Venus is arguably the worst place in the solar system
From another perspective, its atmosphere is "one of the most Earth-like in the solar system", and scientists long ago postulated the idea of establishing floating cloud cities.
Big balloons filled with nitrogen and oxygen would naturally settle at the right altitude, 30 miles above the surface, where gravity, ambient pressure, and radiation aren't far off that of Earth, and temperature hovers around a balmy 86°F.
Since the pressure inside and outside is matched, punctures wouldn't cause explosive decompression, providing time to repair damage or leaks. You wouldn't need a bulky pressure suit to venture outside, just some comparatively simple breathing apparatus, and of course protection from the nasty sulfuric acid in the atmosphere (akin to acid rain). The habs would be coated in Teflon to resist it.
A shockingly useful "quick and dirty" estimate for C to F for temps humans are likely to encounter is 2x + 30. It's not precise at all, but for purposes of "what does that feel like outside" or "should I bring a sweater" it works pretty well.
21C would, by this estimate, be 72F. The true conversion is just shy of 70F, so, again, it's not correct but it's close enough for this kind of conversation.
In this HN subthread: users slowly converge on the conversion formula for Celsius to Fahrenheit (32+9C/5) in greater and greater precision while calling it an “approximation.”
The Fahrenheit scale is European, not American. It was created in Poland well before the United States broke off from Great Britain. We're just slow to change.
Maybe there is a reverse psychological angle to make the current US administration go metric. Fahrenheit->Polish->European->Communist/Woke. Can't have that!
> Maybe there is a reverse psychological angle to make the current US administration go metric. Fahrenheit->Polish->European->Communist/Woke. Can't have that!
1. That nonsensical, because the same logic would apply to Celsius temperatures.
2. Americans don't keep using Fahrenheit because of some aversion to Europe. Though I do have some fondness for it as resistance to the machine-people who are always going on about efficiency and trying to hurry everyone up.
The irony is that (at least I'm pretty sure) the concept of "room temperature" was originally pinned to 70° Freedom Degrees. Your 21°C reference unit is probably a rounded conversion, which explains the sibling comment arguing 23°-25°C as potentially inferior alternatives. An accurate conversion would be 21.1̅°C.
Conceivably, if you had an umbrella to protect yourself from the acid rain, an oxygen mask, and were on a very safe floating platform in the upper atmosphere, you could walk around in a t-shirt and be just fine.
Had to add metric to an imperial unit application since it is to be sold internationally. I live in a Fahrenheit country so I set my phone, computer, and car to Celsius to learn how the the temperatures readings feel.
I 100% agree, "Freedom Fries Units" is quite fitting.
Turns out I prefer Celsius over Fahrenheit in day to day usage.
The US doesn't use Imperial units. It uses US customary units, which are different from Imperial in several significant ways, because the Imperial system evolved after the US split from the British Empire.
Also interestingly, US customary units are defined in terms of metric. So in a sense, the US does use the metric system.
I often correct people regarding the US not using Imperial as well but to be fair the only significant difference these days is in fluid measurements. Weight and length measurements were standardised between US customary and Imperial back in the 1950s
The Venusian atmosphere at that altitude is super dry, only a few score ppm of water making it much drier as Earth's Atacama desert. So while that water vapor is extremely acidic in terms of raw ppm its not too far outside the limit of what OSHA allows and is probably fine since you aren't breathing it.
If I understand correctly there's still a little bit of residual hydrogen bound up in the sulfuric acid molecules. And if you added it all up close to the amount of water you'd get from one of our Great lakes in North America. (At least if you combined it with oxygen, of which there's plenty on Venus).
The article mentioned something about heavy water which I don't understand very much. But it's a problem.
The tragedy of both Mars and Venus is that billions of years ago? It seems like they both might have had abundant liquid oceans of water. Which doesn't mean they would have supported life, but they would have been so much closer to habitable and a much better starting point. Instead, it's like if you're deadbeat brother house-sat them for a weekend and threw a bender and trashed the houses, that's what we're left with now.
A big issue is that neither seem to have developed photosynthetic life[1] and without a lot of oxygen in the atmosphere they don't have an ozone layer. That means that UV light penetrates further and breaks up water into its constituent parts allowing the light hydrogen to be blown away by the solar wind over geological time scales.
[1] It's looking increasingly plausible that Mars developed primitive life, but I'd bet heavily against photosynthesis. That took way longer than chemosynthetic life on Earth.
I think the article speaks to the point you're making also, that the UV light may have been an important (if not primary) mechanism for blasting away Venus' water. So even if someone snapped their fingers and made Venus perfectly terraformed, it probably once again would begin the process of losing its water. And any life would have to survive a brighter sun.
How do you deorbit Venus is such a way that your inflatable balloon city comes to a gentle stop, 30 miles up, and just floats there? Worse still, when people need to leave and return to Earth, how do you launch a rocket from the balloon city and return to orbit? How do visitors or pioneers deorbit and land at the floating city? If there aren't materials to effect a repair, how long until it sinks down into the hellzone? Where are materials manufactured for repairs, and how quickly could they be manufactured and sent there? If a rocket is trying to land and goes off course, does it squash the balloon city like a grape? Saying that holes can be patched is well and good, but there are some truly catastrophic failure modes that don't seem entirely unlikely.
> such a way that your inflatable balloon city comes to a gentle stop, 30 miles up, and just floats there?
Literally how floating works.
> Worse still, when people need to leave and return to Earth, how do you launch a rocket from the balloon city and return to orbit?
By launching your rocket from the ballon city and returning to orbit. (I'm struggling to see the novel problem.)
> Where are materials manufactured for repairs, and how quickly could they be manufactured and sent there?
Why is this unique to Venus versus anywhere else in space?
> If a rocket is trying to land and goes off course, does it squash the balloon city like a grape?
Yes. Same as if your rocket is trying to land at your Moon or Mars base (or hell, your Earth landing pad) and goes off course, it squashes your colony like a crouton.
>By launching your rocket from the ballon city and returning to orbit. (I'm struggling to see the novel problem.)
I believe they are having trouble envisioning how you would launch rockets from a balloon city without disturbing the equilibrium of the balloon city because it is assumed that rockets thrusting down with great force would damage the balloon city in a way it would not easily recuperate from.
I also find the idea difficult to understand, but assume that is because it is in an area I know nothing about and the problems that I think sound bad are actually totally solvable engineering problems otherwise it would not be have been suggested as a solution by engineers expert in that area.
> how you would launch rockets from a balloon city without disturbing the equilibrium of the balloon city because it is assumed that rocks thrusting down with great force would damage the balloon city in a way it would not easily recuperate from
It's a floating platform. Same as the ones SpaceX lands its rockets on. Same as a gunboat firing projectiles.
Will a launching rocket impart force to the platform? Yes. But unless the platform is super weirdly balanced, or the rocket absurdly oversized for the platform, it will stabilise after rocking a bit. (You'd have to design the platform to be stable in winds, anyway.)
And if you do have an absurdly oversided rocket, you don't launch it from your platform. You float it off to the side on a dedicated launch "boat" and have it ditch its floaty as an ultra-early first stage.
>It's a floating platform. Same as the ones SpaceX lands its rockets on. Same as a gunboat firing projectiles.
It's a great comparison that helps me understand it a bit. In many respects, Venus's atmosphere is as heavy as an ocean. That said, I can still see how if you're talking about the upper atmosphere with pressure similar to what you would have on Earth, the force necessary to do a straight vertical takeoff imparted against a platform seems like it could cause problems.
But it might just be the Archimedes thing of "give me a prop large enough and deliver long enough and I can move the world" applied to atmospheric dynamics, e.g. enough buoyancy and you're good to go. I just don't know how much is "enough" when you're talking about Venus and if that runs into prohibitive engineering complexity that makes it different from our familiar Earth examples.
Not saying it can't be done but I think that one question at least, was reasonable.
>And if you do have an absurdly oversided rocket, you don't launch it from your platform. You float it off to the side on a dedicated launch "boat" and have it ditch its floaty as an ultra-early first stage.
The ww2 german "v2 in a tube towed by a U-boat so it can get closer to its target" project being a decent conceptual example of this.
Launching the rocket from a balloon is not a problem. You can have a platform with a hole underneath the rocket's exhaust and the balloon itself can be a torus through which the rocket flies upwards. There would be minimal impact of a rocket launch on the platform if designed properly.
But either way it's a bit less the firey-burney-explodey problem than the sudden loss of a few thousands tonnes of mass that would displace the equilibrium of the launch platform, should you care to re-use that, or the means by which such platforms (capable of supporting said thousands of tonnes of mass).
Just to put some hard numbers on it, a crewed Falcon9 (Crew Dragon) has a launch mass north of a half-million kilograms, or 500 tonnes.
The Russian Soyuz-FG, also human capable, has a launch mass of slightly over 300 tonnes.
If this spacecraft is only a shuttle to low-Venus orbit with another transfer craft for the flight back to Earth (or other points of interest) that should suffice. If the launch craft is intended for the full return trip of 100--250 days, things could get a bit cozy and interesting depending on the number, disposition, and fragrance of inhabitants.
Uncompleted thought: "or the means by which such platforms (capable of supporting said thousands of tonnes of mass)..." are replaced. Given lack of readily available solid substrates in situ a nontrivial challenge.
There is precedent: SpaceShipOne was successfully launched from an airplane [1].
The great force downward is (mostly) irrelevant if there is nothing below. Just hang the rocket between two towers over a void, with the atmosphere below.
>I also find the idea difficult to understand, but assume that is because it is in an area I know nothing about and the problems that I think sound bad are actually totally solvable engineering problems otherwise it would not be have been suggested as a solution by engineers expert in that area.
A refreshingly sober approach that I think is a lot more healthy than hip firing incredulous questions.
I agree though, I don't intuitively understand how it would work. I would think you would do horizontal takeoffs. Also Seveneves by Neil Stevenson gives some interesting examples of ways to escape gravity wells without rockets, but I won't spoil anything there.
I have a silly take on this: to avoid rocking the floating city you throw the rocket overboard, let it re-orient itself upright, then use the main thruster to slow down the fall and then move up.
Yes, ignoring momentum. Do parachutes just get stuck in the air halfway down? When do you inflate it? If you inflate it, can you even deorbit? Do those pop when you deorbit? Do you cover the balloon with big heavy heat shield tiles?
I'm not claiming I understand this at all, but you seem to have some child's grasp of "how floating works".
> By launching your rocket from the ballon city and returning to orbit.
Launching from the solid ground shakes it (the ground) like a leaf. But you're going to launch a rocket from the balloon, and you can't quite see where there might be a problem.
>Why is this unique to Venus versus anywhere else in space?
If I can't get the materials to repair my building in a hurry, I go outside and I wait. Or I stay inside and I wait. And if I can't do that for my Venusian balloon city, I slowly sink into a zone that melts lead and bakes me alive. And if I get the materials after it has stared sinking, repairing it won't reinflate the balloon and have it rise again, because some significant fraction of the air has leaked out.
>If I can't get the materials to repair my building in a hurry
At that point you might as well be asking "what if they forgot to put fuel in the space ship" or "what if the astronaut missed launch because he forgot to set his alarm". That would be bad but that's not about Venus.
The guy you're responding to is an aerospace expert, iirc.
Anyway, the balloon would be relatively stable. The atmosphere gets increasingly dense as you go towards the surface, while the balloon has a particular density which is more than the wispy far atmosphere and less than the dense low atmosphere. Therefore, if you were to drop it at the top, it would fall (while it's more heavy) then approach the altitude where it's equally dense, and start bobbing around there, until it settles at its equilibrium.
Picture a glass cylinder of water and oil. It's cleanly separated with the denser water on the bottom and oil on top. Then drop an ice cube in. It will sink through the oil and then float, in the middle of the cylinder, on the water.
> If I can't get the materials to repair my building in a hurry, I go outside and I wait. Or I stay inside and I wait. And if I can't do that for my Venusian balloon city, I slowly sink into a zone that melts lead and bakes me alive. And if I get the materials after it has stared sinking, repairing it won't reinflate the balloon and have it rise again, because some significant fraction of the air has leaked out.
It's more similar to a boat than a house. If your boat has a leak, you need to repair it very quickly or it ends up at the bottom of the ocean. Yet we've managed to do it relatively reliably.
Sure. Do that when you're in the middle of an ocean that's a few trillion miles wide. It's not as if you can just dive down to the bottom of the ocean there, mine some bauxite, take it back up to your sinking ship, refine it, manufacture new repair materials for the boat, then repair it, is it?
No, you have to have it shipped from a coast a trillion miles away. So again, where are they manufactured, and how long do they take to get there? Can any of this shit even be made in the vicinity of Venus, where transit times might be non-absurd? There are no recoverable materials on the planet itself, are there?
You probably launch and land on a floating platform nearby. Nobody on Earth launches from a city. They launch and land in remote areas. Safety and noise. Lot of noise.
Only free if you discount the costs involved in carrying out genocide against the existing inhabitants. But your point stands, that cost was frequently born by the government, so from the perspective of individual settlers it was often free.
Living on a ship at sea, or underground / underwater, should give enough protection against whatever post-apocalyptic situation exists on Earth, it's pretty much always going to be more survivable than Mars or outer space. You might need a protective suit, air filters etc. Still 100x easier than having no atmosphere at all.
Surprise Dodgeball reference. But I don't think the ocean is as far away as deep space. I also think due to its proximity, it could be entangled in political paradigms that lead to entanglements in international conflicts and the independence from those political paradigms affords a form of insulation.
As in sending a part of species to a hostile place where all living is confined into a one big life support machine, without fresh air (which is very different from freshly uncanned or chemically generated air), without fresh and varied food (which is very different from artificially grown), without open sky and Sun above, without seas, rivers, forests, mountains, without anywhere to wander to find inner peace, in a setting for a psychologic horror where one deranged member of expedition is enough to bring it down.
That is going to contribute so greatly to the redundancy of our species.
I'd much rather be on a cruise ship than a lifeboat, but that doesn't mean cruise ships shouldn't have lifeboats.
No serious advocate of settling Mars, Venus or anywhere else in space seriously believes it will be easier than remaining on Earth, nor are they suggesting that it means we can abandon the Earth entirely, or care less about protecting its biosphere. They simply understand that, no matter much of a relative paradise the Earth is, so long as 100% of humanity exists there then we are placing all our species' eggs at the bottom of a single basket's gravity-well. It will do us absolutely no good if we solve climate change, war, poverty, disease, etc. only to get wiped out by the next comet or mega-asteroid that smashes into us. And, statistically, eventually one will.
This puts the cart before the horse. At least one important question to answer before. Does something absolutely needs to be done? Then we start looking into the best alternative.
What's the concrete threat scenario you avoid by moving to the Venusian clouds? Global warming? Fix it on Earth and if you can't convince people to agree on a solution here, how will you convince them that a Venusian balloon is the best way forward? Nuclear annihilation? Probably digging deep underground is better. Total planetary annihilation? Maybe stations in Earth orbit, or Moon's poles, or L point, etc.
Are we looking for options for which we have the technology and capabilities today, or a few centuries from now? That changes your options from "balloon on Venus" to "terraforming Venus".
The engineering and other practical considerations needed to get such a "station" a realistic chance at long term survival are about as sci-fi for us today as the starship Enterprise. We aren't even at the point where we can sustain an isolated Earth based colony indefinitely in an inhospitable environment. They all need constant maintenance and resupply from the the hospitable environment just a stone's throw away.
It would be one of the worst places. So, you are living over a floating habitat that the only way to get resources it's from out planet. Because, on the surface, the conditions are so hard that even remote mining is impossible.
It would be better the moon, Mars or even moving habits on Mercury. At least you have access to mineral resources, and water (ice).
People don't scale mount everest because there is an macguffin to be found there. They scale it to scale it. Because you can. For the adventure. To assert dominance over the universe.
We can talk about economical benefits or the survival of the species and those do matter. But it's also because colonizing another planet would be fucking epic and go down in history.
With the decline in religion we do need some kind of higher purpose and meaning to rally behind, and going off planet could fit that bill. In a time of increasing divisions it could foster brotherhood.
I understand this became a hot take in recent years, because you can always just "Colonize Earth". I do think there is an independent strategic value in terms of existential threats. It shouldn't be a rationale for abandoning environmental preservation and conservation on Earth.
One thing I see, all too often in Internet comment sections is things that could be complimentary are turned against each other and juxtaposed as if one interferes with the other. I don't know if there's a name for that but it happens often enough that it should have a name.
This question is one of a whole genre of "why" questions that come from supposed pragmatists, but I can't help but think the existence of the question misses the entire point.
Luckily, one of the older questions of this genre was about why anyone would bother to climb Mount Everest, and ol' Mallory had such a good answer that I'll just paste the whole thing here:
> People ask me, 'What is the use of climbing Mount Everest?' and my answer must at once be, 'It is of no use.' There is not the slightest prospect of any gain whatsoever. Oh, we may learn a little about the behavior of the human body at high altitudes, and possibly medical men may turn our observation to some account for the purposes of aviation. But otherwise nothing will come of it. We shall not bring back a single bit of gold or silver, not a gem, nor any coal or iron.
> If you cannot understand that there is something in man which responds to the challenge of this mountain and goes out to meet it, that the struggle is the struggle of life itself upward and forever upward, then you won't see why we go. What we get from this adventure is just sheer joy. And joy is, after all, the end of life. We do not live to eat and make money. We eat and make money to be able to live. That is what life means and what life is for.
Of course, with Venus, there's the joy of exploration and also tons of profits and learning to be had. For example, we could cover the entire planet in giant ads. Think of the CPMs you'd get as people looked out the window on their way to Mercury!
We choose to go to the Moon ... and do the other things, not because they are easy, but because they are hard; because that goal will serve to organize and measure the best of our energies and skills, because that challenge is one that we are willing to accept, one we are unwilling to postpone, and one we intend to win
And because if we don't beat Russia there we're all going to look less good on the global stage, and we simply can't have that. Wait, can we edit that out in post?
On some level I agree with the spirit. But I also think it implicitly concedes that there's not good reasons otherwise, which sells it too short. Existential threats to humanity seem like a pretty good reason, to the point that if reasons mean anything at all it should count as one.
> Yes. Same as if your rocket is trying to land at your Moon or Mars base (or hell, your Earth landing pad) and goes off course, it squashes your colony like a crouton.
The question you answered reads like someone that has missed all of the spectacular fails with Starship tests. Which is the ship designed for these types of adventures, so it seems like a big miss by the GP
No more than for a floating platform on the ocean. (Or frankly any sea or airborne firing platform.)
If your launch mass is a significant fraction of station mass, and you can't counterweight, you could float it off to the side and then have the baloon detach when its engines fire. But none of this is in even the top thousand problems that come with colonising Venus.
Floating on a liquid surface is markedly different from floating within a fluid (liquid or gaseous).
To float on a liquid, one merely needs to maintain a lower average density within the vessel than the surrounding liquid. Assuming a largely hollow vessel (as with a ship or barge), it's possible to add or remove considerable payload without losing stable flotation characteristics as the draft of the vessel automatically compensates for the variation, displacing more or less liquid, and maintaining equilibrium.
To float in a fluid, one must maintain precise neutral buoyancy, which is an entirely different animal. As pressure varies with depth or altitude, the tendency is for a vessel to contract as it sinks and expand as it rises, leading to a runaway buoyancy shift (increasingly negative with depth, increasingly positive with height). Many military submarines operate at comparatively shallow depths, often only slightly more than their overall length* (for larger submarines), given both the immense pressures of even modest ocean depths (a few hundred metres), and the compounding nature and risks of runaway buoyancy loss.
Plans for cargo airships face corresponding problems in that when offloading cargo or passengers it is necessary to vent or otherwise scavenge lifting gas (the expense and/or challenges of either venting or compressing helium are great), or to onboard a corresponding mass of ballast. Where suitable water is plentiful the latter is fairly viable, but there are many applications proposed for cargo airships which suggest transport of heavy cargos sites with limited capabilities for same (no facilities, deserts, salt- or otherwise-contaminated water which might play poorly with buoyancy-compensation systems aboard the airship).
Rocket launch from an inhabited floating atmospheric platform would require accumulation of large stores of fuel (the Tsiolkovsky rocket equation also works against you), as well as presenting various risks associated with enormous barely-contained explosions (should you be lucky). The risks are immense, and hand-waving them away is disingenuous to the extreme.
> To float in a fluid, one must maintain precise neutral buoyancy, which is an entirely different animal
You're right, I was oversimplifying. An aerial or submerged launch platform, then.
> the tendency is for a vessel to contract as it sinks and expand as it rises, leading to a runaway buoyancy shift (increasingly negative with depth, increasingly positive with height)
This is inherent to the cloud city design. Rockets would be a subclass of buoyancy risks, eclipsed entirely by atmospherics.
