Session IV: Frontiers in Geochemistry

hello welcome back hi hi with our exciting post lunch energy hello how was lunch awesome good to know all right well welcome back and and enjoy and be seated comfortably to seminar day 2023 hope you enjoyed your lunch and a chance to explore campus and for you techers online I hope you enjoyed a tour of your own home it's your own student house if you will

thank you and and yeah thank you to you um I think by now everyone has the hang of slido and and that and the questions have been really fantastic and know that it is Caltech 4 is the name of the session we're in now and it is this the session entitled Frontiers in geochemistry with Dr John Eiler Dr Francois tiso and stepping in for Dr Catherine

declear who had an unexpected illness come up uh Heather Knutson and so we'll welcome her in a moment okay um quick description over time the field of geochemistry at Caltech has evolved from a descriptive science to when increasingly concerned with the mechanisms behind its observations this will be a multi-disciplinary panel that will explore the connections between geochemistry planetary science geology and astronomy so and and we

have three panelists uh Dr John Eiler is the Robert P sharp professor of geology and geochemistry Bs University of Iowa 89 Ms University Wisconsin Madison 1991 PhD research and on at Caltech uh where as I said he is now the Robert P sharp professor of geology and geochemistry perhaps as importantly he has described himself recently upon wearing a Super Mario Kart toad hat to Renaissance Fair

as the most popular old person at Ren Fair threw that in there to see if you're listening because it is the post lunch thing so you've got to stay on your toes okay yay Dave's double okay all right next we have Francois tiso assistant professor of geochemistry investigator Heritage Medical Research Institute uh undergrad Ecco Nacional Superior geology listen to my French such as it is the

Leia University of Technology PhD University of Chicago visitingassociate Etc at Caltech since then um I actually wonder if I can break tradition a little bit and John first why don't you come out and sit Ren fair you can imagine him wearing the Super Mario Toad hat okay thank you for that and Francois why don't you come out and we have asked Francois in the spirit of

this morning to actually just cut to the Chase and open with a joke on any of your Fields it can be a chemistry joke uh planetary science whatever you wish yeah I had a very good noble gas choke but all the good ones are gone the planetary science one please oh yes how do solar systems organize a party they just plan it we whether we went

to the stage Dr Heather Knutson a pinch hitting today and her bio is on of course another device Catherine Heather would you like to come out and please I'm glad for Heather okay now there's a professor of planetary science in geological and planetary Sciences at Caltech BS physics Johns Hopkins University 2004 while still in undergrad worked at Space Telescope Science Institute which made her become interested

in astronomy PhD in astronomy from Harvard 2009 then two years as a Miller postdoc fellow in at the department of astronomy at UC Berkeley Cal has been at Caltech since 2011 and we welcome all of our panelists to the stage today for the seminar I'll say it slowly as you get seated entitled Frontiers in in geochemistry that's actually not what it's called but I can't remember

you'll have a slide and then I'll know what our title is fantastic yes it's after lunch so all is permitted okay yeah Frontiers and geochemistry take it away all right thanks so much Sandra and thanks everybody for being here I don't know how to get our slide oh there we go our slides are active so um you know Frontiers in geochemistry honestly that's a little abstruse

like what in the world are they actually trying to talk about what we really want to do with this 40-minute segment is get you primed for a conversation and then have that conversation about uh what is really going on in the exploration of space right now and uh that's a big subject there's a lot going on so to focus it sort of narrow it down we're

going to look at two very specific things that are happening one is a number of opportunities that make this coming decade you know one of the most momentous and active decades in the history of space exploration and uh the second is this focus on chemistry how do we use chemistry as part of space exploration what is that all about so um what is you know what

is creating this opportunity that inspires our discussion so one of them has to be the discovery of extrasolar planets I'm old enough to remember very well the conversation when everybody assumed there were planets other places there must be and yet how could it possibly be that we would see them that we would know things about them confidently well here we are we know about thousands of

planets I said thousands but I actually don't know that I'm like yes it seems like a lot okay let's just say thousands uh so we're there and it's accelerating rapidly this is a brand new era second thing we just flew this thing the James Webb Space Telescope that has radically extended our capabilities for observation that will have a feedback on the search for extrasolar planets but

