Getting To Enceladus and Europa Under Tough NASA Budget

I'm obsessed with Enceladus it is this world here in the solar system where you've got obviously some kind of ocean of liquid water and yet this ocean is being sprayed out into space waiting for us to sample it all we have to do is just fly through that plume of material with a mass spectrometer or two and try to see if we can detect any kind of organic elements compounds the building blocks of life or maybe even life itself it would be an amazing scientific Boon if we could do that but Enceladus is orbiting Saturn it's very far away it's going to take the better part of a decade to get out there is there a way to get there faster cheaper my guest today is Dr manavi Lingham and he has been thinking about this problem and many other problems and he's quite intrigued about the idea of using light sails not to fly out to other star systems although he is also thinking about that but as a way that we could expl really interesting places here in the solar system with radically different spacecraft spend more on the infrastructure to accelerate your spacecraft and that allows you to send more lightweight spacecraft at higher speeds to check out places and maybe this could be the ideal way to explore a world like Europa or Enceladus or Triton so we have a long ranging conversation we talk about this Mission but I think it's really important for you to understand just how wide ranging and uh like how into so many different fields manabi is he talks about astrobiology he has a background in engineering he has a background in physics in astrophysics he can sort of do everything and anything and so if you need somebody to calculate your Fusion drive he can do it if you need someone to find the amount of rogue planets out there he's your guy and so we spend like I said about half the conversation just talking about Europa Enceladus light sales but then we just keep moving and we talk about rogue planets and other ideas what is the smallest possible life form and the other kinds of things that that he's obsessed with so enjoy this fascinating conversation with manasvi Lam manasi why is Enceladus such a fascinating world to you yeah um thank you for that question and just to begin with you I just wanted to say I'm a big fan of today and especially your work on the YouTube channel as well Fraser so it's it's great to be on your channel um yeah now coming back to Enceladus uh you know it's a fascinating Moon because for for a long time as as we all know a small Moon of Saturn which is about 250 kilomet I believe in in terms of it uh radius and one of the most fascinating things about that moon is it's so tiny yet it Happ happens to have an extremely deep ocean that is underneath its icy shell and it's really fascinating because the average depth of Earth's oceans is about 3 kilometers whereas Euro Enceladus may have an ocean that is 10 times deeper despite being such a tiny moon and the best point of uh the best part of it all from the standpoint of an astrobiologist is that it has this big plume of material that is erupting from the surface which is believed to originate from that subsurface ocean we have talked about and so what this means is that there is an unprecedented opportunity to sample the plume and then to look for materials in its surface on its surface and in its interior now the NASA as part of the or the I guess the the planetary science Community as part of their last decadal survey went through all of their priorities and highlighted that yes indeed inel is one of the most interesting places and that it's a high priority and and yet we're seeing the issues with like the budgeting issues with the mar sample return Mission some other budget cuts at JPL like like money is a little tight these days so you're proposing a way potentially that we could get samples either study them locally or return them hopefully in a feasible shorter term process so so what are you proposing posing yeah great thank you yeah indeed as you said you know there is a funding crunch everywhere and so I want to before I tell you the solution that my collaborators and I who are Adam hiber of the inter Institute for intercell studies and Andrea hin who is a professor at University of Luxembourg worked on I want to tell you a little bit well I want to remind the the viewers a little bit about space exploration we all know that it began in 1957 with the launch of spart and of course the first interplanetary missions were in the early 1960s and we've relied on chemical propulsion for 60 years and it's done great I mean it's uh it's been the Bedrock of our space exploration but then the question then comes up at some point either now or in the future are we going to hit some kind of a barrier in so far as chemical propulsion is concerned mostly because of the fact that a rocket has to carry a huge amount of fuel to undertake complex orbital Maneuvers especially to uh pursue deep space exploration of the outer solar system and this is something that we are increasingly running into more as we start to encounter intriguing Targets in the outer solar system so what my colleagues and I have been really interested in is harnessing the potential of Light saes which I will describe in a second and using them to to carry out uh interplanetary exploration perhaps on a scale that has not been achieved so far and so now coming to light cells what are light cells as the name indicates um they are essentially spacecraft that are propelled by light just as a sailboat is propelled by wind so too does light have energy and momentum associated with it and some of that momentum can imparted to a spacecraft thereby accelerating it to a certain speed and it turns out that if you use uh laser you can focus a lot of energy and momentum onto a relatively small area and thereby enable the sale to achieve high high speed and this is of course a principle that is also very old but it is only in recent times that it has seen renewed interest uh thanks to uh some Concepts such as the Breakthrough short Mission and so on right and and people are so obsessed about using this technology to go to other stars but you're proposing let's use this as a way to explore the solar system first exactly um to use the well-known metaphor one must learn to walk before one one can run and so what we are really interested in is demonstrating the potentiality of light sales to Revolution our exploration of the solar system because if we can do that that would be beneficial in two ways one uh SP expiration of the solar system is something that can be valuable in its own right especially given that there are many aborts in the solar system that might Harbor life and secondly