Life on Venus - Deep Dive!

cool so today we're going to be taking a deep dive in to this claim about life on venus my original work had said if you find phosphine on any terrestrial planet it can only mean life and that wasn't an outrageous claim until recently there's this goldilocks zone in the atmosphere that is not too hot not too cold but just right for life and that's exactly where we found phosphine he is a co-author on the two papers detailing the discovery of phosphine gas in the cloud decks of venus as well as determining that the phosphine on venus cannot be explained by conventional processes it's actually a discovery of a biosignature in the on a planet that has already hints that something really really mysterious is happening chemically speaking on it in the cloud decks of venus and we add additional mystery to this list of mysteries that this planet already has and the reason that it's interesting is because we know so little about venus i mean with most fields of science it takes you a long time to read up on everything about the subject but i mean if i would just ask you what do we know about the surface composition of venus you're looking at two-thirds of mankind's entire knowledge of the surface composition of venus as i recall one of the venera probes or maybe several of them saw particulate matter at a certain level in uh venus atmosphere that happened to be the size of a microbe so in an area where you know that things are precipitating out of the atmosphere and are making drops they're getting bigger and bigger they eventually get comparable to the size of a microbe you mean like a drop of water in a cloud or something and then we have things like dark uv absorbing streaks that seem to change and almost bloom and do all these sorts of things uh you mean like um clouds all of this seems to converge on the same level in the venusian atmosphere though correct uh yes when you get clouds forming they form micron sized particulates i'm not quite sure where you're going with this that's correct and that's a that's a very nice observation so if we were to be optimistic then we can say that our phosphine discovery adds another mystery to the layer of layers of mysteries that this planet already has cool so they're speculating about some sort of floating life making blooms in the sky and they made some hundred or so pages of calculations about how it couldn't be other naturalistic stuff none of which is actually terribly impressive because of just how little we know about venus in terms of chemistry i mean it's rocky it's very cloudy there's lots of carbon dioxide in the atmosphere there's very little water and it's very hot now let me add some caveats to this we actually know what the surface looks like in great detail because it was radar mapped by the magellan probe and it had to be done by radar because there are too many clouds to actually see the surface in visible light but even here where we have a very accurate topological map of venus just to give you some idea of how little we know here the highlands are covered in areas that are radar bright which means it's sort of semiconductor metal type stuff but no one knows what it actually is i mean it's likely that it's something that's distilled onto the high ground like snow on the mountains on earth it's just something that is very reflective in the radar now the atmosphere of venus we actually know quite a lot more about mostly because the russians drop some probes into the atmosphere but when it comes to the surface we actually know almost nothing about it that simple question that i asked earlier what's the chemical composition of the rocks on venus now if you ask that to most scientists you'll just get a blank stare because almost nothing is known all of our knowledge comes from essentially a handful of probes that made three x-ray fluorescence measurements from the surface cool that's great what x-ray fluorescence i hear you ask well if you get a material doesn't matter what it is rock say for instance and you blast it with high energy x-rays that's just a very high energy light it knocks some of the stable core electrons out and a very short time later lower energy electrons fall into those holes and release an x-ray of a characteristic energy for the agile element that the hole was created in so boom you measure the energy of the x-rays that come off and you've detected that element now such machines on earth have found all sorts of uses mostly in mining and metallurgy and you can pick them up on ebay for about ten thousand dollars and they're awesome little machines they have compact x-ray sources in them and they can actually give pretty decent results so that's great we just sent one of those to venus we must have great results right well not quite this was done some 40 years ago the words smartphone and internet hadn't even thought of being invented yet and these probes were sent by the soviets a lot of the actual literature on this is actually as you might expect in russian plus this particular x-ray fluorescence machine had to deal with the conditions of venus and how a few hundred degrees about the same pressure as you would get under a kilometer of water and if you're in a nice simple way of working that out a atmosphere of pressure is about 10 meters of