> Rocket launch from an inhabited floating atmospheric platform would require accumulation of large stores of fuel (the Tsiolkovsky rocket equation also works against you), as well as presenting various risks associated with enormous barely-contained explosions
This is a fair criticism. It's also solved by having offboard propellant storage and launch platforms.
> risks are immense, and hand-waving them away is disingenuous to the extreme
Didn't mean to suggest it isn't risky. Just that the risks from the rocket launch component are dwarfed by many, many others, and to the extent there are risks here, they are ones we've already solved on Earth in analogous contexts. (Maintaining buoyancy isn't remotely the main problem with launching rockets from high-altitude blimps.)
Some of y'all have never seen a marina with floating docks and it shows.
More of the same.
This entire problem is basically ye-olde spaceX barge only with different factors in the equation and running in both directions (instead of just landing).
Yes, without a hard cut in buoyancy like you get with something that's way denser than air floating in something way denser than it all the math gets a little wonky but it's all still fundamentally the same. When you load a few million pounds of shit you sink a few thousand feet instead of a few inches like a barge in water would, and when that weight turns out to be a rocket that yeets itself you move around thousands of feet or miles instead of feet like a barge, but when you're floating in the air with nothing to crash into who cares.
An aerostat doesn't float on a liquid at stable equilibrium through draft displacement, it is suspended in a fluid, with the problems noted previously.
Docks and barges (along with general watercraft) may be constructed arbitrarily robustly from strong and resilient materials. Aerostats somewhat less so.
How about if we imagine this at a grander scale? The article I linked suggests:
"A one-kilometre diameter spherical [balloon] will lift 700,000 tons – two Empire State Buildings. A two-kilometre diameter [balloon] would lift six million tons”
With that massive a city I expect you'd be talking like < 1% delta from a rocket launch.
Addressed naively and wrongly hence the ongoing discussion
>An aerostat doesn't float on a liquid at stable equilibrium through draft displacement, it is suspended in a fluid, with the problems noted previously.
If you let a baloon go will it reach space? No, because the atmosphere is not constant density.
Balloon type objects have the nice side effect of expanding and contracting to reach buoyancy/weight/structural equilibrium. It's not like a submarine "flying" though the water. It's more like a fish expanding/contracting to ascend/descend. More literally, it's like a weather balloon that rides at different attitudes depending on what the weight of your payload is. If you really need to change altitude quickly (or perhaps in response to taking on or losing mass) it wouldn't be all that difficult to inflate/deflate (i.e. change displacement) a subset of whatever device provides buoyancy. Think of it like a heavy lift ship flooding itself (reducing displacement) to change draft.
Like I said, the lack of a "hard cut" between atmosphere and ocean makes the math wonky compared to what we're used to, but the physics DGAF.
>Docks and barges (along with general watercraft) may be constructed arbitrarily robustly from strong and resilient materials. Aerostats somewhat less so.
You could say the same thing about boats vs port facilities.
Yeah, it's an engineering problem but it's a fundamentally well understood one. The way your hand gets forced in terms of material choices might make cost go through the roof, but it the design side of things shouldn't be all that terrible.
The analogy isn't letting go of a balloon, it's of dumping a large mass of payload (rocket + fuel) from an aerostat quickly.
The aerostat will rise. It will float higher in the atmosphere, with decreased pressure around it. It will expand. It will then rise still further.
And there's no ready supply of solid or liquid ballast (as would be available on a near-ground cargo drop) to compensate for the lost mass.
This is untenable for any manned / habitable module, and you'd all but certainly want any of same well outside the danger zone of a rocket malfunction.
One likely consequence is that any launch aerostats would be at best highly unstable in their altitude and station-keeping characteristics. It's quite possible that a disposable, single-use design might be required. Given that materials would likely have to be shipped from Earth, or possibly from near-Venus asteroids via space-mining, this considerably increases cost and complexity of any such missions.
Aerostats, as lighter-than-air craft, have vastly more-tightly constrained mass budgets than any water-based floating structures. Ignoring and/or waving that away is obtuse in the extreme. Particularly given the additional concerns and considerations of launch-capable structures. Existing aerostats and rockets operate at the outer limits of engineering design capabilities, and still go boom with some regularity, often due to exceeded structural tolerances.
>The aerostat will rise. It will float higher in the atmosphere, with decreased pressure around it. It will expand. It will then rise still further.
Now explain weather balloons. Why don't they rise to infinite altitude?
Like I said, the numbers are all wonky, but the principals are the same.
If there is too little mass for the amount of bouncy just compress your gas and hold some reserve buoyancy/balloons to inflate if you expect to be able to deal with rapidly increasing mass.
Weather balloons reach a stable equilibrium altitude because 1) they're designed to expand as they rise (at quite an impressive ratio) and 2) they're not suddenly gaining or losing 100s of tonnes of mass.
At least one if not both those prereqs is missing from the observed case. Though discussing the matter further has lost virtually all appeal.
> You fly the rocket on the bottom of a plane, then fire it out
This requires engineering the rocket to withstand structural loads in two directions as well as a ~90-degree rotation under thrust. Not trivial. (It's been a major handicap for airlaunch on Earth.)
Landing on and taking off from floating platforms is like the one part of Venusian colonisation we've actually solved.
Gonathan Goff wrote bunch on what you have to work with in terms of what you can extract from Venus's atmosphere. While metals would need to be imported if you're going to pick some place in outer space to live its hard to do much better.
One fascinating idea I haven't heard talked about is, if we ever are able to make super-strong carbon composites, they could be used on Venus for passive floating dragnets to scrape raw materials from the surface. They could float just enough to drag the surface from one end and be carried along by winds from the other, and then be passively triggered to float back to the upper atmosphere to be harvested.
Thanks to the extreme bouyancy of Venus, a small amount of compressed air could passively lift much more than it would on Earth, making Venus's bouyancy a secret super power. And you could design nets with creative combinations of hooks, one-way valves and so on to gather a payload as it passively drags the surface. And seaweed-style distribution of compressed air capsules could make it fault-tolerant even if ripped into segments by the horrific winds of the middle atmosphere.
The temperature, torsion, and corrosion are as extreme as it gets, and it may not be realistic, and/or it may not be feasible to think such payloads could float through the hurricane force winds and be recoverable in any systematic way at higher altitudes. But it has a tantalizing feeling of "holy heck this bouyancy super power might be useful" in the event we had material strong enough to do it. That would give a hypothetical Venus settlement access to iron, magnesium, aluminum, calcium, some titanium, and bunches of silicon dioxide.
> How do you deorbit Venus is such a way that your inflatable balloon city comes to a gentle stop, 30 miles up, and just floats there?
Aerobraking with the balloon? A balloon the size of a city would slow down very fast in a thick atmosphere like that, then slowly descend until it reaches the stable altitude.
> Worse still, when people need to leave and return to Earth, how do you launch a rocket from the balloon city and return to orbit?
Spaceplane? Take off like a glider on a slope runway, then ignite the rocket.
> If there aren't materials to effect a repair, how long until it sinks down into the hellzone? Where are materials manufactured for repairs, and how quickly could they be manufactured and sent there?
That's a true problem. Local manufacturing would be on the surface. An elevator or cable car could make the connection to the ground facilities, if the winds aren't too strong. But the manufacturing of the materials would be extremely difficult in surface conditions.
> If a rocket is trying to land and goes off course, does it squash the balloon city like a grape?
Nope. See first answer.
> Saying that holes can be patched is well and good, but there are some truly catastrophic failure modes that don't seem entirely unlikely.
Facilities on the surface of Venus ?
What drug did you take?
First. High temperatures in a corrosive atmosphere. Also, there aren't winds. There are currents. At the surface the atmosphere it's supercritical. It's more like a fluid than a gas.
Like, Mars gets all the hype, but you're dealing with bone-dry cold, no atmosphere to speak of, and brutal radiation. Meanwhile, Venus has breathable pressure, decent gravity, and no need for pressurized suits... you just have to float above an acid bath.
That Movie Guy Voice: Above a world ... where the atmosphere will eat the flesh off your body ... and crush your eyeballs flat, only a thin kevlar tether stands between you ... and eternity...
Wow thank you for laying out this info. I've always read the theories on the Venus floating colony but the info on pressure and temp I had no idea about.
Exactly right, and it's a fascinating prospect. Earth like temperature and atmospheric pressure, and better protection from radiation than even Earth. Major advantages Venus has over Mars are that (1) it's closer, (2) aforementioned radiation protection, (3) no issue of aggressive bone decalcification.
Radiation on Mars is brutal and it doesn't get talked about enough.
Anyone without sufficient protection from surface rays would have 5-10 years before they come down with some form of terminal cancer.
When Andy Weier went on book tour for Artemis he talked about how cities have to have an economic rationale for existing, which is why in his story, the Moon would be oriented around tourism. Venus seems to be disadvantaged in terms of having practically no access to rare or heavy metals because you can't safely get to the surface and even if you can, is basalt (which in many ways is great and chemically diverse and rich, like the nutritious potato of surface rocks, but it won't yield concentrated veins of valuable metal).
But what Venus does have is enough carbon ready to be processed into liquid fuel, while skipping complicated mining and extracting and refining processes that complicate the matter on Earth and would similarly complicate it from any other source in the solar system. You would have to source hydrogen from somewhere to synthesize fuel. But in a way that's an advantage, because you could source it from an asteroid, keep it in space, and just send up the carbon feedstock from Venus. You'd probably rather do it that way anyway, avoiding some of the more brutal costs of sending water weight in and out of the gravity well. So you pull the carbon feedstock from Venus, you synthesize fuel in space, and you're the premiere source of rocket fuel in the solar system. Economic rationale! The pin that might burst this bubble is that Venus's carbon feedstock advantage might not matter, because the water rather than the carbon maybe the more critical variable, and the second best options for sourcing carbon (mining, processing) may be good enough that Venus's advantage doesn't matter.
Then there's the buoyancy, another extreme eyebrow raising advantage given Venus's hellscape on the surface. It's remarkably easier to be buoyant on Venus than Earth, in some ways you could consider it an ocean planet, but it's an ocean of extremely thick air. Which is not only extremely important for any hypothesized floating settlements, but might open the door to buoyancy based passive dragnets to scrape and retrieve raw materials from the surface. But that too would hinge on having incredibly powerful carbon weaves netting and economics making it worth it. But still, there's something intriguing there.
Anyway, I feel like there's a wiiiide open lane in public communication and in hard sci-fi for a deep dive on Venus colonization, Kim Stanley Robinson style, and I just want someone to occupy that damn lane already.
> For a time, the mantle would get hotter, since the shell around it would trap heat generated by radioactively decaying compounds inside it. As heat accumulates in the interior, the Earth in Kane’s simulations would experience an uptick in volcanism lasting for about 15 million years.
That totally surprised to me. I had no idea radioactive decay played such a role for earth. It turns out I must have fallen sleep in one of the classes when that was explained.
> The radioactive decay of elements in the Earth's mantle and crust results in production of daughter isotopes and release of geoneutrinos and heat energy, or radiogenic heat. About 50% of the Earth's internal heat originates from radioactive decay
The only context in which I heard it mentioned is the idea of trying to date the earth by its temperature. Assume it was a hot molten mess in the past and has been cooling down ever since. Factor in the rate at which it would radiate heat and all of the energy coming from the sun and... you conclude that the planet is very young. Because you didn't account for radioactive material within the planet, keeping it warm.
Thermal decay dating was also used to estimate the age of the Sun, most famously / notoriously by William Thompson, a/k/a Lord Kelvin. Without knowledge of radioactivity, nuclear chemistry, or nuclear fusion, Thompson presumed latent heat of gravitational collapse for both the Earth and Sun, and came up with an age of "a moderate number of millions of years" for the former, and no more than 500 million years for the Sun.
Rutherford's discovery of the atomic nucleus, and subsequent discoveries of radioactive decay (providing both mechanism and clock for Earth's heat and age) and fusion and helium (the Sun's thermodynamic equation and age) provided a refutation of Thompson's estimates, empirical basis for the current age estimates of the Earth and Sun (about 4.5 billion years), and ultimately of a lifespan for the Sun (about 10--12 billion years) as well as how long habitable conditions on Earth may persist (as little as another 800 million years for some conditions, another 2--3 billion on the outside).
> It turns out I must have fallen sleep in one of the classes when that was explained.
Unless you've studied this at a post-secondary level, I'm afraid that it's quite likely that you've never had it explained to you. My highschool discussed at length the role that the sun, the greenhouse effect, oceans, forests, agriculture, mountain ranges, etc, play on weather and climate, but never actually went through the exercise of energy accounting to determine what keeps the Earth warm.
Which is understandable, because that exercise is non-trivial, and will not actually be convincing to anyone who doesn't have a calculus education.
Radiogenic heating as a primary factor in Earth's heat budget and geologic processes might very well not have even been firmly established when the OP was in school. Alot of what is now confidently taught about Earth's geology and geological history is surprisingly recent compared to other scientific fields. Plate tectonics wasn't firmly established until the 1960s. The Chicxulub impact was highly contentious until the 1990s and not conclusively proven until the 2000s, and AFAIU even today there's still some debate about its role in the Cretaceous extinction, e.g. the interaction with other concurrent events. I wouldn't be surprised if the importance of radiogenic heating wasn't canonical until 1980s, 1990s, or even later and therefore not mentioned in a standard curriculum until Millennials reached high school. I don't remember it being mentioned at all in the 1990s, though re other facts my high school geology and biology textbooks were often many years out of date in some areas--an important and useful coming of age lesson for me, that even academic text books can be and often are sorely antiquated and even outright wrong; and a lesson I might not have learned so early if I hadn't had the advantage of the early Internet.
While radioactive decay plays a significant role in the internal temperature of the Earth, the internal temperature of the Earth plays only a tiny role in the temperature of the surface and atmosphere of the Earth—about 0.03% of the climate energy budget. So for high school geoscience, it’s not worth more than a mention.
Proving the equilibrium requires calculus but simply writing it down doesn't? It's not different from these "water flows into and out of the pool" exercises.
If i remember right, according to one of Asimov's Foundation sequels, the Earth was unique due to its high level natural radioactivity, which allowed it to develop an ecosystem more vibrant than any other planet in the galaxy.
Was just rereading - it was the radioactivity and the large natural satellite that was unique in his universe. Tides are interesting because once you have life in the oceans, it's a kind of forcing function to adapt to land conditions
Forcing function + making a stretch of land which is neither dry nor enterily wet. A gradient. If there are no tides the leap life has to make is much bigger.
"Nucleotide formation and polymerization are both more favored thermodynamically when subunit and nucleotide concentrations increase and the water concentration decreases (i.e., at low water activity)" [1].
Tide pools provide a regularly-cycling low-water and high-water environment. (And you get thermocycling, nutrient refreshment, and a path to the oceans, too.)
They're not a forcing function, generally, because we don't know how life formed. But I believe they're close to one in a RNA-first or metabolism-first origin-of-life universe.
There was a mention of something like that in Starship Troopers as well.
Heinlein describes life on an earth-like planet with low radiation as being "like a kid who takes ten years to learn to wave bye-bye and never does manage to master patty-cake".
He was a popular writer of both fiction and nonfiction, had a PhD in chemistry, and wrote on numerous topics, including science, history, Shakespeare, and the Bible.
He and Arthur C. Clarke had a (tongue-in-cheek) agreement:
The feelings of friendship and respect between Asimov and Arthur C. Clarke were demonstrated by the so-called "Clarke–Asimov Treaty of Park Avenue", negotiated as they shared a cab in New York. This stated that Asimov was required to insist that Clarke was the best science fiction writer in the world (reserving second-best for himself), while Clarke was required to insist that Asimov was the best science writer in the world (reserving second-best for himself). Thus, the dedication in Clarke's book Report on Planet Three (1972) reads: "In accordance with the terms of the Clarke–Asimov treaty, the second-best science writer dedicates this book to the second-best science-fiction writer."
The funny thing is that an oxygen-rich environment is a hell-hole! Oxygen is insanely reactive and will corrode anything. Even early life on earth found oxygen toxic. It was released as a waste product by early life and they were so successful that all that oxygen accumulated resulting in the Great Oxidation Event (https://en.wikipedia.org/wiki/Great_Oxidation_Event).
That likely resulted in many species going extinct!
And the concentration into BIFs, banded iron formations, was all but certainly the result of biological activity.
Our present technology based on iron and steel owes itself to early life on Earth, from 1.6 to as much as 4 billion years ago. As with petroleum and coal-bed formation, a process unlikely to repeat in Earth's future. Iron ores are abundant, but still a finite resource.
Human civilization feels so much more fragile to me since I realized how much we owe our technological progress to the accumulated effects of biological processes over geological timescales. Fossil fuels seem like the most obvious part of this story. If we had to start over "from scratch", would it even be possible? Or have we already so thoroughly exhausted the low-hanging energy stores that a second "industrial revolution" would be effectively impossible if our present civilization collapsed deeply enough?
I wasn't aware that concentrated stores of iron are also an important part of this story!
> Or have we already so thoroughly exhausted the low-hanging energy stores that a second "industrial revolution" would be effectively impossible if our present civilization collapsed deeply enough?
There's plenty of coal left, and we will likely never exploit it, because solar is getting so cheap.
Also, despite long prophecies, peak oil never arrived either. So it doesn't look like we are running out of that stuff.
That's a loss of 2/3 of production to non-scrap effluvia on an annual basis. I'll let you work out the ultimate resource depletion cycle from that. Recycling is useful, but it's no magic bullet, and there are always losses.
The most heavily recycled metal in the US is lead, per USGS data and prior comments of mine, with recovery rates of about 75%, accounting for 40% of net production.
>That's a loss of 2/3 of production to non-scrap effluvia
Considering that the amount of stuff in our world made from steel at any one time is steadily increasing this makes sense.
>The most heavily recycled metal in the US is lead, per USGS data and prior comments of mine, with recovery rates of about 75%, accounting for 40% of net production.
There's little to no "post consumer pre-recycler" use for lead whereas every tom dick and harry can find a use for some old pipes or beams or whatever.
I often like to quip that the [21%] corrosive gas is pretty nice today, and I think I'll go consume a big container of industrial solvent to help counteract the radiation from the uncontrolled nuclear [fusion] explosion in the sky.
I once heard a similar point and it has fascinated me ever since: an alien observing human culture would be appalled at how dangerous our lives are.
Everything around us is bathed in warm oxygen, just waiting to catch fire! Our homes, our clothes, our fields, our possessions, …our hair. Ready oxidation brings vitality to Earth but it’s also ridiculously dangerous.
It might be a lot more sedate, imagine crystalline creatures from deep below the surface of an ice-ball that rely on indirect chemical gradients or geothermal.
"Your planet is how close to that star!? H20 would be liquid! How do you protect yourselves from the polar solvent leaking down into the rock?"
Conversely, a slower rate of reactivity suggests intelligent life might not yet have arisen in such environments, or ever arise before the opportunity passes.
They need a sufficiently dense energy source, sure. But it may not involve their atmosphere at all. Their plants could store solar energy in self-contained chemical batteries, and the aliens could be using those batteries to power their bodies. Instead of having to constantly breathe, they would instead need a daily battery swap.
An oxygen-rich environment is so thermodynamically unstable (it would lead to oxidation and rusting of virtually every other prevalent element) that it would be exceedingly short-lived without the presence of oxygen-liberating biological metabolism. To that extent, a high-oxygen atmosphere is one of the very clear and detectable indicators of probable life which we are capable of detecting even on extra-solar planets (via spectroscopic analysis of reflected or filtered light).
Definitely true, but oxygen is also immensely useful for life evolved to benefit from it, enabling much more complexity. I'm fascinated by the giant insects that got huge back when the oxygen level was much higher.
Related: highly recommend Robert M. Hazen Great Courses and book
And once the water was in Venus' atmosphere, it could reach high altitude, where it would be dissociated by solar radiation. The hydrogen could then escape to space. The signature of this remains in the isotope ratio of deuterium to ordinary hydrogen in the atmosphere there: deuterium enriched by two orders of magnitude above the level seen on Earth.
Ok, so this is all leading to one very specific place: An anarchic society of steampunk airships harvesting Deuterium from the shirtsleeve zone in Venus’ upper atmosphere.
They'd export it to Earth in exchange for other necessities. Airship parts, water, protein bars, TV shows. Earth would then use the deuterium for its 'free unlimited energy' fusion reactors.
Mars, interestingly, was just determined to have a core almost identical to Earth’s as I understand it. This is not the sole determinant of course - you still need enough volatiles, enough gravity to maintain a hold on the lightest elements across billions of years, and tectonics to keep refreshing the atmosphere. Unfortunately for us all, Mars has none of those. There may be other significant factors as well.