the other really interesting thing is that if we can demonstrate that yes light cells are well suited for Planetary Exploration within the solar system that what increase confidence in either governmental agencies or private agencies that yes we can actually now perhaps start to think about extending it to Interstellar scales as well so therefore I think starting with these kind of precursors would make uh the light sale architecture both more viable as well as more exciting in as far as delivering short-term benefits as concern all right well so I guess there's sort of two parts to this process then first let's talk about the the propulsion side of things and then we'll talk about the actual science that that we could do so so let's imagine that that you've made the case that this mission is is going to fly what would it look like how would it sort of function and operate where would the lasers be you know what would be the various pieces of the puzzle that would bring this thing together yeah so there's still a lot of things that that need to be worked out one of the most important among them which you've rightly highlighted is the laser because again for interal propulsion what was required was something on the order of 10 G of energy or so which is a huge amount of energy whereas what uh is required for an interplanetary mission to europ as to europ which is Jupiter's moon or Enceladus is that you would only well quote unquote only require about merely require only 100 Mega of power so then that brings up the question how would you of course uh Supply so much power through laser now some of the most powerful continuous wave lasers can provide a power of about 100 kilowatt which is a thousand times lower than the stipulated amount of 100 megawatt so what you would need is about a thousand such lasers acting in Tandem and using things like Adaptive Optics and so on to achieve uh uh you know synchronization to achieve coherency and so on and then Focus all of that um light energy onto the sale so that is still something you know which is still uh somewhat far from being developed but as we can perhaps discuss later the timeline that we fore is not that this would be done in a few years but in a couple of decades So based on how Laser Technology and advances in Adaptive Optics are going I think that in 20 years it should not be an inconceivable thing to do and should not even perhaps be an impractical thing to do so you see on the one hand the the increasing power of the lasers and the science moving forward and then on the other side thinking about how you could array a whole bunch of lasers together at the same time in some location to build up the shortfall and I mean this is a basic piece of infrastructure once you have this laser array available to planet Earth then Eur and sell a I mean the spacecraft are almost free at this point it's the it's the laser that's the expensive part yeah exactly uh first building the infrastructure and then secondly taking into account that you would of course expend a lot of energy per launch so there's certainly some launch cost associated with it but yeah once you have your infrastructure you could start to utilize it many a time so in some sense although a very loose analogy one might be reminded of reusable rocket that you have this infrastructure that can be used over and over without necessarily building a lot of things from scratch of course the light cells themselves have to be built from Scrat but if you find a way to supply the power then you just yeah keep beaming multiple space into space and indeed one of the things that we looked at was the viability of a swarm of small light saes each carrying a cube set that could carry out um a synchronized expression of some of the potential astrobiological Targets in the solar system and so so would this laser array would it be groundbased or space-based do you think yeah that's a really good question so um of course if one were to have it in space there would certainly be some advantages in so far as you know not affecting the atmosphere would be concerned in so far as not having to worry about transmission through the atmosphere but then again putting such a big system in space might not be practical for you know because you would still have to launch it inter space using conventional propulsion such as a chemical propulsion so what we looked at was the possibility of of having this laser array on Earth and depending on which moon we would be uh targeting we looked at different locations one of the things we found was that as far as say Enceladus is concerned having the light sale architecture and the laser array be somewhere near the Arctic Circle or the Antarctic Circle about 60° North or South might be one possible location and and that just gives you better geometry for being able to access some of these outer regions of the solar system yeah exactly so you you get better launch Windows for achieving the kind of encounter speeds with Europe and or ins that we would want so that's certainly one of the things yes so it's really all about optimizing the trajectory such that you achieve the desired encounter velocity at the point when the light cell intercepts the plumes of Enceladus or perhap even the potential plumes of Europe which have been Ambiguously detected right right okay so so we've got we set up this laser array and it's a huge undertaking by Humanity but now we've got this array in place and we're learning how to use these lasers a rocket launches it has the probe or maybe a swarm of probes that it deploys into orbit and then they're accelerated one by one by the by the laser array out into their Direction yeah exactly uh so we looked at two different possibilities one of which was using uh just uh a single light cell but with a fairly substantial payload of I mean the scientific with payload was uh and including some of the associated subsystem needed such as power Communications and so on would be about 100 kilg so that was one we studied where the total payload is 100 kilogram and then you have a light cell that carries this payload to di Moon the other one which we looked at where you would be of course much more constrain in terms of instrumentation would be to have a swarm of hundreds of uh of these light sails each carrying a payload of kilogram or there about oh wow okay all right all right so now let's talk about the science so you know it's one thing to get these probes out there oh and I guess how long would it take how long would it take to get to Europa versus Enceladus yeah yeah that's a that's a great question so again of course we were looking at some criteria you know like trying to in this case trying to optimize the encounter