water so if it's a hundred atmospheres on venus that's equal to about a kilometer of water alternatively it's about a hundred bar that's about the same pressure as in this cylinder here so this is not going to be 200 bar okay all right make sure you're actually braced into the wall loud enough so it's quite blast comes off that so in many ways it's a small miracle that they got a measurement at all but x-ray sources tend to be fragile and power hungry so they came up with a simpler and very robust solution of just using radioactive nuclei as a high-energy x-ray gamma-ray type source for knocking the electrons off the material so you can look for the secondary electrons coming off now on the plus side that's exceptionally robust it requires no power source and it's guaranteed to work the downside is of course it's not very intense so the measurements that you're going to get and they're going to be a little fuzzy so these probes get down to the surface of venus they drill a little bit of the surface rock they draw that sample in to the actual probe itself they blast it with some x-rays and then they measure the secondary x-ray spectrum coming off the sample and boom this is what we know about the surface of venus that's that's it that's the the measurements from the two venera probes now let's just compare that to x-ray fluorescence measurements from later mars missions although i was fascinated to find this out they still use these radioisotopes as an x-ray source even now so the main difference between these two is first of all they have better detectors on the later machines and secondly the mars missions would typically count overnight to get a spectrum like this while the entire mission lifetime of a venus probe was typically about an hour so we know very little about the surface of venus but then again this is maybe not surprising i mean if i gave you two random measurements of rocks on earth you really couldn't tell a lot about the geology of the earth from those two measurements and the reality is a lot of what makes the geology on earth interesting is the reworking that you get from solvents of one sort or another most notably water at the simplest level you get rain and it runs through rocks it leaches out some of the soluble stuff like salt and then that dries out and you get things like salt flats or you can get oceans doing similar things which can leave salt deposits meters thick alternatively you can get hot water that leaches out minerals from rocks and then it cools down later and deposits those minerals and yeah there's a whole spectrum of ways that this can happen now on venus there are likely to be similar transport processes except you know they might be with different solvents like sulfuric acid or something so what's the mineralogy of venus like well no one has the slightest clue we know that venus is about the same mass as earth and you know if you take a look at the composition of the rocks on the surface they're mostly oxides it's oxides of silica and aluminium that sort of thing very similar to the composition of the earth now it's likely that venus at some point in its distant past had water on it and it's likely that somewhere there's going to be loads of mineral deposits of one sort or another for certain we know that the surface of venus is relatively new how do we know this well if you get a rock it just doesn't do anything it sits there basically in perpetuity so if you get an impact crater on a moon say for instance it's going to be there for the long game and seeing as the number of impacts that you get from meteors and the such like is a reasonable constant so assuming no erosion the more craters you have the older the surface is and this is where you can take a look at moons of jupiter like say for instance callisto and see that it's got a very ancient surface yeah europa also around jupiter has a very new surface now here on earth we have other methods that will erase craters like uh like subduction or erosion but on venus you really don't get that the craters that you see on venus are very well preserved there's very little sign of erosion on the craters on venus so the number of craters essentially gives you a bead on the age of the surface and that comes out as a fairly new surface of half a billion a few hundred million years old and the resurfacing there was from volcanism now volcanism on venus isn't like that on earth with venus it looks to be very much an all or nothing affair you see this is a a general problem with big objects is they can only lose the heat from the surface so let's take the source of almost all the energy for life on earth the sun generates loads of heat yeah it's a giant ball of plasma sat there in space it must be generating loads of heat yeah it's generating about 4 times 10 to the 26 watts but it's also very heavy with a mass of some two times 10 to the 30 kilograms which means if you take about a kilo of the sun it's only generating about a thousandth of a watt of power now if that doesn't sound like much that's because it's not your body doesn't just generate a little more energy than that your body runs at about 100 watts and a typical person weighs about up 100 kilos so give or take humans are about one watt per kilo kilo for kilo that's a thousand times more than the