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Scientists discover evidence for a habitable region on Saturn’s moon Enceladus

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Re: Scientists discover evidence for a habitable region on Saturn’s moon Enceladus

#51

Post by Pica_soO »

Cthulhu_ wrote: post #27
Numberwang wrote: post #7

"Update: An earlier headline read that signs of life were found on Enceladus. We regret any misunderstanding this headline may have caused. NASA has discovered that Enceladus is habitable, not inhabited. " Wow. Maybe basic transport is not the first area where intelligent machines will make their human counterpart superfluous. I'm sure machines can do better than this.

Nope, machines would optimize for number of views / clicks, not for correctness.

Im sure, if we had better telescopes, we could see a tentacle-frozzen alien Galileo drifting in the gas fountain, who until his last moment exclaimed "the sky beyond the sky is not solid".

Re: Scientists discover evidence for a habitable region on Saturn’s moon Enceladus

#52

Post by DanHulton »

WalterBright wrote: post #48
Symmetry wrote: post #47

Earlier quoted context omitted.

It's nuclear weapons that nobody wants in space, not nuclear reactors. Almost every outer solar system probe has had a nuclear power source that relied on decay and the Russians even put reactors on one series of satellites IIRC. And people are working on building reactors. NASA has plans for one[1] in the 100kWe range. But mostly spacecraft have had low power needs and so people haven't wanted to deal with the compl…

I'd rather have nuclear weapons in space than on earth.

I don't think you would. They're a lot more potentially dangerous up there.

Re: Scientists discover evidence for a habitable region on Saturn’s moon Enceladus

#53

Post by pmoriarty »

dmitrygr wrote: post #30

A lot of articles like this overlook a lot of physics that actually matter a lot. Not only would it be incredibly difficult to get humans up there, much more so than Mars, but even once we get there we have serious problems. Just like Mars, we can solve many problems with electricity. We can create water and many chemicals, provide shelter and even ways to grow food. On Mars you can get electricity vs solar, which is…

What about using wind to generate electricity? How are the winds on Enceladus?

Re: Scientists discover evidence for a habitable region on Saturn’s moon Enceladus

#54

Post by kingkawn »

jerf wrote: post #36
bluedino wrote: post #29

Even if it was habitable, isn't most of the problem with going to Mars the fact that it takes a half of a year to get there - not a couple days like the moon? Saturn is YEARS away. Like 4-7 depending on where the planets are at.

I figure that until we build one of the various nuclear-powered boost options that have been proposed, we're not going very far in the solar system. Either we get over our fear of launching OMGNuclear!!!1! stuff, or perhaps we can loft a booster and figure out a way of launching the fuel in enough smaller launches that nobody freaks out at the idea of a few dozen pounds of uranium being dropped into several quadrilli…

You know how sometimes you've got the best possible people, really brilliant, and all the resources, and still things go wrong? Rockets blow up for example. The fear of that happening which you see fit to mock, is justified, and no amount of self-righteous dismissiveness is going to help bridge that difference.

Re: Scientists discover evidence for a habitable region on Saturn’s moon Enceladus

#55

Post by pmoriarty »

jerf wrote: post #36
bluedino wrote: post #29

Even if it was habitable, isn't most of the problem with going to Mars the fact that it takes a half of a year to get there - not a couple days like the moon? Saturn is YEARS away. Like 4-7 depending on where the planets are at.

I figure that until we build one of the various nuclear-powered boost options that have been proposed, we're not going very far in the solar system. Either we get over our fear of launching OMGNuclear!!!1! stuff, or perhaps we can loft a booster and figure out a way of launching the fuel in enough smaller launches that nobody freaks out at the idea of a few dozen pounds of uranium being dropped into several quadrilli…

If North Korea survives another 10 or 20 years, I could see them shooting nukes up in to space.

A lot of ethically questionable scientific research might potentially be performed by so-called "rogue states" that don't feel bound by international norms.

We're seeing something like that in regards to copyright and patents, where some countries that don't respect intellectual property have no problems violating copyright and patents of countries that do.

Similarly, cloning research and human-embryo research that might be banned in some countries is being performed by others. Launching nukes it to space is another opportunity to advance for countries that have no ethical problems with that.

Re: Scientists discover evidence for a habitable region on Saturn’s moon Enceladus

#56

Post by njarboe »

Animats wrote: post #6

So there's this big hydrogen vent in a moon of Saturn. Where's the energy coming from to drive that? Too far from the sun. Enceladus is tidally locked to Saturn, so there are no tidal forces. Enceladus has very low orbital eccentricity, a near-circular orbit, so there are very low tidal forces from that. Some phenomenon must provide energy for the hydrogen jet.

