Hacker News Reader

Comment by XorNot | Hacker News Reader

The biggest problem is it's spin rate: a Venus day is 116 days Earth days or so.

Being completely tidally locked would be better because near the transition zones the permanent sun would make solar power and plants quite productive.

But an ecosystem where the planet spends most of the year in darkness or dim light?

Basically it's relatively easy to redirect comets to provide gas and liquids for the surface of Mars: that's technically demonstrated technology now.

There's almost no plausible way we could add momentum to Venus to give it a more reasonable day night cycle (I have seen some suggestion that shearing asteroids into it might be possible, but just the magnitude of momentum you're trying to add is staggering).

View on HN

If I remember correctly, the habitable-ish cloud layers have super-fast winds that circle the planet once every 4 days or so. [0]

[0] https://en.wikipedia.org/wiki/Atmospheric_super-rotation

> But an ecosystem where the planet spends most of the year in darkness or dim light?

If you're floating you don't have to track the ground.

True but you basically lose the benefits of being on a planet. The point at which you're just floating in atmosphere I would argue you might as well be in orbit for all the resupply complexities, but few of the benefits - I.e. an orbital structure without significant atmosphere around it means high Isp low thrust engines like ion drives are practical to come and go from it and a lot of the energy is free from solar.

> you might as well be in orbit for all the resupply complexities

The difference is in air pressure and gravity.

Gravity means comfort for astronauts. It also makes, I suspect, science and industry a bit easier.

I don’t know what air pressure means. Spacewalks probably get easier. But now your structures have to deal with aerodynamic forces, which is annoying. Making up for that, you’re suspended in a soup of precursors and reagents—that opens up ISRU possibilities. And you should be getting less radiation in atmosphere.

On the whole, if you’re doing planetary science, I think being in the atmosphere is hard to beat. If you’re doing any industry, being near raw materials beats shipping anything unprocessed out of a gravity well. So if you’re staying for a while, you dip in. If, on the other hand, you’re just visiting for a few days, yeah, take a lander and then get back out again.

There are other advantages versus orbital habitats, not least that your station doesn't have to be a pressure vessel - equal pressure within and without makes big structures a lot simpler.

The atmosphere would also block the majority of radiation, which is a huge concern for proposed orbital or Martian settlements.

Even better than just the atmosphere itself: Venus has an induced magnetosphere.

All right, but if outside is one atmosphere of sulfur dioxide, you still don't want any air leaks.

At the right height the pressure would be equalised, and so while a leak isn't great, they'd be slow and manageable.

Does the atmosphere itself track the ground? I'd expect the slow rotation to drive persistent winds, potentially keeping weather systems somewhat tidal-locked as well

> But an ecosystem where the planet spends most of the year in darkness or dim light?

How would that work? Averaged over the planet, you get half the year in darkness and half the year in light. There's no other option.

We have that same ecosystem on Earth.

The atmosphere has a perfectly reasonable 110 hour day/night cycle.

Redirect comets? Technically demonstrated technology? What?

https://science.nasa.gov/mission/dart/

As in the mission has been flown and an asteroid deflection has been achieved.

Reply on news.ycombinator.com