Did We Just Detect Life on Venus?

incredible news has just been announced by a team of astronomers perhaps one of the most important discoveries in decades possible evidence for life has been announced on another planet venus how could venus harbor life and how excited about this announcement should we really be join us today for a rundown of this exciting announcement [Music] what an exciting day marked by the announcement of a chemical marker of biology in the atmosphere of venus today's news is as exciting as perhaps it is surprising to many of us for years we've looked to mars as our best bet for finding life in the solar system indeed nasa has invested far more effort into orbiters landers and rovers on mars than venus which only the soviets have ever landed upon the reason for this is simple the surface temperature is a scorching 460 degrees celsius enough to melt lead and it has a surface pressure similar to that as being a kilometer underneath the ocean and so this result perhaps surprises many of us because after all how could life possibly survive on the surface of venus when even these soviet probes could only last a couple of hours well things do indeed look grim on the surface but they look a little bit better if we head on up 50 kilometers up into the clouds up here the pressures drop and the temperatures become balmy comparable to that of the earth something like 30 to 80 degrees celsius yet more on the earth we do find microbial life in the clouds up to 2 million tons of bacteria are lofted up from the ground via air currents as well as fungal spores and micro algae which are thought to even influence the precipitation rays so the idea of cloud creatures is clearly perfectly legitimate but in order to avoid raining down back onto the hellish surface these microbes would want to have some degree of buoyancy to stay up but because venus has a much thicker atmosphere than the earth then that would actually be easier the next challenge for venusian life is the atmospheric composition the atmosphere is almost entirely made up of carbon dioxide and the clouds are highly acidic comprised of sulfuric acid now most life on earth would pretty much immediately die in such horrifically acidic conditions but there are in fact some microbial organisms on earth which actually thrive in acid known as acidophiles now these acidophiles much like the other extremophiles are the product of billions of years of evolution they have highly sophisticated molecular machinery within them to cope with those conditions and so if there is indeed life in the clouds of venus then a natural explanation would be that actually it started on the surface it evolved it adapted and then ended up going up into this extreme environment much later billions of years after it initially started the idea that venus could have been habitable in the past is also quite plausible of course we don't have a time machine to go back and see how venus really was but recent simulation work led by michael way and anthony dungeolino shows that venus could have maintained liquid water for around 3 billion years only becoming uninhabitable just 750 million years ago that's around the same time that a global resurfacing event occurred indicative of some catastrophic volcanism episode this would have been a very bad time to have lived on venus making pompeii look like a sparkler by comparison although we can infer that this happened by observing the young smooth surface that we see from our probes the cause is ultimately unknown one possibility is that although venus resembles the earth it doesn't have plate tectonics and so all of the internal heat and energy within that planet had no way to vent out until it reached some critical tipping point which ultimately ripped apart the entire surface nevertheless in the three billion years of preceding habitability life could have been present on the surface and evolved the ability to float up into the clouds okay so all of that is really just to say that the idea of life on venus isn't that crazy and in fact it's really been overlooked when it comes to previous nasa missions and indeed many other astrobiology studies now let's come to this new paper led by jane griez and colleagues this very exciting result how is it that astronomers could tell if there was life on another planet without physically going there without landing on the surface or flying through the sky well just like the star trek enterprises sensors you can tell a lot from afar you don't always have to physically take samples to figure out what's going on in this case the team used two telescopes here in the earth which specialize in observing the sky at wavelengths in between the radio and infrared part of the spectrum that's known as the sub millimeter one of these two telescopes alma has been in the news quite a bit in the last few years maybe you've heard of it thanks to its gorgeous images of protoplanetary disks so using alma and another telescope called the jcmt the team found that venus's atmosphere had an absorption feature indicative of the molecule phosphine chemical symbol ph3 and that's really the key to this whole paper it's really just noticing that the wavelength of light where phosphine likes to absorb light light is missing and so we can infer the phosphine is there first off how