it will also impact the study of the solar system another emerging theme is we're sort of gearing up for a much more concerted much more ambitious exploration of the outer solar system focusing on the moons of the Big Planets the Jovian Planets as sort of Little Worlds okay instead of thinking of them as Tiny rocks that aren't that interesting or they're just little Point masses that

surround the the real show of the planet the moons are actually incredibly exciting themselves they're geologically active like IO or uh there are these ice balls that seem sort of inert and yet we have evidence that venting out of them are organic Rich soups of water so they may be some of the most exciting places to look for life in the solar system and then finally

uh the thing that's most important for my own career I think Francois tiso will all say the same is sample return missions we're doing a level of ambition in going out and getting physical objects and bringing them back to the Earth that has never been done before so getting objects from samples from some of the most primitive oldest undifferentiated objects in the solar system so we

learned what it was like at the beginning and then going to Mars and trying to find little bugs or whatever okay so how does this uh how does this work so there's a set of motivating questions and then there's some materials and some methods and things that we use so let's get some of these ideas on the table one of the biggest questions that we ask

is how planets form you'd think it would be a solved issue we live on one we have a bunch we can look at in the solar system it's very unresolved we really don't understand physically chemically how you go from the discs of gas and dust around stars to the planets that we see second thing is planetary diversity every single planet or small kind of interesting Moon

that we have ever seen is unique every one of them is unique and so how do we understand that uniqueness where does it come from how do we process it what do we learn from it that's generalizable habitability so how do we figure out what sets of planets and what kinds of environments are potential homes for life and this is something you might imagine well you

just look for places that are like the Earth who's to say you know there's limits to where life as we could understand it could exist but those limits just keep expanding and expanding and we have to be very open-minded and very observant to figure out what the real places are where we might find life elsewhere will we ever find it okay that I would say the

discussion today about life in the universe is where the discussion about planets was when I was young people have opinions they feel like it should Exist Elsewhere but where is how are you going to find it where are you going to find it and then there is an existential question about life on the earth and anywhere else that we might find it how do you go

from a non-living part of the universe to a living part of the universe it's really an incredibly profound question and it's one that when you try to dig into it it just slips through your fingers it's very very difficult to understand how you're going to address it so there's two different sort of modes of study that you you're going to see represented in this discussion one

of them looks at materials that are really large in scale often very far away like the interstellar medium discs of gas and dust around other stars atmospheres of planets within the solar system or outside of the solar system these are some objects of study and then we have other sort of more intimate small scale things that are more tangible like meteorites rocks that fall out of

the sky and presumably came from space samples we actually went into space and got and then laboratory simulations attempts to reproduce the environments the processes the materials of extraterrestrial things we approach these two sets of uh of objects in very different ways we have remote observation with either Earthbound telescopes or orbiting telescopes and you're going to see Heather talk about that quite a bit and then

we have geochemistry laboratories on the Earth where we try and ask relatively nuanced questions based upon the atoms and molecules that we have right in front of us in the lab so to give you a sense of one of the ways that this works I'd like you to tell you a quick just so story uh about something that was just done as part of the Hayabusa

2 mission this is a mission run by the Japanese space agency to go to the asteroid ryugu which formed initially in the outer solar system came into the inner solar system has done a quick journey in near the Earth and we were able to go out and grab a piece of it so this is the first truly uncontaminated organic matter from outside the Earth that's ever

been studied without exposure to the Earth environment so one of the things that we're interested in studying this is the fact that the chemistry of the universe is organic in some sense when we look around it ourselves like why are we made of the things that we're made of why is life composed of the molecules it's composed of the universe is mostly composed of these things

when you just focus on the big molecules there's all kinds of stuff out there ethers and and nitriles and who knows what okay all kinds of crazy organic molecules that we see in the interstellar medium in disks some of the most abundant of these well for sure the most abundant of them are basically compounds that look like soot okay it's not very promising I don't think

there's anything alive today that's like made out of soot but this is the the Bedrock if if you will of the organic chemistry of the universe you look up in space this is what you see in every direction is uh is these aromatic soot-like molecules that are composed of rings of carbon that join together to make sort of tessellated collections of rings and most people who