energy generation from the sun now even if you restrict this to just the core of the sun alone the energy generation is more that of a a compost heap than a raging nuclear inferno the reason that it stays hot is because you can only cool down by radiating energy into space so this is a universal problem that if you're big you can only really get rid of heat at the surface now there's all sorts of ways that you can actually heat big bodies like this you can have tidal heating as with the moons of the outer planets and that can lead to the most volcanic body in the solar system io or cryovolcanism on the outer icy moons but here on earth one of the key sources of all the heat being generated within the planet is radioactivity it's actually got a lot of radioactive stuff in the earth and when that decays the heat's got nowhere to go it's going to eventually work its way to the surface to be radiated into space and that's a very slow process so what tends to happen is the earth gets hotter and hotter and hotter inside until something cracks and the earth gets a new pimple this is the main mechanism of getting the heat from the inside to the outside however on earth this is a fairly continuous and incremental process due to plate tectonics now believe it or not one of the reasons that this happens is because the surface of the earth is wet and when the crust gets subducted it carries water down with it now i'm not talking like you know a swimming pool type levels of wet we're talking one percent water barely detectable levels of water i mean just to give you a flavor of what i'm talking about here these are rocks right they're actually selenite crystals which is calcium sulfate with a couple of waters so sulfates are about 100 calcium's about 40 a couple of waters are about 40. so it's got a molecular weight of about 170 and 40 odd of them are water so that means this is about 20 by weight water meanwhile rocks that are subducted quite frequently contain a couple of percent water but it's enough once that gets subducted it lowers the melting point a lot of the viscosity depending on how you want to look at it the water essentially acts as a lubricant now i should stress that by the time you're melting this stuff at a thousand-ish degrees at crazy pressures a lot of these things don't fall into simple chemical categories anymore but what is true is when you take the pressure off that system it goes boom in the most spectacular fashion you see when a liquefied gas goes from a liquid or a solid to a gas it expands typically by a factor of a thousand so one percent water is plenty enough to blow this molten magma all over the place the nearest analogy that you can get here is it's like a well shaken champagne bottle and when you take the pressure off it sprays everywhere apart from in this case that it's molten lava that's being sprayed everywhere now if the lava comes up from deep within the planet where there typically isn't as much volatile material there the volcanic eruptions typically look more like they are in hawaii it's basically just hot liquid pouring out onto the surface so what would the earth look like if it didn't have all of this lubricant on the surface to allow the gradual release of all this nuclear energy from the earth well it would probably look like venus you see venus lost its water a long time ago due to the planet's lack of a decent magnetic field which means that the soil wind can just blow the hydrogen atoms off the planet one atom at a time you know it's just one of those things you don't need as much energy to give a hydrogen atom escape velocity as say a big atom like oxygen so it's a reasonable suggestion that after the planet lost its water all of a sudden the plates don't slide around as easily as they used to so you can't release the energy anymore so the planet just gets hotter and hotter and hotter in the inside until when it finally does break through it coats half the planet or more like the entire planet with lava now the reckoning is that the last resurfacing event like this took place about half a billion years ago and i should stress that a lot of this is pretty speculative stuff you know it's more just best guess explanations that match what we know about venus that it's got a a surface that is relatively new it looks like it mostly comes from volcanoes and it resurfaced the entire planet now what venus was like before this is even more speculative but it's generally assumed that the chemical composition of venus is fairly similar to that of earth in that they would have had at some point a decent coating of water on the surface now the simple truth is while there are clearly volcanoes on venus we don't even know for certain if they're active or not there have been large spikes of things like sulfur dioxide which suggest volcanic eruptions but it's pretty indirect stuff it's not even certain what kind of volcanoes these are we simply don't have a decent idea of the magma that is currently building up for the next eruption whether it contains lots of gases like it would in a subduction zone here on earth you know from when the planet was wet or whether it's actually just from deep within the planet and contains relatively little dissolved gases we don't really even know if there's lightning on venus which