velocity so as to maximize our sence return so what we found is that in the case of europ you would be able to reach it in a time scale of 1 to four years whereas in the case of Enceladus you could reach it yeah really fast and then you could reach it for Enceladus in a time scale of three to six years now here I should actually add that because of the power of Life cells being what it is you could reach it extremely fast for example if you look at the relativistic light stes proposed by breakthrough stard you could of course get to these moons in a span of days but here we were actually trying to optimize the science as we will talk about later but it's still a few years which is great because as we know many of the conventional missions are about 10 years a little bit less a little bit more whereas here you can cut down that time by anywhere from a factor of say five to a factor of two or three right right all right so let's talk about that science so um what kind of science would you hope to do as you reach let's say Enceladus yeah yeah uh so yeah coming to Enceladus like I said it's definitely guaranteed that there's a big Ploom of material coming from the surface which is believed to be Source from the underlying ocean but then this brings up the question is there life in that ocean uh or you know could it be just simple microbes or could perhaps there's even fish that are swimming you know in in Enceladus ocean obviously we don't know and the latter seems to be somewhat unrealistic on energetic ground but now let's stick to microb for for the time being so then the question becomes you know how do we detect signatures of life that are present in that plume and one of the strategies that scientist often use is to search for some of the building blocks that make up life things like amino acids things like nucleo bases which are one of the components of RNA and DNA uh lipids which make a cell membranes all all these kinds of molecules now none of them in isolation is enough to assure the presence of life but it certainly gives us some confidence that at least the environment is habitable and perhaps even inhabited so what we set out to do was to look at uh the current instrumentation available and so it turns out that we have this particular type of uh uh instrument known as Mass Spectrum meters and in particular this a subass of them what they allow you to do is to determine the chemical composition of a species of a chemical species and so what we did was we looked at this existing instrumentation and then we also asked ourselves at what velocities would the spacecraft need to encounter the plume in order to detect these molecule because here's the thing if you go too fast the molecules are going to impact the spacecraft at very high velocities as seen from the perspective of the space you'll feel like the molecules are just coming in and bumping into you and so that's not a good thing because if you if they crash into the spacecraft at too high a velocity then they just get uh you know disrupted and which is something not we that we don't want so what we suggested instead was we want to minimize the encounter velocity as much as possible so that you move to an optimal range where you can uh probe the uh plume for sign for the bio signature and what people have shown a lot of planetary science literature that has been done has shown that encounter velocities of 4 to 6 kilomet per second with the plume are desirable and what we found was that um even without having any onboard uh propulsion to slow down you could still just by sending a light cell passively you could achieve an encounter velocity of 6 kilomet per second which is really close to that encount optimal encounter speed di menion so to wrap everything up yeah we uh we would like to use this tool called the mass spectrometer and then the goal would be to uh try and find biomolecular building blocks such as these amino acids nucleobases lipids and so on and with with the appropriate encounter velocity and so that flight time 3 to six years flight time that's really that's not as fast as you could go that's more about making sure you slow down enough that when you do your flyby you're not destroying the the molecules I did a recent interview on this subject sort of talking about different speeds and it's like if you want big like bacteria there are limits to the speed of being able to detect bacteria otherwise you start to splat them on your on your windscreen and so is there like a a slowest speed that you would want to go if you wanted to see something big and more interesting yeah so that's a really good question uh you know it turns out that with the more passive sort of uh I mean flyby you know where you're just passing through the plume and you don't have any other onboard uh you know uh propulsion system for slowing down or executing other orbital Maneuvers without that um yeah you you get to about 6 km per second but going much lower was not very feasible but yes to answer your question there is I mean they have been some suggestions that if you go at speeds of less than 4 kilom per second some of the techniques actually rely on fragmenting the larger molecules into smaller parts and then analyzing the smaller parts and then putting back the data together sort of like uh you know like Lego where you can not only build up from the Block but you can also take it down and construct something else so the suggestion is that the lower bound might be um you know somewhere in the range of two 3 four kilometers per second it's interesting sort of imagine you know do you want to be able to gently collect the samples as you're passing through or is it more like throwing them into a blender and just the speed that you go will will Define that um you know the the balance is always between is there a way to do a sample return Mission or does it have to be in situ and it feels like you know if you're going to try to bring along a mass spectrometer try to do some you know what's the minimum size of that mission to carry along enough science to be able to get a definitive answer to your question yeah so I think with the technology we have uh like I said a total 100 kg payload you know which includes things like um you know a high gain antenna things like um having um the r you know the r the radio isotope generators to poers to do some internal uh you know to power some of the internal systems and then also to have the M spectrometer which would be similar to the one on Europa Clipper which is called suda surface dust analyzer uh when you put all of those together and you also of course allow for some tolerance levels and and maybe some other system that I didn't uh allude to I think about 100 