I've seen increasingly credible arguments that you also need a large satellite. To stabilise the planet's wobble. And, more importantly, create the sort of tidal cycles that prompt RNA worlds in the lab.
The lack of tectonics would only be a problem if you want your terraforming to be 'one and done'.
If you admit that terraforming, even after it's 'done', will require an ongoing maintenance effort, it's simple (but not easy). Eg you can use satellites to spin up an artificial magnetic field to shield against solar wind.
However, I suspect terraforming planets is a waste. Far more bang for your buck to build habitats in space from scratch (eg out of asteroids), than to go down another gravity well. You can spin them for artificial 'gravity'. And you can situate them close to earth where logistics of resupply and communication and trade are much more favourable.
Otherwise, Mercury is the planet to colonise, not Mars.
Mercury gets extremely hot in the sun, and extremely cold at night. So if you dig a bit under the surface it all evens out. Pick the right latitude, and you can get basically any average temperature you feel like, including a comfortable 20C.
(Otherwise, even on the surface it's easy to get comfy temperatures, if you bring retractable parasols. Just don't expect to stroll around outside the base.)
Mercury has the benefit compared to Mars that solar power is extremely plentiful.
It's worth mentioning that one of the more sane ways to terraform a planet is to redirect specific comets to crash into the planet. It would be "free" in the sense that redirecting an orbit is already actively being studied by NASA for planetary defense reasons. To actually terraform a planet in this method would be unreasonably affordable compared to anything else I've ever heard.
edit: Plus, it's nice to split our eggs into multiple planetary baskets. And I suspect people would feel a bit happier living on the surface of a chilly Mars than to become mole people on Mercury, even if it is easier. Maybe summer and winter homes?
I didn't think reasonable really has a definition here. The rendezvous with these comets will take centuries or millennia even if we can get out there and kick them the right way (which is much harder than arranging a miss). Only then do we start terraforming, which takes thousands/millions of years in addition. Who/whatever we're preparing the planet for probably wouldn't be "people" anymore. :)
> Only then do we start terraforming, which takes thousands/millions of years in addition
The methods we could realistically launch into in our lifetimes would take thousands of years, not millions (but also not hundreds) [1]. Projects of these timescales have precedent in human history, usually with a healthy dose of religious zeal.
My impression was that pulverized rock/iron is not actually "soil", so after forming the atmosphere you need lengthy biochemical processes playing out on the surface. I admit though, I don't know too much about this.
I think that we should consider "the future". Yes, it's intangible but consider this; go back 2 centuries and ask someone if they could setup a business concern which produced millions of widgets a year.
They'd think you daffy.
Now beyond that, ask them to produce any manner of modern device with the precision and high consistency we have. Again, they'd think you mad, and think that such was impossible.
Yet here we are.
The next stage in our development via LLMs is not about AI helping humans. It's about robotics. Automated assembly. Robots (not Androids) able to interact with the environment and able to problem solve akin to say.. a mouse.
Soon, entire factories will be entirely automated. Many almost are. We don't need Von Neumann machines to see this future, but we will certainly have robots capable of building entire factories, collecting resources and processing them, and further building machines to spec. And those machines will be able to self-drive, self-operat autonomously.
Anyone playing typical resource games knows about bootstrapping, but once in the asteroid field we're basically resource infinite. Building engines to attach to asteroids, mining asteroids, building factories to create more robots and engines, all of it will be automated.
We toil at self-driving cars, yet this same tech enables self-driving robotics of all types.
So I honestly think that once we bootstrap in space, this sort of thing can happen fast, fast, fast. Decades to send hundreds of thousands of ice-rich resources to Mars.
The soil? Ah, genetic engineering. Really, this is an entirely new field, and frankly is beyond the danger yet benefit of nuclear science. We have the bomb, yet we have nuclear energy and medicine. Well genetics can obviously be far more deadly, and research all over the world, and startups, are already working on employing bacteria and organisms as self-replicating machines to do our bidding.
The dangers are in our face, but oh well! So if we presume survival, then once an atmosphere is produced we can seed the planet with organisms which can survive on rock and yet work with a mania to process it. It's OK if we immediately have moss like grass substitute everywhere. As long as it's working its magic, we get continued O2 production, and we can always create a rabbit pet or something that licks moss to survive. Or are tasty.
My point is, there are indeed many barriers. But we need to view them with where we will be in decades, not where we are now.
> Yes, it's intangible but consider this; go back 2 centuries and ask someone if they could setup a business concern which produced millions of widgets a year.
To go off on a tangent: two centuries ago was the height of the first industrial revolution (at least in Britain). The first time in history when this actually became realistic.
The Industrial Revolution was the first time we had sustained, broad based productivity growth year after year (even if only around 1%, which is quite low by modern standards).
Weirdly enough, we can see sustained productivity growth in artillery and guns long before the wider industry.
Another weird connection: sometimes people look at a toy 'steam engine' that the ancient Romans had access to (https://en.wikipedia.org/wiki/Aeolipile) and wonder if they could have had an industrial revolution. But, to make a proper steam engine you need a lot more than just the right idea. You need a lot of metallurgy and precise crafting.
Specifically one thing you need is precision crafted cylinders that gas can expand in to move a piston. Well, at the time of the Industrial Revolution, European nations had just spent several hundred years locked in existential competition over who can make precision crafted cylinders that gas can expand in to move a bullet.
I wonder though, if not it would have been possible to build stationary steam engines with Roman tech using oversized bronze castings for cylinders. Perhaps set in bedrock to give extra strength.
Weirdly though, electric generators in watermills would have been much more attainable - except nobody had any understanding of electricity.
Steam engines were stationary at first. They were used to eg drive pumps.
> Weirdly though, electric generators in watermills would have been much more attainable - except nobody had any understanding of electricity.
Yes, and proper dynamos were invented only quite a long time after batteries. (So called self-excited generators.)
And you have to compare the early bad electric generators they could have come up with against the gears and shafts they knew to transmit the motive force of the water over short distance eg to the mill stone.
You make a lot of good points. Including that the technology to do all that incredibly dangerous to develop - I still can't see a path to terraforming where in the end it's human people left to take pleasure in Mars.
I had thought due to the eons we'd simply have evolved, but even on shorter time frames there is the transhumanist possibility. When we can engineer rabbit that eats chlorine moss, I don't know what we're aiming for at all. "People" by then could have robust gut culture that just digests the regolith.
There's a difference between considering all this vs thinking it's realistic. It's speculation, as any forecast into the centuries ahead must be.
Even in the event of a full-scale nuclear war, Earth would still be a more comfortable and safe place to live than Mars.
It's like going to the gladiator pits to fight because someone was robbed and shot on the next street yesterday and you don't think your street is safe enough.
> Too many dickheads with a bright idea of putting nuclear warheads on submersibles with a dead man’s switch on this planet
If we're nuking each other on Earth, I find it unlikely we wouldn't aim a nuke or two at that group's colony on Mars.
The only thing a Martian colony is a hedge against is ecological collapse on Earth. Because we did something exceptionally stupid accidentally. Or because a rock came by to say hi.
> The only thing a Martian colony is a hedge against is ecological collapse on Earth. Because we did something exceptionally stupid accidentally. Or because a rock came by to say hi.
Even then, Mars is colder than the Antarctic, drier than the Sahara, has lower air pressure than the top of Mount Everest, has soil poisoned like a superfund cleanup site, has no meaningful ozone layer, has no magnetosphere protecting against CMEs, has half our solar irradiance level, and occasionally has planet-spanning dust storms, so the bare minimum for colonising Mars must be able to survive worse than any possible thing we can possibly do to Earth and also some of the bigger rocks coming by to say hi.
A nuked Earth is still more habitable than Mars, even on their best day.
Wouldn't it be far easier and much more useful to colonize the ocean floor than other planets? It is, after all, 70% of the surface area that just sits there.
> If you admit that terraforming, even after it's 'done', will require an ongoing maintenance effort
The Earth hasn't always been hospitale to humans, much less technological civilisation. Chances are, we'll have to do similar "maintenance" at home, too. (Easiest to grasp: deflecting asteroids.)
> I suspect terraforming planets is a waste. Far more bang for your buck to build habitats in space from scratch
This comes down to how biology works in zero and partial g. One of the most useful set of experiments we could be doing right now, in terms of colonisation, is putting lots of rats and whatnot in tiny space stations and letting their life cycles play out.
Great, and rats will become super adapted to space. Then they'll become endemic to any space habitats humanity builds. Terraforming planets sounds more plausible than not ending up with rats and cockroaches.
That would be great! It would strongly imply humans, over cycles of reproducing in space, would too. I suspect, unfortunately, we'd have to iron out some kinks first [1].
> That would be great! It would strongly imply humans, over cycles of reproducing in space, would too.
Animals in their natural habitat and humans (especially with modern healthcare) are responding very differently to environmental pressure: we would need to accept a high infant and child mortality rate to be able to evolve.
And the humans having a much longer lifetime and a much smaller amount of descendant means that even without technology we would evolve orders of magnitude slower than rats.
Sure. Let's put rats in centrifuges in space and see if they can reproduce successfully. Maybe there is a coriolis boundary. Maybe something weird happens.
> So if you dig a bit under the surface it all evens out. Pick the right latitude, and you can get basically any average temperature you feel like
It seems hard to believe that this would actually work, even though I understand why it should. Although you have to do the digging starting in extreme temperature conditions without an atmosphere.
The Moon has zones like you describe on Mercury, and is a lot closer to colonize. Lack of large magnetic field probably won’t matter as terraforming either is hopeless.
Yes, you can also do a similar strategy on the moon.
You can in principle create artificial magnetic fields. But yeah, you are better off just staying indoors most of the time under a big fat layer of regolith.
Thanks. I'm just parroting some lines I read a decade or so ago on a website that I didn't manage to dig up again. (I wonder if it's still online?)
> I would say the key thing with Mercury is the ability to dig fast.
Why? What are you afraid of?
First, night lasts 88 (earth) days on Mercury. So if you start digging at dusk, you have plenty of time.
Second, Mercury's daytime surface temperature is around 430C (~ 800F ~ 700K). We have plenty of materials, like steel, that can withstand these temperatures easily. Even aluminum only melts at 660C.
So you make a parasol out of steel and span it over your equipment. Important: you make the parasol just big enough to shade your equipment, but otherwise let it see as much of the sky as possible.
Mercury has no atmosphere. So during the day you normally have a small patch of the sky at around 5772K, the sun. The sun has about ~6.6 times the angular area on the sky as from earth. The rest of the sky looks as if it's about 3K in temperature, ie very cold. The effect averages out to Mercury's 700K surface temperature.
The parasol itself will attain the same average temperature as the rest of Mercury's surface (because it's exposed to the same conditions).
But for anyone in the shade under the parasol will replace a patch of sky at 5772K where the sun used to be with one at only 700K where the parasol now blocks the view.
If your parasol is supposed to cover more than just a single point with its shadow, than it needs to be big. From the perspective of each shadow covered point, the parasol will have a bigger angular area than the sun it shades.
So you not only replace some 5772K area with 700K, but also some of the previously 3K area with 700K. Overall, you can probably set up things so that you get something like a balmy 15C on average.
> I would say the key thing with Mercury is the ability to dig fast.
To come back to this: Mercury has lower gravity than earth, so I expect that 'soil' will probably not be as dense?
Musk has a proven track record of using govt subsidies to fund companies to enrich himself immeasurably, and his Nazi turn proves that personal enrichment, not technological advancement, is what is at stake. I don't mean to be preachy but anyone who is providing support for the most racist and perfidious elements of society in Germany and the UK should be disavowed in the strongest terms.
Wow Musk really lives rent free in your head eh? My comment literally about the fact that space travel predates Musk's ambitions by generations, and y'all just double down...
Fun fact, the first person to mention colonising other planets is John Wilkens in the 17th century. I'm sure you'll find a way to connect that to Musk though.
Yeah I don't think we could terraform large pieces of Earth without throwing a very serious wrench into things. The Sahara fertilizes the Amazon, right? So even a nearly lifeless desert isn't acceptable. Maybe the poles?
Agree. But my understanding is the main idea is Mars is supposed to be a "backup" for humanity in the event of a very-low-probability catastrophic event on earth (total nuclear war, solar flare, meteorite collision).
In our lifetimes, unlikely. Over the next 1 million years? Maybe.
I think people misunderstand this goal. It's not 'backup' as in, 'ok, Earth is toast - everybody go live on Mars now.' One of the thing critics get right is that in the overwhelming majority of species ending events on Earth, Mars would still be less hospitable than Earth would. For instance take a massive asteroid impact. It's not the impact that kills you, at least not most people.
But what would happen following a major asteroid impact is a massive amount of matter entering into the atmosphere and effectively blocking out the sun. This results in plantlife dying off which then results in the rapid death of everything on up the foodchain - we starve to death. Yet you'd still mostly be able to breathe the air, your blood wouldn't boil on atmospheric exposure, and so on - it'd still be a rather more pleasant place than Mars.
What Mars can offer is (1) a parallel civilization that can continue on and (2) a lifeboat to Earth. People can return, help reorganize systems of governance and restore order, rescue survivors, and generally get started rebuilding Earth in the case of a mass extinction event. "All" we need from Mars is for it to be relatively self sustaining. I say relatively in that it can provide for the basic necessities - food, habitation, energy, reproduction, and maintenance/repair/replication of those basic necessities. Everything else is a luxury.
And the timelines for that are far closer, even within our own lifetimes. I think this will become more clear over the next decade. China has generally been quite conservative with their space goals and overperforming, and their stated goal for the first crewed mission to Mars is 2033, and every 2 years afterwards to follow indefinitely, as part of a plan to establish a permanent presence on the planet. The first Starship launch to land on Mars will also likely be a game changer for people.
It's simply a flyby, not a landing, which will likely happen in 2035 for them. NASA was laying out various plans for exactly this in the 60s, with a timeline of the first crewed flight to Mars somewhere between the mid 70s and early 80s. And it was completely viable. The only reason this didn't happen is because Nixon defacto cancelled human spaceflight in 1972, in part because he was worried that a loss of life in space would imperil his reelection chances. So we get to live in the timeline where space stagnated for decades.
The only fundamental tech we're missing is a heavier launch vessel, which we've already developed in the past - and have actively in development in the present via Starship. China is also developing their own super heavy vessels. But these developments taking 8 years is quite conservative. We went from practically nothing in 1962 (having only just put a man into orbit, and barely at that) when Kennedy gave his to the Moon speech. 7 years later in 1969 - we'd be landing on the Moon. And that landing posed far greater difficulties than just an extended flight, let alone when they were building from nothing, and we have all of this knowledge and prior experience to build from.
A Mars flyby?? With humans? I don't doubt it, but at the same time I can't imagine spending months in a ship just to look at your destination without ever getting out. Talk about cabin fever.
Haha, well depending on the exact ship they go on they'll probably have substantially more room than the ISS. That was the main motivation for things like people staying 370+ days on the ISS. And long before the ISS even existed, the USSR was also actively pursuing this. In 1988 Valeri Polyakov stayed aboard the Mir Space Station for 240 days. His first words after landing were, "We can fly to Mars." [1]
After that he spent a whopping 437 days on Mir (which had about 1/3rd the pressurized volume of the already claustrophobic ISS) to see how the human body would respond to long-term duration in minimal gravity. Upon landing back on Earth this time he decided to get up and walk from the capsule to his rest point (astronauts are normally carried/rehabbed due to muscular atrophy + dysfunctional balance/orientation, even for far shorter stays), making a point of the fact that he was just fine. Dude was just a complete badass. The USSR would have beaten us to Mars if they hadn't collapsed in 1991.
In any case, it's probably a good idea to do a flyby because there will be, with near 100% certainty, some thing things we hadn't considered and others that we simply were not aware of. By first doing a flyby and then a landing you increase the chances of success. And the people doing the flyby will probably be mostly the same people doing a landing a couple of years later - so it'll be more like "See you soon."
Yeah, it's full-on fantasy. Why would we as a species waste time terraforming a planet proven to let its atmosphere evaporate into space? Why waste energy to drag materials from Earth there instead of spending the same energy and materials to fix whatever problems Earth has?
At least in a billion years we can expect we would be either extinct already from our own actions, or hope to be advanced enough as a species to move Earth's orbital path out a touch every couple millennia to keep us in the Goldilocks zone.
Maybe by then we can terraform the Mars by crashing a few dozen comets and detritus from the asteroid belt into Mars to keep the Martian iron core, add heat enough to keep it molten and spinning for a while, add enough mass to get the gravity about 9.8 m/s2, reboot a tectonic cycle, combine 2 satellites into 1 good one, and try to add water to the system overall.
You know, just a regular Tuesday for whatever species we evolve into.
I guess the argument is, that there is just some initial resource usage to get a self sufficient mars colony and all further development can happen without resource strain on earth
I’m of the opinion we’ll just do massive structures in space, lifting out of a gravity well just doesn’t make sense, if you can manufacture in space and we know there is a tonne of resources off plant in the solar system I don’t see why terraforming a plant is the smart play.
It's funny that you're using the word "deserve". Based on whose moral framework? I'm not sure current moral frameworks on Earth would be against colonizing the Universe if it was possible.
Its not even about deserving it. How are going to maintain a terraforming project or build habitable orbital platforms if we can't manage keeping our natural habitat habitable?
distractions don't solve problems. "just do the projects" doesn't resolve the management issue anyway. the climate crisis is a result of our inability to coordinate mass actions on a planetary scale to avoid damaging our habitat.
Thinking about wild scenarios is fun and sometimes even prudent.
But acting on it at this point is tragic premature optimization. Musk isn't a stupid person so I have to think in his heart he knows his story is more about PR and being seen as a visionary as something that will actually be done in the next thousand or ten thousand years. Even if there is some climate catastrophe that causes 99% of the population to die out and any civilization to collapse, the remaining 1% are better off on Earth than trying to spend their limited manpower to get to Mars, even if some crazy trillionaire has established a beachhead there.
As an analogy, it feels like some person living paycheck to paycheck and having only $20 to spare at the end of each pay period and saving up that money ... not to invest it in some way that improves their lot, but to hire a tax attorney to help them plan how to shelter $1B in income in case they win the lottery.
Walter, I never said he couldn't spend his money how he wants, so that really isn't a counter argument to what I was claiming. Personally, I think most people (Musk is just one) who thinks terraforming Mars is realistic have read too much science fiction and are more enamored of the cool Robinson Crusoe aspect more than it would really serve any purpose.
As for "every one" of his successful business ventures being called crazy, the first one was a dot-com online map of businesses in a given city. Did people say that was crazy? His next venture ended up getting acquired by Paypal, was that considered a crazy business?
He invested in/took over Tesla -- I don't know if it was considered crazy or not at the time. SpaceX obviously is a great success. The brain control company -- we'll see. Grok -- nobody called that a crazy idea. Some of his other ventures, like hyperloop and the boring company, do seem more crazy but those escape your claim because they are in fact not successful. His solar roof company wasn't crazy, but it also isn't a success.
In short, Musk has no doubt had great successes, but there is no need to alter history to claim that at every turn he broke new ground when everyone else said it was crazy or impossible.
Agreed, and adding: Hyperloop wasn't original to Musk (other than name). RAND explored the concept in the 1970s, and there are further earlier concepts:
Look up Robert M. Salter at RAND:
"The Very High Speed Transit System" (August, 1972)
"Trans-Planetary Subway Systems -- A Burgeoning Capability" (February, 1978)
> acquired by Paypal, was that considered a crazy business?
Before he proved it was profitable. BTW, every business venture I started was considered crazy by my peers.
> Grok
Musk was an early investor in AI.
The Boring Company is successful. It has found a profitable market boring holes for infrastructure cables and pipes.
People said him buying Twitter was crazy. Oops! (What annoyed me about that was I had some Twitter stock, and it was forcibly sold to Musk. I wanted X stock instead! Alas, it is private.)
I put my money where my mouth is. I've invested in TSLA and am a happy shareholder.
There is a long list of crazy ideas that businessmen took on, that became so successful everyone later thinks that those ideas were obvious.
Such as an internet phone. Like a personal computer. Like a Xerox copier. Like jet engines. Like a pencil with an eraser on the other end. Like interchangeable parts. Like the circular saw. Like electric power utilities.
Musk is a visionary in the sense that he bought an EV company and took government contracts to mass produce NASA engine designs and launch military and civilian coms networks. Nobody has deeper pockets than Uncle Sam.
The "EV company" he bought consisted of an office and a desk and a kit car. There was no design, not even a plan.
If it was so easy designing and launching rockets for 10% of the cost, why didn't anyone else do it? Why did nobody else make reusable rockets? Rockets that could land on the launch pad? The rapid turnaround and cadence of launches?
Musk did what NASA was unable to do.
