Why is Venus hell and Earth an Eden?
quantamagazine.org
quantamagazine.org
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...
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.
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.
FAHRENHEIT
0: Very cold
100: Very hot
0: Moderately cold
100: Dead
0: Dead
100: Dead-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.
40 F = 4 C (forty is four)
50 F = 10 C
60 F = 16 C (sixty is sixteen)
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.
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.
I 100% agree, "Freedom Fries Units" is quite fitting.
Turns out I prefer Celsius over Fahrenheit in day to day usage.
Also interestingly, US customary units are defined in terms of metric. So in a sense, the US does use the metric system.
https://en.m.wikipedia.org/wiki/International_yard_and_pound
https://en.wikipedia.org/wiki/Comparison_of_the_imperial_and...
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.
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
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 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.
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.
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.
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
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.
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.
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.
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.
Suddenly losing or gaining a few hundred tonnes of mass will do interesting things to a free-floating aerostat.
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?
Then you fly to the colony balloon.
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.
Same reason North America got colonized by religious extremists and weirdos.
Who paid this government?
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.
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.
At first, I thought you were describing the settling of Australia
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 better the moon, Mars or even moving habits on Mercury. At least you have access to mineral resources, and water (ice).
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.
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?Literally how flying planes off Aircraft Carriers works.
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
I think Newton’s third law may cause trouble-but I’m no physicist.
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.
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.
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.)
What is their buoyancy-management system?
You're offloading the problem, not solving it.
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.
Managing ballast might be a challenge…
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.
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.
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?
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.
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.
[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.
Also, if we can deal with Venus, we can reverse global warming in Earth first?
It'd be interesting to see what additional "personal atmospheric floatation" devices would be needed.
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...
Guess it would be like living on a floating oil/gas platform.
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.
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
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
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-...>
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.
"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.
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 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."
That likely resulted in many species going extinct!
Many of our iron ore deposits we still mine today are from that rusting. (That iron used to be mostly dissolved in the oceans.)
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.
I wasn't aware that concentrated stores of iron are also an important part of this story!
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.
The iron doesn't go anywhere (ok, except for the iron making up our space probes). It is infinitely recyclable.
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://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...>
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.
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.
"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?"
Far more an Eden, then.
Related: highly recommend Robert M. Hazen Great Courses and book
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.
This scheme would have some negative aspects.
BTW, hydrogen on Mars is enriched in D by a factor of 5 relative to Earth.
This is not likely the sole reason, but it must be a factor.
Mercury does have a magnetic field, Mars does not.
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.
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?
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.
Multiple baskets is good, but why planetary?
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.
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 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.
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].
And: if rats can survive somewhere, it's a pretty small step to make it survivable for humans.
This is just a semantic punt to "stewardship". (Why is habitability capitalised?)
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.
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.
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.
I would say the key thing with Mercury is the ability to dig fast.
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?
There would be little point in terraforming Mars. There’s plenty of places on Earth to terraform
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.
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.
In our lifetimes, unlikely. Over the next 1 million years? Maybe.
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.
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.
One of these is a challenge at the frontier, the other an exercise in stewardship. They attract different personalities.
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.
Our beloved natural balanced ecosystems are just an artifact of the fact that unbalanced systems change until they reach some equilibrium.
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.
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.
You can create habitats from scratch, or you can have colonies on the moon.
Even Mercury is better than 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.
...how? It's further. It has no atmosphere. There is no water or carbon.
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I'm going to steal this.
It doesn't have a magnetic field, but that could be due to the slow rotation.
Venus has too much atmosphere. That's the problem.
Inner thought: here come the downvotes, baby!
Still a favorite after 30 years.
That's some brave stuff to try to pull off.
Many people are risk averse and would find the total failure of many years of work at the very least very disappointing.
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)
Well, they become some of the hottest missions pretty quickly!
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.
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.
I liked the nyt microbes in the crust article https://www.nytimes.com/2024/06/24/magazine/earth-geomicrobi... along those lines.
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.
Trisolarans notwithstanding.
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
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.
/s
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?
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.
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.
No, it obviously wasn't.
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.
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.
> 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.