kilog especially when we are talking about 20 years from now should be doable now that being said um it is somewhat hard to predict the pace of miniaturization so the 100 kgr estimate I think is a fairly conservative one that you know would be certainly achievable 20 years from now but moving to the Other Extreme of swamps and then using these Cub set well right now we certainly don't have Mass spectrometer that I'm aware of which can uh recognize these biomolecules Which is less than a kilogram and then when you add in all the other auxiliary system yeah I'm not sure you can do it in say a kilogram at the moment but 20 years from now again it's rather hard to focus which is why you know we accounted for one more conservative scenario where with a 100 kog payload you would be able to incorporate all the Salient subsystem but then we also looked at this somewhat futuristic pathway whereby maybe you can use a 1 kgam payload to incorporate uh all the instrumentation you need and another advantage of the swarm of course it has a lot of redundancy built in b and a lot of flexibility built in as well because you can have different uh probes with different payloads which can be complimentary or supplementary to each other I so I mean this idea of say 100 kogam spacecraft I mean you're proposing the light sale idea but couldn't you also put this spacecraft on top of a falcon heavy plan a couple of of planetary flybys past Jupiter maybe to build up a little bit more velocity and and pull off the same Mission and maybe even have a way to go into orbit or be able to stick around longer yeah that's a great question so I have two answers for that both both are uh important but in different ways the first thing I will say is one of the things we also study in the paper and perhaps it can be linked in the description somewhere is that we do talk about the possibility of having onboard propulsion as well so it would be primarily a life Trail but with you know some amount of onboard fuel for maneuvering as well so that would indeed allow for some kind of further Maneuvers in involving Jupiter or Saturn and also perhaps just slowing down and trying to get into orbit so you do multiple flyby and you can even perhaps have an Orbiter in the ex case so we do certainly look at those hybrid architectures as one could call them which have both the light cell component as well as the chemical propulsion component that's one answer I would I would offer and the second one is I would say even if it were to be true that chemical propulsion you know is the way to go for encel if we go to something like say 500 Au or 100 Au some hundreds of au of course right now there's no interesting Target we have found although there are some ideas that planet 9 if it exists may be prevalent it turn I mean there's always the solar gravitational lens I mean exactly yeah yeah that's a very good point yeah exactly the FGL is one more crucial and documented uh yeah piece of I mean location that is certainly so for all of those it turns out that at least with the current Rockets we have uh you're not going to be able to get there you know with the mass ratio one has the requisite Delta V requirements will not be met unless you probably do an endless number of Ling short so there are certainly limits up to which chemical propulsion can operate so this sort of hardens back to my original point that we see this as a precursor and if it were to materialize that it would show the world well look light sales can also um assist Humanity in understanding our solar system better and in exploring the uh the deep space around us so I think in that regard also um it could be a great demonstration and which case one could use it to venture out further and further out into the solar system so you know at 500 Au you could have the solar gravitational lens at about a, Au the old Cloud would start and some of the other work we have done in the last year entails you know looking at potentially free floating Planet just wandering through the planet the solar system so all of these I think are Target that are not accessible to chemical propulsion but lifestyle architectures could enable us to explore this world and Enceladus and Europa could be the first step in what could be a very rich and rewarding Journey but it it it it feels to me and you know this is your specialty but but it feels to me like like Europa Enceladus are are like Phase 2 kinds of of targets that would require as you said maybe a 100 lasers kicking in each one in the multi megawatt range to be able to work together to to form this this array I mean that's a serious um piece of infrastructure that's going to have to be built not to mention the the political issues about who gets to own it and the where it gets pointed and and so on like this idea of sending these light Sals is so exciting at the smallest scale I mean is there a what what would be sort of like the smallest interesting mission that you can imagine with this kind of of technology I mean could you send these tiny 20 G Sales to do flybys of asteroids and take pictures and things like that with a smaller laser and smaller spacecraft yeah that's a that's a great question so you know we did indeed of course because it projected 20 years into the future we we do implicitly assume you know a few assumptions which I think can and should be of course question which does include things like you know Humanity having relatively stable uh Society you know that still investing in science and so on so you know it goes back to the geopolitical implication you said it also assumed that we have some technical uh Mastery already over life sell architecture so this is where I think your question would come in so you know Europa and Enceladus are about 5 to 10 Au away from from Earth depends on the exact number I mean the the configuration of the various planets Earth and these object but I think one cannot certainly right away do those missions so I think it does I do agree with you that one should start even smaller you know maybe with a mega uh scale uh laser array instead of 100 Mega where you send a very lightweight probe to a nearer asid maybe1 Au or or about One AU away just again do a proof of concept then perhaps The Next Step would be to do a flyby of the Moon then Mars then you know lots of other objects along the way so yeah I think it has to be very much step by step and as for what the lowest Mass should be uh you know again breakthrough stash short famously looked at gr Mass probe and certainly those uh you know seem to be feasible but that being said of course they can't do a huge amount of uh sign because of their uh Power requirement because of their uh you know their size requirements