study these have a sort of casual guess about how they form they look like soot maybe they form like soot okay maybe they condense around hot Stars another heretical idea is that they form by very low temperature reactions at like 10 Kelvin in the interstellar medium may be excited by light that interacts with the atoms and molecules that are there so we just did an experiment

meant just a few months ago where we took the ryugu sample extracted from it uh these soot-like molecules and subjected them to a really new form of mass spectrometry that is it's called Fourier transform Mass spectrometry where you basically take the molecules you're interested in and you put them into a little cavity and you excite emotion so they're sort of harmonically oscillating around in this space

and uh you you don't you never really collect them you just listen to them and the frequencies of their motion uh tell you their mass and we use this to map out the isotopic structures the presence of rare heavy atoms within the structure and what we discovered is that the rare heavy atoms of carbon carbon 13 instead of being randomly distributed across multiple molecules like would

happen in a high temperature environment with lots of entropy and thermal energy they're grouped together cluster together something that we know thermodynamically is a signature of very low temperature chemistry the soot that populates the Universe it's made in interstellar space at like 10 Kelvin and that is the first step on the path through the organic chemistry that sort of lands at us so let me now

turn it over to Francois thank you John so we're going to move from these Interstellar media particles and ask the question of how do you go from that to a solar system with planets like our own and in my line of work we study really our solar system and then Heather can expand to extrasolar systems but the the general idea if you look at any textbook

you'll see something like this where a giant parcel of molecule what we call molecular cloud which is just Cloud gas and dust the particles that John Ware was talking about is going to collapse unto itself under its own gravity and it's just by the requirement of physics conservation of angular momentum you're going to end up with something that is disc shaped and then those particles will

accrete into planets and it's very vague the way I describe it because it's very vague the way we understand this process but a few years ago these images that were just theoretical were really bolstered and strengthened by the observation of the first planetary system in formation this is an actual image for once even though it looks exactly like the diagram on the left this is the

T3 uh Alma image that is that was taken a few years ago you see at the center in very bright a protostar and around it a disk of gas and dust and this is a very large feature Au is astronomical unit that's the distance between the Earth and the Sun so you can see that this is a very very large object and what you can see

even though the image is a little fussy because it's a very difficult image to acquire is that there are gaps in the disk the places where there is no light meaning that there is no more particles in in that portion of the disk and in between those gaps where we think planets are forming there is very densely populated regions of of material that can form more

Planet as the disk evolves so this is uh this is all very nice and it shows us how some planetary system very far away from us can form and the question I'm trying to answer and we're studying here at Caltech is is this uh our solar system formed so to do that well we have to turn to our solar system and we have to look at

the objects in our solar system and we have grown planets that are very difficult to sample the Mars sample return Mission will be very exciting because it will bring back contextualized sample and we'll discuss that more but one thing that is very often left out is that in between Mars and Jupiter there's the asteroid belt and the asteroid belt does not look very impressive when you

when you just look at a cross section but it's actually populated by an enormous amount of material a very very large amount of small fragments that are the remnant of planetary formation and solar system formation and sometimes we're lucky enough that one of these objects gets Disturbed from its orbit and Falls onto Earth and we're lucky enough when it's a small one otherwise there is no

civilizations left and and we get things like this so this is one very famous meteorite it's called alien day because it fell in Mexico in 1969 you can recognize on top of it there's this Fusion crust that is typical of burning through the atmosphere of the earth upon entry and what we do in the lab is that we take these objects we clean up the fusion

crust because we don't want any Earth and Atmospheric nation and we bring them into the lab and we digest them into nasty acids which is why we need a very clean and acid resistant lab and and we use Mass spectrometric techniques that were in great part pioneered here at Caltech to study very minute differences in their composition and and we do that because it tells us

everything we need to know to reconstruct the chronology and the evolution of the soil system we get ages at very fine resolution that's how we know by studying these objects that's how we know that the solar system is 4.567 billion years old plus or minus 0.1 percent uncertainty so very very fine knowledge here and we we learn other things too we learn like how closely related

are the different objects in the solar system so you don't have to be nice to cosmokers to see that if I plot those two parameters which you can ignore what they are you get two clusters this everyone can see except here you have Earth Moon Mars so you have a bunch of planets and other meteorites here and here you have meteorites that have in common the

