Have you heard the big news? Of course you have, evidence of phosphine on Venus which could be a biosignature of life on our evil twin planet. There have been a lot of surprising stories about Venus, so let’s get you all caught up.
Press and embargo policies (Nature)
Hints of life on Venus (Royal Astronomical Society)
Could Venus have been habitable (EPSC-DPS 2019)
Researchers Discover What May Be 37 Active Volcanoes on Venus (Smithsonian Magazine)
Life in the Clouds of Venus? (Nature, behind paywall)
Tardigrades (Arizona State University)
Phosphine as a Biosignature Gas in Exoplanet Atmospheres (Astrobiology)
Corona – planetary geology (Wikipedia)
In Search of Panspermia (NASA)
Microbes Survive, and Maybe Thrive, High in the Atmosphere (Science Magazine)
Life in Extreme Heat (National Park Service)
BepiColombo overview (ESA)
NASA’s Discovery Program (NASA)
Will NASA’s Next Mission to Venus Be a Balloon? (Scientific American)
India Has a New Planetary Target in Mind: Venus (Space.com)
Russia Wants to Return to Venus, Build Reusable Rocket (The Moscow Times)
Basics of Space Flight (NASA)
PODCAST: Dark matter discrepancy; unique supernova; extreme galaxies plus guest Dr. David Grinspoon (Daily Space)
Transcriptions provided by GMR Transcription Services
Fraser: Astronomy Cast, Episode 578, Venus Updates. Welcome to – we can’t do – we can’t just Venus updates, that’s boring. Okay. Let me do this again. Ready?
Fraser: Astronomy Cast, Episode 578, Life on Venus, question mark, exclamation mark, question mark. Welcome to Astronomy Cast, our weekly facts-based journey through the cosmos, where we help you understand not only what we know, but how we know what we know. I’m Fraser Cain, publisher of Universe Today. With me, as always, is Dr. Pamela Gay, a senior scientist for the Planetary Science Institute and the director of CosmoQuest. Hey, Pamela, how are you doing?
Pamela: I’m doing well. It has been the weirdest of weeks. I don’t know about you, but every time we get one of these NASA media advisory or Royal Astronomical Society media advisory, they’re just completely vague. Someone asks, so, it’s not aliens, is it? And this time when someone asked that, I found myself just sitting there going …
Pamela: It’s been a weird week.
Fraser: It’s funny. So, I don’t know if people know about this, so the policy for Universe Today and if any of my writers are listening just a reminder, is that we don’t look at embargoed stories.
Fraser: So, if you send Universe Today an embargoed story, we will delete it. We won’t break your embargo, but we won’t look at your embargoed story. We are not interested until after the embargo has been lifted and the news is publicly available to everybody. And the reason why is I find that it allows people to decide who’s a journalist and who isn’t a journalist, is sort of a way to control the know and the know nots. And for the longest time, a lot of really respectable, who I thought science journalists, were being held out of the embargo news information. It’s not so bad these days. And then the other thing is sort of artificially inflate –
Pamela: [Crosstalk] Yeah.
Fraser: – the newsworthiness of a piece of news. And so, you and a couple of the writers on my team were like, we got a really important embargoed news story that’s come across my desk. Can we work on this?
Pamela: Well, I wasn’t sent –
Fraser: [Crosstalk] Yeah.
Pamela: – the embargoed information either.
Pamela: But one journalism outlet that I’m not going to slander, I accidentally pressed the publish instead that of the schedule button in –
Fraser: [Crosstalk] Yes.
Pamela: – WordPress.
Fraser: Yeah, we saw that.
Pamela: And so, the article was out there.
Fraser: [Crosstalk] Yeah.
Pamela: And of course, this led to people going through and putting the pieces together.
Pamela: [Crosstalk] So –
Fraser: Apparently, you could even figure it out by looking at Wikipedia and seeing which articles in the astronomy and science section have been modified recently.
Pamela: Oh, gee, that –
Fraser: [Crosstalk] Yeah.
Pamela: – I hadn’t notice.
