Live data from Hacker News

Saturn's largest moon may be the only place beyond Earth where humans could live

blogs.scientificamerican.com

311–320 of 393 posts

Re: Saturn's largest moon may be the only place beyond Earth where humans could live

#311
post #128

What’s more likely in the next 5000 years that we colonize Mars or that we scan the human brain and move it to software so that it doesn’t need a specialized atmosphere to persist?

That's a very interesting question. I would guess that if moving brain into software is at all possible, there will be very little reason to build anything other than huge computers, and maybe that's the answer to Fermi paradox.

Re: Saturn's largest moon may be the only place beyond Earth where humans could live

#312

The dangers of radiation on Mars are greatly exaggerated. The dangers of low gravity on Titan and elsewhere are greatly understated, as is the immense distance between Mars and Titan. A floating habitat on Venus is harder and less attractive in every way than a rotating space station, which is clearly our next milestone in space. In terms of planets though, there's a reason Mars gets the most attention: it's obviousl…

A floating habitat on Venus is actually more attractive. Venus (upper atmosphere): -human livable temperatures with modest temperature control -Earth-like pressure (Himalayans) leads to slow leaks that can be patched, and pressure can be increased inside to stop the leaks inward -protected by thick atmosphere from radiation, meteors, asteroids -strong magnetic field against radiation -atmosphere still thin enough for…

I’d throw in if a rotating station is still in LEO (seems likely for a first attempt) it would have the benefit of Earth’s magnetic field for shielding. Not if used for traveling to another body though.

Re: Saturn's largest moon may be the only place beyond Earth where humans could live

#313

Serious question, since this is out of my swim lane. The Author keeps talking about the effects of Galactic Cosmic Rays, do we have any usable materials we can build habitats out of that can block them? I mean usable in the sense we can produce in scale and they are non toxic to humans.

For Cosmic Rays the only thing is just a lot of atomic nuclei. You need pure mass. This is why a transit to Mars or Saturn is going to be hard for us to pull off in the near term. All those nuclei are expensive to get into orbit right now. Outside of that, there is a 'graded Z' shield. Here, you make a layer cake of various atomic nuclei (the Zs), going from heavier to lighter. Typically Tantalum down to Tin and down…

Artificial magnetic fields are another possible solution.

Re: Saturn's largest moon may be the only place beyond Earth where humans could live

#314
post #252

Earlier quoted context omitted.

The only thing going for the moon is its proximity to Earth. Mars has more than double the gravity of the moon, an atmosphere, nearly earth-like day night cycle and satellites have a much easier time orbiting mars

The only thing going for the moon is its proximity to Earth. Oh...that's all . So let's ignore for just a second the logistical advantages of figuring out how to actually mount a manned mission to build something non-trivial on another body when you're 3 days away, not 6 months away. Pretend that isn't important. The moon has water, raw materials, enough gravity things don't just float away, abundant solar and we've…

The moon is just as much of an un-funded wank fantasy as mars... grow up dude

Re: Saturn's largest moon may be the only place beyond Earth where humans could live

#315
post #211

Earlier quoted context omitted.

There's no atmospheric absorption though, so that would compensate a bit. Building very tall structures would be easy in the low gravity, and you wouldn't need to worry about earthquakes or storms.

I'd often though that a rail or even cable should be strung to the top of Mt Everest, you'd make a fortune off of it shuttling tourists up and down all day.

That would be quite the engineering feat - Everest is not exactly construction friendly.

Pikes Peak used to have a train going to the top, but they closed it a couple of years ago. https://www.cograilway.com/rates-times.asp

Re: Saturn's largest moon may be the only place beyond Earth where humans could live

#316

Everyone in the comments here debating the merits of Mars vs the Moon vs Titan seems to have missed the whole point of this article. The author is arguing that anywhere other than Titan is infeasible due to recent research suggesting that Galactic Cosmic Rays cause significant brain damage (not just increased risk of cancer). In fact, the article argues that the danger is so severe that even getting to Titan quickly…

I expect colonizing the solar system will not be completely practical without genetic modification of the colonists to partially adapt to local environments.

One reason I'm bullish on humans being a stepping-stone to electronic/software life forms, is that we are ill-equipped in every way to meaningfully travel the universe: from short life spans, to radiation vulnerability, to the complexity of converting electrical energy into bio-available energy, to psychological effects of long journeys in cramped quarters.