is stunning if you think about it this is what lightning looks like on earth but different space probes have returned different results cool so let's come to the prospect of floating life on venus let's start by defining life as loosely as we can to give us the best chance of a hit here so i'm going to call life a modestly complex series of self-replicating chemical reactions on earth all life all of it falls into the category of cellular life you basically have a blob with an outside called a cell membrane and that cell membrane is made up of detergent type molecules which are they're not that far off oil so the bare minimum that you're going to need in this self-replicating reaction is it's going to be able to need to produce more cell membranes somehow now on the inside of that cell membrane you have a bunch of self-replicating chemical reactions all of this is going on in water again this is all life on earth the extremophiles all of it falls into the category of basically 70 water and 30 biomolecular crap of one sort or another now that biomolecular crap is made up of four basic families there's the proteins there's the dna type molecules the sugars and the oily lipids that make up the cell membrane now you don't have to think about this long or hard to work out that create a copy of all of these things requires some rather specific chemistry and you don't have to know that much about chemistry to know that there's only one element that has that spectrum of ability to form chemical compounds and that's carbon mostly in compounds with hydrogen nitrogen and oxygen now this is the key point that i listed in my last video is that life is two-thirds water and water is two-thirds by nuclei hydrogen and even the biomolecules which are the rest of the 30 percent of life is about 50 hydrogen but this is the rub there's basically no hydrogen on venus so life here it's just a complete non-starter it's like claiming that you can make omelets without eggs or in more detail there isn't enough hydrogen to make proteins on venus or lipids or cell membranes or base pairs or sugars so of all the mechanisms that might be producing phosphine in the atmosphere of venus it turns out that life is the easiest one of all to exclude but for some reason the authors of the paper didn't do that so far our technique has been proving all the things that it isn't and we've exhausted everything we've got with our knowledge of venus and phosphine and chemistry and geology and planetary dynamics we cannot make phosphine in any non-biological way that's great and you can't make it biologically either because none of the molecules that you would need to make life are there there aren't even the components that you would need to make the molecules of life there now think about the requirements of getting all of this into the atmosphere remember if these microbes go anywhere near the ground it's barbecue time so if there is going to be life in the atmosphere it's got to be able to create some membranes well those basically have zero volatility they decompose before they become volatile and the same is true of the sugars and the proteins and the dna so any organism that is actually floating in the clouds of venus would have to be able to synthesize all of these on its own just from the raw materials in the air and they're simply not there and also the truth that the third crucial point is missing there is very little hydrogen available on venus and actually venus is a planet that is that is famous from famous because of his hydrogen depletion trying to make any biomolecules similar to those found in the swamp life on earth that is known to make phosphine i'll give you a clue you can't but these are just circumstantial evidences for why life can't exist in the clouds of venus and phosphine signal was detected on the altitude from 53 around 53 kilometers to around maybe 60 or something like that now this is right within this region of the atmosphere of venus when these cloud decks are present and this is a right within the region when the temperatures are around around 30 degrees maybe to maybe to the 60 degrees in the bottom bottom of the bottom of this layer which which are actually conduct conductive or conducive to some complex chemistry in in principle yeah with the teensy problem that none of the ingredients for life are there the nearest analogy that you can get to this is like saying an oven is the right temperature to cook cake therefore in principle there could be a cake in the oven even though you know you know that the elements required to create the cake are not there but you know what would be a real killer experiment here is if say for instance someone had sent a probe to venus and dropped it through the atmosphere and examined the aerosols within those clouds i mean that would certainly show up if there was loads of life there producing this phosphate right now oddly the russians actually did some sampling on venus like this so i'm going to summarize the results from their latest probe which is now some 40 years ago what he did is it sucked air through a filter which caught a load of the aerosols in the air and the first thing that we're going to take a look at is how much there was in those aerosols well it was on the order of a billionth of a gram per cubic