Venus is not a great place to be. Its surface reaches temperatures up to 475°C, which is hot enough to melt lead. Even high up in the atmosphere where the temperatures and pressures aren’t so intense, the sky is plagued by clouds of sulphuric acid. But Venus probably wasn’t always so bad – it may have once been a temperate world similar to Earth, before a runaway greenhouse effect ruined the place.
In this episode of Dead Planets Society, our hosts Chelsea Whyte and Leah Crane attempt to turn back time on Venus, helping it live up to its habitable planet potential. Planetary scientist Paul Byrne at Washington University in St. Louis joins them once again in this uncharacteristically benevolent mission to fix Venus.
The first step is to clean out that dense, hot, sulphur-filled atmosphere – a difficult task, although easier than terraforming Mars would be, thanks to Venus’ larger size. This could be done using some of the same technologies proposed to help mitigate global warming on Earth… or it could be done by using a giant potato gun that shoots asteroids. It’s anyone’s guess which path our hosts will choose to go down, but one thing is for sure: it is not going to be great for the rest of the solar system. And things will only get more chaotic when they move Venus into a cooler orbit farther from the sun in order to maintain its new, friendlier climate.
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Dead Planets Society is a podcast that takes outlandish ideas about how to tinker with the cosmos – from snapping the moon in half to causing a gravitational wave apocalypse – and subjects them to the laws of physics to see how they fare.
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Transcript
Chelsea Whyte: Alright, well, you’re selling me now. A gondola on Venus?
Leah Crane: Except for the sulphuric acid.
Paul Byrne: It’s a minor detail.
Leah Crane: If you love Venus we’ve got a time share to sell you. Welcome to Dead Planets Society.
Chelsea Whyte: This is a podcast where we imagine what it might be like if we were given cosmic powers to rearrange the universe. I’m Chelsea Whyte, senior news editor at New Scientist.
Leah Crane: And I’m Leah Crane, physics and space reporter at New Scientist. Today we’re doing something a little bit out of character for us. We’re fixing Venus.
Chelsea Whyte: Yes, I mean, it needs it, right?
Leah Crane: Absolutely.
Chelsea Whyte: Because the thing about Venus is it’s kind of similar to Earth, right? It’s a similar size, it’s sort of a similar distance from the sun, but it’s just truly horrible there. It’s incredibly hot, it’s got these clouds of sulphuric acid, there’s just volcanoes everywhere. I mean, it’s awful, right?
Leah Crane: Yeah, it’s very unpleasant, and we want to make it suck less. We’ve got a few ideas on how to do that. We might get rid of some of the atmosphere which is making it so bad, or maybe even go through the whole process of terraforming to make it a little more like Earth.
Chelsea Whyte: Right, so, we might, I don’t know, set off some of those volcanoes, or smash another planet into Venus, our favourite thing. Or maybe just move it, maybe just tug Venus out into another place in the solar system.
Leah Crane: Yeah, I think we should do all of that.
Chelsea Whyte: Okay.
Leah Crane: And in our attempts to make Venus suck less we’ve brought back Paul Byrne, who is a planetary scientist at Washington University in St. Louis.
Chelsea Whyte: So, he told us why Venus sucks and what happened to Venus to make it so unpleasant for life there.
Paul Byrne: Okay, so, to be clear it is potentially, yes, sure, it’s unpleasant. It doesn’t suck, though, okay, so I take exception. There’s only one body in the solar system that sucks. But Venus is hard, Venus is pretty hard, and we actually don’t know why. There’s two leading reasons but before I even get there it’s worth talking about how it is hard, how it is difficult.
The surface temperature at Venus is the same as a self-cleaning oven. Now, often when people describe stuff in popular literature they describe it as it’s hot enough to melt lead. I personally don’t do any soldering, I have no intuition for what it takes to melt lead. But I do know that when your oven is in the self-cleaning mode you don’t touch it. That’s the average normal temperature of the surface of Venus. And here’s the thing, it’s the same temperature during the day and during the night, and it’s the same temperature at the pole as it is at the equator.
Right, the whole thing is around the same temperature everywhere. But in addition to this pretty bad temperature there happens to be really, really high pressure. It’s basically about 90 times more pressure than room pressure on Earth. So it’s equivalent to about 900 metres, or about a half a mile under the ocean on Earth, that’s the pressure. So it’s pretty bad.
Chelsea Whyte: Can I ask, why is it the same temperature during the day and at night?
