water on the surface of Mars billions of years ago. And by our limited understanding of what life can be, you know, based on life on Earth, we know that liquid water is a critical part of that. You know, we all are made of mostly water. So, you know, if we can, you know, if we've, you know, the reason why we're so interested in finding liquid water on the surface of Mars is because that is the soul's item by which life exists as we know it. So, you know, we've been determined to find that kind of evidence. And, you know, unfortunately, the more we learn about Mars, the more we realize how inhospitable it is. But we haven't eliminated the possibility that there was life at some point on the planet. So in saying all of that, how hospitable is Mars to life? You're saying we're finding out more and more how inhospitable it is. But what makes it so inhospitable? So there are a number of number of things. So Mars is, unfortunately, a lot colder than Earth and it's further from the sun. The average temperature is about minus 50, minus 60 degrees Celsius. It can, on a really, really like hot, sunny summer's day, potentially get up to like 20 or 30 degrees Celsius. But generally speaking, we have not observed liquid water on the surface of Mars right now. And it's not just a question of it being too cold. It's also the atmosphere is just too thin. It's, you know, it's less than one percent that of sea level. Atmospheric pressure. So even if there was liquid water, it would just evaporate immediately. So the challenge is the surface right now, if you were to stand there, you would need a space suit just to protect you from the difference in temperature, the lack of pressure and air pressure and also the radiation. Mars doesn't have a magnetosphere like Earth to shield us from the solar wind. They're combined with a very thin atmosphere and the lack of ozone. All of that kind of very destructive ultraviolet radiation from the sun, as well as kind of what we call cosmic radiation. So things like gamma rays that come from, you know, black holes, billions of light years away. All of that radiation goes straight and goes straight to the surface without being blocked. And so, you know, it is so from a it's cold. There's not enough air. There's not really there's not really any liquid water. It's quite irradiated. And more recently, we've confirmed that, you know, we've, you know, we've have a number of these, you know, these landers that have been looking at the kind of the soil content on the surface of Mars, and they found evidence of quite toxic materials such as perchlorates, which is a molecule of chlorine and oxygen. And when you heat that up or expose it to ultraviolet radiation, it releases chlorine atoms, free radicals that will attack and destroy organic molecules. So, you know, that is at a sufficient level where we consider toxic to life on Earth. So all of these things happen together, you know, really don't paint a very nameless picture. You certainly wouldn't want to go there for a holiday. And really, you know, to re-emphasize it, the most inhospitable place on Earth is still nicer than the most hospitable place on Mars, partly because you can just you can breathe the air. So what I'm hearing is it's very inhospitable to anything that lives on Earth. Right now, yes, right now is was it the same billions of years ago? So that that is one of my next questions. But first, do you think this this understanding of how hospitable it is is limited by our understanding of life on Earth? Do you think? Absolutely, yes. So we, you know, we're facing like so, you know, we know that there are even even on Earth, there are extremophile bacteria that can tolerate conditions or would immediately kill a human being, you know, whether that's radiation, temperature, you know, even just hydration, you know, you, for example, tardigrades are famous for being able to resist almost anything, including basically being, you know, vacuum frozen, they can be reanimated as soon as they're exposed to water again. So, you know, we are very limited by our understanding of life on Earth. And if there is a potential completely different like alien biosphere that we don't know about the works, like, you know, we use this different building blocks of molecules, it may not operate on the same restrictions that life on Earth does. So we are really working from, unfortunately, a sample size of one when it comes to understanding what life is capable of. Yeah. And just before I ask that question, you mentioned that maybe it wasn't so hospitable, maybe it was a bit more hospitable in the past. Would there was it more hospitable in the past? And what would have made it like that? So we haven't got we're not entirely certain about this because we are talking about, you know, trying to understand what a planet was like billions of years ago. Sorry. But we believe that for, you know, so Earth and Mars are about both about four and a half billion years old, like the rest of the kind of rocky planets in the solar system. And but we believe that maybe for the first billion years or so, both planets were quite similar in terms of their climate. So they were both hot, wet, they had thick atmosphere. And it took about a billion years for life to first evolve on Earth, the first evidence that we have of you've just simple, single celled organisms on Earth is from about three and a half billion years ago. So it's around that one billion year mark. And we believe that around that same time, there was still liquid water on Mars, there was still an atmosphere is still warm enough for there to be, you know, for water to be a liquid. So it is possible that, you know, if that could happen on Earth, if the building blocks of life spontaneously assemble themselves into a complicated enough structure that it could perpetuate itself like a cell, why couldn't that also happen on Mars? Now, the challenge is that the two planets then diverged as Mars cooled down, you know, if it had a magnetosphere, that magnetosphere disappeared, the atmosphere started getting stripped away by the solar winds. The surface got colder and colder and colder. All of the liquid water froze and went and, you