as well and because certainly you would not be a to carry things like mass spectrometers at those masses so yeah I think it it really depends on the kind of science you want to do but if it just Imaging you want to put a camera yeah that absolutely could be done with a gr m b and yeah you could start off really small and explore near Earth asteroids and then from there you could go on to look at Moon and so on I mean there there was an idea that I I liked this idea of electric sales I don't know if you I'm sure you've looked into electric sales as well well and there was this proposal that you would launch a fleet of these tiny little electric s spacecraft and then they would fly out on on orbits that would fly out to say 10 what a 100 different asteroids but then the key is like you wouldn't be able to communicate with them but instead you would wait for them to fall back down into the inner solar system get close to the Earth and then you could communicate so so that I think you know then you have that Advantage like you don't need as much laser power because you don't need to set you don't want to send them at at High Velocity you want them to fall back to you and then you're asking yourself like what could you have a like a falcon heavy with that's that has a 10 kilowatt laser on board that then throws out a whole bunch of of little mini probes around it and just starts accelerating them away one at a time to sort of test out the technology I mean it it feels to me like there is this giant Gap in practicality right now that you're seeing these presentations from break true star shot I'm reading papers from people like you and and a lot of people in this field you know Marshall Eubanks who I've interviewed many times he's one of your collaborators you know that that there's all this hand waving about that technology but is but where does it start like if we know that the age of light sales has begun what does that first and knowing that you're going to need that infrastructure of the laser system what is what do you think think is like the first practical kinds of demonstrations of this technology that we could probably see because I don't think you said well first we have to spend a trillion dollars building a laser Ray that we don't know if it's going to work that doesn't seem feasible to me right right yeah and that's a great point and I think yeah I think certainly you know a lot as I said these proposals do assume a lot of maturity in lightell technology as the starting point and that is indeed one of the thing that I think is um you know want of a better word is a limitation of all these papers and so what I would say is that uh yeah by the way I do love electric sales as well and as you said I I have written a couple of papers on them too yeah but coming back to life cells I I think yeah we should probably start even putting aside near asteroids you know there's still Things We Don't Know About Us magnetos very well or say to pick a more specific example maybe the Magneto pause or the Magneto tail I mean various components of first magnetosphere so that is of course um just something like 10 Earth radi so it's much closer than the moon so I think even exploring that and then getting some insights would be valuable especially if you have a swarm of this Pro then you could you could sort of surround many different areas of Earth's magnetosphere and then map out it threedimensional structure better than you know having a single space CL trying to trace out the outlines of the magnetosphere so I think these kind of missions you know would be of course very valuable not just for uh planetary astronomist or astrobiologist but for planetary scientists space scientists and so on and for that um again depending on the mass of the probe maybe you could get away with something that's a mega or less and for that you would only need you know a few tens of uh let's say 10 kilow lasers that that would be needed and to achieve uh coherency and Precision in terms of uh synchronizing those T of lasers should be doable I mean I think right now the record you know seems to be about a dozen or so it's not exactly my area of expertise so I I think that yeah that's where one would start and obviously even that would still be a fairly expensive Miss you know one would still obviously be talking in the billion in the millions and the laser infrastructure would be on the order of a billion you know to begin with but certainly not a trillion as some of the more ambitious proposal demand and so I think one would want to scale everything up by a factor of 10 so let's say 1 billion in total total capital expenditure 10 lasers then the next step would be 10 billion 100 lasers and and so kind know to keep adding to an infrastructure structure that's already there rather than building many different outposts like choose one location which could be uh convenient from geopolitical standpoint ethical standpoint technical standpoint of having good launch window good atmospheric conditions and then kind of keep building it Brick by Brick that's how I might Envision it but then this is also a somew Speculator yeah I I mean I think about the world of of AI right now that that once this idea of large language models were developed and we saw the power of these things like chat gpt2 and eventually Chad gp3 and chat P4 suddenly people realize there's ways to make money from this and then there's an investment and it's incremental and you know say Chad gbt cost $5 million to train and then gbd4 is is on the order of 100 million or 50 million and then now we're seeing they're starting to pull together budgets that are going to have some of these training Runs cost into the billions tens of billions they're they're piling on the computers and so and so it's like you need this transition from the the and that it's such a heavy infrastructure cost it's really hard to figure out how you get there from here because it it you know we all learned about breakthrough starshot I feel like it's 10 years ago when they made their anoun I'm sure how long it was that that that they made their announcement and there's been a lot of great ideas you guys have been producing a lot of documents a lot of papers but a lot of it is like question mark question mark question mark like laser multi-trillion dollar laser array goes here and yeah absolutely there are there are new uh materials that need to be developed and and so on um I'd like to shift gears now and and just talk about your process because I highly recommend you go look at uh's um like list of papers on Google Scholar and for people who like enjoy my channel the kinds of topics that I focus on each one of these is catnip to people you're proposing