Fraser: Yeah, pretty clever –
Pamela: [Crosstalk] That is awesome.
Fraser: – to figure that out. But yeah, so, I was just as unaware as everybody come Monday morning when the announcement was made. And it was totally worth it. What a great announcement to hear. It was, maybe, possibly aliens, finally, which we’ll get into during the show.
Pamela: Yes. Yes, we will.
Fraser: All right. So, have you heard the news. Of course, you have. Evidence of phosphine on Venus, which could be a bio signature of life on our evil twin planet. There have been a lot of surprising stories about Venus. So, let’s get you all caught up. All right. Pamela, what’s the news this week?
Pamela: Okay. So, this week’s news and we’re gonna have so many articles that we need to explain to give context to this news. This week’s news is the bio signature molecule phosphate, which is one phosphorus atom and three hydrogen atoms, has been found in the atmosphere of Venus in amounts that can only be explained in ways that we know the universe tends to be creative, but using physics and chemistry and biology that we know, the only way to get this much phosphine into an atmosphere is to stick microbes in that atmosphere.
Fraser: There was a great article. I think it was the BBC did this. They said you can have pollution from industry or penguin poops.
Pamela: Yeah, pick one.
Fraser: Yeah, pick one. And so, we know there are definitely not factories or penguins on the surface of Venus. Therefore, super-weird to see this chemical in the atmosphere of Venus.
Pamela: And this particular atmospheric gas is produced by a variety of anaerobic bacteria. This is single-celled life forms that don’t need any oxygen and there’s not exactly a lot of free oxygen at Venus either. So, what we’re seeing is consistent with a kind of life that could exist there and intriguingly just in the past couple of months a number of popular level articles and one professional article detailing how you can have the cycle of life in the Venusian atmosphere.
Fraser: Yeah. It’s pretty funny. There was a bunch of these papers on phosphine on how life in the Venusian atmosphere could be generating phosphine like a month ago.
Pamela: Yeah. Yeah.
Fraser: So, I actually had one of these – I had this paper by Sara Seager and team about how bacterial life could survive in the cloud tops of Venus and what the mechanism might be. We can get into this later on in the episode. I was like, oh, that’s such a cool idea. I’m totally going to do a video about that. And so, I put it on my list of videos. Little did I realize Sara Seager playing three-dimensional chess here had this all cued up and ready to go for them when we got the announcement of phosphine on Venus. So, like where could it be coming from and she can just go wrote the paper. Pretty smart.
Pamela: And I asked her about that during an interview I did on The Daily Space. And she said that they hadn’t initially planned to write that paper, but they’ve been working with a journalism student who was doing such a good job that they decided just, move ahead with everything. So, it is the fluke of having the right intern in the right place to motivate things forward that led to that earlier paper coming out.
Fraser: Okay. So, we’ve got the discovery of this incredibly weird element phosphine or molecule, sorry, in the atmosphere of Venus. We don’t know of a natural process. So, this is to the how do we know what we know part. How did they discover this molecule in the atmosphere of Venus?
Pamela: You pointed a couple of telescopes. So, literally what happened here is people have been suggesting since – well, looking for biosignatures was a thing that along with methane, phosphine was a particularly good bio signature. And unlike methane, which is super easy to make geochemically, phosphine doesn’t seem to have the same geochemical wave being produced, at least not at Venus.
So, Jane Greaves was looking in the Venusian atmosphere following up on a number of other research threats. So, just in the past year, we’ve had coming out of the European Planetary Sciences Conference last September, the idea that up until as recently as 750 million years ago, Venus may have had water oceans and a habitable environment before something catastrophic took place. We’ve had papers showing that if you use modern numerical models to analyze the Magellan data looking at the surface features on Venus, it looks there’s still active volcanism –
Fraser: [Crosstalk] Right.
Pamela: – there. And then, when you couple all of this with the known problem that there are these UV absorbing splotches in Venus’ atmosphere that have no known explanation, except there’s bacteria on Earth that have the same characteristics.