statistically significant is this detection well the authors report this to be a 15 sigma detection now for a point of comparison the higgs boson was announced as a five sigma detection so on the face of it that looks like a very secure announcement and that's really important because in the past we've seen many two to three sigma announcements that ultimately about half of them never ended up being true but sometimes even high significance detections disappear for example and somewhat famously in 2011 the opera experiment found evidence for faster than light neutrinos to 6.2 sigma confidence but it turned out to be just a systematic error in their analysis so on the face of it 15 sigma looks very secure but let's remember that until it's independently verified we should remain cautious now why does this indicate life well just last year some of the authors of this detection paper wrote another paper arguing that phosphine is a previously unidentified example of a biosignature biosignature is really just a way of saying a chemical that indicates life oxygen is a classic example of a biosignature it's reactive and should hang around in an atmosphere and so something in our case photosynthesis must be producing it phosphine as a biosignature is certainly less well studied but it is associated with anaerobic ecosystems here on the earth however the actual metabolic pathway by which it is being produced in these anaerobic bacteria remains unknown okay so if we accept phosphine as a biosignature and we accept that it was securely detected by this team does that mean then that we have indeed seen direct evidence for life on venus no not quite and the reason is because phosphine indeed could be produced by life but it could also be produced by non-life things such as geochemistry or photochemistry that just means when light is interacting with chemicals now the authors are certainly aware of this and argue that no known chemical pathways are likely responsible that is of course without life but chemistry is a myriad of mind-bogglingly complex possibilities so there's always the chance of an unknown unknown being responsible here and so this is why the authors themselves even state that even if confirmed we emphasize the detection of phosphine is not robust evidence for life only for anomalous and unexplained chemistry so those were my initial thoughts but perhaps much like you as soon as i heard of this announcement my initial reaction was hey i want to hear what other experts in the field think about this so i jumped onto a call with a columbia university colleague of mine dr caleb schaaf who is the director of the astrobiology center at columbia university caleb thank you so much for joining me you know as soon as i saw this result you were one of the first people i thought of to ask so i want to ask you what was your initial reaction when you first heard about this result and having looked at it a little bit more closely how are you feeling about it now are you excited are you skeptical i'd say i'm cautiously excited about this and definitely very intrigued this is a super interesting result and i think it's going to prompt a lot of new inquiry into this area that has been bubbling around for a while in people's minds but i think a lot of steps have to happen next to really convince people like me and yourself that there's something going on here that is related to like life the first thing i think that's going to have to happen is there's got to be confirmation of the data itself it's going to have the independent acquisition of these kinds of measurements independent analysis and then perhaps the most difficult part of this to really convince us that this phosphene has no other source than life is to really understand the chemistry that's taking place in the upper reaches of the venusian atmosphere and that chemistry we suspect is awfully complex and for example we think that there may be quite complicated chemistry taking place with or without life on the surface of droplets in the the cloud condensates the compounds that are condensing out as clouds in the venusian atmosphere if you combine that with the ultraviolet light coming in from the sun you have the opportunity for lots of what's called photochemistry photochemistry is notoriously complicated especially when you have an interface between things like droplets and gas and so on so i think a lot of work is going to have to be done to convince us that there's really no other way to make this phosphene except through perhaps some biochemical reaction and then the other aspect of it that i think is going to involve a lot more detailed study is that the nature of phosphine production on earth by biology is not totally well understood okay we think it happens because of organisms processing organic material processing things like phosphates and turning them into phosphine as a as a byproduct but we don't have a full picture of how that happens on earth and that leads to the the final thing i think is going to be really interesting and possibly a marker of whether or not we could believe that life is involved that is taking the amount of phosphine that seems to have been measured which is of the order of 20 parts per billion which is still a tiny amount but evaluating that in terms of how much life would it take living