only thing they have in common is that they're very carbon Rich they're very organic and water rich and so you have things that are very water Rich here things that are very water poor here and they're separated there is no Continuum and and the amazing thing is that there is no Continuum because you can imagine as the solar system is forming and the disc is moving

there you should have a lot of mixing and everything should collapse to essentially the same average value but somehow two different composition a clearly distinct were preserved the way we interpret this is that at some point very early in the formation of the solar system very early in this history Jupiter formed so if you think about this image I showed you with the gaps in the

disk of gas and dust this this would be a jupiter-like planet forming and Jupiter is so big that it prevents any exchange between the outer solar system and the inner solar system so this way we take objects that are stored magically stored for 400 billionaires in the asteroid belt we study them into the lab and we can say things about the very earliest step of the

formation of our solar system and other will take it away from there to look at extra solar system all right so we can learn a lot about planet formation and about the present day properties of the solar system by sending Rovers to other planets by looking at meteorites by doing sample return uh but if we want to know about planets orbiting other stars we can't do

any of those things so how do we study planets that are so far away that we'll never be able to visit them these planets are so far away that often we can't even see them so they're next to very big very bright stars and planets are pretty tiny and kind of faint so how do we even know that there's a planet around another star so most

of the planets we know of today were discovered using the transit technique and so what we're doing here is we're relying on an accident of geometry so we're hoping that the planet's orbit is aligned so that it will pass in front of the Star as seen from the Earth and if we're lucky enough and it does and we measure the brightness of the Star as the

planet goes in front we'll see the planet Blocks part of the star's light and that little dimming in brightness tells us there's a planet there this video is actually a video of Venus passing in front of the Sun so that gives you a sense for the size of an Earth-like planet going in front of a sun-like star it's a pretty small dip but it is actually

one that we can measure and this is how we found most of the many thousands of planets that we now know of orbiting nearby Stars if we want to study well if we want to find and study planets like the Earth though it actually is still a really difficult thing to see a planet that tiny around a star as big as the sun and in particular

if we want to know more than just there is a planet there if we want to characterize the planet in detail if we want to know what is its atmosphere made of Might it be habitable those are questions that are very difficult to answer for an Earth orbiting a sun but uh luckily their astronomers are pretty clever and we came up with a shortcut or a

solution to this problem which is if we study an earth-sized Planet orbiting a much smaller star than the sun in this case an M dwarf something that's maybe only 10 percent the size of the sun it turns out that little dimming and brightness is much bigger the planet's blocking more the star's light and those planets are both easier to find and also easier to study so

for the next foreseeable future if we want to study earth-like planets around other stars we're going to be studying systems like the one on the right an Earth orbiting a very small very dim m4th but we don't know if small planets orbiting small Stars will look the same as the Earth so they might be earth-sized but it's possible that their properties could be very different than

what we think of when we think of Earth or even Venus or Mars so something that my group has been working on and thinking a lot about recently is this question of what are small planets like around small Stars one important difference small stars are less luminous that means that the disk of gas around them tends to be colder and you're going to have more regions

of the disc where water condenses and freezes out small planets grow by creating things that are solid in their region of the disks so small planets around these cool Stars might grow by accreting a lot more water ice than the rocky planets in the Solar Systems I've accreted so we are trying to figure out if that means that there are what we term water worlds so

things that are maybe like Earth but with a thick mantle of water on top orbiting these nearby cool stars and if so how common they are all right okay so let's finish up this uh discussion with uh a look at two issues that are very forward-leaning things that are going to be happening over the next decade 15 years something like that and that are going to

be right at the heart of our study of uh chemistry and evolution and Origins and all these things that we're talking about so uh arguably the biggest sample return Mission that's going to be physical objects back to the Earth is Mars sample return this is well underway where uh we've already collected many of these specimens here is an image of the jezero crater topographic image of

the Jezreel Crater where the Mars perseverance Rover has been driving around for close to three years and one of the things that it did was to drill out cores sort of the size of a piece of chalk of rock from a variety of lithologies and they've been packaged up in hermetically sealed old little containers and they are awaiting some clever plan yet to be established to