Pamela: It’s sort of starts to become we really need to be looking for life here kind of situation. And what I have to admit I didn’t know until I was prepping to talk about this this week was the idea that Venus might have life in its atmosphere goes all the way back to the late 60s and hinges on those dark UV absorbers to a certain degree.
Fraser: Right, right. So, I think one of the things that I really loved about this announcement was how careful and how skeptical the researchers themselves were, which was that they did really, really meticulous observations to determine the presence of the phosphine in the atmosphere of Venus.
And then, spent an enormous amount of time looking at every possible natural source that could be generating it from volcanoes to lightning to meteorite strikes in the atmosphere to – and even to the point where they said, okay, yeah, volcanoes could produce phosphine, but you would need 200 times as much volcanism on Venus as we have here on Earth. And although, there might be evidence of recent volcanism on Venus, not 200 times as much as Earth.
Pamela: Right, right. And so, this is where they had a really cool interdisciplinary group working on this. So, you had Clara Sousa-Silva who’s the phosphine expert who is looking at what are all the chemical attributes. You had Sara Seager, who is very much a theoretician looking at how do you understand things in the context of the atmosphere. They brought in people to look at geochemical processes, to look at photo chemical processes. And across all of these different things, they also had to consider, okay. So, we had a low signal to noise observation with the James Maxwell Clark telescope down in Hawaii. So, let’s apply for telescope time to get a better set of observations from the Atacama Large Millimeter Array and they got those observations.
They went through the trouble of trying to figure out, are there overlapping molecular lines that we need to worry about at this wavelength. They did their homework to make sure this wasn’t different molecules stepping all over there phosphine observation. They checked every box. And …
Fraser: Yeah. And so, they absolutely found phosphine.
Fraser: And they very rigorously ruled out every possible natural source of phosphine.
Pamela: That we know of.
Fraser: That we know of.
Pamela: [Crosstalk] And –
Fraser: Exactly. Yeah, yeah, yeah.
Pamela: And that’s the problem is as new paper after new paper keeps finding, the universe s to be far more creative than our theorists. So, there always has to be that nagging concern of, well, what if there’s physics that I hadn’t thought of going on here.
Fraser: Yeah. Yeah. And right now, it’s probably almost certain that they will discover physics that they didn’t understand before, that there will be some geologic process, some weird combination of sunlight hitting phosphorus-rich acids that combined in different ways. We do know that phosphine – because it has those hydrogen atoms combines very rapidly with oxygen. It oxidizes as quickly as it can. And so, you can see phosphine in Saturn and Jupiter because they’re oxygen-poor environments. Any Oxygen –
Pamela: And hydrogen-rich. They have –
Fraser: [Crosstalk] And hydrogen … Yeah.
Pamela: – free hydrogen available to do the bonding.
Fraser: Right. While Earth and Venus are oxygen-rich. We’ve got plenty of carbon – in Venus, you’ve got all that carbon dioxide.
Pamela: And with Venus, the thing is that it doesn’t have that free hydrogen that we see in the gas giants. And so, in this reducing environment, it’s really hard to figure out where did those hydrogen’s come from. And so, this is where – the person with the PhD really wants to say, I’m sure we’re going to find physics that we just don’t know about right now.
Fraser: Yeah, yeah. I just said that, too.
Pamela: But here’s the thing, and this is one of the things that I’m really struggling with on this discovery, is NASA has invested a great deal of funding since the mid-90s into understanding what molecules are biomarkers. What molecules, when we see them in extrasolar planets, mean this planet probably has life and we found one of those molecules in a world that I have to wonder if it was an exoplanet, would we be sitting here going, no. Or would we be saying a biomarker was found and …
Fraser: [Crosstalk] Yes.
Pamela: And because it’s Venus, which let’s face it, most of us have been like, that’s the one place not to go looking for life, does this force us to be over skeptical.
Pamela: It’s this really weird internal conflict of wait, but we identified biosignatures for a reason and we found one, but now we’re saying it’s probably not life.
Fraser: Yeah. What’s wonderful about this is that we do have an opportunity now to double-check. So –
Pamela: [Crosstalk] Yes.