know, either the blood that sublimed into the interspace or underground and left behind this dry, arid surface that we've seen now. And, you know, we've looked at, you know, so I believe the curiosity mission looked at, you know, looking at soil samples and it was able to ascertain from the minerals present that there had been no with that soil had not interacted with water in about 500 million years. So, you know, we are talking it is extremely arid even by, you know, even compared to the deserts on Earth, where it rains at least once every 10 years, you know, we're dealing with a surface that has been inhospitable for a very, very long time. But that doesn't mean it wasn't hospitable at some point in the past and it may have been hospitable like Earth for long enough for life to evolve. So that's what we're really trying to find is we're looking at that top surface of Mars, trying to see if there was, if there's evidence that life ever did manage to start on that planet, even if it didn't manage to get that far. Wow. So it just, it seems so mind blowing to me that you can do research on that. I mean, how do you, how do you plan to do this kind of research? But how do you do science on such a distant area, something that's so far away? Well, meticulous planning is a part of it. So I work on the Mars 2020 Perseverance mission and generally speaking, how that works is, you know, every sorry, doorbell, every Martian day, which we call a Sol, we start off by planning on Earth what the rover is going to do that day. And we come up with a whole plan for the whole day and we turn that into a sequence of instructions, which we then transmit to the rover, the rover then executes those instructions. And then we then transmit the results back to us via one of the satellites that we have in orbit around Mars that allows us to get back even more data, which was hundreds of megabits a day, or a Sol rather. So, you know, we're able to do quite a lot in, you know, in each Sol, but we are limited by what the rover can see. You know, we receive images from the rover that allow us to kind of build a picture of what's around it. We can identify rocks that we're particularly interested in and we can say, OK, well, you know, we thought it's something that looks very exciting. That looks like it might be a clay, which could have been deposited by the action of water on rock. And we want to look to see what's trapped in that clay. So we will the next day or the next Sol, we will instruct the rover to, you know, drive up to that rock, extend the robotic arm and to place one of our scientific instruments above the rock in question and then scan it and then we get the data back, the next Sol. Now, like speaking as a laboratory scientist, I'm used to doing experiments and getting the results within 20 minutes to an hour. So it is quite, for me, frustrating having to wait, you know, up to 24 hours to see the data that comes back. But it's always so exciting to do science on another planet. So it sounds like you get a lot of data that's data that's transmitted back to you and you sort of say, OK, the Mars, the Mars, the rover is limited to what it can see, but you also get a lot of this data. How do you actually process it? Do you need a lot of researchers to process that data? Or can you sort of focus in on individual sections of it? Well, so the rover can take has a suite of scientific instruments and we are all a lot of specialists in particular instruments. So, you know, for example, I work on an instrument that's called Sherlock and like everything in NASA, it's an acronym. It stands for standing habitable environments with realm and luminescence for organics and chemicals. It is a spectrometer that's mounted onto the robotic arm. It uses an ultraviolet laser to scan the rock beneath the instrument. And we look at the light that comes back. Some of it will be fluorescent. So molecules that have absorbed the ultraviolet light and then emitted, say, blue light. And, you know, that's an extremely sensitive way of detecting certain kinds of molecules such as DNA and proteins. They have very distinctive fluorescence spectra. We also get Raman scattering, which is a technique that I'm particularly a specialist in, which is basically, you know, some of this light bounces off the molecules and excites vibrations in them. So you imagine that the atoms of the molecules start moving. And when they do that, they absorb some of that light and change the frequency of the light that comes back. And that is very, very specific to the chemical structure of the molecules. So it's sometimes called like a molecular fingerprint. And that's a really effective way of identifying organic molecules without destroying them. So, you know, as we're scanning these rocks with Sherlock, we're getting back the spectra that can tell us about what kinds of organic molecules and minerals are present in those rocks. And, you know, so my job is usually, you know, the morning that that data gets transmitted back to Earth and gets turned into something that's human readable. I'm the human reading it and interpreting those spectra to tell the rest of the team, well, I think we may have seen this. But it could also be this. You know, it's, you know, we are getting we're getting these spectra. They're not under laboratory controlled circumstances and conditions. So, you know, we we have to do our best, but it's never going to be quite as detailed and controlled as, say, doing the same experiment on Earth. So that's kind of one of the reasons why we're sort of focused on cashing samples in this mission. The intention is with Mars 2020 is that we're going to collect a total of 43 samples from the surface of Mars that will be sealed in sample tubes and eventually brought back to Earth in around around 2031. And when those, you know, so these will be samples that we've found on the surface that we are particularly excited in because we have initial data taken by the rover that suggests that there's something really important or really interesting in that rock, but we need confirmation. So we need to bring that back to Earth and analyze those rocks under very carefully controlled laboratory