launch them back into space and get them back to us where we can study them so all kinds of things are going to be done with these samples scientists like Francois will ask questions to refine our understanding of the accretion of the planet and its differentiation and things like that the geologists are going to get really excited about sedimentology how did you create the deposits that

look sort of like Deltas on the earth or alluvial fans but we didn't go there and spend billions of dollars to look at alluvial fans we went there to hunt for life so at the center of the work on this will be an effort to find organic molecules and figure out how they were made and so part of that will be a comparison with the context

of all of the other organic chemistry that's happening in the universe without the aid of life can we tell them apart another part is sort of a detective Story the clues that we get will not be very good the organic matter that sits for billions of years in rocks gets Disturbed destroyed reacts it's chemically modified can we see through that can we understand what it was

before it underwent that transformation and then finally can we recognize molecules that are products of life that's somehow different from the life on the earth so these are huge challenges my lab is going to be involved in using these measurements of isotopic distribution in molecules as signatures of life versus non-life Evolution versus preservation so and then a last thing Heather will comment on all right so

that's already a pretty hard problem but I have an even harder problem for you which is how could we tell if an extrasolar Planet had life on it we have much less information so when we find these planets the first thing we measure is their size so I can give you a list of planets that are the same size as the Earth and you might want

to know which of those planets could potentially have life so astronomers usually refer to this as which are the habitable planets and so they usually mean planets that could have liquid water on the surface so kind of temperate planets but if all you have is size you might notice Earth and Venus are the same size they orbit at distances from the Sun that aren't too different

but they are very different places and one of them is significantly less habitable than the other that is in large part because of the atmospheres that they have so if I knew not just the sizes of these two planets but if I knew something about what their atmospheres were made of and how much atmosphere they had I would know a lot more about whether or not

that planet might be a place where life could survive I could even do a little bit better than that so you might notice that Earth's atmosphere although it's mostly N2 also has a significant amount of oxygen so that oxygen is produced by life and it wouldn't be there if there wasn't life on the earth so if I looked at a planet like the Earth and I

measure a signal like that abundant oxygen I might be able to infer the presence of life just by measuring the gases that are present in that planet's atmosphere so that's that's the game for exoplanets we'll never be able to go there we'll never be able to sample things from the surface but we might be able to measure the gases that are present in the atmosphere and

if we can do that we might be able to figure out which ones could be habitable and even infer the possible presence of life we can do that for the transiting planets that I mentioned so planets that pass in front of their star when the planet goes in front of the star part of the Starlight passes through the planet's atmosphere and that imprints absorption from the

planet's atmosphere onto that light so we can actually see absorption from the atmospheres of exoplanets when they pass in front of their host star and so this is the technique that we're currently using with the James Webb Space Telescope to make some of the first ever measurements of the atmospheres of these Rocky exoplanets and we don't know yet what we're going to find the data have

come down but it's still being reduced right now and so we don't know what that answer is yet but we hope we will soon our presentation Sandra take it away yes thank you all right and your questions again we are using our slido Caltech 4. so what's the coolest thing we've learned from the jwst James Webb says the coolest thing the coolest thing we've learned so

far um we haven't it works yeah exactly yeah yeah definitely it's a big complicated telescope it took six months after it launched before we knew it was going to work and it had finished all of its deployments so now that it's doing science uh the first thing it did was look at a big puffy gas giant planet kind of like Jupiter but a lot closer in

those are much easier planets to study you don't want to do the really hard thing first you want to do an easier thing first to make sure it works so some of the first measurements we made were of this big hot puffy gas giant and we saw some gases that we didn't expect in the atmosphere of that gas giant and it turns out those gases were

made by photochemistry so the photons from the Star are breaking apart molecules and they're recombining to make new gases that wouldn't normally be there so that was kind of a fun surprise from the very first object that we looked at all right um whoops how important is plate tectonics in the evolution of life that's a melding of that's a great question so I I think the

on the earth we often connect these two together uh because plate tectonics permits the recycling of volatile elements that are needed to sustain the ocean and to sustain carbon dioxide and other things in the atmosphere if you turned off plate tectonics you might hydrate the crust lose the water from the surface the CO2 might get Bound in minerals and you might really shift yourself into an