centimeter or two milligrams per cubic meter now i'm sure most of you at this point will be saying two milligrams per cubic meter obviously okay so i'm going to put that into context of clouds here on earth so here we're just looking at the liquid water content of clouds the actual gaseous water content is actually much higher than any of these numbers but the liquid water content of clouds so with the cumulonimbus those are the rain clouds you're looking at about one to three grams that's about a thousand milligrams of water whereas with the high wispy clouds like cirrus you're looking at about 30 milligrams the actual amount of aerosols in the clouds on venus is about 10 times lower than the wispiest clouds here on earth now i've got to say some of these venus probes you've really got to tip your hat to them in terms of what they achieved albeit with a fairly high failure rate and with some of the results understandably fuzzy i mean the prospect of getting a probe to go through an atmosphere and pull out some four milligrams of aerosol then analyze it with x-ray fluorescence that's pushing the limit but it looks like they did that and more and got some sensible results out of it nonetheless some of their results are really very robust and one of those is that the clouds are mostly dominated by sulfuric acid then going into phosphorus oxides now that immediately raised an eyebrow for me i mean what the hell are phosphorus oxides doing in the atmosphere you see here on earth if you were to say pour out some phosphorus oxides like that onto the surface they would very quickly react with water to give phosphoric acid which would then precipitate to give some very insoluble stuff like calcium phosphate which is a pretty decent rock and that's one of the key reasons why we just don't have phosphorus oxide on the surface of the earth but this is weird i mean why isn't this stuff in a more stable form like say for instance calcium phosphate on the surface of venus but once you actually find that it's a known fact that the phosphorus oxides are fairly volatile and make up a large portion of the particulates in the venous atmosphere and all of a sudden the riddle of how you get volatile phosphorus compounds like phosphine in the atmosphere becomes a hell of a lot less cryptic now earlier i had proposed lightning making phosphides and the searchlight because phosphide to produce phosphine when they react with sulfuric acid but that would probably require phosphate deposit of one sort or another and if you know that venus is mostly covered with the lava flows that seems unlikely further you've got to get good lightning for that and the low lightning well you would get that off things like volcanoes but only if they contain lots of volatiles like water and such life and that's pretty doubtful on venus now here on earth there are essentially no volatile phosphorus compounds but once you find out that on venus is the dominant particulate in the atmosphere just below the cloud decks is partially reduced volatile phosphorus oxides that now immediately becomes the most obvious front runner for how you're going to get other volatile phosphorus compounds in the atmosphere of venus like say for instance phosphine and it really doesn't take long to join up the dots you take this p4o6 which they reckon is the dominant form of the phosphate in the atmosphere and react that with a little bit of water you get this phosphorous acid and what do you know you get a couple of phosphorous acids together and you get phosphine this party is over now in rejecting an obvious mechanism you have to have some pretty strong evidence they do actually say they've considered this and that their calculations show that these cannot happen on venus look they're quite clear that phosphorus acid is not stable to evaporation and only exists in the cloud layer huh that's bizarre i wonder what it decomposes to and it's got decomposed to something well it's wiki and wiki agrees that it's not stable as a gas that uh it decomposes i wonder what it decomposes to it decomposes to phosphine but i can see why they might want to reject the obvious answer well again and again you'll come up against this sort of thing in science you get an unexpected result and your options are all scientists we know it is wrong like conservation of energy or something and you will be heralded as one of the greatest scientists of our time or you just screwed up the experiment you know you put the gauge on upside down you take the wrong measurement or you just misunderstood what you're measuring something incredibly mundane with maybe the best example of this being ponz and fleischmann and their announcement that they discovered cold fusion sure it was incompatible as nuclear science that had been established for in decades sure if they had managed to get cold fusion they would have all died from the high energy particles coming off that cold fusion but none of that mattered they went and told the world anyway this was going to revolutionize mankind now this is an area that might be called pathological science with maybe the most classical example being polly water where scientists claimed that they had found a new form of water and if it got into the oceans it could turn them all into syrup killing all life on earth