BTW, the Saturn V rocket engines were scaled up V2 engines. The essential bits were from the V2 engine - cryo fuels, turbo pumps, nozzles cooled by the fuel, boundary layer cooling, baffles to make the engine stable.
The Saturn V engines were lovingly built by hand. Musk's engines are mass produced.
NASA is a government agency, the US government made SpaceX happen by pushing polices to privatize various aspects of the space agency. I'm not denying the Musk is a good business guy, but his imaginings have nothing to do with the actual work that happens at the companies that he owns. Mars is a neat sales pitch, but SpaceX makes money from mass producing NASA rockets and selling launch services to starlink (and the military version of starlink). The "vision" there is landing a juicy government contract and agreeing to mass produce a proven rocket design.
Lots of reasons for this. The Moon is a complete hell hole - 2 week long nights, night time temperatures that drop to around -200f, daytime temperatures in excess of 250f, extremely low gravity (to the point that one might expect a higher impact of the countless health consequences of 0g exposure on humans), minimal material resources and so on. There is also no atmosphere at all which complicates landing, means even the smallest micrometeorite will impact the surface (which is why the Moon looks like it does), and contributes to highly dangerous particular dust everywhere - much worse than than on Mars.
By contrast Mars is bizarrely similar to Earth. It has almost identical axial tilt resulting in a similar seasonal cycle, a similar annual cycle, extensive mineral resources, some atmosphere simplifying landing - providing protection from meteorites, etc. It has temperature ranges that, like Earth, vary wildly due to seasonality, but are locally consistent. For instance on a summer day near the equator, it hits about 20C on Mars. If not for the blood boilingly low atmosphere, it'd be down right comfy.
Anyhow, kind of a rambling disorganized comparison because I'm in a rush - but yeah, Mars is almost eerily Earth like. In that if life was a video game Mars would be the kind of obvious 'next level', to a degree that makes it feel scripted. Even some chemical reactions like the Sabatier Reaction [1] (Martian atmosphere + electrolyzed ice => methane + oxygen + water) just feel too convenient to be true, but they are.
> Lots of reasons for this. The Moon is a complete hell hole - 2 week long nights, night time temperatures that drop to around -200f, daytime temperatures in excess of 250f, extremely low gravity (to the point that one might expect a higher impact of the countless health consequences of 0g exposure on humans), minimal material resources and so on.
Dig a bit, and temperatures even out. Same as on Mercury.
About the light: you are going to stay indoors anyway.
About gravity: spin! You can build something that looks a bit like a giant funnel, spin that, and live on the inside. If you set up the speed of rotation and degree of incline right, the centripetal force and the moon's gravity will combine to point perpendicular to the surface you are standing on.
You are right that Mars has some interesting peculiarities. But the logistics are a million times harder than getting to and from the moon. So good luck getting a rescue mission there.
In addition, I would advice against contaminating Mars with earth life, if we still want to study it, and figure out if it ever had life. (The moon is and always has been almost certainly sterile.)
With radical ideas it's likely that anywhere can become habitable - there have even been ideas to create floating cities in the thick atmosphere of Venus. But places that require esoteric and ever more complex solutions are obviously less desirable than those that don't. And Mars is 100% 'easy mode' in terms of our first colonization outside of Earth.
Yes, the higher atmosphere of Venus is surprisingly habitable. You call Mars 'easy mode', but you can fill (acid-proof) balloons with Earth atmosphere, and they will float in Venus at more or less exactly the spot that has a nice temperature and pressure for humans to enjoy.
It's just going to be come a place for the ultra rich Musk types to seclude themselves from the rest of us so they can finally build their dream libertarian paradise that is "totally self sufficient" and absolutely, we assure you, not reliant on earth in any way.
Given Venus's atmospheric pressure, I'm not sure that "no magnetic field protecting the atmosphere" is a big part of the story. It's got plenty of atmosphere left.
I think it's still brave to attempt a mission with significant chance of failure that risks resources, careers, and reputation. And had it been a _manned_ mission to Venus, the adjective that comes to mind is not brave but pointless, foolish, or sadistic.
Economically brave. Imagine building the most advanced and expensive piece of technology your society ever created, with small margins of success and the knowledge it'll last less than an hour before imploding upon itself.
So... We know the composition of the atmosphere. We know the temp bands going down to the surface. We know the pressure bands going down to the surface.
So, have we started to brainstorm of how to spray a whole host of bacteria and viruses, including sulphur eaters, extremeophiles, and genetically modified organisms, and use satellites to launch into the atmosphere?
Sure, it would be humanity's first planetary geoengineering endevour but its not like it'll get worse than 61 MPA and 600c
And the cost of a few space vehicles is what? Wouldn't be THAT expensive. And we'd learn a bunch.
Hmm, maybe China would be interested. Opening up new earth-sized landmasses would be incalculable gains for humanity.
Oh but that's not even the best part. The rare total solar eclipse - those two sky-objects are so similar in size! - motivates (terrified) ancient man to observe, record, theorise, mathematise.
I've always wondered about the feasibility of adding a reflective solar shield between Venus and Sol to cut the feedback loop that keeps surface temps so high, eventually reducing cloud cover and revealing what lies beneath. In addition, such a project might be good practice in case we ever needed a modified version for Earth, and may even be useful to add energy to celestial bodies (e.g. heat up the dark side of an asteroid by placing it at the focus of a large parabolic mirror). Venus having an atmosphere and having almost the same mass as Earth has always made it, not Mars, my favorite target for terraforming and colonization.
What stuck out to me is how fragile Earth's long-term stability actually is. We've gotten insanely lucky with things like plate tectonics, subduction, and just the right volcanic activity to keep CO2 cycling.
And over sufficiently long terms, the Earth's not been all that stable.
There've been multiple Snowball Earths (based on geological evidence), and a few episodes in which (even had land-based life existed) the continents were barely habitable.
Even today large expanses (Antarctica, the Sahara and other deserts) are only barely habitable. Still Edens compared with the rest of the Solar System.
At these time scales, major terraforming projects become viable, from building large sunshades in orbit to one near Earth-Sun L1 (balancing light pressure and gravity, it would be closer to the Sun than L1), to even raising Earth’s orbit through a fleet of gravity tugs. Venus would be an excellent case for a planet-sized sunshade, btw, as well as a solar wind magnetic lens to replace lost hydrogen and make liquid water as the planet cools. The latter could be useful for Mars.
I can't believe people haven't read James Lovelock's works re the Gaia hypothesis. The feedback loop is that plants produce an oxygen rich atmosphere right up to the point where lightning strikes would start fires that kill off enough plant life, reducing the oxygen in the atmosphere. Send plants to Venus now and in 500 billion years we can move there.
Earth's internal heat regulation is such an underrated hero in the climate story. Half of Earth’s heat comes from internal sources, constantly driving plate tectonics and helping regulate CO₂. Venus lacks that it’s like a pressure cooker with no release valve.
Tectonic and volcanic activity release CO2 into the atmosphere. They comprise a major part of Earth's carbon cycle. Over time, carbon would be depleted from the outer lithosphere without this replenishment, and one of the mechanisms by which the Earth ultimately becomes unsuitable for life is a slowing of the tectonic cycle and depletion of said carbon.
This point is addressed (briefly) in TFA:
If or when Earth’s large-scale subduction shuts off in about 3.5 billion years, kneecapping the planet’s ability to bury carbon...
See also:
"Evolution of Earth’s tectonic carbon conveyor belt" (2022)
Concealed deep beneath the oceans is a carbon conveyor belt, propelled by plate tectonics. Our understanding of its modern functioning is underpinned by direct observations, but its variability through time has been poorly quantified. Here we reconstruct oceanic plate carbon reservoirs and track the fate of subducted carbon using thermodynamic modelling....
This is somewhat speculative, and the precise nature / timing of carbon collapse may differ. But what strikes me is that the various pathways by which Earth exits its Goldilocks state are numerous and comparatively soon on a geological timescale. We're far nearer the evening of Earth's day than its morning, by multiple such measures.
One odd theory i heard is that Earth is actually one giant superorganism. (When you look at how well all the ecosystems internact with each other it kind of makes sense). Like any organism, when invaded by a virus it heats up in a fever in order to kill it...
Isn't the answer just: we grew up (evolved) on Earth, so from our perspective it's an Eden? Everyone's home planet must seem like an Eden to them, right?
Whether or not Theia was the cause - having a fast-spinning Earth and huge satellite in a low orbit* make Earth's situation profoundly different from that of Venus.
Venus's albedo is so high that the insolation at the surface is even less than Earth's. Yet it's hotter than Mercury, which is closer to the sun than Venus.
The article says that volcanism is the reason, and that solar heating would not cause this result on its own, even though it's everyone's first guess.
Although there's very little information about the most interesting part. What did they use for their modelling? The results suggest somehow that the modelling includes a lot of manual handwaving...
> They’ve been pushing their model Earth to its extremes
Is your model anywhere good enough to be able to get useful outcomes from this process? I would suspect not. I mean, we know this planet's state is partially owed to the many unique comet impacts that have occurred during it's life, are you modelling those?
There are real limits to what life can be supported due to basic chemistry/laws of physics. e.g. "Venus is so hot — hot enough to melt lead — that the acid rain evaporates as it’s falling." That life evolved on Earth and not Venus is not an accident.
Merely "because humans evolved on Earth and not on Venus" is just a dismissive contrarian take that says absolutely nothing of any value what-so-ever.
I blame Jurassic Park for popularizing the adage "life finds a way". It's good so far as it goes as a celebration of the miraculous creativity of life. But taken to the extreme it means failing to respect pretty powerful physical limits that are devastating to any form of organic chemistry.
Venus is arguably the worst place in the solar system
From another perspective, its atmosphere is "one of the most Earth-like in the solar system", and scientists long ago postulated the idea of establishing floating cloud cities.
Big balloons filled with nitrogen and oxygen would naturally settle at the right altitude, 30 miles above the surface, where gravity, ambient pressure, and radiation aren't far off that of Earth, and temperature hovers around a balmy 86°F.
Since the pressure inside and outside is matched, punctures wouldn't cause explosive decompression, providing time to repair damage or leaks. You wouldn't need a bulky pressure suit to venture outside, just some comparatively simple breathing apparatus, and of course protection from the nasty sulfuric acid in the atmosphere (akin to acid rain). The habs would be coated in Teflon to resist it.
More about this crazy idea here:
https://www.bbc.com/future/article/20161019-the-amazing-clou...
Venus is room temperature with low radiation, if you dig in.
Living on Venus was floating around as an easier alternative to living on the Mars surface.
Room temperature is 21°C, I have no idea how many freedom fries units that is.
A shockingly useful "quick and dirty" estimate for C to F for temps humans are likely to encounter is 2x + 30. It's not precise at all, but for purposes of "what does that feel like outside" or "should I bring a sweater" it works pretty well.
21C would, by this estimate, be 72F. The true conversion is just shy of 70F, so, again, it's not correct but it's close enough for this kind of conversation.
I try to remember: 0 = freezing 10 = chilly 20 = comfy 30 = warm 40 = scorching.
30's hot, 20's pleasing, 10 is not, and 0's freezing.
Also fun:
FAHRENHEIT
CELSIUS KELVINfor what it's worth: add 9 degrees F (or 18 if it's easier to remember) for every 5 degrees C (10 C, easier), and peg 32F to 0C. You get:
-40F=-40C
-22F=-30C
-4F =-20C
14F =-10C
32F = 0C
50F = 10C
68F = 20C
86F = 30C
104F= 40C
and then approximate in between from there. It's quick enough for me now that I skip the 2x+30.
In this HN subthread: users slowly converge on the conversion formula for Celsius to Fahrenheit (32+9C/5) in greater and greater precision while calling it an “approximation.”
Always interesting what's easier for some people. Personally 9/5x + 32 is much easier for me to remember and calculate
These points make it easy to remember for me, adding ~5C for 10 F.
40 F = 4 C (forty is four)
50 F = 10 C
60 F = 16 C (sixty is sixteen)
10c is 50f (easy to remember) 27c is 81f (it's all threes!)
The Fahrenheit scale is European, not American. It was created in Poland well before the United States broke off from Great Britain. We're just slow to change.
Maybe there is a reverse psychological angle to make the current US administration go metric. Fahrenheit->Polish->European->Communist/Woke. Can't have that!
> Maybe there is a reverse psychological angle to make the current US administration go metric. Fahrenheit->Polish->European->Communist/Woke. Can't have that!
1. That nonsensical, because the same logic would apply to Celsius temperatures.
2. Americans don't keep using Fahrenheit because of some aversion to Europe. Though I do have some fondness for it as resistance to the machine-people who are always going on about efficiency and trying to hurry everyone up.
The irony is that (at least I'm pretty sure) the concept of "room temperature" was originally pinned to 70° Freedom Degrees. Your 21°C reference unit is probably a rounded conversion, which explains the sibling comment arguing 23°-25°C as potentially inferior alternatives. An accurate conversion would be 21.1̅°C.
Conceivably, if you had an umbrella to protect yourself from the acid rain, an oxygen mask, and were on a very safe floating platform in the upper atmosphere, you could walk around in a t-shirt and be just fine.
> Room temperature is 21°C
Debated, was 23 or 25 in my college textbooks: https://en.wikipedia.org/wiki/Room_temperature
> I have no idea how many freedom fries units that is.
Kind of a bad attempt at humor? Imperial units is fine.
Imperialist here. Freedom fries was funny.
Had to add metric to an imperial unit application since it is to be sold internationally. I live in a Fahrenheit country so I set my phone, computer, and car to Celsius to learn how the the temperatures readings feel.
I 100% agree, "Freedom Fries Units" is quite fitting.
Turns out I prefer Celsius over Fahrenheit in day to day usage.
The US doesn't use Imperial units. It uses US customary units, which are different from Imperial in several significant ways, because the Imperial system evolved after the US split from the British Empire.
Also interestingly, US customary units are defined in terms of metric. So in a sense, the US does use the metric system.
https://en.wikipedia.org/wiki/United_States_customary_units
I often correct people regarding the US not using Imperial as well but to be fair the only significant difference these days is in fluid measurements. Weight and length measurements were standardised between US customary and Imperial back in the 1950s
https://en.m.wikipedia.org/wiki/International_yard_and_pound
That is good to know. Also linked from that article:
https://en.wikipedia.org/wiki/Comparison_of_the_imperial_and...
68.9deg F
[dead]
The Venusian atmosphere at that altitude is super dry, only a few score ppm of water making it much drier as Earth's Atacama desert. So while that water vapor is extremely acidic in terms of raw ppm its not too far outside the limit of what OSHA allows and is probably fine since you aren't breathing it.
If I understand correctly there's still a little bit of residual hydrogen bound up in the sulfuric acid molecules. And if you added it all up close to the amount of water you'd get from one of our Great lakes in North America. (At least if you combined it with oxygen, of which there's plenty on Venus).
The article mentioned something about heavy water which I don't understand very much. But it's a problem.
The tragedy of both Mars and Venus is that billions of years ago? It seems like they both might have had abundant liquid oceans of water. Which doesn't mean they would have supported life, but they would have been so much closer to habitable and a much better starting point. Instead, it's like if you're deadbeat brother house-sat them for a weekend and threw a bender and trashed the houses, that's what we're left with now.
A big issue is that neither seem to have developed photosynthetic life[1] and without a lot of oxygen in the atmosphere they don't have an ozone layer. That means that UV light penetrates further and breaks up water into its constituent parts allowing the light hydrogen to be blown away by the solar wind over geological time scales.
[1] It's looking increasingly plausible that Mars developed primitive life, but I'd bet heavily against photosynthesis. That took way longer than chemosynthetic life on Earth.
I think the article speaks to the point you're making also, that the UV light may have been an important (if not primary) mechanism for blasting away Venus' water. So even if someone snapped their fingers and made Venus perfectly terraformed, it probably once again would begin the process of losing its water. And any life would have to survive a brighter sun.
How do you deorbit Venus is such a way that your inflatable balloon city comes to a gentle stop, 30 miles up, and just floats there? Worse still, when people need to leave and return to Earth, how do you launch a rocket from the balloon city and return to orbit? How do visitors or pioneers deorbit and land at the floating city? If there aren't materials to effect a repair, how long until it sinks down into the hellzone? Where are materials manufactured for repairs, and how quickly could they be manufactured and sent there? If a rocket is trying to land and goes off course, does it squash the balloon city like a grape? Saying that holes can be patched is well and good, but there are some truly catastrophic failure modes that don't seem entirely unlikely.
> such a way that your inflatable balloon city comes to a gentle stop, 30 miles up, and just floats there?
Literally how floating works.
> Worse still, when people need to leave and return to Earth, how do you launch a rocket from the balloon city and return to orbit?
By launching your rocket from the ballon city and returning to orbit. (I'm struggling to see the novel problem.)
> Where are materials manufactured for repairs, and how quickly could they be manufactured and sent there?
Why is this unique to Venus versus anywhere else in space?
> If a rocket is trying to land and goes off course, does it squash the balloon city like a grape?
Yes. Same as if your rocket is trying to land at your Moon or Mars base (or hell, your Earth landing pad) and goes off course, it squashes your colony like a crouton.
>By launching your rocket from the ballon city and returning to orbit. (I'm struggling to see the novel problem.)
I believe they are having trouble envisioning how you would launch rockets from a balloon city without disturbing the equilibrium of the balloon city because it is assumed that rockets thrusting down with great force would damage the balloon city in a way it would not easily recuperate from.
I also find the idea difficult to understand, but assume that is because it is in an area I know nothing about and the problems that I think sound bad are actually totally solvable engineering problems otherwise it would not be have been suggested as a solution by engineers expert in that area.
on edit: changed rocks to rockets
> how you would launch rockets from a balloon city without disturbing the equilibrium of the balloon city because it is assumed that rocks thrusting down with great force would damage the balloon city in a way it would not easily recuperate from
It's a floating platform. Same as the ones SpaceX lands its rockets on. Same as a gunboat firing projectiles.
Will a launching rocket impart force to the platform? Yes. But unless the platform is super weirdly balanced, or the rocket absurdly oversized for the platform, it will stabilise after rocking a bit. (You'd have to design the platform to be stable in winds, anyway.)
And if you do have an absurdly oversided rocket, you don't launch it from your platform. You float it off to the side on a dedicated launch "boat" and have it ditch its floaty as an ultra-early first stage.
>It's a floating platform. Same as the ones SpaceX lands its rockets on. Same as a gunboat firing projectiles.
It's a great comparison that helps me understand it a bit. In many respects, Venus's atmosphere is as heavy as an ocean. That said, I can still see how if you're talking about the upper atmosphere with pressure similar to what you would have on Earth, the force necessary to do a straight vertical takeoff imparted against a platform seems like it could cause problems.
But it might just be the Archimedes thing of "give me a prop large enough and deliver long enough and I can move the world" applied to atmospheric dynamics, e.g. enough buoyancy and you're good to go. I just don't know how much is "enough" when you're talking about Venus and if that runs into prohibitive engineering complexity that makes it different from our familiar Earth examples.
Not saying it can't be done but I think that one question at least, was reasonable.
Oops, that should be "and a lever long enough"
>And if you do have an absurdly oversided rocket, you don't launch it from your platform. You float it off to the side on a dedicated launch "boat" and have it ditch its floaty as an ultra-early first stage.
The ww2 german "v2 in a tube towed by a U-boat so it can get closer to its target" project being a decent conceptual example of this.
No need for a launch boat. Just light the fuse and eject it from your balloon. Think subsurface missle launch by an Ohio-class sub.
Launching the rocket from a balloon is not a problem. You can have a platform with a hole underneath the rocket's exhaust and the balloon itself can be a torus through which the rocket flies upwards. There would be minimal impact of a rocket launch on the platform if designed properly.
Heck, you could just drop the rocket and have it ignite (one hopes) with lateral thrust, clearing the launch aerostat.
Or consider the aerostat disposable (at a significant replacement cost, see: <https://news.ycombinator.com/item?id=45333674>).
But either way it's a bit less the firey-burney-explodey problem than the sudden loss of a few thousands tonnes of mass that would displace the equilibrium of the launch platform, should you care to re-use that, or the means by which such platforms (capable of supporting said thousands of tonnes of mass).
Just to put some hard numbers on it, a crewed Falcon9 (Crew Dragon) has a launch mass north of a half-million kilograms, or 500 tonnes.
The Russian Soyuz-FG, also human capable, has a launch mass of slightly over 300 tonnes.
If this spacecraft is only a shuttle to low-Venus orbit with another transfer craft for the flight back to Earth (or other points of interest) that should suffice. If the launch craft is intended for the full return trip of 100--250 days, things could get a bit cozy and interesting depending on the number, disposition, and fragrance of inhabitants.
