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.
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.
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.
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!
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
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...
> 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
> 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?
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.
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.
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.
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.
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.
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.
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.
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?
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.
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[ 4.3 ms ] story [ 69.9 ms ] threadThis is not likely the sole reason, but it must be a factor.
Mercury does have a magnetic field, Mars does not.
Inner thought: here come the downvotes, baby!
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
Still a favorite after 30 years.
https://archive.org/details/NOVA_VenusUnveiled
That's some brave stuff to try to pull off.
Well, they become some of the hottest missions pretty quickly!
That likely resulted in many species going extinct!
Related: highly recommend Robert M. Hazen Great Courses and book
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
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?
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.
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...
It'd be interesting to see what additional "personal atmospheric floatation" devices would be needed.
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.
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.
I liked the nyt microbes in the crust article https://www.nytimes.com/2024/06/24/magazine/earth-geomicrobi... along those lines.
Trisolarans notwithstanding.