conditions. So there will be a second rover that will be launched in, I believe 2036, but we'll go and pick up these sample tubes from perseverance, carry them back to a lander, which will have a rocket. The rocket will then transfer the sample tubes into orbit to a satellite that will then bring back to Earth. And so hopefully in 2031 or 2032, we will have about a kilogram of Mars rock that is pristine, fresh from the surface with no contamination by anything on Earth that we will then be able to analyze under very carefully controlled conditions to really confirm what we observed and what we detected on the surface. And it's so exciting because, you know, we so far the only material from Mars we've ever been able to analyze are pieces of meteorites, you know, Martian meteorites are bits of Mars that got knocked off the planet by impacts and those rocks have flown through space for millions of years until finally at some point they they had an unlucky interaction with Earth, burned up in our atmosphere and then maybe, you know, a chunk of the size of your fist may have landed in a field or in Antarctica and was found by human beings some time later. Now, we found, you know, we found many of these rocks, but then, you know, the unfortunate issue is as soon as they're on Earth, there's potential of contamination, you know, life exists on Earth. Everywhere, even Antarctica is not a sterile environment. So getting pristine, controlled and protected samples directly from the surface of Mars, especially when we have that context, right? We have the images of where these rocks are. We know where these samples were taken. We have preliminary data taken by instruments like Sherlock that will tell us about the context that that sample came from. We can put it into like the wider geographical strata of Mars and we can figure out exactly what was going on. Crazy. It just seems like there is so much coordination behind all of these studies, like knowing that you're going to do these decades in advance, planning for that. I guess you definitely don't want to retire before that comes. It comes back to our very patient. I can't even imagine. Oh, my gosh. So can you tell me like right now it might be difficult for you to say and maybe you can't even say. But is there something you would hope to see on these samples or expect to see at this stage? Or can you really not even predict? It's impossible to predict what we will find. We have sent multiple instruments on other rovers and landers before. But speaking as a Raman spectroscopist specializing in that particular technique, we see we're getting the first Raman spectra ever taken on in other worlds. So, you know, it's unprecedented. And so we don't know exactly what kind of data we're going to get back. The rocks that we're looking at, you know, we're looking at a particular site on Mars that no one's ever been to before. No rover has been to a place like that before. So, you know, everything about the mission is is unprecedented. So whatever data we collect is kind of exciting in you. And, you know, the challenge of like trying to corroborate measurements that were done halfway around the planet, done, you know, taken five years ago by curiosity in a different situation, putting together that jigsaw is a real challenge, but it's a very, very exciting one. I'm afraid I've confused your question. Well, I'm sorry, that's fine. You answered it, but everything you're saying is so interesting. I'm happy to hear it all. But you did just say something about the sites that you're using in the fact that, you know, it's the first time you're actually looking at this particular area. How how are those sites selected? Is there a particular criteria they have to fulfill? Or is it a bit more random than that? It depends on the on the goals of the mission that have been defined by the team. The team itself, the science team, comes together to basically have a big argument about where we want to send it. So for perseverance, we narrowed it down to three locations and then finally ended up choosing one of them. And the because the goal of perseverance, well, one of the goals of perseverance is to look for evidence of past life or habitability on Mars. A long time ago, we decided that we wanted to go to a location that was a very a best chance of finding that kind of information. So we chose Jezero crater. This is a crater in the. Isidus Planitia, so it's in the northern hemisphere of Mars. And the reason why we picked it is because we can kind of we can see from orbital images that at some point, Jezero was a lake. It was a crater that was filled with water. And we can tell that because we can see a river channel or was once a river channel snaking its way into the crater. And then there is a delta like a basically a fan of sedimentary deposits that's left behind. Whereas the fast flowing river enters the lake, slows down and drops all of the, you know, the finely powdered sediments that it was carrying. We see these deltas all over Earth. You know, the Nile Delta is a fantastic example of one of these kinds of fans. And we know from Earth those kind of sedimentary deposits are often like clays and and they are full of organic material that was present in that water at the time. So if we're going to go looking for evidence of past life and past habitability, if we're looking for, you know, either what was what is left over from what from a living thing that existed billions of years ago or were the building blocks of a potential living thing, then that's a fantastic place to go. Because we know that there was flowing water. We see these clays and carbonate minerals from orbit that we can that we associate with, you know, water evaporating and leaving behind these kinds of minerals and organics. So, you know, we want to go to that kind of location to see there to maximize the chance that we might find something. So we picked that location. We've landed in that in that crater near the delta. And we're starting to look at the rocks on the crater floor. And we're trying to figure out, you know, what was the history there? So where did these rocks come from? And, you know, all of that will help us build a picture