Paul Byrne: Because the atmosphere is so thick, and the atmosphere moves relatively slowly. Although here’s the other thing, the atmosphere actually rotates around the planet much faster than the planet itself rotates. But there’s so much air that it’s had a long time to basically even out the temperature everywhere.
Chelsea Whyte: Yeah, it sounds really miserable.
Paul Byrne: Yeah it’s not great. Although let’s- just to step back for a sec, it is also worth bearing in mind that the only other place in the solar system that is room temperature in pressure is the Venus clouds, at around 55 kilometres or about 30-odd miles up it is room temperature in pressure, in Venus.
Chelsea Whyte: That does sound lovely, okay.
Paul Byrne: Okay, there are sulphuric acid clouds, you can’t have it all. But if you put on some protective suit, and you put on re-breather because the atmosphere is 97 per cent CO2, but you could go out in shirt sleeves, if your shirt sleeves were-
Chelsea Whyte: Were in a suit.
Paul Byrne: Yes, but the point is it wouldn’t be a vacuum, it would be quite balmy. And you could stand there on the railing of a gondola, of a giant airship, 55 kilometres up and it would be about the same as being two or three kilometres above the surface on Earth, quite pleasant.
Chelsea Whyte: Alright, well, you’re selling me now. A gondola on Venus.
Leah Crane: Except for the sulphuric acid.
Paul Byrne: It’s a minor detail.
Leah Crane: Okay, now that we’ve covered why Venus sucks, let’s fix it.
Chelsea Whyte: Okay, are we talking about science fiction-style spacesuits being a reality, or are we talking about terraforming?
Paul Byrne: I would want folks listening to this to put this in context: that science fiction is so much closer to us than we’re going to terraform a planet. That is magic. But if we were to do it, Venus would be a better choice because the gravity at Venus is 82 per cent the gravity of Earth, it would be not all that dissimilar. It’s not much of the size of Earth, the horizon would be a sensible distance away. We would be able to live there and everyone would be a little more athletic, by a little bit, but not by much. And it would be a pretty good place. It’s another Earth.
Now, the way you do it is, yeah, you’d have to try and scrub that atmosphere. Now, I think human-driven climate change is going to require us making a huge number of fundamental changes to society. There’s no way around that. But it also seems we can’t escape the idea that we’re going to use some sort of technological means to fix it as well. Relying entirely on that is greenwashing and is a moral hazard, but it’s hard to avoid some kind of technological capability. And one of those things we’re going to have to develop is some kind of carbon sequestration technology where we draw carbon out of the atmosphere and do something with it, turn it in to building materials, whatever. Then perhaps it’s not such a stretch that, say, in a thousand years that technology would evolve to the point where we could deploy it autonomously on the surface of Venus, and it could begin to suck the carbon out of the atmosphere.
Chelsea Whyte: Send some little scrubber bots to, you know, rope around?
Paul Byrne: Yes, many millions of them. It also might take several thousand years, so good luck getting anyone to sign up to a project, you know, the cathedrals were difficult to build in Europe for the last millennium but they only took a few hundred years. This thing would take a very, very long time. But that’s probably how you would do it. If you sucked the CO2 you would be taking out- because here’s the thing, there’s about the same amount of water vapour in the atmosphere of Venus as there is on Earth. It’s just proportionally much, much less because there’s proportionally much, much more air. But you wouldn’t have that hard a time. There’s some nitrogen there, there’s a little water vapour there. You might have to add oxygen, but you could probably do that. I think that’ll be a lot easier than having to try and somehow give Mars an atmosphere when it has no ability to hold on to one.
Leah Crane: Right, that was really my next question, was if we can just get the bad stuff out, or if it needs, like, full dialysis. But it sounds like if we can get rid of all that carbon dioxide it would be a step.
Paul Byrne: I have not done any- you know, we may hear from someone after they hear this who has gone through some exhaustive set of calculations. I have not done those calculations. But I can tell you qualitatively, if you pull off the CO2 there’s enough mass at Venus. It’s about 80 per cent, 82 per cent Earth mass. So there’s quite a lot of planet there. It’s going to be able to hold on to a lot of atmosphere. A big question we’ve had for a long time is to what extent is a magnetic field required for an atmosphere? And certainly the kind of prevailing view, I think, for Mars is that Mars doesn’t have an atmosphere because it has no magnetic field, and so solar weather strips it away. Venus has no magnetic field, and it has 90 times more atmosphere than Earth does, so I don’t think a magnetic field is all that important. And in fact, depending on the species, meaning the chemistry, the magnetic field can actually help accelerate the loss of some parts of an atmosphere, which we now know that of Mars. It’s probably much more to do with how big the planet is.
