HN Theater @HNTheaterMonth

> terraforming Venus, rather than the much more feasible notion of colonizing Mars

I've heard from multiple experts now that you may have this backwards. SpaceTime even made a video about it long ago [1]

1. https://www.youtube.com/watch?v=gJ5KV3rzuag

PBS Space Time did a short (7 minute) episode called "Should We Colonize Venus Instead of Mars?" [1] that gives several advantages Venus has as a colonization target compared to Mars (and covers some of the difficulties).

[1] https://www.youtube.com/watch?v=gJ5KV3rzuag

Don't miss the PBS Space Time episode suggesting we should colonize Venus instead of Mars which gives some good arguments and goes through the basics.

[1] https://www.youtube.com/watch?v=gJ5KV3rzuag

This idea is explored in an episode of the excellent PBS Space Time: https://www.youtube.com/watch?v=gJ5KV3rzuag

In short, Venus has many advantages over Mars.

I wish we would focus on Venus. It have similar gravity to Earth's. There is an excellent video about it https://www.youtube.com/watch?v=gJ5KV3rzuag.

⬐ Chickenality

The atmospheric pressure and temperature on Venus are far too high for it to be habitable. Even if those problems were surmountable, there is no liquid water, and the days are very very long.

⬐ gkfasdfasdf

> The atmospheric pressure and temperature on Venus are far too high for it to be habitable.

Which is why the video proposes floating cities. I agree with GP, Venus deserves more consideration.

Venus is pretty sweet as it is. Go high enough in the atmosphere, and you have about Earth atmospheric pressure and room temperatures. That altitude in the Venus atmosphere is effectively an Earth biosphere sized almost-Earthlike living space.

One convenient circumstance: A breathable Earthlike atmosphere will float at that altitude, so it would be easy to live in floating balloon habitats.

https://www.youtube.com/watch?v=gJ5KV3rzuag

https://www.youtube.com/watch?v=BI-old7YI4I

⬐ dTal

It seems a good deal less convenient when you factor in the clouds of concentrated sulfuric acid. Any habitat is going to have to be just as hermetically sealed from the outside world as if you were on Mars, with the additional caveat that everything be acid-proof (including suits). At least Martian atmosphere won't melt your face off if it ever gets inside!

⬐ logfromblammo

Your habitat won't float as well once I transport some asteroid-mined calcium and magnesium to Jupiter, turn it all into hydrides, package it with transition-metallic catalysts (Co, Ni, Fe, Ru), and shoot it into Venus.

  MgH2 -> Mg + H2 (thermolysis @ 287 degC)
  CO2 + H2 --Fe-> CO + H2O (water-gas shift)
  CO + H2 --Fe-> C + H2O (Bosch)
  CO2 + 4 H2 --Ni-> CH4 + 2 H2O (Sabatier)
  2n+1 H2 + n CO --metal--> CnH(2n+2) + n H2O (Fischer-Tropsch)
  2 Mg + CO2 -> 2 MgO + C 
  CaH2 + 2 H2O -> Ca(OH)2 + 2 H2
  Ca(OH)2 + CO2 -> CaCO3 + H2O

⬐ stcredzero

We might have to switch to double-hulls, with the outer section filled with hydrogen. That would be concerning in an atmosphere with appreciable free oxygen, but I suppose you have a plan for that.

⬐ logfromblammo

The chemical intervention is only sufficient to get the excess of CO2 out of the atmosphere, which would get the surface pressure down to maybe 3 bar of mostly N2. From there, we'd still have to cool the atmosphere down far enough to support thermophilic autotrophic microbes in the new surface lakes. They would produce oxygen, but slowly, so there wouldn't be any appreciable free oxygen available for a long time.

The primary concern would be that Earth-gas would not be a good enough lifting gas in the CO2-depleted Venus atmosphere to keep the floating habitat at a cool enough altitude. Hydrogen-filled chambers would certainly work for that, but you would have to bring that hydrogen with you to Venus. By the time atmospheric oxygen becomes a risk, you would just land the dirigible and burn the hydrogen in a controlled fashion.

⬐ stcredzero

but you would have to bring that hydrogen with you to Venus

Why not extract the hydrogen out of the clouds of acid?

⬐ logfromblammo

Because that would involve bringing along a reactive metal, bringing one H2 molecule with you is less mass than any of the metal atoms that would react with H2SO4 to give you the same amount of hydrogen. But perhaps more difficult to handle as a gas.