of, you know, what exactly was going on in Jet's Rope. So can we corroborate those mineral detections or observe from orbit? And can we detect the presence of organic molecules that may have been preserved in those minerals? Yeah. OK, so is there a threshold above which you can definitely say you've found life? At what point can you say that you have evidence for that? Do you need like a complex protein string or something more? It's a that's a very, very big question. And I think it's one that will be debated for decades. It's only not a question that I can casually answer. But certainly, you know, it's a very typical thing to say what is evidence of life, you know, what is a biosignature, as we call it. We often talk about potential biosignatures because often, you know, if it's a if Sherlock did detect a organic molecule, the next question will be, is that what's that molecule made by a biological process or was it made by an abiotic process, a non-living process? So there's a lot of molecules that can be produced by natural geochemistry. You know, we've looked at meteorites that are older than the solar system and we found really simple organic molecules. So we know that these things can occur spontaneously in space as well as in dead rocks. So, you know, the the challenger of saying, well, you know, is this biological? You really have to eliminate every possible non-biological explanation. And so there is a question of like, how likely it is that this just happens spontaneously? So the bigger and more complicated organic molecule, the less likely it would occur spontaneously. So if we found, for example, a string, a protein string made up of a specific set of amino acids. So all life on Earth operates on, you know, Bill's protein from 22, 23 simple amino acids. Our DNA is based on four nucleobases and five of you include RNA. And so, you know, those are very simple building blocks, but they're repeated in complicated patterns. If we found something like that, we would start, you know, it becomes less and less likely that that is a purely non-biological product. And we have to start considering the possibility that it might be biological. So it's interesting. It means we don't actually have to know specifically what the building blocks of life are. If we did find a completely alien, you know, bio biosphere that used different building chemical building blocks, as long as there was a defined set of them that were being organized in complicated patterns, it's the complicativeness, it's the complexity of it that is actually really matters for when it comes to defining an organic biosignature. But even if we found a, you know, a complicated molecule using Sherlock, it would be difficult to corroborate that. You know, I mean, there are other instruments on the rover, but each of them is designed to do a specific thing. And, you know, so if we could corroborate it with the second instrument, that would be amazing. But there isn't a huge amount of overlap in what these instruments are designed to do. So it was like it's very, very likely that what we would do is we would say we think we found something that could be a biosignature, and so we need to bring it back to earth. So then the next step would be to take a sample, store it in the tube, and then hopefully in the 2030s, we would actually be able to look at that biosignature with more complex, more advanced techniques under control conditions on earth and say for sure, whether or not we've detected something that is so unlikely to happen spontaneously, that it has to be evidence of past life. So, you know, it is a it's a very it's like, you know, you really you have to build your case. There is no one defining piece of evidence. I think that would ever prove that we saw we found evidence of past life. We would need to build that case by doing multiple measurements with different techniques to corroborate one another and create a detailed story about what was going on and when to be able to understand exactly what could have happened and what could have produced it. Yeah, I mean, all the research that you're doing also sounds like it needs a lot of collaboration between different researchers, different experts, different specialists. How how do you manage that during, you know, regular times and has that changed since the pandemic started? It's interesting because, you know, a mission team, especially for a mission as big as perseverance, involves people from all over the world. So there's always someone who's attending a meeting in the middle of their night. Unfortunately, we generally try to operate on Pacific time because perseverance is officially run out of to the Jet Propulsion Laboratory. So we're based in California, but we have people on the team who live in Australia, France, Spain, Norway, Canada. You know, they're all like we're all over the world. So you unfortunately kind of have to get used to some sometimes, you know, unsociable hours. It was even worse during the start of the mission because we were actually working on Mars time. And unfortunately, a Mars day is about 45 minutes longer than an Earth day. So every every day our schedule was moving by 45 minutes. So at some, you know, every couple of weeks you were working in the middle of the night and then a few weeks later you'd be working during the day. And yeah, that was a very tough process for us. We were quite clueless like a logistical nightmare. Yes, I like my sleep and I found it very difficult. Like you are talking about finding sort of the building blocks of life. But do you think there's a chance of finding anything more complex, maybe maybe on Mars or maybe somewhere else? Or is that not in the realm of possibilities? I is definitely within the realm of possibilities. Whether or not we are equipped to detect it is another question because, you know, we've created these instruments to do the best job they can under the circumstances, but they still have to work on Mars without any maintenance. You know, we are operating under less than ideal conditions. And it is possible that we may just scan the wrong rock. You know, if we just moved a centimeter to the right, we might have seen a biosignature, but