environment where life as we understand it on the surface uh can't be sustained or it would have to change but don't get too uh hide bound to that because some of the most promising places that we are looking for Life uh outside of the Earth are not only places that don't have plate tectonics they're radically different environments from any environment that happens on the earth like

one of the images that I showed early in our presentation was of sort of plumes of little droplets and crystals being vented out of the icy crust of the small moon Enceladus this is just an icy carapace over a hundred kilometer deep or more ocean to an undifferentiated core it has nothing to do with any terrestrial environment and yet the Cassini spacecraft flew through it looked

at some of these particles and gas being vented and saw they were rich in diverse organic molecules this actually might be the exact sort of organic Rich soup that we are really hoping that we find in other places like in evidence for them in Martian rocks there it is active live in an environment that has absolutely nothing to do with terrestrial planet environments it's an icy

block way out in the outer solar system so don't get too committed to a simple idea like that thank you Dean asks is there a significance difference in the chemical signature of systems with hot Jupiters versus systems with distant gas giants like ours yeah this is a really interesting question is why do planetary systems turn out the way they do so why did we end up

with the solar system looking the way it does with Jupiter far out and Earth close in and why does it go differently sometimes around other stars we don't have a good answer to that yet but we think that the chemical makeup of the star might be an important factor some stars have more elements like iron and other sort of heavy heavy elements than others those heavy

elements are the building blocks of planets so stars with more iron and other elements will make more and bigger planets earlier so you might be more likely to have the planets interact with each other maybe a planet gets tossed out maybe another one gets sent inward so we don't have a good answer but the the properties of the star are definitely an important part of the

story um this is a poignant question has any of you checked in on how Pluto is doing for Pluto I really should have Mike Brown the man who killed Pluto but um answer that should Pluto be reinstated and we don't mean he's biased don't ask Mike Brown you don't ask the the the murderer about about whether the victim deserved to live or not because he had

good reasons he says he had his reasons we'll see uh Hospitality well let's see the last thing I saw about Pluto had to do with uh the the uh the dynamic geology of its nitrogen glaciers that basically the surface is more active geologically than you might imagine but it's doing things with like molecular ices of nitrogen and other things I don't know about so yeah so

it's there doesn't matter whether you call it a planet or not it's not going away another one is we are planning sample return missions from Mars and potentially other solar system bodies what's the risk of returning viable and dangerous organisms billion in these samples it's a very good question it's part of everything that John capped under things to figure out the first thing that will happen

to the Mars sample return is that they will be kept in a a locality that a local that will still have to be built it still has to be built right now and we don't know yet we haven't determined how we're going to keep things from spreading if there is anything inside How likely um anyone's guess is as good as mine you know that this is

going to be an essential question that dictates how we go about doing our job a decade from now will this the fear of contamination of the Earth by organisms from Mars that we were worried we haven't recognized we're worried we're not seeing them even when we try to see them if we're afraid enough of that we will not release the samples from a contained environment and

they won't go into Labs that are really capable of answering the most sophisticated questions if we overcome that fear we will uh we'll just do treat them normally like we did the the lunar samples or who knows maybe we'll find something living in there and then the the terms of the debate change a technical question are we specifically looking for evidence of phosphates on other planets

phosphates being the key to life on Earth absolutely so so in fact one of the most controversial and fun arguments in the uh in the search for life literature was the discovery of a phosphine molecule a phosphorus hydrogen compound in Venus maybe Heather could comment on that because it was a space uh you know a telescopic observation yeah I think this is a good illustration of

why it's really hard to look for Life using just the gases in the planet's atmosphere so you're looking for gases that don't belong that shouldn't be present without life constantly making them and initially phosphine seemed like that kind of gas in that case there was actually an even more basic debate which is there really phosphine and Venus's atmosphere and that actually turned out to be hotly

debated back and forth for a while uh is there phosphine at all if so exactly how much of it there is and exactly what is it due to I think that actually argument is still ongoing as we speak and then phosphate itself the po4 group uh this is an essential nutrient you need it for NAD HP you know all the rest of it so you need

to have it in your central metabolism and we think everything that has ever lived on Earth that we know of or any of its ancestors that we can easily reconstruct used phosphate as an essential nutrient phosphate in the environment in the absence of life is kind of inert I mean it'll do things but it's not vigorously cycled the way life cycles it and so when you