deep space missions return sample return missions from proximus sari um you are willing to think some pretty out of the-box ideas and do the math uh where does this come from yeah um yeah that's great question I think um you know it's just sort of nice to have an answer that would be somewhat unorthodoc but I think I have the most boring answer ever which is probably it goes back to Carl San to some degree you know a lot of my family members uh my parents and so on my grandparent too actually were all big fans of Carl San especially his cosmo series which a you know in the early 1980s it was before my time but I grew up on stories about it and so on so I think it definitely you know put that spark in me and of course having had a rather um a bit of a Meandering academic life has sort of helped because you pull in different skills at different points in your life I mean my undergrad was in engineering the PHD was in physics uh post doal appointments were in astronomy applied math so I think all of these have contributed something or the and yeah I think in in so far as exploring unorthodox ideas of course on the one hand it's it's really fun to do but on the other hand one wants to stay as grounded as possible so that's that's been obviously a challenging thing to do and so yeah it's it's still something that trying to figure out every day it's interesting though right you've got this this the first piece of the puzzle is engineering right and then the and then the second piece of the puzzle is the astronomy and and and astrophysics and and and so on that you're s rooting those ideas in in a more practical okay but is this going to really work so like what's your process like like do you you know you have these shower thoughts are you just like driving in the car and you're like I wonder what it would take to dismantle Mercury and turn it into a Dyson Sphere or whatever right like like and like for most people I think they have a filter where they go that that's ridiculous but you clearly take these ideas one step further yeah no I yeah I think it's um it's sort of you know it's yeah a lot of them do indeed come in in places like the shower or when one is washing dishes I I I like to wash dishes by hand I've never used a dishwasher all right you're a crazy person now I take it all back yeah so you know it's it's kind of interesting place to get ideas but then I think to the second part of your question I would say some part of my work has been very conventional you know I started off in plasma physics and doing pretty conventional things about say magnetic reconnection which is documented in the magnetosphere which we were talking about things like that but still you know do those do some fairly uh standard work for instance I've done fair amount of work on atmospheric escape from exoplanets which again you involv using a lot of plasma physics but these in in more I would say Innovative or out there ideas also are part of the whole Corpus and I think it's having both has help because these more grounded Works help keep the more speculative Works a bit more grounded as well and then the more imaginative Works help add a creative element to the more routine work as well so I think they all feed off each other so it's being I think that energy that really work so I mean can you give me an example of an idea maybe one that you've had recently where you're like I wonder if this is possible and then you because you don't like your your instincts don't tell you immediately that this idea is feasible or not and then you sit down and you're like nope this will never work so like most okay so most people they have instincts where they say like in their mind they say why don't they just and then they say something like you know why don't they just I don't know the classic example I always get is like why don't you just why don't you just uh have the the Ingenuity helicopter fly over top of a Rover to blast off the sand and then that'll clear off the dust why don't they have a little fan that they blow onto it whatever and so I think that that this future that we have can go in so many different directions and and as you sort of are creatively looking at these different pieces and you're putting them together in your mind I new outcomes are coming and so at some point you kind of go ha I wonder if that would work and then you sit down and you do the math and you're like nope that's ridiculous do you know have you had one of those recently yeah I think in in a sense although it was not completely in the engineering realm and a bit more in the science realm was the following so you know the the popular narrative is that Proxima centu is the closest Extra solar planet to Earth I mean it's just it's repeated so often that you know we take it for granted and yeah it makes sense why people say that because Proxima centuri is the closest star to Earth and we are implicitly brought up to believe that planets exist around stars but one of the things that we've been learning from whether it be gravitational microlensing studies of uh of planets on extremely elongated orbits or planets that are actually not bound to a or the interstellar object that we've been finding in the solar system such ASA and Boris all of these are telling us that there's a lot of um bodies that are just traveling through space just floating through space so one of the things that struck me was well how close are how close on average is this nearest Planet size object like say we take an object the size of mass how how close is that is it closer than Proxima centory so we took all the available constraints and then tried to map it out in this paper with Marshall Eubanks and Andrea Stein again and um yeah we found that the nearest plane sized objects would be almost an order of magnitude closer to Earth than Proxima Cent so some of them would be instead of being 4.2 Li years away would be half a lie away or you know one liye so they could be a lot closer so this was one of those things where one doesn't really think about it because we are again Tau to think of exoplanets as being around star but once we sort of let go of that notion you turn the crank and then you work out where the closest could be it turns out to be quite a bit closer potentially based on the available data and then the followup part to that the inhering part was well5 LS is still pretty far I mean it's um it's not exactly as far as Proxima but it's still plenty far and then the question was could chemical propulsion get there and then we looked at it with the current technology answer was a resounding no no matter what kind of OB maners you do what kind of slingshots you do I mean there might be some super crazy scheme you