we just got unlucky. You know, everything we do is to try to minimize the risk of missing something important. But, you know, it is the reality of this kind of experimental science, planetary science is that you're limited in what you can do, even if a mission does last eight years. You know, we spend a couple of days studying a particular rock, but we can't scan the whole thing. So, you know, the whole question of what if and what did we miss is one that probably plagues me and my colleagues and will forever. But, you know, we try our best and we're hopeful that, you know, if there is a signature there, we will find it through exhaustive, you know, kind of like trying, you know, really trying to figure out priorities. Like, well, this rock looks like it's made of clay. You know, so that's going to be a high priority. We'll look that we'll use the right instruments and we'll interpret all the data as best we can based on the limitations that we have. And, you know, the main intention of bringing everything, bringing samples back was to overcome that limitation, right? To bring those samples back to be able to do more detailed analysis is will be a, you know, kind of a light speed leap in what we what we can do in terms of our understanding of Mars, because we're no longer limited to what the rover can do on a given day. We can do all sorts of experiments as our leisure on Earth. So, you know, it is really like a, you know, I don't want to say that we're not going to find anything. I think the realist in me has to say, you know, acknowledge that it's possible. We may just, you know, if there are biosignatures present, we may miss them or we may just not be equipped to detect that specific kind of biosignature. But we have done our best to ensure that we have the best possible chance of catching those signatures, getting that data and being able to interpret it correctly. One of the big challenges, obviously, I mentioned earlier on is we're seeing the more data we collect, the more smart looks as a prospect for finding life. That's still very limited to the top surface. You know, we're looking at the top, you know, few millimeters of Mars, really. We've not really dealt much below that surface. And we know that those rocks are that top surface is exposed to ultraviolet light. But if you go a centimeter down, you know, if you drill a braid away, grind away the top surface of the rock, you might find intact material, organic material that hasn't been exposed to as much radiation. So that's one of the intentions of perseverance. We have it not only do we have a drill for extracting samples, but we also have an abrasion tool so we can remove the top centimeter of what we would call weathered material. So it's materials being exposed to radiation and the ambient conditions of Mars for potentially millions of years. And we can find what is, hopefully, more intact, better preserved material underneath. So, you know, that's that's part of our way of trying to, you know, get past these limitations, right? But if considering how inhospitable the surface of Mars is right now, if we're if we're interested in looking for extant life, so life that still exists on Mars, then the surface probably isn't a good bet. We might want to go like much, much deeper because as you go, like, you know, hundreds of meters below the surface, it gets warmer. It's possible if you go and there's also less radiation. So, you know, if if we're really determined to try to establish whether or not there is like something still living on Mars, scratching the surface won't be enough. We might have to go hundreds of meters below the surface where there could still be liquid water and it could still be living things. But like, yeah, that's that's the challenge, right? You know, we've we've landed, we've successfully landed 10 robots on Mars in 10 different locations. Imagine trying to do that on Earth and trying to infer the existence of humans based on 10 random spots on Earth. You know, it is a sampling issue. So what I'm hearing is that we're only scratching the surface surface both sort of like literally and metaphorically on Mars. If if you could do anything, any type of research you had, the world that Mars is your oyster, I guess, and you had all of the resources, all of the rovers, all of the instruments at your fingertips. What is the one thing you would do? What is the one research question you would want to find the answer to? With unlimited resources. I upset my fellow Martian scientists here by saying that with unlimited resources and technology, I would send a submarine to Europa because I think that the so Europa is an icy moon of Jupiter and it has this crust of ice that is several kilometers thick. But we we believe that there is a subsurface ocean beneath that. Now, it may not receive any sunlight, but it still gets a lot of energy in terms of kind of the tidal forces acting on the moon. Keep the core of the of the of the moon hot. So that allows it to be liquid water and it will can also drive geothermal chemistry. And one of the kind of dominant theories as to how life evolved on earth is in this kind of hot, salty ocean that starts three and a half billion years ago, we had hydrothermal vents at the ocean's floor. There were pumping out chemicals like reducing agents and things like that. The chemical and chemical and thermal energy that could be used to jump and start the formation of organic living cells. Now, it's possible that something similar happened on Mars, but in the surface that we have access to, we can't see that. There's no more water. The planet's cooled down. There's no more hydrothermal activity, but Europa is very possible that there is still ongoing hydrothermal activity at the bottom of that ocean. So, yeah, with unlimited resources and technology, I would absolutely send a lander with a drill and a submarine drill down through those kilometers of ice and insert a submarine into that subsurface ocean to start looking for extant life. Because I think across the entire solar system, the icy moons are becoming an increasingly better prospect for finding still existing life. Mars, I think is, you know, is important for us