Fraser: – if we didn’t see phosphine in the atmosphere of Venus, then it would I think it would sit on that – it would be the gold standard of biosignatures that have been worked out so far as you talked about. Up until this point, people thought, oh, it’s oxygen, it’s ozone, it’s water vapor, it’s methane –
Pamela: [Crosstalk] Methane.
Fraser: – yeah, it’s methane. It’s all these things and now it turns out we’ve found natural processes that can supply each one of these. But this one molecule, phosphine, has held out defying any natural cause that isn’t life or industry in an oxygen-rich world. And suddenly it’s been discovered on a world that’s very close that we can double check because now you can send a spacecraft, you can send a balloon, you can go and examine it more closely, and try to figure out what the source of this is. But if James Webb detected phosphine around Gliese 582 or whatever –
Fraser: – there’s no double-checking. You can’t go and send a spacecraft to just give the atmosphere a sniff. And so, this is a wonderful opportunity.
Pamela: So, here’s the story we have right now from various observations. We have from the Magellan data of the surface and understanding from crony. These are the geologic signatures in the shape of the ground saying this is where there’s a hot plume of magma beneath the surface. We have evidence from Magellan’s radar data of the surface that there are order of 30 volcanoes that appear to have been geologically, recently active.
We have brand new climate models, thanks to advances in computing, and the advances in the computing also got us the volcano results. Thanks to advances in computing, we have new atmospheric models that consider – well, okay. So, we’re now understanding that during the Great Heavy Bombardment, watery things crashed into the inner worlds. Mars had oceans or still has oceans. Venus should have had oceans.
So, let’s run the climate models assuming the water is there. And it appears that from these models as recently 750 million years ago, you had Earth-ish, Earth-hot environment capable of sustaining life and having oceans. 750 million years ago here on Earth, we had the beginning of colonies of single-celled organisms. So, things like sponges that are made of single-celled organisms that act as a group, we had those. And so, you can imagine on the same time-scale life, having the ability to come into existence on Venus or panspermia to have done whatever –
Fraser: [Crosstalk] Right.
Pamela: – it felt doing between these three planets.
Fraser: Yeah. I think it’s – that’s the other question is, if we do find life on Venus or Mars or Europa or Enceladus, are we related?
Fraser: And when?
Pamela: And so, we have those questions. And then, we have today the active and changing pattern of UV dark absorbers in the atmosphere of Venus that have characteristics that are mirrored by actual bacteria that can temporarily rise up into the Earth’s atmosphere for hours or days, but no longer than that.
Pamela: But the conditions in Venus’ atmosphere where it has essentially standing water in the atmosphere in the form of moisture droplets means that what is transitory on Earth can be permanent.
Fraser: [Crosstalk] Yeah.
Pamela: – on Venus.
Fraser: So, let’s talk about that paper that Sara Seager and team published about what possible mechanism, how could life be surviving on Venus?
Pamela: So, the first thing to remember is don’t go to the surface of Venus unless you’re trying to melt a spacecraft ‘cause that’s how you melt a spacecraft.
Fraser: Right. Yeah.
Pamela: The surface is hundreds and hundreds of degrees, whatever unit you pick, it’s death. But if instead you go up in the cloud layer between roughly 50 kilometers up and 60 kilometers up, you’re looking at an atmosphere that has earth-like temperatures –
Fraser: And Earth-like pressures.
Pamela: – and one atmosphere pressure. Now, as soon as you get down as low as 30 kilometers, 33, 35 kilometers, it’s death again. But you have that window. And so, the idea is that Venus like every atmosphere has currents within the atmosphere. And it has what are called Hadley cells which are circulation regions in the atmosphere where in the equatorial areas you have hot air rising. And then, it comes down cooler towards the poles.
And so, the idea is that there’s this haze layer down in the 30s kilometers up and air from this desiccated, dried-out, death-haze layer is able to rise up. Now, what if there were spores desiccated life-forms in that haze layer. They can then act as seeds to moisture droplets. We have the same thing happens here on Earth.