in the clouds of venus to make that concentration of phosphine and what kind of initial compounds initial phosphorus compounds would those organisms be consuming in the first place so you know we might get a number out of that that says an enormous amount of life has to live in the clouds in order to produce that level of phosphate and that might be problematic that might suggest that we're missing something that's more ordinary in nature just to do with chemistry in the venusian atmosphere so it's exciting i'm cautiously super excited about it it's really intriguing the lovely thing is it's going to prompt a lot more work on precisely these sorts of questions about biosignatures about how we smell life as it pops up in the universe in ways that we're not so familiar with phosphine is not the thing that most people first think of when we think about looking for life in the universe what would it take to prove it to you you know would it be more of these observations and more modeling or is a would we have to go to venus in order to completely convince you yeah i think the most convincing thing would be to go and sample the clouds in venus um you know this is one of the drawbacks of all sorts of remote sensing of the universe is ultimately you're not there ultimately you're making inferences and you're trying to make you're trying to weigh arguments against each other to look for which one seems to be the most probable i think it's gonna be very hard especially when we're talking about life which is this sort of magical thing for us to convince us all unless you go and you find a sample of it i mean the good news about this and a really exciting proposition and people have thought about the possibilities of going to sample venus's atmosphere by dropping balloon-like payloads into the atmosphere that can scoop up samples and then return them to an orbiter and bring them back to the earth or even examine them in situ this is going to prompt much more interest in that and in some ways it's an easier thing to do that than to spend decades analyzing chemical models and and arguing over the fine details why not just go to venus scoop up some of that cloud and take a look at it that'd be so exciting i really hope that this spearhead's renewed interest and of course nasa hasn't had much interest in the past but renewed interest to go to venus and do these exciting experiments thank you so much caleb and good luck with your classes on zoom i know this is a new experience for all of us but uh it was good seeing you thank you for your input on this my pleasure nice to talk venus has long been enticing to us and this result is capturing the world's attention today if indeed venus has life then it would be a monumental discovery but the case is certainly not closed here there are good reasons to be excited but also good reasons to remain cautious after all many of us remember watching bill clinton on the white house lawn announced the discovery of life on mars back in 1996 a claim that has now been widely rejected by the scientific community the good news is that there are lots of ways which we can follow up and check on this result first off observers can re-analyze the same data or even collect new independent observations of venus to check if this claim is real second theorists and modelers can map out the chemical pathways to check is there some missing way of producing phosphine that doesn't require life and third perhaps most excitingly we can actually go to venus there's lots of good reasons to do this but this new paper adds a big feather to the cap glide through the atmosphere and take in situ samples to resolve the mystery to give us data which we just can't obtain from afar that's because as good as our senses are just like in star trek you really can't beat an away team and so if this discovery spearheads excitement in new venus missions then this is a massive win for planetary science either way and looking ahead if we confirm life on mars one day then we'll have to solve the last lingering question whose answer could change the way we think about ourselves in the universe is the life on venus an example of an independent start to life or are earth-based and venus-based life related to each other through the contamination of meteorites in the past an idea known as panspermia if the former though then we would have two independent stars to life right here in our very own solar system that would be game changing and it would certainly shift my own perspective about how abundant life is in the universe after all if it happens two times here in our own backyard then surely life is everywhere in the cosmos what an exciting time to be alive to probe these questions in our lifetimes so i want to hear what you guys think about this detection please let me know how excited about this are you how skeptical about this are you let me know down below in the comments and until next time stay thoughtful and stay curious [Music] you

Channel: Cool Worlds

Views: 1,061,933

Rating: 4.8614564 out of 5

Keywords: Venus, Life on Venus, Life Detected Venus, Venusian Life, Venus Biosignature, Venus Biomarker, Does Venus have life, life clouds venus, extraterrestrial life venus, alien life venus, alien life

Id: CNLsgd_NzWk

Length: 17min 6sec (1026 seconds)

Published: Mon Sep 14 2020