because it's the most Earth-like planet that we found. And it will help us understand how life evolved on Earth, but the possibility of there still being life there now is unfortunately looking slimmer and slimmer. So, yeah, I would, if we could, and I know that several of my colleagues are really pushing for it, though the Europa people are desperate to get a lander out there. And with any luck, you know, with patience willing, it'll happen in maybe the 2030s or 2040s. But, yeah, that for me would be the biggest, the grandest challenge would be to get below that ice into that ocean to see if there's still if there's something living there. So I definitely have some follow up questions for that. But before I do, I just want to remind everyone who is watching live that you can put questions into the Q&A box. I can see that there's already one question there waiting for us. I will be getting those really soon. We are actually kind of running out of time quite quickly, unfortunately. So if you do have any questions of your own, please put them into the Q&A box. But as for my follow up questions, I would say, so you're talking about like what you would like to see in an ideal world. But astrobiology has come a long way in the last few decades. Well, in what direction would you hope it develops in the next few decades? What would you like to see happen? Would you be shifting away from Mars and potentially to somewhere else? Or will that upset yet more people if you answer that question? Oh, well, I mean, I think Mars is I mean, Mars has been the focus of such attention, partly because it's a relatively easy planet to get to and land on compared to say Venus, where, you know, the we've we haven't been we haven't landed on Venus in decades. And the longest lasting mission survived for maybe two hours, I think, before it got crushed by the intense pressure and temperature of the Martian others of the Venusian surface. So like then Mars is a convenient planet to explore in that regard. I hope that we continue to explore it because as I said, you know, we want to answer these questions. We have to keep sampling. We have to keep studying more and more of the surface and ideally go below the surface as well. You know, there are exposed lava tube systems. You can there are ways to get underground relatively easily with the right kind of equipment. It's not a mission that we've ever tried before, but I think that that would be a really exciting next step. So the whole question of life underground on Mars, I think would be the next big thing for at least astrobiology and the exploration of Mars specifically. But, you know, there are rumblings about, you know, trying to send landers to icy moons like Europa and Enceladus and even potentially Triton in the, you know, which is, I believe, you know, embarrass myself. I think it's the moon of Neptune, Neptune or Uranus. So, yeah, no, I mean, it's a really exciting time. You know, every mission is, you know, a massive technological challenge because we're always doing stuff that we've never tried to do before. Perseverance is looks very similar to curiosity. It's based on the same chassis, but, you know, we're taking a whole new suite of of of instruments, some of which, like Sherlock, have never done before on another planet, as well as a sample, a sample drilling and stashing system, right? We're taking these samples, sealing them, and we're going to bring them back. That is a massive undertaking. So, you know, we're always treading new ground. And it's incredible to see how much has changed just in the last 10 years. Nice. So I am actually going to turn to the Q&A box now. And there is a question that kind of feeds on to that, looking into the future, which is what do you have to study to become an astrobiologist? And perhaps, you know, what career advice would you offer someone who wants to become an astrobiologist as well? Honestly, I don't think there's a single answer to that question. I certainly came by a securitist non-traditional route. Like I said at the start, I didn't study astronomy or biology. I'm a chemist, really, a physical chemist. But, you know, so what I brought to the table was knowledge of a particular, like, analytical technique, a particular kind of spectroscopy that we that we're now doing on Mars. So I'm providing the analysis of those spectra. I help other astrobiologists by telling them what we're trying to find, you know, what we're finding, you know, and not just what we're detecting, but also what we're not detecting. So, you know, there's there's a hundred and one different ways you can do it. Like I like planetary science in general is just science, but on another planet. So you can be a geologist, you can be an atmospheric scientist. You can be you can be a biologist or chemist. You know, it's all of these things intersect and overlap. There is no one direct way to do it. I believe there are some universities actually do courses in astrobiology now. But I would say that, you know, there's if you're an expert in something, you probably can probably contribute in some way. And in terms of career advice, perhaps, how did you get started? Is there an internship that you did or did you sort of find a research project that was looking specifically for the area of expertise that you had? Is there places people should be looking if they want to get a job in this area? Well, I can definitely recommend. I believe it may I think it may only be open to American citizens, but NASA does have a fantastic internship program for high schoolers, undergrads and postgrads to get an opportunity to see what it's like working at a NASA center. And, you know, that kind of like first hand experience and getting to know people is a fantastic way to get your foot in the door. I personally I did my degree in chemistry and then I did a PhD in physics, specializing in material science. And then I you I leveraged my knowledge of spectroscopy to get a postdoctoral fellowship. But I, you know, I mean, even that was difficult. I applied four times before I got in. But that was like, you know, that was me getting my foot in the door. And, you know, I think I've been very useful to the project. And