And what we also know, to about roughly the same order of magnitude, is that the rate of atmosphere loss at Venus, Earth and Mars per year is about the same. The difference between Earth and Venus and Mars is that Mars is tiny, its mantle has de-gassed. That is to say, the stuff that was inside it has largely come out. And most of that stuff came out a really long time ago. So even if you were to somehow put some sort of science fiction super duper magnetic shield protector thing in front of Mars, that’s not going to do anything because Mars’ ability to have an atmosphere has gone. Its ability to vent an atmosphere out of the interior, onto the surface, has ended. In the case of Venus, yes, sure, it’s losing a lot of atmosphere but it also seems to be capable of replenishing it somehow. How do you replenish an atmosphere? You have volcanoes.
Leah Crane: We already know volcanoes are really important on Venus, they might actually be the reason it’s so horrible. If a bunch of volcanoes went off all at once they could have thrown Venus into this runaway greenhouse effect.
Chelsea Whyte: And that’s definitely plausible, right, because Venus has so many more volcanoes than I ever thought it would. Right, aren’t there, like, thousands?
Leah Crane: Yeah, Paul and his colleague, Rebecca Hahn, counted them and there’s at least 85,000 volcanoes.
Chelsea Whyte: Wild, yeah. But cool, right? Because that means we have a lot of power to work with.
Paul Byrne: I do want to emphasise, volcanoes giveth and taketh away. They are the very means by which we have an atmosphere and oceans today. It comes out of the interior. But sometimes if they get a little too energetic, clearly they can destroy all the climate.
Chelsea Whyte: Like, calm down guys, let’s take it easy. Yeah.
Paul Byrne: Yeah, yeah, exactly. So the thing is, in some respects, once you’ve pulled down the CO2 you might expect that Venus is able to stay relatively habitable, relatively climate. It might be the wrong mix of gasses. It might still be a CO2 atmosphere. But one bar would be a lot easier to walk around in if CO2, because then you’d need a re-breather, than 90, which is, like, no, we don’t send divers down that deep. And the temperature would also be a lot cooler. Now, you might need to go and do a lot of other chemical changes to the atmosphere, I don’t know how you’d begin to do that. But as a first step Venus is going to be an easier target to terraform. And will leave you with a much, much more Earth-like world.
Leah Crane: There’s a big part of me that just wants to bring a giant cosmic needle and lance the atmosphere, I do wonder if it would be plausible to smash something into it so hard that a bunch of the atmosphere gets thrown away. Paul had some ideas on that.
Paul Byrne: Yeah, it would be, yes. So, we call that impact loss, impact-induced loss. And, so, if you think of an atmosphere it’s a gas, right, it’s a mixture of gas. But all gasses are very small solid objects, small particles. And they behave and follow physics that we pretty well understand, certainly at Earth. And there are different mechanisms that make stuff more or less likely to leave, and if you smack something into an object fast and powerful enough you probably will dissipate quite a bit of the atmosphere. And certainly over the impact site you will expose it to space for a very short period of time before the wind can carry it back in. I mean, these are scales of processes that, you know, we have not yet seen in a movie because they are too difficult to visualise, but would be catastrophic.
It just depends on if your objective is purely to smack something in to something else, cosmic billiards style, sure, have at it. You might spend quite a bit of time, though, depending on how big the impactor is, with quite a bit of molten stuff on the surface of Venus. So if it’s a place you want to go and put people onto later on you’re going to have to wait a while. You might have to wait several million years for that to happen. So it just really depends what your priorities are.
Chelsea Whyte: I mean, we got to break some eggs to make an omelet, I feel like.
Paul Byrne: I’m not arguing against this, I’m just saying if you wanted to terraform Venus this is not a good approach. If you wanted to smack something into Venus to get a cool video, this would be a way you could do that.
Chelsea Whyte: I’m curious also if there’s any effect if Venus isn’t where it is. Like, if we drag Venus somehow further away from the sun would that help with our endeavour here?
Paul Byrne: It’s not straightforward, you pull it out double the distance and it’s half the temperature, it’s not that straightforward. But yeah, it would probably get a little cooler. And in doing so then it might actually get a little less pressure-y, which would help.
Chelsea Whyte: But now I’m thinking of combining Leah’s idea of, like, first of all you’d need something big, like a mega-nuke, I don’t know. But if we could- could we nuke it hard enough to move it?
Paul Byrne: No, no.
Chelsea Whyte: No, okay. So, but what if I think bigger than a nuke? Like, what if we take Mercury and slam it into Venus?