Uncompleted thought: "or the means by which such platforms (capable of supporting said thousands of tonnes of mass)..." are replaced. Given lack of readily available solid substrates in situ a nontrivial challenge.
There is precedent: SpaceShipOne was successfully launched from an airplane [1].
The great force downward is (mostly) irrelevant if there is nothing below. Just hang the rocket between two towers over a void, with the atmosphere below.
[1]: https://en.wikipedia.org/wiki/SpaceShipOne#Launch_aircraft
>I also find the idea difficult to understand, but assume that is because it is in an area I know nothing about and the problems that I think sound bad are actually totally solvable engineering problems otherwise it would not be have been suggested as a solution by engineers expert in that area.
A refreshingly sober approach that I think is a lot more healthy than hip firing incredulous questions.
I agree though, I don't intuitively understand how it would work. I would think you would do horizontal takeoffs. Also Seveneves by Neil Stevenson gives some interesting examples of ways to escape gravity wells without rockets, but I won't spoil anything there.
I have a silly take on this: to avoid rocking the floating city you throw the rocket overboard, let it re-orient itself upright, then use the main thruster to slow down the fall and then move up.
>Literally how floating works.
Yes, ignoring momentum. Do parachutes just get stuck in the air halfway down? When do you inflate it? If you inflate it, can you even deorbit? Do those pop when you deorbit? Do you cover the balloon with big heavy heat shield tiles?
I'm not claiming I understand this at all, but you seem to have some child's grasp of "how floating works".
> By launching your rocket from the ballon city and returning to orbit.
Launching from the solid ground shakes it (the ground) like a leaf. But you're going to launch a rocket from the balloon, and you can't quite see where there might be a problem.
>Why is this unique to Venus versus anywhere else in space?
If I can't get the materials to repair my building in a hurry, I go outside and I wait. Or I stay inside and I wait. And if I can't do that for my Venusian balloon city, I slowly sink into a zone that melts lead and bakes me alive. And if I get the materials after it has stared sinking, repairing it won't reinflate the balloon and have it rise again, because some significant fraction of the air has leaked out.
>If I can't get the materials to repair my building in a hurry
At that point you might as well be asking "what if they forgot to put fuel in the space ship" or "what if the astronaut missed launch because he forgot to set his alarm". That would be bad but that's not about Venus.
The guy you're responding to is an aerospace expert, iirc.
Anyway, the balloon would be relatively stable. The atmosphere gets increasingly dense as you go towards the surface, while the balloon has a particular density which is more than the wispy far atmosphere and less than the dense low atmosphere. Therefore, if you were to drop it at the top, it would fall (while it's more heavy) then approach the altitude where it's equally dense, and start bobbing around there, until it settles at its equilibrium.
Picture a glass cylinder of water and oil. It's cleanly separated with the denser water on the bottom and oil on top. Then drop an ice cube in. It will sink through the oil and then float, in the middle of the cylinder, on the water.
Last I heard, though acidic, the Venusian atmosphere is not made of oil and vinegar. Nor does it have hard strata lines.
Suddenly losing or gaining a few hundred tonnes of mass will do interesting things to a free-floating aerostat.
> If I can't get the materials to repair my building in a hurry, I go outside and I wait. Or I stay inside and I wait. And if I can't do that for my Venusian balloon city, I slowly sink into a zone that melts lead and bakes me alive. And if I get the materials after it has stared sinking, repairing it won't reinflate the balloon and have it rise again, because some significant fraction of the air has leaked out.
It's more similar to a boat than a house. If your boat has a leak, you need to repair it very quickly or it ends up at the bottom of the ocean. Yet we've managed to do it relatively reliably.
>Yet we've managed to do it relatively reliably.
Sure. Do that when you're in the middle of an ocean that's a few trillion miles wide. It's not as if you can just dive down to the bottom of the ocean there, mine some bauxite, take it back up to your sinking ship, refine it, manufacture new repair materials for the boat, then repair it, is it?
No, you have to have it shipped from a coast a trillion miles away. So again, where are they manufactured, and how long do they take to get there? Can any of this shit even be made in the vicinity of Venus, where transit times might be non-absurd? There are no recoverable materials on the planet itself, are there?
You probably launch and land on a floating platform nearby. Nobody on Earth launches from a city. They launch and land in remote areas. Safety and noise. Lot of noise.
Then you fly to the colony balloon.
I'm sure we can figure out stuff, but I guess my point is, why would we do that at all?
How fucked up Earth needs to be than living on a floating oil platform above Venus is better? The point is already hard to make for the Moon or Mars.
Because it's cheaper to live on a f-ed up half-built construction site of a planet than it is to fight with entrenched interests on earth.
Same reason North America got colonized by religious extremists and weirdos.
The free, abundant land choke full of natural resources was probably more important.
There was plenty of death and danger involved in colonizing a foreign land you've never been to with 16th-18th century era technology.
Only free if you discount the costs involved in carrying out genocide against the existing inhabitants. But your point stands, that cost was frequently born by the government, so from the perspective of individual settlers it was often free.
> But your point stands, that cost was frequently born by the government,
Who paid this government?
It's less about the earth being uninhabitable and more about redundancy of species.
Living on a ship at sea, or underground / underwater, should give enough protection against whatever post-apocalyptic situation exists on Earth, it's pretty much always going to be more survivable than Mars or outer space. You might need a protective suit, air filters etc. Still 100x easier than having no atmosphere at all.
What if the threat is not environmental collapse but hostile government?
If they can reach your submarine, they can reach your space colony.
Surprise Dodgeball reference. But I don't think the ocean is as far away as deep space. I also think due to its proximity, it could be entangled in political paradigms that lead to entanglements in international conflicts and the independence from those political paradigms affords a form of insulation.
Aye, this! Redundancy of species...
As in sending a part of species to a hostile place where all living is confined into a one big life support machine, without fresh air (which is very different from freshly uncanned or chemically generated air), without fresh and varied food (which is very different from artificially grown), without open sky and Sun above, without seas, rivers, forests, mountains, without anywhere to wander to find inner peace, in a setting for a psychologic horror where one deranged member of expedition is enough to bring it down.
That is going to contribute so greatly to the redundancy of our species.
I'd much rather be on a cruise ship than a lifeboat, but that doesn't mean cruise ships shouldn't have lifeboats.
No serious advocate of settling Mars, Venus or anywhere else in space seriously believes it will be easier than remaining on Earth, nor are they suggesting that it means we can abandon the Earth entirely, or care less about protecting its biosphere. They simply understand that, no matter much of a relative paradise the Earth is, so long as 100% of humanity exists there then we are placing all our species' eggs at the bottom of a single basket's gravity-well. It will do us absolutely no good if we solve climate change, war, poverty, disease, etc. only to get wiped out by the next comet or mega-asteroid that smashes into us. And, statistically, eventually one will.
>As in sending a part of species to a hostile place where all living is confined into a one big life support machine
At first, I thought you were describing the settling of Australia
Got a better alternative?
This puts the cart before the horse. At least one important question to answer before. Does something absolutely needs to be done? Then we start looking into the best alternative.
What's the concrete threat scenario you avoid by moving to the Venusian clouds? Global warming? Fix it on Earth and if you can't convince people to agree on a solution here, how will you convince them that a Venusian balloon is the best way forward? Nuclear annihilation? Probably digging deep underground is better. Total planetary annihilation? Maybe stations in Earth orbit, or Moon's poles, or L point, etc.
Are we looking for options for which we have the technology and capabilities today, or a few centuries from now? That changes your options from "balloon on Venus" to "terraforming Venus".
The engineering and other practical considerations needed to get such a "station" a realistic chance at long term survival are about as sci-fi for us today as the starship Enterprise. We aren't even at the point where we can sustain an isolated Earth based colony indefinitely in an inhospitable environment. They all need constant maintenance and resupply from the the hospitable environment just a stone's throw away.
It would be one of the worst places. So, you are living over a floating habitat that the only way to get resources it's from out planet. Because, on the surface, the conditions are so hard that even remote mining is impossible.
It would be better the moon, Mars or even moving habits on Mercury. At least you have access to mineral resources, and water (ice).
For what it's worth, there are some (limited) resources in the atmosphere itself. Here's some discussion on whether you could extract water: https://www.reddit.com/r/venus/comments/srt95x/could_water_b...
People don't scale mount everest because there is an macguffin to be found there. They scale it to scale it. Because you can. For the adventure. To assert dominance over the universe.
We can talk about economical benefits or the survival of the species and those do matter. But it's also because colonizing another planet would be fucking epic and go down in history.
With the decline in religion we do need some kind of higher purpose and meaning to rally behind, and going off planet could fit that bill. In a time of increasing divisions it could foster brotherhood.
I understand this became a hot take in recent years, because you can always just "Colonize Earth". I do think there is an independent strategic value in terms of existential threats. It shouldn't be a rationale for abandoning environmental preservation and conservation on Earth.
One thing I see, all too often in Internet comment sections is things that could be complimentary are turned against each other and juxtaposed as if one interferes with the other. I don't know if there's a name for that but it happens often enough that it should have a name.
> why would we do that at all?
This question is one of a whole genre of "why" questions that come from supposed pragmatists, but I can't help but think the existence of the question misses the entire point.
Luckily, one of the older questions of this genre was about why anyone would bother to climb Mount Everest, and ol' Mallory had such a good answer that I'll just paste the whole thing here:
> People ask me, 'What is the use of climbing Mount Everest?' and my answer must at once be, 'It is of no use.' There is not the slightest prospect of any gain whatsoever. Oh, we may learn a little about the behavior of the human body at high altitudes, and possibly medical men may turn our observation to some account for the purposes of aviation. But otherwise nothing will come of it. We shall not bring back a single bit of gold or silver, not a gem, nor any coal or iron.
> If you cannot understand that there is something in man which responds to the challenge of this mountain and goes out to meet it, that the struggle is the struggle of life itself upward and forever upward, then you won't see why we go. What we get from this adventure is just sheer joy. And joy is, after all, the end of life. We do not live to eat and make money. We eat and make money to be able to live. That is what life means and what life is for.
Of course, with Venus, there's the joy of exploration and also tons of profits and learning to be had. For example, we could cover the entire planet in giant ads. Think of the CPMs you'd get as people looked out the window on their way to Mercury!
On some level I agree with the spirit. But I also think it implicitly concedes that there's not good reasons otherwise, which sells it too short. Existential threats to humanity seem like a pretty good reason, to the point that if reasons mean anything at all it should count as one.
pretty fucked up if it runs into an asteroid or a comet!
> By launching your rocket from the ballon city and returning to orbit. (I'm struggling to see the novel problem.)
Literally how flying planes off Aircraft Carriers works.
Speaking as a former naval aviator, we haven't cracked the whole "cats and traps with an SSTO" bit yet.
> Yes. Same as if your rocket is trying to land at your Moon or Mars base (or hell, your Earth landing pad) and goes off course, it squashes your colony like a crouton.
The question you answered reads like someone that has missed all of the spectacular fails with Starship tests. Which is the ship designed for these types of adventures, so it seems like a big miss by the GP
> By launching your rocket from the ballon city and returning to orbit. (I'm struggling to see the novel problem.)
I think Newton’s third law may cause trouble-but I’m no physicist.
It’s not even science fiction
https://youtube.com/shorts/MqiSQD6HipQ
> I think Newton’s third law may cause trouble
No more than for a floating platform on the ocean. (Or frankly any sea or airborne firing platform.)
If your launch mass is a significant fraction of station mass, and you can't counterweight, you could float it off to the side and then have the baloon detach when its engines fire. But none of this is in even the top thousand problems that come with colonising Venus.
Floating on a liquid surface is markedly different from floating within a fluid (liquid or gaseous).
To float on a liquid, one merely needs to maintain a lower average density within the vessel than the surrounding liquid. Assuming a largely hollow vessel (as with a ship or barge), it's possible to add or remove considerable payload without losing stable flotation characteristics as the draft of the vessel automatically compensates for the variation, displacing more or less liquid, and maintaining equilibrium.
To float in a fluid, one must maintain precise neutral buoyancy, which is an entirely different animal. As pressure varies with depth or altitude, the tendency is for a vessel to contract as it sinks and expand as it rises, leading to a runaway buoyancy shift (increasingly negative with depth, increasingly positive with height). Many military submarines operate at comparatively shallow depths, often only slightly more than their overall length* (for larger submarines), given both the immense pressures of even modest ocean depths (a few hundred metres), and the compounding nature and risks of runaway buoyancy loss.
Plans for cargo airships face corresponding problems in that when offloading cargo or passengers it is necessary to vent or otherwise scavenge lifting gas (the expense and/or challenges of either venting or compressing helium are great), or to onboard a corresponding mass of ballast. Where suitable water is plentiful the latter is fairly viable, but there are many applications proposed for cargo airships which suggest transport of heavy cargos sites with limited capabilities for same (no facilities, deserts, salt- or otherwise-contaminated water which might play poorly with buoyancy-compensation systems aboard the airship).
Rocket launch from an inhabited floating atmospheric platform would require accumulation of large stores of fuel (the Tsiolkovsky rocket equation also works against you), as well as presenting various risks associated with enormous barely-contained explosions (should you be lucky). The risks are immense, and hand-waving them away is disingenuous to the extreme.
> To float in a fluid, one must maintain precise neutral buoyancy, which is an entirely different animal
You're right, I was oversimplifying. An aerial or submerged launch platform, then.
> the tendency is for a vessel to contract as it sinks and expand as it rises, leading to a runaway buoyancy shift (increasingly negative with depth, increasingly positive with height)
This is inherent to the cloud city design. Rockets would be a subclass of buoyancy risks, eclipsed entirely by atmospherics.
> Rocket launch from an inhabited floating atmospheric platform would require accumulation of large stores of fuel (the Tsiolkovsky rocket equation also works against you), as well as presenting various risks associated with enormous barely-contained explosions
This is a fair criticism. It's also solved by having offboard propellant storage and launch platforms.
> risks are immense, and hand-waving them away is disingenuous to the extreme
Didn't mean to suggest it isn't risky. Just that the risks from the rocket launch component are dwarfed by many, many others, and to the extent there are risks here, they are ones we've already solved on Earth in analogous contexts. (Maintaining buoyancy isn't remotely the main problem with launching rockets from high-altitude blimps.)
How do those offboard propellent storage and/or launch platforms keep from plummeting to the planetary surface?
What is their buoyancy-management system?
You're offloading the problem, not solving it.
>What is their buoyancy-management system?
Some of y'all have never seen a marina with floating docks and it shows. More of the same.
This entire problem is basically ye-olde spaceX barge only with different factors in the equation and running in both directions (instead of just landing).
Yes, without a hard cut in buoyancy like you get with something that's way denser than air floating in something way denser than it all the math gets a little wonky but it's all still fundamentally the same. When you load a few million pounds of shit you sink a few thousand feet instead of a few inches like a barge in water would, and when that weight turns out to be a rocket that yeets itself you move around thousands of feet or miles instead of feet like a barge, but when you're floating in the air with nothing to crash into who cares.
The dock/barge case is addressed here: <https://news.ycombinator.com/item?id=45330638>
An aerostat doesn't float on a liquid at stable equilibrium through draft displacement, it is suspended in a fluid, with the problems noted previously.
Docks and barges (along with general watercraft) may be constructed arbitrarily robustly from strong and resilient materials. Aerostats somewhat less so.
How about if we imagine this at a grander scale? The article I linked suggests:
"A one-kilometre diameter spherical [balloon] will lift 700,000 tons – two Empire State Buildings. A two-kilometre diameter [balloon] would lift six million tons”
With that massive a city I expect you'd be talking like < 1% delta from a rocket launch.
>The dock/barge case is addressed here: <https://news.ycombinator.com/item?id=45330638>
Addressed naively and wrongly hence the ongoing discussion
>An aerostat doesn't float on a liquid at stable equilibrium through draft displacement, it is suspended in a fluid, with the problems noted previously.
If you let a baloon go will it reach space? No, because the atmosphere is not constant density.
Balloon type objects have the nice side effect of expanding and contracting to reach buoyancy/weight/structural equilibrium. It's not like a submarine "flying" though the water. It's more like a fish expanding/contracting to ascend/descend. More literally, it's like a weather balloon that rides at different attitudes depending on what the weight of your payload is. If you really need to change altitude quickly (or perhaps in response to taking on or losing mass) it wouldn't be all that difficult to inflate/deflate (i.e. change displacement) a subset of whatever device provides buoyancy. Think of it like a heavy lift ship flooding itself (reducing displacement) to change draft.
Like I said, the lack of a "hard cut" between atmosphere and ocean makes the math wonky compared to what we're used to, but the physics DGAF.
>Docks and barges (along with general watercraft) may be constructed arbitrarily robustly from strong and resilient materials. Aerostats somewhat less so.
You could say the same thing about boats vs port facilities.
Yeah, it's an engineering problem but it's a fundamentally well understood one. The way your hand gets forced in terms of material choices might make cost go through the roof, but it the design side of things shouldn't be all that terrible.
The analogy isn't letting go of a balloon, it's of dumping a large mass of payload (rocket + fuel) from an aerostat quickly.
The aerostat will rise. It will float higher in the atmosphere, with decreased pressure around it. It will expand. It will then rise still further.
And there's no ready supply of solid or liquid ballast (as would be available on a near-ground cargo drop) to compensate for the lost mass.
This is untenable for any manned / habitable module, and you'd all but certainly want any of same well outside the danger zone of a rocket malfunction.
One likely consequence is that any launch aerostats would be at best highly unstable in their altitude and station-keeping characteristics. It's quite possible that a disposable, single-use design might be required. Given that materials would likely have to be shipped from Earth, or possibly from near-Venus asteroids via space-mining, this considerably increases cost and complexity of any such missions.
Aerostats, as lighter-than-air craft, have vastly more-tightly constrained mass budgets than any water-based floating structures. Ignoring and/or waving that away is obtuse in the extreme. Particularly given the additional concerns and considerations of launch-capable structures. Existing aerostats and rockets operate at the outer limits of engineering design capabilities, and still go boom with some regularity, often due to exceeded structural tolerances.
>The aerostat will rise. It will float higher in the atmosphere, with decreased pressure around it. It will expand. It will then rise still further.
Now explain weather balloons. Why don't they rise to infinite altitude?
Like I said, the numbers are all wonky, but the principals are the same.
If there is too little mass for the amount of bouncy just compress your gas and hold some reserve buoyancy/balloons to inflate if you expect to be able to deal with rapidly increasing mass.
Weather balloons reach a stable equilibrium altitude because 1) they're designed to expand as they rise (at quite an impressive ratio) and 2) they're not suddenly gaining or losing 100s of tonnes of mass.
At least one if not both those prereqs is missing from the observed case. Though discussing the matter further has lost virtually all appeal.
You fly the rocket on the bottom of a plane, then fire it out. Assuming these cloud cities have landing strips, right?
Managing ballast might be a challenge…
> You fly the rocket on the bottom of a plane, then fire it out
This requires engineering the rocket to withstand structural loads in two directions as well as a ~90-degree rotation under thrust. Not trivial. (It's been a major handicap for airlaunch on Earth.)
Landing on and taking off from floating platforms is like the one part of Venusian colonisation we've actually solved.
Or you just drop it off the side.
Gonathan Goff wrote bunch on what you have to work with in terms of what you can extract from Venus's atmosphere. While metals would need to be imported if you're going to pick some place in outer space to live its hard to do much better.
https://selenianboondocks.com/category/venus/page/2/
One fascinating idea I haven't heard talked about is, if we ever are able to make super-strong carbon composites, they could be used on Venus for passive floating dragnets to scrape raw materials from the surface. They could float just enough to drag the surface from one end and be carried along by winds from the other, and then be passively triggered to float back to the upper atmosphere to be harvested.
Thanks to the extreme bouyancy of Venus, a small amount of compressed air could passively lift much more than it would on Earth, making Venus's bouyancy a secret super power. And you could design nets with creative combinations of hooks, one-way valves and so on to gather a payload as it passively drags the surface. And seaweed-style distribution of compressed air capsules could make it fault-tolerant even if ripped into segments by the horrific winds of the middle atmosphere.
The temperature, torsion, and corrosion are as extreme as it gets, and it may not be realistic, and/or it may not be feasible to think such payloads could float through the hurricane force winds and be recoverable in any systematic way at higher altitudes. But it has a tantalizing feeling of "holy heck this bouyancy super power might be useful" in the event we had material strong enough to do it. That would give a hypothetical Venus settlement access to iron, magnesium, aluminum, calcium, some titanium, and bunches of silicon dioxide.
Yeah, if you can't send robots to the surface to mine necessary minerals, don't bother building floating cities.
> How do you deorbit Venus is such a way that your inflatable balloon city comes to a gentle stop, 30 miles up, and just floats there?