in the end of course it just turned out that their experimental kit was kind of dirty and when they repeated it with clean kit everything was fine but again to advance the hypothesis of poly water without shame you basically had to ignore everything that you knew about atomic physics just like to propose the hypothesis of life on venus you basically have to ignore everything you know about self-replicating chemical reactions so this pathological science has some characteristics like it's difficult to detect or reproduce check well accepted theories are overlooked check and loss of objectivity check it would be like taking a single picture like this and saying well it could be there's something in the optical path the telescoping dirt on the lens or something but also it could be and we shouldn't be ashamed of proposing this it could be a fleet of alien spacecraft this hypothesis for of life production of phosphine as a legitimate hypothesis so we shouldn't be ashamed that we actually put this hypothesis forward which would mean that this is definitive proof that we're not alone in the universe and then going on for the best part of an hour fantasizing about what this means is you know when we finally if this is life and we confirm it and then we will be absolutely surprised how absolutely ingenious are the biochemicals solutions to the problem of sulfuric acid that microbial life is more like is actually almost a an inevitable consequence of the existence of the universe and if this is life based on sulfuric acid and instead of water then it also then it changes more than everything if i even say this but it also proves that the path to the origin of life does not really leave lead only through water and that would be a phenomenal discovery and so my life might not just be next door it might just be extremely common and inevitable which means that there's thousands and thousands of possibilities for life in the galactic neighborhood just waiting to be discovered so as you can see it changes everything it changes literally everything yes yeah you can see how you know given the mundane explanation of lens is kind of dirty i know it's kind of obvious and yeah you can sort of see it but yeah well now it could be an alien space fleet we should definitely consider it as a a hypothesis and maybe i know base future missions to venus about this speculation we hope we can send a mission a space mission to venus look for complex molecules that would be indicative of life and maybe somehow even look for life itself and if we found it could be game changing for everyone i would be very happy to have a mission that has astrobiology in at its core that actually tries to look for life as its main goal and maybe even capture it look i'm all for sending probes to venus but not for wasting them looking for life when the best evidence that you have for life is just wishful thinking combined with ignoring everything that you know about self-replicating chemical reactions now i've got to say this is nowhere near as promising as ponds and flashmen i mean let's be real if this paper had been honest it would have been there's all this phosphorus just below the cloud decks of venus and a very small concentration of phosphine in the atmosphere and we're not quite sure how that happens this wouldn't even make a gamma ray publication it would just barely be a footnote in the catalogue of things that we don't understand about venus but they had to put in maybe its floating life and this could change the way that we understand life and if this is life based on sulfuric acid and instead of water then it also then it changes more than everything if i even say this and boom it becomes front page news i mean contrary to the author's claims life isn't some infinitely tenacious process that will always find a way we have to be aware that and i like this quote from jurassic park when dr ian malcolm says that life will find a way and i'm absolutely sure that you know you said life sometimes surprises i would say that life always surprises us i mean the mere fact that the driest places here on earth which are ten times wetter than that of venus don't have blooms of phosphine producing floating bacteria should be ample proof of this and the conditions here on earth are much nicer than those on venus so if life can't find a way here where we know there's lots of potential life that could evolve into that niche what makes you think you're going to get it on venus where the conditions are much harsher we're just going near the ground will barbecue any life so that's the video for today and uh remember mars is superb at the moment as of me putting out this video in october 2020 it's stunning high in the sky at about midnight and if you get a chance to look at it through a telescope it's going to be better for about the next month than it's going to be for the next 15 years meanwhile venus rises somewhat before dawn so if you enjoyed this video i'd be grateful if you give it a thumbs up and if you really enjoyed this video and want to support this channel you do it directly through patreon and there thanks for watching [Music] you

Channel: Thunderf00t

Views: 102,090

Rating: 4.8750963 out of 5

Keywords:

Id: 8UJSHKIFiD8

Length: 37min 8sec (2228 seconds)

Published: Thu Oct 15 2020