I'd tend to Jupiter's outer big moon, Callisto, as a good place to live. The surface is a vacuum, sure, but it's got surface ice which probably has liquid water underneath making it (and Ganymede and Europa for the same reason, and Venus 50 km up, and Earth) one of the few places in the solar system you could theoretically go outside with just a breather and no space suit. Plus it's got protection from charged particles via Jupiter's magnetic field without suffering from Jupiter's own radiation. And you've got both volatiles and minerals accessible on the surface which strikes me as really nice.
Saturn's largest moon may be the only place beyond Earth where humans could live
81–90 of 393 posts
Re: Saturn's largest moon may be the only place beyond Earth where humans could live
#82terraform venus. it's much closer, has a nice .9g and maybe a viable long-term project https://en.wikipedia.org/wiki/Terraforming_of_Venus
It is theorized that Venus once had an Earth like atmosphere. Venus has virtually no magnetic field unlike Earth. Without the protection of something like the Van Allen radiation belt the Sun would have easily blown off any thin high density atmosphere and eventually cook off any surface level hydrocarbons into a thick hazy atmosphere with a super greenhouse effect. Any terraforming effort would have to take that int…
I suppose any attempt at terraforming has to create oceans if we want an Earth-like habitat (theoretically this could be achieved by re-directing enough comets at Venus or Mars provided we can utilise that kind of energy in the future). Could perhaps a form of sulphur-fixing bacteria be developed to colonise these oceans and remove it from the atmosphere as sediment?
As for the magnetic field, if the lack of convection in the core is a problem (perhaps due to the core completely solidifying) couldn't we just dump enough heat energy into it to restart the dynamo action? In the future it's not completely unrealistic to think antimatter production and storage will improve, that's certainly a way of releasing absurd amounts of energy.
Re: Saturn's largest moon may be the only place beyond Earth where humans could live
#83Let's colonize LEO. You get radiation protection from earth's magnetosphere. You get zero G for funsies. You get a new perspective on earth and interesting new kinds of manufacturing. It's not too far away, so you can get there and back in a day. It's far enough in space that you need to improve your closed cycle systems. You might survive a number of different cataclysms. It seems like a good stepping stone.
> 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…
So, the ISS orbit crosses the South American Magnetic Anomaly sometimes which does give them a bit of inner Van Allen belt radiation sometimes. But they're still completely protected from direct emissions of charged particles from Sun. They would get much, much more radiation if they were orbiting out by the Moon even before you start worrying about solar storms.
Re: Saturn's largest moon may be the only place beyond Earth where humans could live
#84Colonize the moon first: 1. plenty of solar power 2. close to earth 3. easy to launch out of its gravity well 4. lunar base technology can be iterated far more rapidly
So what about the radiation then?
Re: Saturn's largest moon may be the only place beyond Earth where humans could live
#85Earlier quoted context omitted.
Why not do both?
If there is one thing I’ve learned, from many posters on HN in many different topic, it’s that human civilisation is apparently incapable of achieving more than one goal at a time.
It’s more that we can’t achieve a single civilization goal, but are always wishing we could solve a cooler problem than the ones at hand.
Re: Saturn's largest moon may be the only place beyond Earth where humans could live
#86Earlier quoted context omitted.
I interpreted all of the things you listed as indications that statistics and scientific analysis have limitations and can't predict success or failure, not as indications that he would fail and die in the end. This is perhaps the main theme of the film: "There is no gene for the human spirit." You seem to have a thesis that the film is a tragedy and are working backwards from there. This goes against essentially eve…
> I interpreted all of the things you listed as indications that statistics and scientific analysis have limitations and can't predict success or failure, not as indications that he would fail and die in the end. I did so for the "heart beats". But every other point has nothing to do with statistics or scientific analysis. I really can't say definitively that he died on his way to titan, but the evidence is fairly ov…
Thank you both for this discussion, it was quite enjoyable to read!
Re: Saturn's largest moon may be the only place beyond Earth where humans could live
#87Earlier quoted context omitted.
I like how we're optimistic in terraforming and colonizing distant bodies with different gravity, pressure, atmosphere, temperatures, while equally panicking trying to control a few degrees of temperature on our home planet. But I think research on how to colonize other planets will help us in dealing with local climate change.
Stopping climate change isn't even hard, just place a large solar sail on a sun synchronous orbit to block part of the sun's energy from reaching Earth.
Now I'd like to know what you consider hard if launching a solar sail is not.
Re: Saturn's largest moon may be the only place beyond Earth where humans could live
#88Let’s colonize Mercury. It’s not actually hot at the poles - it’s shaded enough from the consistent low angle to the sun that there’s even water ice. And the planet is full of useful metals (more than earth), and as much solar energy as you can handle. The article dismisses Mercury out of hand as “too hot” but I think it’s our best bet. https://www.universetoday.com/130109/how-do-we-colonize-merc...
Getting stuff to mercury is hard though. IIRC it takes around 16,000 m/s of dV to get from LEO to the surface of mercury. Titan would take even more (19,000) but a huge chunk of it can be reduced by making use of aerobraking.
Going to mercury on rockets alone is a non-starter, because when you drop your perihelion low enough to rendezvous with it, your velocity near Mercury will be ridiculous, and there is not enough atmosphere at Mercury to shed the velocity so you have to do it the hard way.
However, there is a very efficient trajectory that could be used by solar sailing ships for a fast, cheap route to Mercury once every 16 months. You leave Earth for Venus, where you do a gravity assist to drop your perihelion significantly below the orbit of Mercury, just to get low enough that a reasonable solar sail can get reasonable thrust even with significant cargo. Then you can use your infinite delta-v to match your aphelion with Mercury, and can do an efficient capture trajectory.
Re: Saturn's largest moon may be the only place beyond Earth where humans could live
#89As a doctrine, colonization hasn't worked too well for humanity. It assumes an ethnocentric view where the colonizer has the right to take or use resources that they believe they "discovered". Just because there aren't any humans there, doesn't mean it doesn't already belong to someone. And just because we are able to take over a moon, doesn't mean we have the right to. Instead of colonizing, we should be talking abo…
Belong to who? All known solar space and beyond is literally devoid of any life at all. Are you assuming super aliens? Or perhaps a god of some kind, who pre-claims ownership? And if so, how did these beings get their "right" to have it?.
What exactly countermands our right to the take over the moon or any other part of local space? Name some concrete thing, not just an arbitrary notion of rights.
The obvious from these, to what purpose zero impact exploration of space? Sure, nothing should be destroyed just because... But you do realize that you're not talking about fragile ecosystems here, but vast dead landscapes that are the literal products of cataclysmic destructive processes that are in many places still ongoing?
Your comment is so absurdly out of context for the environments we're all discussing here that it's tempting to think you're trolling.
Re: Saturn's largest moon may be the only place beyond Earth where humans could live
#90Earlier quoted context omitted.
SpaceX's new Starship uses methane, which can be created from CO2 and energy. That's how they're going to refuel them on Mars; there is no reason they can't do that on Earth too. If it is made from atmospheric CO2 and clean energy it is carbon neutral.
Methane is a "greenhouse gas" itself, worse than co2. Mostly a problems from cattle digesting food. So burning it actually reduces climate change.
The methane is burnt and turned into CO2, it's not released.