they were certainly useful enough that they kept me on after the first two years. I'm now in my fourth year as a postdoc and I'm getting to take part in mission operations, planning what the rover is doing, interpreting the data that comes back. It's been an absolute roller coaster. I do not regret it at all. So perseverance pays off pun intended. I mean, like if as career advice goes, I consider myself a multidisciplinary scientist. And I think that there's sometimes that sort of viewed as a bit of a that kind of career hopping, like changing research fields, multiple times during your career is sometimes viewed as a bit flighty. You know, you're not you're not committing to one thing. You will never get that far as a result. But I really believe it brings out it gives you a different perspective because you you don't have the same background and the same expertise as the rest of the people in your field. So you can bring different solutions and different interpretations to the table. And I actually this is so this is actually my last year working at JPL. And after that, I'm in next year, I'm going to be taking up a Marie Curie fellowship at the Natural History Museum in London, where I'm going to be studying microplastic pollution and how it affects seabirds. And the the the unifying threads throughout my career has been the spectroscopic techniques. You know, I I've used them. I've used those techniques to study semiconductor molecules in solar panels. I'm now using it to look for biosignatures on Mars. And next year, I'm going to be studying how plastic degrades and how it affects animals. So, you know, like changing research fields is not something to be ashamed of. It can it can give you a different perspective and you can, you know, gives you opportunities other people may not have. Wow, that's amazing. And I think that kind of overlap in that interdisciplinary aspect actually applies to a lot of different scientific divisions and areas. And it seems to be a common thing that we're seeing more and more of. So that it sounds like you've had quite a wild career. That's going to certainly wasn't what I predicted. So we do just have a few minutes left. There are a couple more questions I'm going to ask you quickly that are in the Q&A box, and then I'm going to finish with one of my own. So one of the questions we have here, and it might be one you've already touched upon is what it makes sense to design a sampling mission targeting Martian ice and a Martian Martian ice body to find microorganisms. How feasible and relevant would that be? I mean, it sounds very exciting to me. We know that the Martian ice cap is composed of kind of a mixture of carbon dioxide ice, so dry ice and water ice. And, you know, it's possible that they provide like the ice caps on Earth do a kind of stratigraphic chronological record of Martian. Martian climate. So, you know, even if you weren't looking for, you know, biosignatures that I think would be a really, really useful target. It hasn't been done yet. But I would like to think that a mission like that could definitely happen at some point in the future that it answers the quest. That would allow us to answer questions that we have not been able to answer yet. So, yeah, that would be awesome. Cool. And the last question we have in the Q&A is what is the research a research approach of an image processing? Something like is something like model simulation also possible in the field? Absolutely. I mean, the mission touches on that. So we have a an instrument sweet called MEDA, which does basically atmospheric and kind of climate measurements for the rover. I mean, you know, so every day we're sort of logging temperature, you know, pressure. We're looking at kind of the ambient, light and dust cover. And so there's a big thing for basically atmospheric modeling and trying to understand, like, you know, not just how does the atmospheric Mars behave because it's quite a different kind. You know, it's a different atmosphere to that on Earth. It's very thin. So it won't transfer any heat in quite the same way that Earth does. You know, so there's and it also transport material, right? You know, we know that there are these giant dust storms sometimes cover the planet. So modeling that based on the the experimental data that's being measured in situ. That's a really big deal because that helps us understand, you know, the transport of material energy across and potentially, you know, water ice and vapor across the planet that will help us narrow down things like, well, you know, if we detect this this particular molecule in the atmosphere, how likely is it that those molecules were put there by just, you know, atmospheric transport? Or is it being produced by some kind of chemistry? Or is it, you know, evidence of some sort of, you know, unobservable biological process going on underground that's outpitting a particular organic molecule? Now, we've seen seasonal fluctuations in methane, but right now it looks like they can be explained by simple geological chemistry. But, you know, to be able to make that reach that conclusion, you need to understand how the answer behaves. And that's where modeling comes in. So interesting. So we've answered everyone's questions in the Q&A box now. I'm going to just ask a couple more concluding questions. We've gone way over the 45 minutes I anticipated, but that's fine. All of the answers are super interesting. And I think everyone watching is actually still with us. So that's great. So my first concluding question for you is, why should humans care about astrobiology or space science more broadly speaking? It's a tough question. And it's a very, it's frankly, it's a question we do need to be asking ourselves, especially at the moment when there are such like pressing matters that require attention. But I think that we can't lose sight of these big questions about where we came from, you know, how did life evolve? Understanding other planets gives us an insight into how Earth, you know, the how the climate of Earth has changed over, you know, geological times of billions of years. We, you know, we're helping constrain and like narrow down our understanding of