You could bring along MgH2, then once you hit the atmosphere, you can thermally decompose it into Mg and H2, then react the Mg with sulfuric acid to get MgSO4 and another H2.

⬐ Simon_says

If you go to all the trouble to get out of one gravity well, what's the point of anchoring yourself?

⬐ macintux

Some of us are fond of the conveniences of a gravity well.

⬐ stcredzero

Escaping radiation? Scenery? Proximity to lots of other people? There's a good chance that the barrier of a gravity well is going to go the way of the barrier of mountainous terrain.

Also, exchanging the fixed geography of land for the fluid geography of fluid might result in changes to the underlying nature of society. In hunter gatherer days, dissenters could simply walk to a different part of the environment. Farmer's fields and defensive walls anchored people to particular pieces of land. If everyone lived in mobile floating habitats, everyone would be free to move. This is quite likely to change the nature of government.

You also get this in a Dyson Swarm, but there's a matter of scale. A minimum viable space colony is likely to be larger and more expensive than a minimum viable floating Venusian compound.

⬐ amorphid

I can see the appeal of doing because it's cool. That's the primary reason I'd consider going into space. I'm not sure roughing it in a balloon would be the my idea of a good time once the novelty wore off. I wonder if there'd be some tangible benefit to colonizing Venus for adventurous entrepreneurial types... "There's gold in and/or on them thar clouds!" There's nothing like bajillions in potential profits to get people excited about moving to the a frontier. Actually...

With floating cities, the idea of a space elevator isn't that crazy. What could we do with space elevators on Venus?

⬐ stcredzero

I'm not sure roughing it in a balloon would be the my idea of a good time once the novelty wore off.

What if the small balloons were the size of a Las Vegas resort, and the average ones where something like Manhattan?

I wonder if there'd be some tangible benefit to colonizing Venus for adventurous entrepreneurial types... "There's gold in and/or on them thar clouds!"

The society that might arise in an entirely fluid, borderless geography might have a certain attraction. Venus might wind up being the next Las Vegas, writ large in the 21st century.

With floating cities, the idea of a space elevator isn't that crazy. What could we do with space elevators on Venus?

You could have ultra-high altitude balloons that can act as staging centers for rotorvators. Those would be way cheaper than space elevators to manufacture.

⬐ TheOtherHobbes

There is zero chance of building viable space elevators or floating cities around Venus without magical 100% scifi technology.

The lower atmosphere of Venus is denser than the surface of Earth’s ocean, but with extremely violent currents. The upper atmosphere - at the “inhabitable” level - has similar but much less dense winds, with the added henefit of a charmingly toxic and aggressive haze of sulphuric acid.

It might just about be possible to build a floating research station, at vast effort and expense, but floating cities are not going to happen without some near-magical breakthroughs in materials science and engineering.

And without access to the surface, there isn’t much to do above Venus anyway.

⬐ stcredzero

floating cities are not going to happen without some near-magical breakthroughs in materials science and engineering.

The acid clouds aren't that bad. People have even worked out how to manufacture PTFE out of the Venusian atmosphere, so there's your acid proofing right there. We already know how to build lighter than air craft.

And without access to the surface, there isn’t much to do above Venus anyway.

Access to the surface is perfectly doable using teleoperated robots. You can lower them onto the surface with a store of a phase-change substance for cooling. Dry ice might be suitable for that. When they run out, you haul them back up.

There's wasn't that much to do in the desert where Las Vegas is located, either.

>Mars, not easy; Venus, impossible

Mars may very well be much easier, but the bias towards Mars may also be largely cultural: https://m.youtube.com/watch?v=gJ5KV3rzuag

Interestingly, there is actually a case to be made that Venus may be more feasible to colonize than Mars. It has been argued the lack of attention to Venus has more to due culture than science. PBS Spacetime did an episode on this: https://m.youtube.com/watch?v=gJ5KV3rzuag

Thought about that as well.

There's a nice PBS Space Time episode where they invented a word about it : "surfacism".

https://www.youtube.com/watch?v=gJ5KV3rzuag

⬐ perilunar

O'Neill wasn't talking about the clouds of Venus though, he was talking about colonies in orbit or beyond, made from materials mined from asteroids.

⬐ oniony

Mars is a stepping stone, both figuratively and literally.

⬐ perilunar

The asteroids are the stepping stones. Mars is more like a small hole.

Obligatory XKCD: https://www.xkcd.com/681/