know where you do an endless number of such Maneuvers and get there but in so far as doing one or two orot Maneuvers and you know Jupiter over solar Rob doing slingshots none of them were U actually getting us there in a reasonable time it was like 50 years or so and that's why that doesn't seem very reasonable 50 years but Voyager has been traveling for 50 years still giving us data so then we had to look at a whole bunch of other propulsion electric sales light sales electric propulsion nuclear thermal nuclear electric blah blah blah so yeah that was one work where you know it all sprang from thinking about what exactly is a planet and then how close is said Planet yeah and and it is kind of exciting uh there was a brown dwarf that was discovered fairly recently that had uh methane emissions so probably some kind of interaction with a moon and so when you think about Enceladus or Europa you've got these tidle interactions between a a moon and a gas giant well maybe you get the same thing so the the planet itself might not be habitable or but maybe you have two stars you know maybe you have a gas giant out there with planets orbiting around it and they're habitable to some extent oh yeah definitely and then the other possibility is you you may not have life on the surface but you may have life underneath the surface again just like European encel and then you could have tidal heating which might even heat the surface enough that perhaps even surface habitability is possible so I've actually been spending quite a bit of time over the years on rope planets I think the first work we did was in 2019 so it is a bit of a recurring theme but with every year of course we get more data so we able to constrain the potential abundance and distances of these uh Rog planets uh more and more and of course we also start to incorporate more of the inhering factors into consideration such as how would we explore these worlds on a relatively short time scale of one or two human Generations right right which is always ideal um you know for the researchers Who start the work to be able to see the results of the research but um but then but then also I mean you know they always say like the what is it you want to plant a plant a tree that you may the wise man plants a tree that he may never be able to sit under its shade right that that we're so caught up in this fast turnaround time oh we we need to be able to make this within 20 years whatever but if we're patient the voyagers are going to reach the equivalent of the nearest star system in 50,000 years uh they just you know they weren't pointed in the right direction and they they won't be able to operate for that length of length of time and so when you think about those rogue planets coming by they probably come much closer oh yeah yeah right oh yeah definitely yeah no the the one we are talking about you know do pass within uh because as we said the closest one might be you know about5 light years from Earth so yeah definitely quite a bit slower not not too far out in fact some of these rope planets will pass um at distances that are comparable or perhaps even slightly smaller than the outer edge of the O Cloud which contains the F they they definitely not close I mean they're not sorry they're not far they are passing by relatively speaking in our neighborhood I mean so which is fun because um instead of us having to vure out into all reaches of the Galaxy which right now is a very science fictiony idea and not you know something very realistic yeah we are just waiting for all these objects to come to us and we can just survey them in our backyard so to speak right hitch a ride as they continue on to to other other locations but like just this process of what we're doing right we're sitting here and we're brainstorming we're talking about different ideas that's one thing but the the next step is to commit to actually writing a paper to doing the math to to spending however many you know you produce 10 15 papers a year each one is a month's work in addition to your teaching and and and so on so for you what what crosses that line between you just doing like a a backof the envelope calculation with with Andreas and you know and and other collaborators or what's you actually see to okay fine this is a paper when do you how do you draw that line between that yeah uh well I think one of the things that's sort of helped although it's not always a fail safe is the idea of testing your hypothesis or your claim of course to some degree you can always model anything but then the other thing one wants to know is is there a concrete plan whereby you could uh further analyze the hypothesis or test the hypothesis ideally or falsify it to use the paparian metric and so on so I think um that's sort of being you know mostly a guiding line that uh if one speculates it would have to be rather discipline speculation that could be subjected to some form of falsification now of course for some of the more futuristic ining project it's not really about falsification but in those works it's more about figing out okay do we have enough of a concrete part yes we do have to handwave away some of the specific such as say the geopolitics of putting 100 megawatt area in some part of the world obviously that those kind of consideration are super important but one does indeed sweep them under the rug but some others we can and do predict certain things such as saying okay with for this light cell this is the optimal trajectory to achieve a certain objective and then like we've discussed perhaps life styes can be scaled up and so at various points one can have checkpoint to see their viability and so circling back to the scientific idea you know I've done of course a lot of work on trying to understand the habitability of exoplanets and the potential for life on different kinds of exoplanet well for all of those you can try to identify putative bio signatures or some other geological markers that might manifest and if so again you have a concrete plan for you know testing these things and then trying to figure out uh whether they work so I think that's been my guideline so one or two of the work that we did not pursue further did not meet the criteria that I spoke about so they were just uh you know mostly sort of there might have been some doodling on you know pieces of paper like like these but uh yeah after that they never saw the light of the that's great uh what are you obsessed with right now well uh yeah one thing that I mean this is perhaps the current one so it has nothing to do with our discussion one thing that is really taken up a lot of my time and interest is thinking about how small can a living organism get so that's something that