Aerobraking with the balloon? A balloon the size of a city would slow down very fast in a thick atmosphere like that, then slowly descend until it reaches the stable altitude.
> Worse still, when people need to leave and return to Earth, how do you launch a rocket from the balloon city and return to orbit?
Spaceplane? Take off like a glider on a slope runway, then ignite the rocket.
> If there aren't materials to effect a repair, how long until it sinks down into the hellzone? Where are materials manufactured for repairs, and how quickly could they be manufactured and sent there?
That's a true problem. Local manufacturing would be on the surface. An elevator or cable car could make the connection to the ground facilities, if the winds aren't too strong. But the manufacturing of the materials would be extremely difficult in surface conditions.
> If a rocket is trying to land and goes off course, does it squash the balloon city like a grape?
Nope. See first answer.
> Saying that holes can be patched is well and good, but there are some truly catastrophic failure modes that don't seem entirely unlikely.
Possibly.
But the biggest question is why go there?
Facilities on the surface of Venus ? What drug did you take?
First. High temperatures in a corrosive atmosphere. Also, there aren't winds. There are currents. At the surface the atmosphere it's supercritical. It's more like a fluid than a gas.
Like, Mars gets all the hype, but you're dealing with bone-dry cold, no atmosphere to speak of, and brutal radiation. Meanwhile, Venus has breathable pressure, decent gravity, and no need for pressurized suits... you just have to float above an acid bath.
I think part of it is that everyone knows that the sun will expand. Why move closer when you can get further away?
It'll be a minute before that becomes a concern.
Also, if we can deal with Venus, we can reverse global warming in Earth first?
Just don't fall off the side of those platforms.
It'd be interesting to see what additional "personal atmospheric floatation" devices would be needed.
You can't because you need to be encapsulated in a balloon to keep the toxic atmosphere out.
EVAs are still likely necessary. Tethering would be useful.
Indeed, though to keep it interesting we should put pinholes through every tenth one
I see a new action/thriller space movie on the horizon.
Cue Sandra Bullock for At the End of My Tether.
That Movie Guy Voice: Above a world ... where the atmosphere will eat the flesh off your body ... and crush your eyeballs flat, only a thin kevlar tether stands between you ... and eternity...
Nice link, shifts the perspective a bit.
Guess it would be like living on a floating oil/gas platform.
Living like little organelles inside a giant cell membrane
Wow thank you for laying out this info. I've always read the theories on the Venus floating colony but the info on pressure and temp I had no idea about.
Exactly right, and it's a fascinating prospect. Earth like temperature and atmospheric pressure, and better protection from radiation than even Earth. Major advantages Venus has over Mars are that (1) it's closer, (2) aforementioned radiation protection, (3) no issue of aggressive bone decalcification.
Radiation on Mars is brutal and it doesn't get talked about enough. Anyone without sufficient protection from surface rays would have 5-10 years before they come down with some form of terminal cancer.
When Andy Weier went on book tour for Artemis he talked about how cities have to have an economic rationale for existing, which is why in his story, the Moon would be oriented around tourism. Venus seems to be disadvantaged in terms of having practically no access to rare or heavy metals because you can't safely get to the surface and even if you can, is basalt (which in many ways is great and chemically diverse and rich, like the nutritious potato of surface rocks, but it won't yield concentrated veins of valuable metal).
But what Venus does have is enough carbon ready to be processed into liquid fuel, while skipping complicated mining and extracting and refining processes that complicate the matter on Earth and would similarly complicate it from any other source in the solar system. You would have to source hydrogen from somewhere to synthesize fuel. But in a way that's an advantage, because you could source it from an asteroid, keep it in space, and just send up the carbon feedstock from Venus. You'd probably rather do it that way anyway, avoiding some of the more brutal costs of sending water weight in and out of the gravity well. So you pull the carbon feedstock from Venus, you synthesize fuel in space, and you're the premiere source of rocket fuel in the solar system. Economic rationale! The pin that might burst this bubble is that Venus's carbon feedstock advantage might not matter, because the water rather than the carbon maybe the more critical variable, and the second best options for sourcing carbon (mining, processing) may be good enough that Venus's advantage doesn't matter.
Then there's the buoyancy, another extreme eyebrow raising advantage given Venus's hellscape on the surface. It's remarkably easier to be buoyant on Venus than Earth, in some ways you could consider it an ocean planet, but it's an ocean of extremely thick air. Which is not only extremely important for any hypothesized floating settlements, but might open the door to buoyancy based passive dragnets to scrape and retrieve raw materials from the surface. But that too would hinge on having incredibly powerful carbon weaves netting and economics making it worth it. But still, there's something intriguing there.
Anyway, I feel like there's a wiiiide open lane in public communication and in hard sci-fi for a deep dive on Venus colonization, Kim Stanley Robinson style, and I just want someone to occupy that damn lane already.
> For a time, the mantle would get hotter, since the shell around it would trap heat generated by radioactively decaying compounds inside it. As heat accumulates in the interior, the Earth in Kane’s simulations would experience an uptick in volcanism lasting for about 15 million years.
That totally surprised to me. I had no idea radioactive decay played such a role for earth. It turns out I must have fallen sleep in one of the classes when that was explained.
https://en.wikipedia.org/wiki/Earth%27s_internal_heat_budget
> The radioactive decay of elements in the Earth's mantle and crust results in production of daughter isotopes and release of geoneutrinos and heat energy, or radiogenic heat. About 50% of the Earth's internal heat originates from radioactive decay
Dually: geothermal energy installations (& volcanism) release much more than simply energy into the biosphere
https://www.ntanet.net/hot-rocks-radioactive-waste-radon-fro...
You are welcome to consider that as a matter of hormesis and resources, of course
The only context in which I heard it mentioned is the idea of trying to date the earth by its temperature. Assume it was a hot molten mess in the past and has been cooling down ever since. Factor in the rate at which it would radiate heat and all of the energy coming from the sun and... you conclude that the planet is very young. Because you didn't account for radioactive material within the planet, keeping it warm.
Thermal decay dating was also used to estimate the age of the Sun, most famously / notoriously by William Thompson, a/k/a Lord Kelvin. Without knowledge of radioactivity, nuclear chemistry, or nuclear fusion, Thompson presumed latent heat of gravitational collapse for both the Earth and Sun, and came up with an age of "a moderate number of millions of years" for the former, and no more than 500 million years for the Sun.
Rutherford's discovery of the atomic nucleus, and subsequent discoveries of radioactive decay (providing both mechanism and clock for Earth's heat and age) and fusion and helium (the Sun's thermodynamic equation and age) provided a refutation of Thompson's estimates, empirical basis for the current age estimates of the Earth and Sun (about 4.5 billion years), and ultimately of a lifespan for the Sun (about 10--12 billion years) as well as how long habitable conditions on Earth may persist (as little as another 800 million years for some conditions, another 2--3 billion on the outside).
<https://www.teachastronomy.com/textbook/Our-Sun-The-Nearest-...>
<https://en.wikipedia.org/wiki/Lord_Kelvin#Age_of_Earth> citing Burchfield, Joe D. (1990). Lord Kelvin and the Age of the Earth. University of Chicago Press. p. 43. ISBN 978-0-226-08043-7. <https://en.wikipedia.org/wiki/Special:BookSources/978-0-226-...>
> It turns out I must have fallen sleep in one of the classes when that was explained.
Unless you've studied this at a post-secondary level, I'm afraid that it's quite likely that you've never had it explained to you. My highschool discussed at length the role that the sun, the greenhouse effect, oceans, forests, agriculture, mountain ranges, etc, play on weather and climate, but never actually went through the exercise of energy accounting to determine what keeps the Earth warm.
Which is understandable, because that exercise is non-trivial, and will not actually be convincing to anyone who doesn't have a calculus education.
Radiogenic heating as a primary factor in Earth's heat budget and geologic processes might very well not have even been firmly established when the OP was in school. Alot of what is now confidently taught about Earth's geology and geological history is surprisingly recent compared to other scientific fields. Plate tectonics wasn't firmly established until the 1960s. The Chicxulub impact was highly contentious until the 1990s and not conclusively proven until the 2000s, and AFAIU even today there's still some debate about its role in the Cretaceous extinction, e.g. the interaction with other concurrent events. I wouldn't be surprised if the importance of radiogenic heating wasn't canonical until 1980s, 1990s, or even later and therefore not mentioned in a standard curriculum until Millennials reached high school. I don't remember it being mentioned at all in the 1990s, though re other facts my high school geology and biology textbooks were often many years out of date in some areas--an important and useful coming of age lesson for me, that even academic text books can be and often are sorely antiquated and even outright wrong; and a lesson I might not have learned so early if I hadn't had the advantage of the early Internet.
While radioactive decay plays a significant role in the internal temperature of the Earth, the internal temperature of the Earth plays only a tiny role in the temperature of the surface and atmosphere of the Earth—about 0.03% of the climate energy budget. So for high school geoscience, it’s not worth more than a mention.
Proving the equilibrium requires calculus but simply writing it down doesn't? It's not different from these "water flows into and out of the pool" exercises.
If i remember right, according to one of Asimov's Foundation sequels, the Earth was unique due to its high level natural radioactivity, which allowed it to develop an ecosystem more vibrant than any other planet in the galaxy.
Was just rereading - it was the radioactivity and the large natural satellite that was unique in his universe. Tides are interesting because once you have life in the oceans, it's a kind of forcing function to adapt to land conditions
Forcing function + making a stretch of land which is neither dry nor enterily wet. A gradient. If there are no tides the leap life has to make is much bigger.
And perhaps the advantages of this gradient extend up as far as aquatic apes.
Not sure what this means.
I assume they are referencing the long-debunked theory that man evolved from a line of apes that became semi-aquatic for a while.
Yup that's where I was aiming. Is it thoroughly debunked ? It's a cool idea.
Fascinating
Why are tides a forcing function? Marine life has been perfectly content just not going near a beach.
> Why are tides a forcing function?
"Nucleotide formation and polymerization are both more favored thermodynamically when subunit and nucleotide concentrations increase and the water concentration decreases (i.e., at low water activity)" [1].
Tide pools provide a regularly-cycling low-water and high-water environment. (And you get thermocycling, nutrient refreshment, and a path to the oceans, too.)
They're not a forcing function, generally, because we don't know how life formed. But I believe they're close to one in a RNA-first or metabolism-first origin-of-life universe.
[1] https://www.nature.com/articles/s41467-018-07389-2
Very interesting, thank you!
I was thinking more on the lines of "if marine life never found itself stranded on land, it wouldn't need to evolve to survive on the land"
There was a mention of something like that in Starship Troopers as well.
Heinlein describes life on an earth-like planet with low radiation as being "like a kid who takes ten years to learn to wave bye-bye and never does manage to master patty-cake".
Wasn't Asimov a science fiction writer?
He was a popular writer of both fiction and nonfiction, had a PhD in chemistry, and wrote on numerous topics, including science, history, Shakespeare, and the Bible.
He and Arthur C. Clarke had a (tongue-in-cheek) agreement:
The feelings of friendship and respect between Asimov and Arthur C. Clarke were demonstrated by the so-called "Clarke–Asimov Treaty of Park Avenue", negotiated as they shared a cab in New York. This stated that Asimov was required to insist that Clarke was the best science fiction writer in the world (reserving second-best for himself), while Clarke was required to insist that Asimov was the best science writer in the world (reserving second-best for himself). Thus, the dedication in Clarke's book Report on Planet Three (1972) reads: "In accordance with the terms of the Clarke–Asimov treaty, the second-best science writer dedicates this book to the second-best science-fiction writer."
<https://en.wikipedia.org/wiki/Isaac_Asimov#Other_authors>
He was both a science and science fiction writer. Check out "View From a Height" for example. An excellent book.
https://en.wikipedia.org/wiki/View_from_a_Height
He wrote a book about jokes and how to tell them. Quite good.
The funny thing is that an oxygen-rich environment is a hell-hole! Oxygen is insanely reactive and will corrode anything. Even early life on earth found oxygen toxic. It was released as a waste product by early life and they were so successful that all that oxygen accumulated resulting in the Great Oxidation Event (https://en.wikipedia.org/wiki/Great_Oxidation_Event).
That likely resulted in many species going extinct!
Yes, first everything rusted, and then the excess oxygen collected in the atmosphere.
Many of our iron ore deposits we still mine today are from that rusting. (That iron used to be mostly dissolved in the oceans.)
And the concentration into BIFs, banded iron formations, was all but certainly the result of biological activity.
Our present technology based on iron and steel owes itself to early life on Earth, from 1.6 to as much as 4 billion years ago. As with petroleum and coal-bed formation, a process unlikely to repeat in Earth's future. Iron ores are abundant, but still a finite resource.
<https://en.wikipedia.org/wiki/Banded_iron_formation>
Human civilization feels so much more fragile to me since I realized how much we owe our technological progress to the accumulated effects of biological processes over geological timescales. Fossil fuels seem like the most obvious part of this story. If we had to start over "from scratch", would it even be possible? Or have we already so thoroughly exhausted the low-hanging energy stores that a second "industrial revolution" would be effectively impossible if our present civilization collapsed deeply enough?
I wasn't aware that concentrated stores of iron are also an important part of this story!
> Or have we already so thoroughly exhausted the low-hanging energy stores that a second "industrial revolution" would be effectively impossible if our present civilization collapsed deeply enough?
There's plenty of coal left, and we will likely never exploit it, because solar is getting so cheap.
Also, despite long prophecies, peak oil never arrived either. So it doesn't look like we are running out of that stuff.
>Iron ores are abundant, but still a finite resource.
The iron doesn't go anywhere (ok, except for the iron making up our space probes). It is infinitely recyclable.
It doesn't concentrate itself, at scale.
That's what ores are. Ores are useful because they are concentrated, the result of some ore-formation or ore genesis process.
The "not going anywhere", after it's been dispersed throughout the lithosphere, is precisely the problem.
<https://en.wikipedia.org/wiki/Ore_genesis>
But scrap metal is still purer than any ore.
And ferrous mineral recycling accounts for roughly 33% of present production (2018 data, most current available):
<https://www.epa.gov/facts-and-figures-about-materials-waste-...>
That's a loss of 2/3 of production to non-scrap effluvia on an annual basis. I'll let you work out the ultimate resource depletion cycle from that. Recycling is useful, but it's no magic bullet, and there are always losses.
The most heavily recycled metal in the US is lead, per USGS data and prior comments of mine, with recovery rates of about 75%, accounting for 40% of net production.
<https://news.ycombinator.com/item?id=20164506>
<https://news.ycombinator.com/item?id=26412585>
Source citation: "USGS 2020 Minerals Yearbook: Recycling — Metals"
<https://www.usgs.gov/centers/nmic/recycling-statistics-and-i...>
>That's a loss of 2/3 of production to non-scrap effluvia
Considering that the amount of stuff in our world made from steel at any one time is steadily increasing this makes sense.
>The most heavily recycled metal in the US is lead, per USGS data and prior comments of mine, with recovery rates of about 75%, accounting for 40% of net production.
There's little to no "post consumer pre-recycler" use for lead whereas every tom dick and harry can find a use for some old pipes or beams or whatever.
That just means it's currently more economical to mine iron ore than it is to mine landfills.
And we are presumably still adding to the total stock of iron in human circulation.
I often like to quip that the [21%] corrosive gas is pretty nice today, and I think I'll go consume a big container of industrial solvent to help counteract the radiation from the uncontrolled nuclear [fusion] explosion in the sky.
Industrial solvent? Does this mean "inside air"?
I'm thinking water
I once heard a similar point and it has fascinated me ever since: an alien observing human culture would be appalled at how dangerous our lives are.
Everything around us is bathed in warm oxygen, just waiting to catch fire! Our homes, our clothes, our fields, our possessions, …our hair. Ready oxidation brings vitality to Earth but it’s also ridiculously dangerous.
It's very unlikely the aliens would not have something very similar going on in their own biosphere. Life needs energy to operate, after all.
It might be a lot more sedate, imagine crystalline creatures from deep below the surface of an ice-ball that rely on indirect chemical gradients or geothermal.
"Your planet is how close to that star!? H20 would be liquid! How do you protect yourselves from the polar solvent leaking down into the rock?"
Conversely, a slower rate of reactivity suggests intelligent life might not yet have arisen in such environments, or ever arise before the opportunity passes.
They need a sufficiently dense energy source, sure. But it may not involve their atmosphere at all. Their plants could store solar energy in self-contained chemical batteries, and the aliens could be using those batteries to power their bodies. Instead of having to constantly breathe, they would instead need a daily battery swap.
An oxygen-rich environment is so thermodynamically unstable (it would lead to oxidation and rusting of virtually every other prevalent element) that it would be exceedingly short-lived without the presence of oxygen-liberating biological metabolism. To that extent, a high-oxygen atmosphere is one of the very clear and detectable indicators of probable life which we are capable of detecting even on extra-solar planets (via spectroscopic analysis of reflected or filtered light).
Far more an Eden, then.
Definitely true, but oxygen is also immensely useful for life evolved to benefit from it, enabling much more complexity. I'm fascinated by the giant insects that got huge back when the oxygen level was much higher.
Related: highly recommend Robert M. Hazen Great Courses and book
I hope humans are like Cyanobacteria in that in destroying the environment we create the substrate for something grander.
I fear that
This is a good time to point people to one of the best PBS TV series about "Our Planet Earth" (unrelated to BBC series of the same name) aired in 1986 - https://en.wikipedia.org/wiki/Planet_Earth_(1986_TV_series)
Episodes on Youtube: https://www.youtube.com/results?search_query=planet+earth+pb...
Everybody needs to watch this to understand how exquisitely balanced our planet is.
And once the water was in Venus' atmosphere, it could reach high altitude, where it would be dissociated by solar radiation. The hydrogen could then escape to space. The signature of this remains in the isotope ratio of deuterium to ordinary hydrogen in the atmosphere there: deuterium enriched by two orders of magnitude above the level seen on Earth.
Ok, so this is all leading to one very specific place: An anarchic society of steampunk airships harvesting Deuterium from the shirtsleeve zone in Venus’ upper atmosphere.
What would they want with it?
They'd export it to Earth in exchange for other necessities. Airship parts, water, protein bars, TV shows. Earth would then use the deuterium for its 'free unlimited energy' fusion reactors.
To make enough giant H bombs to blow Venus' atmosphere into space?
This scheme would have some negative aspects.
BTW, hydrogen on Mars is enriched in D by a factor of 5 relative to Earth.
Deuterium might be the oil of the future as one can do fusion with it easily (in comparison).
Venus does not have a molten core, and there is no magnetic field protecting the atmosphere from the solar winds.
This is not likely the sole reason, but it must be a factor.
Mercury does have a magnetic field, Mars does not.
Mars, interestingly, was just determined to have a core almost identical to Earth’s as I understand it. This is not the sole determinant of course - you still need enough volatiles, enough gravity to maintain a hold on the lightest elements across billions of years, and tectonics to keep refreshing the atmosphere. Unfortunately for us all, Mars has none of those. There may be other significant factors as well.
I've seen increasingly credible arguments that you also need a large satellite. To stabilise the planet's wobble. And, more importantly, create the sort of tidal cycles that prompt RNA worlds in the lab.
Where can I read more about the tidal cycles' influence on RNA synthesis?
Without tectonics, is terraforming Mars even possible as a long term solution? This "Mars colonization" strategy seems like a pipe dream, no?
The lack of tectonics would only be a problem if you want your terraforming to be 'one and done'.
If you admit that terraforming, even after it's 'done', will require an ongoing maintenance effort, it's simple (but not easy). Eg you can use satellites to spin up an artificial magnetic field to shield against solar wind.
However, I suspect terraforming planets is a waste. Far more bang for your buck to build habitats in space from scratch (eg out of asteroids), than to go down another gravity well. You can spin them for artificial 'gravity'. And you can situate them close to earth where logistics of resupply and communication and trade are much more favourable.
Otherwise, Mercury is the planet to colonise, not Mars.
Mercury gets extremely hot in the sun, and extremely cold at night. So if you dig a bit under the surface it all evens out. Pick the right latitude, and you can get basically any average temperature you feel like, including a comfortable 20C.
(Otherwise, even on the surface it's easy to get comfy temperatures, if you bring retractable parasols. Just don't expect to stroll around outside the base.)
Mercury has the benefit compared to Mars that solar power is extremely plentiful.
It's worth mentioning that one of the more sane ways to terraform a planet is to redirect specific comets to crash into the planet. It would be "free" in the sense that redirecting an orbit is already actively being studied by NASA for planetary defense reasons. To actually terraform a planet in this method would be unreasonably affordable compared to anything else I've ever heard.
edit: Plus, it's nice to split our eggs into multiple planetary baskets. And I suspect people would feel a bit happier living on the surface of a chilly Mars than to become mole people on Mercury, even if it is easier. Maybe summer and winter homes?