find evidence of phosphate being very vigorously geochemically cycled it's a kind of indirect biosignature it's not enough to prove the case that there was life in an environment but it says the Hunt is on maybe somebody was there doing this kind of chemist history what do you hope to learn when Vera Rubin goes online the Chilean Observatory which is being constructed thoughts that's a good question

phosphates no as a lab scientist I can say I hope to learn what it is because I don't know what that Observatory is but maybe somebody who does know I I think I've spent so much time being really excited that James Webb is up and running that I haven't thought as much about that one not not a problem just a pond and we already covered jokes

for today so we can skip those um I I think Dave zobel again my um I I think perhaps ending on this um many folks it's many folks continue to believe that they have a snowballs chance to be among the first settlers on Mars and that it'll be a hoot perhaps you could Enlighten them about whether it will be a hoot a hoot a ren Fair

a ren fair if they throw Ren Fair on Mars I'm going look it's just good fun so can life yes I I guess the question is could humans exist there uh for how long yes for 30 seconds absolutely you can definitely you can make it there for sure in what health is a question I mean one of the big problems of course the radiation uh during

the during travel from Earth to Mars you at this point everyone that does that that Journey will arrive there with massive cancer and so there's no trip back it's it's a one-way trip and maybe you get six months or a year to do something there but it is a very difficult Journey at this point so yeah often the discussion is about resource uh acquisition like can

we get uh we generate oxygen can is there water there's plenty of resources if you have modern chemistry and a big enough power supply and water and CO2 you can make pretty much whatever you want if you're really determined about it but there are these other factors like you mentioned radiation exposure Landing an object on Mars that's big enough that it could contain one or more

but there's a big difference like this is an engineering problem you don't just have a clever thought you actually have to build it it has to work you have to test it uh so there's a lot about this that is very speculative right now maybe wrapping up with two questions one is more slightly more technical which will be how important is citizen scientists access to Big

Data from observatories has it brought us new knowledge we hear a lot about that and ending with a question for each of you what is your dream space mission that hasn't been planned yet citizen science access to Big Observatory data I think science always works better when the data is public and so there's a number of NASA telescopes that just take all their data and and

dump them out there a great example a lot of the transiting planets we found all that data is public any of you guys could download that and look for little dips in brightness if you want um actually is a citizen science project to do exactly that that has found some planets orbiting other stars that no one had noticed before uh so I think that the more

people look at and share the data and the more eyes we have on it the the more we discover dream space yeah yeah so it's a dream space mission I can tell you a dream space mission so the the specific kind of uh exotic isotope chemistry that my group studies that I gave you one little vignette about it returns uh an unprecedented level of depth of

detail of your understanding of how organic molecules got assembled so if you're searching for life in the solar system that's a kind of information you really want and up until relatively recently the only objects that could make measurements of this sort were the size of like a cement truck uh they were never going to fly so we now know just after the last several years of

work that an object that's electrostatically controlled in the size of your thumb can make these sorts of measurements that's a thing that can fly and so I am really optimistic that sometimes you know maybe not within my career but within my students careers there will be a flight instrument that makes very diagnostic isotopic Fingerprints of the organic molecules around Enceladus on the surface of Mars and

other solar system environments able to answer questions about the biogenicity of organic molecules in situ elsewhere in the solar system any other quick thoughts your dream space mission uh the biggest telescope possible in space planets around other stars they're really tiny the signals we measure are very difficult so it's all about collecting as much light from that star as you can so the more light you

have the more you can measure the smaller the planets are the easier it is to look for things like oxygen in the atmosphere of an Earth-like planet and finally Francois you get the last word instead of going out let's bring it in and I would like a return mission to Venus because we know nothing about Venus we can't study it it that would be fantastic technologically

possible I'm happy to chat about this after yeah that would be the dream Mission okay please give a warm handle thanks to our panel discussion fascinating Frontier to geochemistry Dr Eiler Dr tiso and Dr Knutson so now we'll take a almost a 15 minute break it looks like and we'll see you back here at the hour at three for space time and fear survival decisions along

defensive circuits see you then okay thank you what