Similar to the Earth, it would be a combination of heat from radioactive decay and the original heat of accretion slowly radiating away.

Re: Scientists discover evidence for a habitable region on Saturn’s moon Enceladus

#57

Post by ZenoArrow »

bluedino wrote: post #29

Even if it was habitable, isn't most of the problem with going to Mars the fact that it takes a half of a year to get there - not a couple days like the moon? Saturn is YEARS away. Like 4-7 depending on where the planets are at.

Where does the article say anything about it being habitable for humans? The article is about the possibility of finding alien life.

Re: Scientists discover evidence for a habitable region on Saturn’s moon Enceladus

#58

Post by njarboe »

knz wrote: post #43
jerf wrote: post #38

Earlier quoted context omitted.

I'm really sort of surprised that nobody is seriously discussing how to build a nuclear reactor in space yet. I just don't see how space civilization can get going without nuclear power. Fusion would be way cooler, but fission should do. (Fusion would require not just that some small-city-sized installation works on Earth but that something small enough to usefully fit in other structures can generate power. We know…

> I'm really sort of surprised that nobody is seriously discussing how to build a nuclear reactor in space yet. Isn't the fear that this would start another nuclear arms race? I'm not sure if the threat is that much worse (considering how effective the nuclear triad is) but any perceived advantage would have consequences that increase the threat of nuclear war.

It seems like for nuclear power to be accepted it needs to change its name like every other product using radiation or the word nuclear. One of my favorites is how Nuclear Magnetic Resonance Imaging dropped the the Nuclear. Many people now use radioisotopic instead of radioactive when they want to avoid the negative feelings around the word radioactive. Maybe isotopic power? Use it for both fission and fusion.

Re: Scientists discover evidence for a habitable region on Saturn’s moon Enceladus

#59

Post by Symmetry »

WalterBright wrote: post #48
Symmetry wrote: post #47

Earlier quoted context omitted.

It's nuclear weapons that nobody wants in space, not nuclear reactors. Almost every outer solar system probe has had a nuclear power source that relied on decay and the Russians even put reactors on one series of satellites IIRC. And people are working on building reactors. NASA has plans for one[1] in the 100kWe range. But mostly spacecraft have had low power needs and so people haven't wanted to deal with the compl…

I'd rather have nuclear weapons in space than on earth.

Nuclear weapons in space can be dropped on Earth with very little warning. An ICBM has an obvious launch flare but nuclear weapon equipped satellites might be able to deploy their nukes with almost no warning.

Re: Scientists discover evidence for a habitable region on Saturn’s moon Enceladus

#60

Post by jerf »

kingkawn wrote: post #54
jerf wrote: post #36

Earlier quoted context omitted.

I figure that until we build one of the various nuclear-powered boost options that have been proposed, we're not going very far in the solar system. Either we get over our fear of launching OMGNuclear!!!1! stuff, or perhaps we can loft a booster and figure out a way of launching the fuel in enough smaller launches that nobody freaks out at the idea of a few dozen pounds of uranium being dropped into several quadrilli…

You know how sometimes you've got the best possible people, really brilliant, and all the resources, and still things go wrong? Rockets blow up for example. The fear of that happening which you see fit to mock, is justified, and no amount of self-righteous dismissiveness is going to help bridge that difference.

The thing is, even if a rocket blows up and a few dozen pounds of uranium get strewn about, it isn't anywhere near the disaster people think it is. Until we can rationally compute dangers instead of simply assigning infinities to the dangers, we're not going to get anywhere.

There is ~4.5 billion tons of uranium already in sea water [1].

If that fact surprises you, you may just have not known it. If that fact scares you or makes you want to deny it, you're probably still stuck in the irrational fear I'm talking about. The world is not a pristine place with no radioactivity in it until Man comes along and somehow, like, manufactures it from nothing but his sheer Evil for the nefarious purpose of destroying the environment, mu-hu-ha-ha-ha. It's a thing that's already out there. It's not that terrifying if we take basic precautions that, it turns out, we already take because you know what's way scarier than a few dozen pounds of uranium falling near you? A flaming exploding rocket falling on you. So we already don't launch over cities and such.

And we really won't progress as long as people can not only act irrationally about the real dangers, but think they're being more moral by being irrational about the dangers than people actually using their brains and that it's vital to yell at the people using their brains and attempt to socially pressure them into just going with the herd and assigning infinite danger to the scariness of OMGRadiation!!!1!.

[1]: http://large.stanford.edu/courses/2012/ph241/ferguson2/

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