I didn't think reasonable really has a definition here. The rendezvous with these comets will take centuries or millennia even if we can get out there and kick them the right way (which is much harder than arranging a miss). Only then do we start terraforming, which takes thousands/millions of years in addition. Who/whatever we're preparing the planet for probably wouldn't be "people" anymore. :)
> Only then do we start terraforming, which takes thousands/millions of years in addition
The methods we could realistically launch into in our lifetimes would take thousands of years, not millions (but also not hundreds) [1]. Projects of these timescales have precedent in human history, usually with a healthy dose of religious zeal.
[1] https://en.wikipedia.org/wiki/Terraforming_of_Mars
My impression was that pulverized rock/iron is not actually "soil", so after forming the atmosphere you need lengthy biochemical processes playing out on the surface. I admit though, I don't know too much about this.
> pulverized rock/iron is not actually "soil", so after forming the atmosphere you need lengthy biochemical processes playing out on the surface
We're already working on crops that can grow in lunar and Martian regolith [1].
[1] https://pmc.ncbi.nlm.nih.gov/articles/PMC4146463/
I think that we should consider "the future". Yes, it's intangible but consider this; go back 2 centuries and ask someone if they could setup a business concern which produced millions of widgets a year.
They'd think you daffy.
Now beyond that, ask them to produce any manner of modern device with the precision and high consistency we have. Again, they'd think you mad, and think that such was impossible.
Yet here we are.
The next stage in our development via LLMs is not about AI helping humans. It's about robotics. Automated assembly. Robots (not Androids) able to interact with the environment and able to problem solve akin to say.. a mouse.
Soon, entire factories will be entirely automated. Many almost are. We don't need Von Neumann machines to see this future, but we will certainly have robots capable of building entire factories, collecting resources and processing them, and further building machines to spec. And those machines will be able to self-drive, self-operat autonomously.
Anyone playing typical resource games knows about bootstrapping, but once in the asteroid field we're basically resource infinite. Building engines to attach to asteroids, mining asteroids, building factories to create more robots and engines, all of it will be automated.
We toil at self-driving cars, yet this same tech enables self-driving robotics of all types.
So I honestly think that once we bootstrap in space, this sort of thing can happen fast, fast, fast. Decades to send hundreds of thousands of ice-rich resources to Mars.
The soil? Ah, genetic engineering. Really, this is an entirely new field, and frankly is beyond the danger yet benefit of nuclear science. We have the bomb, yet we have nuclear energy and medicine. Well genetics can obviously be far more deadly, and research all over the world, and startups, are already working on employing bacteria and organisms as self-replicating machines to do our bidding.
The dangers are in our face, but oh well! So if we presume survival, then once an atmosphere is produced we can seed the planet with organisms which can survive on rock and yet work with a mania to process it. It's OK if we immediately have moss like grass substitute everywhere. As long as it's working its magic, we get continued O2 production, and we can always create a rabbit pet or something that licks moss to survive. Or are tasty.
My point is, there are indeed many barriers. But we need to view them with where we will be in decades, not where we are now.
> Yes, it's intangible but consider this; go back 2 centuries and ask someone if they could setup a business concern which produced millions of widgets a year.
To go off on a tangent: two centuries ago was the height of the first industrial revolution (at least in Britain). The first time in history when this actually became realistic.
The Industrial Revolution was the first time we had sustained, broad based productivity growth year after year (even if only around 1%, which is quite low by modern standards).
Weirdly enough, we can see sustained productivity growth in artillery and guns long before the wider industry.
Another weird connection: sometimes people look at a toy 'steam engine' that the ancient Romans had access to (https://en.wikipedia.org/wiki/Aeolipile) and wonder if they could have had an industrial revolution. But, to make a proper steam engine you need a lot more than just the right idea. You need a lot of metallurgy and precise crafting.
Specifically one thing you need is precision crafted cylinders that gas can expand in to move a piston. Well, at the time of the Industrial Revolution, European nations had just spent several hundred years locked in existential competition over who can make precision crafted cylinders that gas can expand in to move a bullet.
That is interesting.
I wonder though, if not it would have been possible to build stationary steam engines with Roman tech using oversized bronze castings for cylinders. Perhaps set in bedrock to give extra strength.
Weirdly though, electric generators in watermills would have been much more attainable - except nobody had any understanding of electricity.
Steam engines were stationary at first. They were used to eg drive pumps.
> Weirdly though, electric generators in watermills would have been much more attainable - except nobody had any understanding of electricity.
Yes, and proper dynamos were invented only quite a long time after batteries. (So called self-excited generators.)
And you have to compare the early bad electric generators they could have come up with against the gears and shafts they knew to transmit the motive force of the water over short distance eg to the mill stone.
You make a lot of good points. Including that the technology to do all that incredibly dangerous to develop - I still can't see a path to terraforming where in the end it's human people left to take pleasure in Mars.
I had thought due to the eons we'd simply have evolved, but even on shorter time frames there is the transhumanist possibility. When we can engineer rabbit that eats chlorine moss, I don't know what we're aiming for at all. "People" by then could have robust gut culture that just digests the regolith.
There's a difference between considering all this vs thinking it's realistic. It's speculation, as any forecast into the centuries ahead must be.
> Plus, it's nice to split our eggs into multiple planetary baskets.
Multiple baskets is good, but why planetary?
We probably won't get hit by a planet-ending meteor any time soon, but who really knows? Good for that not to be our end.
Yes, so? You can have spinning space habitats, instead of needing another planet.
People would almost certainly prefer a planet.
Too many dickheads with a bright idea of putting nuclear warheads on submersibles with a dead man’s switch on this planet.
Even in the event of a full-scale nuclear war, Earth would still be a more comfortable and safe place to live than Mars.
It's like going to the gladiator pits to fight because someone was robbed and shot on the next street yesterday and you don't think your street is safe enough.
[dead]
> Too many dickheads with a bright idea of putting nuclear warheads on submersibles with a dead man’s switch on this planet
If we're nuking each other on Earth, I find it unlikely we wouldn't aim a nuke or two at that group's colony on Mars.
The only thing a Martian colony is a hedge against is ecological collapse on Earth. Because we did something exceptionally stupid accidentally. Or because a rock came by to say hi.
> The only thing a Martian colony is a hedge against is ecological collapse on Earth. Because we did something exceptionally stupid accidentally. Or because a rock came by to say hi.
Even then, Mars is colder than the Antarctic, drier than the Sahara, has lower air pressure than the top of Mount Everest, has soil poisoned like a superfund cleanup site, has no meaningful ozone layer, has no magnetosphere protecting against CMEs, has half our solar irradiance level, and occasionally has planet-spanning dust storms, so the bare minimum for colonising Mars must be able to survive worse than any possible thing we can possibly do to Earth and also some of the bigger rocks coming by to say hi.
Mostly agreed, though the dust storms aren't really that much of a problem, exactly because the atmosphere is so thin.
My understanding is the dust storms still block out a lot of sunlight, so even there a base needs something more than PV + overnight batteries.
A nuked Earth is still more habitable than Mars, even on their best day.
Wouldn't it be far easier and much more useful to colonize the ocean floor than other planets? It is, after all, 70% of the surface area that just sits there.
I think you'd be better off colonising the ocean's surface than the floor.
I mean, we can build space habitats, we don't need to settle planets.
> If you admit that terraforming, even after it's 'done', will require an ongoing maintenance effort
The Earth hasn't always been hospitale to humans, much less technological civilisation. Chances are, we'll have to do similar "maintenance" at home, too. (Easiest to grasp: deflecting asteroids.)
> I suspect terraforming planets is a waste. Far more bang for your buck to build habitats in space from scratch
This comes down to how biology works in zero and partial g. One of the most useful set of experiments we could be doing right now, in terms of colonisation, is putting lots of rats and whatnot in tiny space stations and letting their life cycles play out.
Great, and rats will become super adapted to space. Then they'll become endemic to any space habitats humanity builds. Terraforming planets sounds more plausible than not ending up with rats and cockroaches.
> and rats will become super adapted to space
That would be great! It would strongly imply humans, over cycles of reproducing in space, would too. I suspect, unfortunately, we'd have to iron out some kinks first [1].
[1] https://pmc.ncbi.nlm.nih.gov/articles/PMC8675004/
> That would be great! It would strongly imply humans, over cycles of reproducing in space, would too.
Animals in their natural habitat and humans (especially with modern healthcare) are responding very differently to environmental pressure: we would need to accept a high infant and child mortality rate to be able to evolve.
And the humans having a much longer lifetime and a much smaller amount of descendant means that even without technology we would evolve orders of magnitude slower than rats.
Rats can be pretty tasty.
And: if rats can survive somewhere, it's a pretty small step to make it survivable for humans.
So we'll need responsible stewardship over Earth's Habitability? No problem!
> we'll need responsible stewardship over Earth's Habitability
This is just a semantic punt to "stewardship". (Why is habitability capitalised?)
typo. Also I'm being sarcastic.
> This comes down to how biology works in zero and partial g.
Why? Just spin the thing.
> Why? Just spin the thing
Sure. Let's put rats in centrifuges in space and see if they can reproduce successfully. Maybe there is a coriolis boundary. Maybe something weird happens.
If you make your centrifuge big enough, it's fine.
But yeah, sticking rats in a centrifuge is probably a better first step than starting with humans.
> If you make your centrifuge big enough, it's fine
We don't know this! We don't know how (or even if) an embryo develops under the Coriolis force, or with a gravity gradient.
If you make it big enough, there's no discernible gradient and not much of a Coriolis force.
> So if you dig a bit under the surface it all evens out. Pick the right latitude, and you can get basically any average temperature you feel like
It seems hard to believe that this would actually work, even though I understand why it should. Although you have to do the digging starting in extreme temperature conditions without an atmosphere.
The Moon has zones like you describe on Mercury, and is a lot closer to colonize. Lack of large magnetic field probably won’t matter as terraforming either is hopeless.
Yes, you can also do a similar strategy on the moon.
You can in principle create artificial magnetic fields. But yeah, you are better off just staying indoors most of the time under a big fat layer of regolith.
That is some out of the box thinking!
I would say the key thing with Mercury is the ability to dig fast.
> That is some out of the box thinking!
Thanks. I'm just parroting some lines I read a decade or so ago on a website that I didn't manage to dig up again. (I wonder if it's still online?)
> I would say the key thing with Mercury is the ability to dig fast.
Why? What are you afraid of?
First, night lasts 88 (earth) days on Mercury. So if you start digging at dusk, you have plenty of time.
Second, Mercury's daytime surface temperature is around 430C (~ 800F ~ 700K). We have plenty of materials, like steel, that can withstand these temperatures easily. Even aluminum only melts at 660C.
So you make a parasol out of steel and span it over your equipment. Important: you make the parasol just big enough to shade your equipment, but otherwise let it see as much of the sky as possible.
Mercury has no atmosphere. So during the day you normally have a small patch of the sky at around 5772K, the sun. The sun has about ~6.6 times the angular area on the sky as from earth. The rest of the sky looks as if it's about 3K in temperature, ie very cold. The effect averages out to Mercury's 700K surface temperature.
The parasol itself will attain the same average temperature as the rest of Mercury's surface (because it's exposed to the same conditions).
But for anyone in the shade under the parasol will replace a patch of sky at 5772K where the sun used to be with one at only 700K where the parasol now blocks the view.
If your parasol is supposed to cover more than just a single point with its shadow, than it needs to be big. From the perspective of each shadow covered point, the parasol will have a bigger angular area than the sun it shades.
So you not only replace some 5772K area with 700K, but also some of the previously 3K area with 700K. Overall, you can probably set up things so that you get something like a balmy 15C on average.
> I would say the key thing with Mercury is the ability to dig fast.
To come back to this: Mercury has lower gravity than earth, so I expect that 'soil' will probably not be as dense?
Seems like Mercury could be a good opportunity for automated drones and research
Tectonics isn’t the issue
There would be little point in terraforming Mars. There’s plenty of places on Earth to terraform
The whole point of Mars (or any other second planet) is redundancy. If something happens to earth we have a backup plan, as a species.
There isn't anything that can happen to Earth that would make it worse than Mars.
>The whole point of Mars (or any other second planet) is redundancy.
No. It's some combination of cowardice, greed and ego, by those involved.
You can bet your ass those guys are not thinking about saving the species. Lol. Furthest thing from their minds.
Solve the Earth's problems on Earth instead, no need to run off to Mars.
That's just kicking the can down the road.
> those guys
Who do you think are "those guys"? Talking Musk? NASA? All the people who have dreamt of traveling the stars the last 100 years?
Remember, we landed on the moon before Elon Musk was born. He's also not the first to talk about landing or living on Mars.
And it's not to hedge against us destroying the planet. It's to hedge against an asteroid or other occurrence we can't control.
Musk has a proven track record of using govt subsidies to fund companies to enrich himself immeasurably, and his Nazi turn proves that personal enrichment, not technological advancement, is what is at stake. I don't mean to be preachy but anyone who is providing support for the most racist and perfidious elements of society in Germany and the UK should be disavowed in the strongest terms.
Wow Musk really lives rent free in your head eh? My comment literally about the fact that space travel predates Musk's ambitions by generations, and y'all just double down...
Fun fact, the first person to mention colonising other planets is John Wilkens in the 17th century. I'm sure you'll find a way to connect that to Musk though.
https://en.m.wikipedia.org/wiki/Space_colonization
Are there? Most places on earth have an established environment. There are things living in some very hostile to human areas.
Yeah I don't think we could terraform large pieces of Earth without throwing a very serious wrench into things. The Sahara fertilizes the Amazon, right? So even a nearly lifeless desert isn't acceptable. Maybe the poles?
Agree. But my understanding is the main idea is Mars is supposed to be a "backup" for humanity in the event of a very-low-probability catastrophic event on earth (total nuclear war, solar flare, meteorite collision).
In our lifetimes, unlikely. Over the next 1 million years? Maybe.
I think people misunderstand this goal. It's not 'backup' as in, 'ok, Earth is toast - everybody go live on Mars now.' One of the thing critics get right is that in the overwhelming majority of species ending events on Earth, Mars would still be less hospitable than Earth would. For instance take a massive asteroid impact. It's not the impact that kills you, at least not most people.
But what would happen following a major asteroid impact is a massive amount of matter entering into the atmosphere and effectively blocking out the sun. This results in plantlife dying off which then results in the rapid death of everything on up the foodchain - we starve to death. Yet you'd still mostly be able to breathe the air, your blood wouldn't boil on atmospheric exposure, and so on - it'd still be a rather more pleasant place than Mars.
What Mars can offer is (1) a parallel civilization that can continue on and (2) a lifeboat to Earth. People can return, help reorganize systems of governance and restore order, rescue survivors, and generally get started rebuilding Earth in the case of a mass extinction event. "All" we need from Mars is for it to be relatively self sustaining. I say relatively in that it can provide for the basic necessities - food, habitation, energy, reproduction, and maintenance/repair/replication of those basic necessities. Everything else is a luxury.
And the timelines for that are far closer, even within our own lifetimes. I think this will become more clear over the next decade. China has generally been quite conservative with their space goals and overperforming, and their stated goal for the first crewed mission to Mars is 2033, and every 2 years afterwards to follow indefinitely, as part of a plan to establish a permanent presence on the planet. The first Starship launch to land on Mars will also likely be a game changer for people.
2033 is really not conservative estimate for crewed Mars mission.
It's simply a flyby, not a landing, which will likely happen in 2035 for them. NASA was laying out various plans for exactly this in the 60s, with a timeline of the first crewed flight to Mars somewhere between the mid 70s and early 80s. And it was completely viable. The only reason this didn't happen is because Nixon defacto cancelled human spaceflight in 1972, in part because he was worried that a loss of life in space would imperil his reelection chances. So we get to live in the timeline where space stagnated for decades.
The only fundamental tech we're missing is a heavier launch vessel, which we've already developed in the past - and have actively in development in the present via Starship. China is also developing their own super heavy vessels. But these developments taking 8 years is quite conservative. We went from practically nothing in 1962 (having only just put a man into orbit, and barely at that) when Kennedy gave his to the Moon speech. 7 years later in 1969 - we'd be landing on the Moon. And that landing posed far greater difficulties than just an extended flight, let alone when they were building from nothing, and we have all of this knowledge and prior experience to build from.
A Mars flyby?? With humans? I don't doubt it, but at the same time I can't imagine spending months in a ship just to look at your destination without ever getting out. Talk about cabin fever.
Haha, well depending on the exact ship they go on they'll probably have substantially more room than the ISS. That was the main motivation for things like people staying 370+ days on the ISS. And long before the ISS even existed, the USSR was also actively pursuing this. In 1988 Valeri Polyakov stayed aboard the Mir Space Station for 240 days. His first words after landing were, "We can fly to Mars." [1]
After that he spent a whopping 437 days on Mir (which had about 1/3rd the pressurized volume of the already claustrophobic ISS) to see how the human body would respond to long-term duration in minimal gravity. Upon landing back on Earth this time he decided to get up and walk from the capsule to his rest point (astronauts are normally carried/rehabbed due to muscular atrophy + dysfunctional balance/orientation, even for far shorter stays), making a point of the fact that he was just fine. Dude was just a complete badass. The USSR would have beaten us to Mars if they hadn't collapsed in 1991.
In any case, it's probably a good idea to do a flyby because there will be, with near 100% certainty, some thing things we hadn't considered and others that we simply were not aware of. By first doing a flyby and then a landing you increase the chances of success. And the people doing the flyby will probably be mostly the same people doing a landing a couple of years later - so it'll be more like "See you soon."
[1] - https://en.wikipedia.org/wiki/Valeri_Polyakov#Cosmonaut_care...
Yeah, it's full-on fantasy. Why would we as a species waste time terraforming a planet proven to let its atmosphere evaporate into space? Why waste energy to drag materials from Earth there instead of spending the same energy and materials to fix whatever problems Earth has?
At least in a billion years we can expect we would be either extinct already from our own actions, or hope to be advanced enough as a species to move Earth's orbital path out a touch every couple millennia to keep us in the Goldilocks zone.
Maybe by then we can terraform the Mars by crashing a few dozen comets and detritus from the asteroid belt into Mars to keep the Martian iron core, add heat enough to keep it molten and spinning for a while, add enough mass to get the gravity about 9.8 m/s2, reboot a tectonic cycle, combine 2 satellites into 1 good one, and try to add water to the system overall.
You know, just a regular Tuesday for whatever species we evolve into.
> Why waste energy to drag materials from Earth there instead of spending the same energy and materials to fix whatever problems Earth has?
One of these is a challenge at the frontier, the other an exercise in stewardship. They attract different personalities.
I guess the argument is, that there is just some initial resource usage to get a self sufficient mars colony and all further development can happen without resource strain on earth
I’m of the opinion we’ll just do massive structures in space, lifting out of a gravity well just doesn’t make sense, if you can manufacture in space and we know there is a tonne of resources off plant in the solar system I don’t see why terraforming a plant is the smart play.
That makes sense, but it can easily take a century to get that production ready.
Meanwhile, SpaceX is preparing to start prepping Mars colonization in a few years.
I know, Elon's timelines always break. But his insane goals are also always reached after considerable delays.
My cat always comes when it's called. Not right away though.
I believe the TV show "The 100" experimented with this idea. The inhabitants of the orbiting colonies wait out the contamination of Earth.
https://en.wikipedia.org/wiki/The_100_(TV_series)
AFAIK - of those, collision is the only one which could plausibly make earth less habitable than a substantially terraformed mars.
The Sun will get hotter over time and expand, eventually descendants will have to decamp to elsewhere, like Mars.
If humanity develops the need for "burner planets" then maybe we don't deserve to expand past our solar system...
It's funny that you're using the word "deserve". Based on whose moral framework? I'm not sure current moral frameworks on Earth would be against colonizing the Universe if it was possible.
Its not even about deserving it. How are going to maintain a terraforming project or build habitable orbital platforms if we can't manage keeping our natural habitat habitable?
Maybe projects like this would distract us from stupid tribalism ?
Maybe it would profoundly exacerbate preexisting inequality under the guise of betterment for "all" mankind.
distractions don't solve problems. "just do the projects" doesn't resolve the management issue anyway. the climate crisis is a result of our inability to coordinate mass actions on a planetary scale to avoid damaging our habitat.
Someone gets to choose who lives on these outposts.
Maybe if we worked together, we could actually use robots to do a lot of the initital work, then head over for fun when it's getting nice?
Once can dream I guess...
Not the argument. The elimination of life on earth can happen due to non human causes. An impact of the sort that created the moon would do the job.
We are the only known intelligent life the universe has ever produced. Anti-natal ecoism is a bit of a fallacy.