Paul Byrne: Okay, so-
Chelsea Whyte: Could I move it out far enough to cool it down and also, you know, do what we talked about earlier with, like, setting in motion some of this loss of these gasses?
Paul Byrne: So, this gets really hard. If you smashed Venus and Mercury together, a lot would depend on how you did it and how fast they were going. Were they going head first? Were they, kind of, coming together at the same speed? Was it a glancing blow or a direct blow? If you put the two of them in full speed ahead, like two trains hitting each other, you would vaporise the two of them and make a new planet.
Chelsea Whyte: Well, I don’t want to do that. I want to, sort of nudge-
Leah Crane: Mercurus!
Paul Byrne: Yes, you’d have Menus. Or Vercury. So that would be- I don’t know what the objective would be. Again, I’m not advocating against any of these ideas, I’m just saying you’re not going to have two planets at the end, you’re going to have one new one that’s about the size of the two of them combined.
Chelsea Whyte: Now, we have a special offer for our listeners. You can get four weeks of New Scientist free, followed by a monthly subscription price of 9.99. That’s in dollars or pounds. You’ll get unlimited access to our website and app, plus subscriber benefits including newsletters, essential guides, and invitations to subscriber-only events.
Leah Crane: Go to newscientist.com/dpsoffer now to get your free month of New Scientist.
Chelsea Whyte: And if you’re in London, join us at New Scientist Live on October 8th where we’ll be recording a live episode of Dead Planets Society. The event will take place across the weekend of October 7th to 8th, and it’s sure to be jam-packed with fascinating talks and hands-on experiences. We’d love to see you there.
Leah Crane: We’re back, and we wondered if it might be easier to, instead of chucking one big planet at Venus, throw lots of little stuff at it.
Chelsea Whyte: Ooh, yes, rain down.
Paul Byrne: And if each of these big impacts, they blew off 1 per cent of the atmosphere, then you have 99 of them to blow down 99 per cent of the atmosphere.
Leah Crane: So, what we’re saying is go to Venus with an automatic weapon that fires nukes?
Paul Byrne: No, nukes are too small.
Leah Crane: Oh, automatic weapon that fires large asteroids.
Chelsea Whyte: Like a t-shirt gun with asteroids in it.
Paul Byrne: Yeah. Like a potato gun but the potatoes are asteroids.
Chelsea Whyte: Correct.
Leah Crane: I love that.
Paul Byrne: Yeah. And then you just- and you pop them, then you’ve probably got to do some maths to figure out which angle, blah blah blah, right, you know, you fire the first few, you get the hang of it, see how much destruction you cause.
Chelsea Whyte: But, so, but this would help us with the atmosphere but would it move the planet?
Paul Byrne: No, I don’t- not meaningfully. Because think about it, it’s like, so, it’s the idea, you know those, I don’t know, I grew up watching a lot of action movies that were stupid but guilty pleasures of mine, and particularly in 80s movies, when someone go shot by a gun they flew out a window. And, like, that’s just not how physics works, right? So the thing is if we wanted to move Venus we would have to hit it with something going disproportionately fast. Now, by the way, I don’t know how we build the asteroid potato gun because there’s an enormous amount of energy involved in the motion of these objects so we’re going to have figure that out too.
Chelsea Whyte: This is Dead Planets Society, we have it, it exists, it’s ours.
Paul Byrne: Okay, fine, this thing is- okay, but the point is there’s a whole pile of potential energy in this thing now, right, because it’s spinning and moving. So yeah, you could probably angle it a certain way and position a certain way in Venus’s orbit but the way to get Venus to move is to speed up its orbit, basically. That’s the way we need to do it. Because orbit is a function of speed, not altitude, right, you can orbit Earth a meter above the ground if you were going fast enough. Now, I don’t think you should do that but, you know, you could. So that is to say, we would need to change Venus’s orbital speed around the sun. That’s how we would pull it out. So we would need to basically, if we hit it fast enough that enough things from behind in the direction it’s going, that might be enough to basically increase the orbital altitude it has.
Leah Crane: But then our gun would have to have zero mass because we don’t want our gun attracting it backwards in its orbit, slowing it down?
Paul Byrne: Well, yeah, the gun raises a lot of issues of its own, actually. Yeah.
Chelsea Whyte: Well, we could also put those, remember those planet moving rockets in The Wandering Earth?
Paul Byrne: Yes, that’s actually better because you wouldn’t need a gun then, you would just go to the asteroid belt with many, many automatic systems, and then you would just put rocket engines on these things and then you would fly them into the inner solar system.