has not been studied a whole lot but it again turns out to have a lot of real world implications for astrobiology because in 1996 there was this maturite alen Hills 84001 and people claim that you know they had found these putative micro Nano fossils I should call them microfossils that were um you know that was found ostensibly found and it led to a whole lot of media attention I believe there was a press release by President Bill Clinton on white La yeah so you know I mean again I think it was a very interesting paper it actually kickstarted modern astrobiology now we think that it you know it doesn't seem to stand up very well to scrutiny and there's many reasons why I mean many of the uh non-biological mechanism can replicate similar patterns and so on but one of the things that people bring up is yeah you know those microfossils more accurately nanop fosil are too small to be uh actual actually compatible with living system and but then the question is how do we know I mean and the most simplest answer is people just compare with known uh bacteria ARA and so on on Earth but I think there are ways to approach it from the standpoint of what kind of biochemistry do you need what kind of uh biophysical constraint do you have what kind of metabolic constraint do you have so lots of different constraint so that's something that's been of a lot of for me lately and do you have a sense I mean you know we always sort of talk about viruses you know we argue our viruses life are they not life and then there's whatever is the smallest life form right now like some kind of archa or whatever does it appear that you could you could miniaturize the smallest life form by a few orders of magnitude and still have it function as life yeah so that's a that's a very good question so you know my investigation did lead me to write one paper I think it was in 21 or 22 and then I had one more in 24 so a few months back but this is I think I see this I see this probably as a multi-year program again so yeah coming so so therefore whatever answer I give you is going to be a preliminary one now with that caveat out of the way and you know we scientists love our cavat if we have given the chance we would just fill you know the entire sections with caveat but yeah now coming back so the smallest bacteria and ARA that we know of seem to have uh sizes that are about 100 to 150 nanom in diameter so that seems to be about the value that we know of right now empirically so some of the theoretical work I've done has shown that perhaps the size in terms of the diameter would go down to about 50 nanometers or so but not a whole lot more so in other words it is quite uh it is not too far removed from the absolute minimum we are actually observing on earth now viruses are of course a different story because the requirement you have to build a virus is a lot lesser than having a fully free living organism that you know doesn't have to rely on some form of parasitism or some form of dependency on another organism so I think um yeah so I would say that the limits that the theoretical models seem to be predicting appear to be quite compatible and close to the limits that we observe on Earth which again seems to have some interesting implication that perhaps evolution is not something you know where um the whole b space of the parameter space is not being orbitally explored that is to say you can't have a 1 nanometer back iium but rather it is constrained by certain physical and chemical requirements so I think that has been the one big question that you know I've been grabbling with over the last couple of years which is what are the chemical and physical constraint on living system and then how could these constraints inform Us in the search for life even Life as we don't know it as well oh it's really interesting it's kind of a fascinating thing all on its own it has implications to the work that you're think about with the Enceladus Pro but also the search for Life both in extreme environments here on Earth and maybe in in other places when you've got other planetary conditions that might have a have a change to the world well M thank you so much for taking the time to chat with me today I really appreciate it you like as I said partway you're sort of one of the most creative but grounded uh space researchers out there and I appreciate you taking the time to chat with me today yeah thank you so much foring uh yeah uh um you know you've done great work in terms of popularizing so many different aspects of space sciences and I look forward to following your work in both Universe today as well as on your channel thank you so much for having all right thanks a lot I hope you enjoyed that conversation with manasi Liam now I'm going to chat about sort of my thoughts on the interview but first I'd like to thank our patrons thanks to AB Kingston Andre gross Dennis alberty douge Stewart Dustin cable Jeremy M Jim Burke Jordan young Josh Schultz Mark antis Modo Paul robock Steven Kaki stepen fer Munley and Vlad shipin who support us at the master of the universal level and all of our other supporters on patreon I really can't understate how interesting the list of topics that uh that monos has worked on and just how wide ranging they are and I promise you that if you sort of look through the list look through the papers each one of them is catnip to the kinds of people who are interested in this channel futuristic propulsion systems uh searching for rogue planets methods of determining astrobiology there's even lrange Point papers it's amazing um and and I'm really fascinated by scientists who will do the work that's sort of everyone's expecting the kinds of papers that are going to get into the kinds of journals but who are also willing to step outside of that comfort zone to take on ideas that maybe are a little bit out there and yet are scientific questions and are worth thinking through more deeply putting in the time to do the math to try and figure out if these ideas are feasible or not and so you know I'm going to put a list of his Google Scholar list of papers and then I High recommend you just go through that list and just click on any that strike your fancy and I'm sure you'll be rabbit huling for several weeks all right I hope you enjoyed this interview I've got lots of other interviews about light sales about Enceladus about collecting samples from geysers so uh that also should keep you busy all right we'll see you next time

Channel: Fraser Cain

Views: 22,731

Keywords: universe today, fraser cain, space, astronomy, exoplanets, James Webb, jwst, James Webb space telescope, tess, Ariel space telescope

Id: GxGl80RDrkI

Length: 60min 46sec (3646 seconds)

Published: Tue May 21 2024