Software-life, on the other hand, can tailor its physical form(s) to particular environments, consume solar/nuclear energy directly, and even shut off its consciousness during long journeys.

Don't get me wrong, I'm all in favor of solar system colonization, interstellar generational ships, etc; and manual genetic manipulation (or repair) may be a necessary tool to accomplish that. But in terms of life forms being well-adapted to their ecological niche, humans becoming a space-faring species is a billion times more difficult than a mudskipper learning to breathe air.

Re: Saturn's largest moon may be the only place beyond Earth where humans could live

#317

The dangers of radiation on Mars are greatly exaggerated. The dangers of low gravity on Titan and elsewhere are greatly understated, as is the immense distance between Mars and Titan. A floating habitat on Venus is harder and less attractive in every way than a rotating space station, which is clearly our next milestone in space. In terms of planets though, there's a reason Mars gets the most attention: it's obviousl…

A floating habitat on Venus is actually more attractive. Venus (upper atmosphere): -human livable temperatures with modest temperature control -Earth-like pressure (Himalayans) leads to slow leaks that can be patched, and pressure can be increased inside to stop the leaks inward -protected by thick atmosphere from radiation, meteors, asteroids -strong magnetic field against radiation -atmosphere still thin enough for…

> the escape velocity from Mars requires a massive rocket equivalent to the one we use to leave Earth and therefore more fuel leaving less payload for delivering other resources or supplies

Wait, what? Isn't escape velocity from Mars lower than that from Venus? The surface gravity is far lower on Mars.

I also note that you list "no surrounding breathable atmosphere" as a negative for a rotating space station, but the surrounding atmosphere on Venus isn't exactly breathable either...

Re: Saturn's largest moon may be the only place beyond Earth where humans could live

#318

The dangers of radiation on Mars are greatly exaggerated. The dangers of low gravity on Titan and elsewhere are greatly understated, as is the immense distance between Mars and Titan. A floating habitat on Venus is harder and less attractive in every way than a rotating space station, which is clearly our next milestone in space. In terms of planets though, there's a reason Mars gets the most attention: it's obviousl…

The distance would be mitigated with a 1g thrust drive. It would reduce the transit time between Earth and Mars to three days, with the ship accelerating to midpoint and decelerating from there.

We just need a craft that can thrust that strength for three days straight.

Re: Saturn's largest moon may be the only place beyond Earth where humans could live

#319

Earlier quoted context omitted.

> You get radiation protection from earth's magnetosphere. Only in very specific orbits (NOT the ones we are currently using, btw.) The Earth's magnetosphere actually captures dangerous radiation and various anomalies in the belt distribution cause portions of low-Earth orbits to be irradiated. > You get zero G for funsies. And the medical issues. > interesting new kinds of manufacturing. There are a handful of (very…

I'm not trying to take the wind out of the sails of any vehicles going elsewhere, just think LEO is a good place to start. Something like, before crossing an ocean, let's cross the Florida straits over to the Bahamas. > The Earth's magnetosphere actually captures dangerous radiation and various anomalies in the belt distribution cause portions of low-Earth orbits to be irradiated. Pick the favorable orbits. We have d…

LEO is more like 'camping in the back yard'.

All I ever learned from that is that I hate camping... and would much rather have a house / hotel room.

Extending that analogy further, maybe we can figure out how to build a "mother in law apartment" in our "back yard" first.

Re: Saturn's largest moon may be the only place beyond Earth where humans could live

#320

Earlier quoted context omitted.

Mars is definitely the easiest place to colonize, by far. It's much closer than the gas giants, there's no craft capable of taking people to Saturn even devised, let alone constructed. Meanwhile, we have SpaceX actively building a rocket for Martian colonization. Second, the Venusian atmosphere is oppressive as hell, you'll not be solving that problem anytime soon, as we can't even solve Earth's much easier atmospher…

> SpaceX actively building a rocket for Martian colonization. It's unknown whether it is capable of protecting the human cargo on its way to Mars. Maybe a design with habitation encased in the propellant tanks is a better idea for longer transits. In any case, Starship is well positioned for Earth and Moon travels, as well as for sending equipment to LEO and the Moon.

This is just silly. Of course it’s known if we can transport humans to mars. The answer is yes. The only question is how much it will cost. All you have to do is surround the craft with mass. It doesn’t even have to be attached to the craft. The cost of giving the mass enough energy to get out of orbit and over to mars is the only question.
Post reply on HN