It is around dust particles in the atmosphere that rain droplets form or this is how we know you can seed clouds and it works. So, you have these these spores that act as the seeds of moisture droplets that are rising up through the atmosphere. And as they rise up, they can get bigger and bigger, taking this desiccated life-form, re-moisturizing it, allowing it to thrive, to multiply. And as the water droplet or moisture droplet, rather, gets bigger and bigger and bigger, it’ll eventually get too big as it’s circling through the atmosphere. And as it falls back down that water droplet, moisture droplet will fragment.
And eventually, the life will be driven to desiccate out again. And we see life-forms desiccate out here on Earth. This is something tardigrades do. It’s why you can shoot them up into space and they come back. And they come back to life.
Pamela: We could have tardigrade-like lifecycles.
Pamela: But a different extremophile or heck, maybe even tardigrades.
Fraser: Now, you keep saying water and then you keep editing yourself to say liquid. Let’s talk about that liquid because there’s some water – I think there’s like 15% water, but there’s 85% not-water sulfuric –
Pamela: [Crosstalk] Right.
Fraser: – acid.
Pamela: Right, right. And so, yes, the Venus atmosphere is largely death by acid, largely death by acid. But largely is not the same thing as completely death by acid. Here on Earth, we have extremophiles that are quite happy to deal in just about any environment you put them, whether it be radiation, acidity, heat. We can find the life to live through it and a lot of it’s at Yellowstone.
Fraser: The one interesting thing is they’ve actually looked at the level of acidity in this sulfuric acid. And it’s super bad. It’s –
Fraser: – it’s worse than – it is more acidic than any environment that life has been able to survive in. But the key is that you’ve got these droplets of water that are dissolved into the acid.
Pamela: [Crosstalk] Yes.
Fraser: And so, the thought is that in fact, you could have the life living in the water that’s in the acid as long as it stays in the water droplet parts inside the acid, then it’s able to survive going through this cycle. And so, the liquid builds and builds and builds as these droplets rise up in the atmosphere and then rain back down. And hopefully, the microbe has completed its entire life cycle before it turns into rain and falls back down before its spores end up back down at that 33 kilometer haze altitude. And the whole cycle continues. But theoretically, they did the math, and this could go for hundreds of millions, billions of years just over and over and over again.
Pamela: And this is where you can start to speculate wildly. I’m admitting this is science-based wild speculation –
Fraser: My favorite kind.
Pamela: – that when whatever catastrophic event occurred that caused the runaway greenhouse event on Venus, whenever that occurred if it was a world our own that had a vast diversity of microbes capable of surviving and pretty much any niche in the environment you can imagine, there’s the chance that some of them could have figured it out how to rise up in the clouds or been carried up and just happened to survive and find a way to evolve over the generations to be what was needed. Life finds a way.
Fraser: So, suddenly, everyone is asking what spacecraft are at Venus that can help confirm this discovery.
Fraser: Yeah. The Japanese Akatsuki spacecraft into there and it can see wind and –
Pamela: [Crosstalk] Yes.
Fraser: – atmosphere.
Pamela: And that is all well and good, but not entirely useful.
Fraser: Yeah. BepiColombo from the European Space Agency is on its way to Mercury and is going to be able to do a fly-by of Venus and be able to do some detections. But we’re gonna need something custom-built for this.
Pamela: And ideally what we want to do is take things on balloons or gliders and have a way to go down to these various altitudes within the atmosphere, and ideally, carry an instrumentation package that allows them to grab up samples of the atmosphere, and then look at them –
Pamela: – under a microscope they took with them.
Fraser: Right. Or sample return them home.
Pamela: See, that starts to become far too large of a mission at that point. We want answers faster than that.
Pamela: [Crosstalk] Sure, do that in a –
Fraser: [Crosstalk] Yeah.
Pamela: – generation or so, but –
Fraser: [Crosstalk] Yeah.
Pamela: – life is short. Build the discovery class mission now.
Fraser: Yeah. There’s a couple of missions that have been in the works.
Fraser: There’s one from NASA. There’s one …
Pamela: [Crosstalk] DaVinci.