Read about the great oxidation event other commenters have mentioned. Biology doesn't so much care about an ideal of balance.
Our beloved natural balanced ecosystems are just an artifact of the fact that unbalanced systems change until they reach some equilibrium.
Thinking about wild scenarios is fun and sometimes even prudent.
But acting on it at this point is tragic premature optimization. Musk isn't a stupid person so I have to think in his heart he knows his story is more about PR and being seen as a visionary as something that will actually be done in the next thousand or ten thousand years. Even if there is some climate catastrophe that causes 99% of the population to die out and any civilization to collapse, the remaining 1% are better off on Earth than trying to spend their limited manpower to get to Mars, even if some crazy trillionaire has established a beachhead there.
As an analogy, it feels like some person living paycheck to paycheck and having only $20 to spare at the end of each pay period and saving up that money ... not to invest it in some way that improves their lot, but to hire a tax attorney to help them plan how to shelter $1B in income in case they win the lottery.
The crazy ones are the ones that get sh*t done.
Musk was initially written off initially as crazy for every one of his successful business ventures.
And it's his money to spend as he sees fit.
Walter, I never said he couldn't spend his money how he wants, so that really isn't a counter argument to what I was claiming. Personally, I think most people (Musk is just one) who thinks terraforming Mars is realistic have read too much science fiction and are more enamored of the cool Robinson Crusoe aspect more than it would really serve any purpose.
As for "every one" of his successful business ventures being called crazy, the first one was a dot-com online map of businesses in a given city. Did people say that was crazy? His next venture ended up getting acquired by Paypal, was that considered a crazy business? He invested in/took over Tesla -- I don't know if it was considered crazy or not at the time. SpaceX obviously is a great success. The brain control company -- we'll see. Grok -- nobody called that a crazy idea. Some of his other ventures, like hyperloop and the boring company, do seem more crazy but those escape your claim because they are in fact not successful. His solar roof company wasn't crazy, but it also isn't a success.
In short, Musk has no doubt had great successes, but there is no need to alter history to claim that at every turn he broke new ground when everyone else said it was crazy or impossible.
Agreed, and adding: Hyperloop wasn't original to Musk (other than name). RAND explored the concept in the 1970s, and there are further earlier concepts:
Look up Robert M. Salter at RAND:
"The Very High Speed Transit System" (August, 1972)
"Trans-Planetary Subway Systems -- A Burgeoning Capability" (February, 1978)
<http://www.rand.org/pubs/papers/P4874.html> PDF: <http://www.rand.org/content/dam/rand/pubs/papers/2008/P4874....>
<http://www.rand.org/pubs/papers/P6092.html> PDF: <http://www.rand.org/content/dam/rand/pubs/papers/2009/P6092....>
Similar / more: <http://en.academic.ru/dic.nsf/enwiki/6107059>
All talk and no action.
Going to Mars isn't a new concept, either. There are probably a thousand scifi stories about such.
But Musk is the first to take action.
> Did people say that was crazy?
Nobody did it before.
> acquired by Paypal, was that considered a crazy business?
Before he proved it was profitable. BTW, every business venture I started was considered crazy by my peers.
> Grok
Musk was an early investor in AI.
The Boring Company is successful. It has found a profitable market boring holes for infrastructure cables and pipes.
People said him buying Twitter was crazy. Oops! (What annoyed me about that was I had some Twitter stock, and it was forcibly sold to Musk. I wanted X stock instead! Alas, it is private.)
I put my money where my mouth is. I've invested in TSLA and am a happy shareholder.
There is a long list of crazy ideas that businessmen took on, that became so successful everyone later thinks that those ideas were obvious.
Such as an internet phone. Like a personal computer. Like a Xerox copier. Like jet engines. Like a pencil with an eraser on the other end. Like interchangeable parts. Like the circular saw. Like electric power utilities.
BTW, I think Musk's biggest barrier to getting to Mars is his age. He's running out of time. He can start it, but I expect others will finish it.
What he's doing is freakin' awesome, and I wish for him (and humanity) to achieve it!
Musk is a visionary in the sense that he bought an EV company and took government contracts to mass produce NASA engine designs and launch military and civilian coms networks. Nobody has deeper pockets than Uncle Sam.
The "EV company" he bought consisted of an office and a desk and a kit car. There was no design, not even a plan.
If it was so easy designing and launching rockets for 10% of the cost, why didn't anyone else do it? Why did nobody else make reusable rockets? Rockets that could land on the launch pad? The rapid turnaround and cadence of launches?
Musk did what NASA was unable to do.
BTW, the Saturn V rocket engines were scaled up V2 engines. The essential bits were from the V2 engine - cryo fuels, turbo pumps, nozzles cooled by the fuel, boundary layer cooling, baffles to make the engine stable.
The Saturn V engines were lovingly built by hand. Musk's engines are mass produced.
NASA is a government agency, the US government made SpaceX happen by pushing polices to privatize various aspects of the space agency. I'm not denying the Musk is a good business guy, but his imaginings have nothing to do with the actual work that happens at the companies that he owns. Mars is a neat sales pitch, but SpaceX makes money from mass producing NASA rockets and selling launch services to starlink (and the military version of starlink). The "vision" there is landing a juicy government contract and agreeing to mass produce a proven rocket design.
That’s an incredibly good analogy.
If you want a backup, why use Mars?
You can create habitats from scratch, or you can have colonies on the moon.
Even Mercury is better than Mars.
Lots of reasons for this. The Moon is a complete hell hole - 2 week long nights, night time temperatures that drop to around -200f, daytime temperatures in excess of 250f, extremely low gravity (to the point that one might expect a higher impact of the countless health consequences of 0g exposure on humans), minimal material resources and so on. There is also no atmosphere at all which complicates landing, means even the smallest micrometeorite will impact the surface (which is why the Moon looks like it does), and contributes to highly dangerous particular dust everywhere - much worse than than on Mars.
By contrast Mars is bizarrely similar to Earth. It has almost identical axial tilt resulting in a similar seasonal cycle, a similar annual cycle, extensive mineral resources, some atmosphere simplifying landing - providing protection from meteorites, etc. It has temperature ranges that, like Earth, vary wildly due to seasonality, but are locally consistent. For instance on a summer day near the equator, it hits about 20C on Mars. If not for the blood boilingly low atmosphere, it'd be down right comfy.
Anyhow, kind of a rambling disorganized comparison because I'm in a rush - but yeah, Mars is almost eerily Earth like. In that if life was a video game Mars would be the kind of obvious 'next level', to a degree that makes it feel scripted. Even some chemical reactions like the Sabatier Reaction [1] (Martian atmosphere + electrolyzed ice => methane + oxygen + water) just feel too convenient to be true, but they are.
[1] - https://en.wikipedia.org/wiki/Sabatier_reaction
> Lots of reasons for this. The Moon is a complete hell hole - 2 week long nights, night time temperatures that drop to around -200f, daytime temperatures in excess of 250f, extremely low gravity (to the point that one might expect a higher impact of the countless health consequences of 0g exposure on humans), minimal material resources and so on.
Dig a bit, and temperatures even out. Same as on Mercury.
About the light: you are going to stay indoors anyway.
About gravity: spin! You can build something that looks a bit like a giant funnel, spin that, and live on the inside. If you set up the speed of rotation and degree of incline right, the centripetal force and the moon's gravity will combine to point perpendicular to the surface you are standing on.
You are right that Mars has some interesting peculiarities. But the logistics are a million times harder than getting to and from the moon. So good luck getting a rescue mission there.
In addition, I would advice against contaminating Mars with earth life, if we still want to study it, and figure out if it ever had life. (The moon is and always has been almost certainly sterile.)
With radical ideas it's likely that anywhere can become habitable - there have even been ideas to create floating cities in the thick atmosphere of Venus. But places that require esoteric and ever more complex solutions are obviously less desirable than those that don't. And Mars is 100% 'easy mode' in terms of our first colonization outside of Earth.
Yes, the higher atmosphere of Venus is surprisingly habitable. You call Mars 'easy mode', but you can fill (acid-proof) balloons with Earth atmosphere, and they will float in Venus at more or less exactly the spot that has a nice temperature and pressure for humans to enjoy.
> Even Mercury is better than Mars
...how? It's further. It has no atmosphere. There is no water or carbon.
How is Mercury further? On average it's the closest planet to earth.
Mars's atmosphere is pretty useless for humans.
> How is Mercury further?
Δv, the only metric that matters. Mercury is at 5.5 km/s from LEO, vs 3.6 km/s from LEO for Mars.
To be fair to JumpCrisscross, he never claimed Mercury was further away. It's just "further".
> Mars's atmosphere is pretty useless for humans
Oxygen, carbon, nitrogen and hydrogen make up 95+ percent of a human by mass. Mars has all four, the first three in the atmosphere.
It's just going to be come a place for the ultra rich Musk types to seclude themselves from the rest of us so they can finally build their dream libertarian paradise that is "totally self sufficient" and absolutely, we assure you, not reliant on earth in any way.
Heh, apparently ChatGPT gets touchy when you explore creative ways to make earth less inhabitable than Mars, especially around pathogens and grey goo
> content removed
> <red> This content may violate our terms of use or usage policies
> There’s plenty of places on Earth to terraform
I'm going to steal this.
If we fuck up terraforming Mars, it's bad, but not ecological collapse level bad. On the other hand, we're already fucking up terraforming Earth.
Was it ever anything else then a dream?
Given Venus's atmospheric pressure, I'm not sure that "no magnetic field protecting the atmosphere" is a big part of the story. It's got plenty of atmosphere left.
First order the explanation is simply, Venus is a hellhole because of atmospheric greenhouse effect exacerbated by proximity to the sun.
Venus is thought to have a (at least partially) molten core.
It doesn't have a magnetic field, but that could be due to the slow rotation.
Could be for a million reasons honestly. Could’ve cooled too quickly or too slowly as well.
> no magnetic field protecting the atmosphere
Venus has too much atmosphere. That's the problem.
A huge problem, it's also part of the solution. Venus protects itself from radiation even better than Earth due to its atmosphere.
[Not to bore its audience, the Bible had to be brief on that part of the process, but] God iterated several version before delivering.
Inner thought: here come the downvotes, baby!
Watch this magnificent documentary about the mystery of the surface of Venus.
Still a favorite after 30 years.
https://archive.org/details/NOVA_VenusUnveiled
Russian missions to Venus IMO are some of the coolest missions.
That's some brave stuff to try to pull off.
can you apply 'brave' to unmanned missions? challenging, yes.
I think it's still brave to attempt a mission with significant chance of failure that risks resources, careers, and reputation. And had it been a _manned_ mission to Venus, the adjective that comes to mind is not brave but pointless, foolish, or sadistic.
Taking a risk on a project that takes many years with a good chance of total failure can be brave.
Many people are risk averse and would find the total failure of many years of work at the very least very disappointing.
Economically brave. Imagine building the most advanced and expensive piece of technology your society ever created, with small margins of success and the knowledge it'll last less than an hour before imploding upon itself.
And then trying again 16 times.
(I've just learned there are plans to try one more time: https://en.wikipedia.org/wiki/Venera-17)
Apple applied "courage" to removing the headphone jack.
> Russian missions to Venus IMO are some of the coolest missions.
Well, they become some of the hottest missions pretty quickly!
So... We know the composition of the atmosphere. We know the temp bands going down to the surface. We know the pressure bands going down to the surface.
So, have we started to brainstorm of how to spray a whole host of bacteria and viruses, including sulphur eaters, extremeophiles, and genetically modified organisms, and use satellites to launch into the atmosphere?
Sure, it would be humanity's first planetary geoengineering endevour but its not like it'll get worse than 61 MPA and 600c
And the cost of a few space vehicles is what? Wouldn't be THAT expensive. And we'd learn a bunch.
Hmm, maybe China would be interested. Opening up new earth-sized landmasses would be incalculable gains for humanity.
The Moon, gently stirring and moving the inner core like oatmeal.
And keeping the axis of rotation consistent - and keeping the day length short and consistent.
Oh but that's not even the best part. The rare total solar eclipse - those two sky-objects are so similar in size! - motivates (terrified) ancient man to observe, record, theorise, mathematise.
Yummy. Mind the heat!
I've always wondered about the feasibility of adding a reflective solar shield between Venus and Sol to cut the feedback loop that keeps surface temps so high, eventually reducing cloud cover and revealing what lies beneath. In addition, such a project might be good practice in case we ever needed a modified version for Earth, and may even be useful to add energy to celestial bodies (e.g. heat up the dark side of an asteroid by placing it at the focus of a large parabolic mirror). Venus having an atmosphere and having almost the same mass as Earth has always made it, not Mars, my favorite target for terraforming and colonization.
What stuck out to me is how fragile Earth's long-term stability actually is. We've gotten insanely lucky with things like plate tectonics, subduction, and just the right volcanic activity to keep CO2 cycling.
And over sufficiently long terms, the Earth's not been all that stable.
There've been multiple Snowball Earths (based on geological evidence), and a few episodes in which (even had land-based life existed) the continents were barely habitable.
Even today large expanses (Antarctica, the Sahara and other deserts) are only barely habitable. Still Edens compared with the rest of the Solar System.
At these time scales, major terraforming projects become viable, from building large sunshades in orbit to one near Earth-Sun L1 (balancing light pressure and gravity, it would be closer to the Sun than L1), to even raising Earth’s orbit through a fleet of gravity tugs. Venus would be an excellent case for a planet-sized sunshade, btw, as well as a solar wind magnetic lens to replace lost hydrogen and make liquid water as the planet cools. The latter could be useful for Mars.
It's interesting that this article places the boiling of Earth's oceans much further in the future than Wikipedia's Timeline of Earth's Future.
https://en.wikipedia.org/wiki/Timeline_of_the_far_future
I can't believe people haven't read James Lovelock's works re the Gaia hypothesis. The feedback loop is that plants produce an oxygen rich atmosphere right up to the point where lightning strikes would start fires that kill off enough plant life, reducing the oxygen in the atmosphere. Send plants to Venus now and in 500 billion years we can move there.
I struggle to find plants that can survive and do photosynthesis in temperatures of molten tin and sulphuric acid rain though
I've heard of if but am put off by the flaws as suggested in the wikipedia article https://en.wikipedia.org/wiki/Gaia_hypothesis#Criticism_in_t...
I liked the nyt microbes in the crust article https://www.nytimes.com/2024/06/24/magazine/earth-geomicrobi... along those lines.
Earth's internal heat regulation is such an underrated hero in the climate story. Half of Earth’s heat comes from internal sources, constantly driving plate tectonics and helping regulate CO₂. Venus lacks that it’s like a pressure cooker with no release valve.
Without that internal churning and subduction pulling CO2 into the mantle, you’re basically stuck in a slow-burn oven, like Venus
How does Earth's internal heat regulate CO2?
Tectonic and volcanic activity release CO2 into the atmosphere. They comprise a major part of Earth's carbon cycle. Over time, carbon would be depleted from the outer lithosphere without this replenishment, and one of the mechanisms by which the Earth ultimately becomes unsuitable for life is a slowing of the tectonic cycle and depletion of said carbon.
This point is addressed (briefly) in TFA:
If or when Earth’s large-scale subduction shuts off in about 3.5 billion years, kneecapping the planet’s ability to bury carbon...
See also:
"Evolution of Earth’s tectonic carbon conveyor belt" (2022)
Concealed deep beneath the oceans is a carbon conveyor belt, propelled by plate tectonics. Our understanding of its modern functioning is underpinned by direct observations, but its variability through time has been poorly quantified. Here we reconstruct oceanic plate carbon reservoirs and track the fate of subducted carbon using thermodynamic modelling....
<https://www.nature.com/articles/s41586-022-04420-x>
"How plate tectonics has maintained Earth's 'Goldilocks' climate" (26 May 2022)
(Popular article based on the same research.)
"Timeline of the Far Future"
See "The Sun's increasing luminosity begins to disrupt the carbonate–silicate cycle..." ~500 to 600 my.
<https://en.wikipedia.org/wiki/Timeline_of_the_far_future>
This is somewhat speculative, and the precise nature / timing of carbon collapse may differ. But what strikes me is that the various pathways by which Earth exits its Goldilocks state are numerous and comparatively soon on a geological timescale. We're far nearer the evening of Earth's day than its morning, by multiple such measures.
One odd theory i heard is that Earth is actually one giant superorganism. (When you look at how well all the ecosystems internact with each other it kind of makes sense). Like any organism, when invaded by a virus it heats up in a fever in order to kill it...
Doing things in a chaotic way will increase entropy. Increased entropy is heat.
Isn't the answer just: we grew up (evolved) on Earth, so from our perspective it's an Eden? Everyone's home planet must seem like an Eden to them, right?
Trisolarans notwithstanding.
I don't see any mention of the Theia Impact theory - https://en.wikipedia.org/wiki/Giant-impact_hypothesis - of the Earth/Moon system's formation.
Whether or not Theia was the cause - having a fast-spinning Earth and huge satellite in a low orbit* make Earth's situation profoundly different from that of Venus.
* https://en.wikipedia.org/wiki/Moon#System_evolution for starters
Because we are built for Earth. Next question.
Beauty is in the eye of the beholder.
I guess we need to start colonizing other worlds then.
We need to yes. Maybe the tech can help us with the required geohacks here.
Even in the Goldilocks zone a planet still need so many specific things going for it to be the paradise Earth is. Anthropic principle strikes again!
It’s because there’s no Arby’s on Venus. If we put an Arby’s up there it would start looking a lot better
good point
Earth is hell also...
Because of the distance from the sun
Venus's albedo is so high that the insolation at the surface is even less than Earth's. Yet it's hotter than Mercury, which is closer to the sun than Venus.
The article says that volcanism is the reason, and that solar heating would not cause this result on its own, even though it's everyone's first guess.
From TFA: "The sun alone cannot be responsible for making Venus the awful place it is today."
That’s part of it but the dense CO2 atmosphere is the major issue. Don’t worry, we are trying to get there as fast as we can to Hell as well.
What’s the worst case CO2 on earth? Is it as bad as Venus?
Almost the entire length of the linked article is spent answering that question in detail.
Although there's very little information about the most interesting part. What did they use for their modelling? The results suggest somehow that the modelling includes a lot of manual handwaving...
Don't forget the corrusive atmosphere that is acid and eats up space probes.
Depends on elevation. It’s quite habitable with enough height.
Nitrogen oxygen at one atmosphere is a lifting gas on Venus. You could live in an enormous zorb if you can keep it sealed.
Quite. Its just so.
Still disappointed it's not a swamp as promised by 20th century science fiction.
Give it another few hundred million years.
[dead]
[dead]
Because God created that way? Duh what kind of question is this
/s
> Why Is Venus Hell and Earth an Eden?
Because humans evolved on Earth and not on Venus.
If we evolved on Venus then it would be our Eden.
> They’ve been pushing their model Earth to its extremes
Is your model anywhere good enough to be able to get useful outcomes from this process? I would suspect not. I mean, we know this planet's state is partially owed to the many unique comet impacts that have occurred during it's life, are you modelling those?
> If we evolved on Venus then it would be our Eden
I don't think we can just anthropic principle this one away. We couldn't have evolved on Venus. It's valid to ask whether any complex life could.
> Is your model anywhere good enough to be able to get useful outcomes from this process? I would suspect not
Got it, reflexive blanket dismissal comment.
> It's valid to ask whether any complex life could.
That's obviously the point I was making.
> Got it, reflexive blanket dismissal comment.
No, I said my _suspicion_ is that you cannot, and you're being a hypocrite.
> That's obviously the point I was making.
No, it obviously wasn't.
> That's obviously the point I was making
It obviously isn't given you followed up with "if we evolved on Venus."
> I said my _suspicion_ is that you cannot
Which you followed up by dismissing the work for suspecting it did not consider [insert random armchair complication].
> you're being a hypocrite
Nope. I actually read and thought about your comment, initially in good faith.
There are real limits to what life can be supported due to basic chemistry/laws of physics. e.g. "Venus is so hot — hot enough to melt lead — that the acid rain evaporates as it’s falling." That life evolved on Earth and not Venus is not an accident.
Merely "because humans evolved on Earth and not on Venus" is just a dismissive contrarian take that says absolutely nothing of any value what-so-ever.
> Because humans evolved on Earth and not on Venus.
> If we evolved on Venus then it would be our Eden
That's about the connotations of the words "Hell" and "Eden", not about the facts being discussed.
And why did humans evolve on Earth but not Venus? In fact no life evolved on Venus that we know of.
I blame Jurassic Park for popularizing the adage "life finds a way". It's good so far as it goes as a celebration of the miraculous creativity of life. But taken to the extreme it means failing to respect pretty powerful physical limits that are devastating to any form of organic chemistry.