how our own planet behaves by studying other worlds and looking for evidence of life on other planets helps us understand where we came from. You know, there is still the possibility that life may have evolved on another planet and then been transferred to Earth. Three and a half billion years ago, the pan-Spermia theory is still a it's still a possibility. We can't rule it out yet. So, you know, if we do find evidence of past life on a planet like Mars and it's made from the exact same building block as us, you know, we found distant relatives, you know, I think from a really fundamental point of view, like almost like philosophical, you know, we are that investigating things like this allows us to put ourselves and define our position in the universe in a way that, you know, a lot of more practical sciences, while they are immediately useful and solving problems like, you know, dealing with microplastics and stuff like that, you know, we can't lose sight of the big picture. You know, we should always keep pushing for these things. And as horrendously expensive as a Mars mission is, it's still a drop in the ocean compared to, you know, all the money that is spent on other things in the world. So, you know, I feel like we can afford it and it shouldn't have to come at the cost of anything else. We're not in competition with more pressing matters. We should be able to address them and explore the solar system at the same time. I think that for me, the real challenge is how do we do it ethically, right? You know, we're exploring Mars. We're sending these rovers there. We're looking for evidence of life, but we have to do it in a careful way, because we don't want to discover that there was life on Mars by accidentally killing it. So planetary protection, ensuring that we don't accidentally transfer microbes to Mars and, you know, either create, you know, the simplest case, just create false positives, because we think we found life on Mars, but it's actually just something we brought along, you know, up to the distant extreme, which is that, you know, we could be bringing in invasive species effectively. So, you know, I think that there's, for me, the question of exploring the solar system for the scientific gain is worth it. But the challenge is how do we do, how do we explore the solar system? And increasingly in the future, how do we use the resources that are off-world in a way that is ethical, that doesn't destroy these kind of, these, you know, environments, these habitats that, you know, we haven't fully explored. We don't want the hubris of trudging all over our planet or we need to discover that we've ruined it too late. You know, so I think, you know, we've done a very good job of, you know, for example, places like Antarctica. They're still relatively pristine environments on Earth, but that's partly because they're not very useful to us. If we start, you know, extracting resources from a planet like Mars, who's to say how much damage we'll do before we realize what we've done. So I'm all for the exploration of the solar system. I think we can justify it scientifically, absolutely. I think we just have to be very thoughtful about how we do it. And so far, thoughtful and methodical and thorough describes, has described planetary exploration. These missions are very carefully worked out. We do spend a long time making sure that what we send into space is clean. And we try to remove as many microbes as we can so that they are sterile by the time that they arrive at their destination. But like you said, like, you know, when I said, you know, it'd be great to send a submarine to Europa. We don't want to introduce organisms that weren't there that could supplant what is there. You know, I think we need to be careful. We are talking about, you know, true untouched wildernesses of nature beyond Earth. We, you know, we're going to change them by exploring them and we need to do that in a thoughtful and caring way. That is a great take home message for the audience that's listening here today. Is there any other key messages that you would like to communicate, any final words that you'd like to express before we finish the webinar today? Well, I mean, so the webinar was called past life on Mars. And I think that, you know, I really want to underline the fact that we haven't found evidence yet, no conclusive evidence, but this is a question that we're going to be asking for a very, very long time. You know, what we're doing is we're assembling a jigsaw and every, every soul that we're working on Mars running this, moving this rover around collecting data, we gradually are putting together new pieces of the jigsaw. And at some point we will have a picture and that picture will tell us whether or not life existed at some point on Mars in the past and potentially whether or not it was related to us. That may be a long way in the future. We're not expecting to answer that with this, this mission or one instrument alone. This is a work in progress, but whatever we find, whatever that answer is, it's going to be very exciting in terms of what it means for how life can evolve, how likely it is, you know, and whether or not we are alone in the solar system. So, you know, it's, it's a big project and we're asking very, very, very big question. It's going to take a long time, but it'll be worth it. That's also a great takeaway message. So I think actually we're almost just short, just shy of an hour here. So that's why we're going to finish the webinar today. A huge, huge thank you to Joby for coming on and talking to us all about his, your work and answering all the questions, still a lot of questions to be answered, but some of the questions that we had and a huge thank you to everyone who participated in the session today, who asked their own questions and thank you for to Simon Clark who actually set the webinar up today. Once again, this webinar will actually be uploaded onto the IGU's YouTube channel. So if you would like to rewatch parts or share it with anyone, you could do that. And if you have any questions about the webinar, you can address those to webinars at igu.eu. So thank you very much. Thank you for having me. Thanks.