Fraser: Yeah, there’s one from – which would just be dropped into the atmosphere. There’s some suggestions of balloon-based missions, which will hover in the atmosphere of Venus and even go up and down in altitude, follow some of these thermals. The Indian Space Agency has a mission in the works. The Russians have one.
Pamela: And Rocket Lab.
Fraser: Yeah. Yeah, we saw a Rocket Lab actually has a Venus mission that they had been planning, that they dusted off. Again, coincidence maybe.
Pamela: So, the Rocket Lab one is the one that amuses me the most. It’ll probably be the fastest to complete. The entire spacecraft will be about 15 kilograms. They’ll have three kilograms for instrumentation, not a lot of power. But let’s see how creative we can get in figuring out how to do this. We built a little tiny, itty-bitty helicopter for Mars. All we need is a balloon for Venus.
Fraser: Yeah. Yeah. But there are some other plans as well, things like the Havoc Mission, which would send blimps, even human-operated blimps to the cloud tops of Venus. And then, they would use a blimp-based rocket to return back to Earth ‘cause it’s still – you’re still gonna have about 90% of the force of gravity once you’re in the – it’s easy to get to Venus, easy to enter the atmosphere as long as you stay off the ground. But it is tricky to get home again.
Pamela: I feel the need to point out that like Mars, Venus doesn’t really have that whole magnetic field thing going for it. And so, if you don’t your astronauts, sure, send them there before we have figured out how to take care of radiation.
Fraser: Well, it does have that atmosphere, though. It helps.
Pamela: It helps, but you’re not gonna be too deep in the atmosphere –
Pamela: – so.
Fraser: Yeah. You’re gonna be up pretty high.
Pamela: And there’s the whole getting there part. Although, it’s faster to get there. And the cool thing about Venus, unlike Mars, is because we’re outside Venus’s orbit there’s multiple –
Pamela: – landing approaches per year.
Fraser: Yeah. We can go there pretty much any time we want, unlike Mars, we have to go every two years. So –
Pamela: [Crosstalk] Right.
Fraser: – lot more opportunity to go there and a lot more opportunity to come back with that sweet sample return mission that should be in the works right now. All right. So, now, you’re all cut up everybody on the discovery on Venus. Obviously, we will keep you filled in every new discovery that gets made as this goes. It’s one of the most exciting discoveries in the field of planetary science and astrobiology in years and could act as the cornerstone of our future searches for life across the universe. So, hopefully this is really – this is really exciting.
Pamela: It really is. And if you wanna hear interviews with David Grinspoon, who’s one of the researchers who’s been studying the potential for life or with Sara Seager who’s one of the authors of these research papers, check them out over in dailyspace.org. This is the short-form daily podcast we put out from CosmoQuest.
Fraser: Fantastic. All right. Well, thanks, Pamela. Do you have some names for us this week?
Pamela: I do as always. Our show is brought to you by you. You are the reason we’re able to keep doing what we do year after year after year. So, right now I would like to thank Jordan Young, Barry Gowen, Berka Roland, Romgi Omatou, Jeffrey David Mycorsini, Andrew Palestra, David Trug, Brian Cagle, the giant nothing, Dan Littman, Robert Plasma, Laura Kedelson, William Les Howard, Paul Jarmon, just Cunningham, Cory Davalo, and Emily Patterson. Thank you, all so much, for being here and being part of the numerous people that support our show.
Fraser: Thank you, everybody. And we’ll see you all next week.
Pamela: Thank you.
Pamela: Astronomy Cast is a joint product of Universe Today and the Planetary Science Institute. Astronomy Cast is released under a creative commons’ attribution license. So, love it, share it, and remix it. But please credit it to our hosts, Fraser Cain, and Dr. Pamela Gay. You can get more information on today’s show topic on our website, astronomycast.com.
This episode was brought to you thanks to our generous patrons on Patreon. If you want to help keep this show going, please consider joining our community at patreon.com/astronomycast. Not only do you help us pay our producers a fair wage, you will also get special access to content right in your inbox and invites to online events. We are so grateful to all of you who have joined our Patreon community already. Anyways, keep looking up. This has been Astronomy Cast.