Chelsea Whyte: Drive them in to it, yes.
Paul Byrne: Yes, you wouldn’t need a gun, you just need basically, it would be like, you know, a big car park and then suddenly these things will start to depart into the inner solar system. And you hope to God that your guidance and navigation is accurate, because if they could fuse one large rocky world to the other, you’re getting fired.
Leah Crane: So, I have reservations about the moving Venus thing because I kind of feel like moving it nearer to Earth could wreck Earth.
Paul Byrne: So, here’s the thing, right, right now Venus and Earth don’t have a huge amount to do with each other, right, and it’s true that if you were to move Venus farther out, potentially even beyond Earth, or even you could move it into Earth’s orbit, as long as they’re far from each other it won’t really matter.
Chelsea Whyte: Could they equilibrate, like, with Venus exactly opposite us, on the sun, in the same orbit?
Leah Crane: Put Venus in L4?
Paul Byrne: I guess we could. I don’t know what that would do to Earth. I don’t know how much Venus would have any impact on Earth compared to the unbelievable massive gravitational effect of the sun. I don’t think it would have much of an effect on us.
Chelsea Whyte: Let’s bring Venus here, I want twin Earths please.
Paul Byrne: So, if we did that we could-, so, here’s the thing. If Venus was the other side of the sun to us the whole time, we wouldn’t ever see it.
Chelsea Whyte: That’s okay, we could still go there.
Paul Byrne: Well, do you know what, there are these things called Lagrange points, and the Lagrange points are these places where you could put things that are gravitationally, relatively speaking, stable. That’s where, for example, L2, the second Lagrange point, is where the Webb telescope is. Well, Lagrange points four and five are 60 degrees before and after an object measured from the central thing, in this case the sun, along the same orbit. So you could potentially put- and there’s even a bunch of small asteroids that trail and lead Earth in Earth’s orbit at these two Lagrange points. You could put Venus there.
Chelsea Whyte: And let the asteroids hit it.
Paul Byrne: That would be an added benefit.
Chelsea Whyte: I think we’ve just solved Venus. Bring it on over to our neighbourhood, it’ll turn into Earth.
Paul Byrne: We’re going to put it at L4. It also would make it a lot easier to get to, which is also going to save some money. Although clearly if we have a space potato effect, we have no issue of money. This is obviously a post-scarcity society if we can afford to send 10,000 asteroids into Venus.
Chelsea Whyte: I think it sounds like it’s worth it. Every penny.
Paul Byrne: I think it is too. I’m here for the jobs that moving Venus will create.
Chelsea Whyte: Can you believe we’ve got a solid campaign platform right here? I don’t know what I’m running for, like, solar system queen?
Leah Crane: President of Earth.
Paul Byrne: I’m just saying that, you know, until we dominate the position of the planets in the solar system can we truly say that we are guardians of our world? No.
Chelsea Whyte: Yeah, exactly.
Paul Byrne: We should move things.
Leah Crane: Earth number one, Earth number one. Oh, I love it so much.
Chelsea Whyte: So, we started out trying to fix Venus and we ended up making ourselves the supreme monarchs of the solar system.
Leah Crane: Sounds like a resounding success to me.
Chelsea Whyte: Thank you to Paul Byrne for joining, and to all of you for listening to Dead Planets Society. We’ve had some great suggestions for cosmic chaos that we might undertake from listeners so far. Lee Devereaux from Baltimore wrote in to ask, what would happen if we were able to transport the rings of Saturn and have those rings around Earth instead? He asked would it just be really cool to see rings around our planet, or if there might be more dire consequences. I’m guessing it’s the latter. That’s definitely one for us to look in to in the future. Thanks, Lee.
Leah Crane: If you have any questions to add to our list our email is deadplanets@newscientist.com. Plus on October 8th we’ll be recording a live episode of Dead Planets Society and New Scientist Live in London. You can find out more about NS Live and get your tickets at live.newscientist.com.
Chelsea Whyte: And if you just want to chat about any of our episodes so far, hit us up on Twitter, or X, I suppose. I’m @chelswhite, and Leah is @downhereonearth. See you next time.
Paul Byrne: It’s almost certain that Earth will turn in to Venus, it’s almost certain. And the reason is because the sun is getting brighter. And it’s probably going to happen relatively soon.
Leah Crane: Tomorrow.
Paul Byrne: Yeah, it’s actually next week so get your stuff in order now, right, we’re going to have an amazing summer, right, the oceans are going to boil.
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