Scientists discover evidence for a habitable region on Saturn’s moon Enceladus(phys.org)
phys.org
Scientists discover evidence for a habitable region on Saturn’s moon Enceladus
https://phys.org/news/2017-04-scientists-evidence-habitable-region-saturn.html
76 comments
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 quadrillion gallons of ocean, or something.
Because the numbers just don't work for chemical rockets. The already-harsh rocket equations get even worse when you have to carry along the mass to feed, water, and breath, too.
Because the numbers just don't work for chemical rockets. The already-harsh rocket equations get even worse when you have to carry along the mass to feed, water, and breath, too.
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/
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/
This stuff has been studied for a long time and is still being studied - https://www.nasa.gov/topics/technology/features/ntrees.html
So I don't know what you are raving about.
So I don't know what you are raving about.
He's talking about public perception, not about NASA research.
Public perception has nothing to do with it. The Russians and Chinese don't care about public perception. Why aren't all their rockets using nuclear propulsion?
This is very expensive research. Nuclear propulsion is definitely going to be utilized it just isn't a budget priority right now.
I think that what you're describing is some sort of variant of the "Won't somebody please think of the children" rhetorical tool (or the fallacy "Appeal to Emotion"). I don't know what to do about it, but I can recognize it.
>...The fear of that happening
Yes, anything involving radiation causes fear. The reality is that the atomic bomb tests deposited tons of plutonium in the atmosphere and no one has detected any health consequences from that. I am not sure why someone would say a few dozen more pounds of plutonium would matter.
Yes, anything involving radiation causes fear. The reality is that the atomic bomb tests deposited tons of plutonium in the atmosphere and no one has detected any health consequences from that. I am not sure why someone would say a few dozen more pounds of plutonium would matter.
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.
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.
The Soviets kinda spoiled it for everyone when they smeared one of their reactors all over Northwest Canada.
Yeah, a Hohmann transfer to Saturn would take a very long time. The trip is long enough, though, that it would make a lot of sense to spend months accelerating under an electric drive in order to achieve a faster transfer. But it is 10 km/s even for Hohmann burn and once you get there you need to shed 4 km/s. In theory you could aerocapture but that isn't something we have the technology for right now. Well, we know how to aerocapture straight into a descent so you could go that route if you're headed to Titan but not anywhere else around Saturn.
Okay, so it's simple: first we build a base on Titan as the transportation hub for the Saturn system, and transfer there to get to Enceladus [autocorrect wants to change this to Enchiladas].
Wouldn't it make sense to have a methane mining base on Titan anyway?
Wouldn't it make sense to have a methane mining base on Titan anyway?
Refueling on Titan might make a lot of sense. Getting methane is pretty much just a matter of piping it or freezing it out of the atmosphere. Getting oxygen from the CO2 in the atmosphere would be an industrial process and require considerable energy but it beats having to carry the oxygen with you.
Apollo missions took about three days to reach the moon. But the quickest trip to the moon was the New Horizons probe, which zipped past the moon in just 8 hours 35 minutes on its way to Pluto. However, the spacecraft didn't even slow down or approach lunar orbit.
The article isn't talking about human habitation. It says that we collected evidence that may suggest that there are hydrothermal vents below the surface which may be able to support microbial life like Earth's hydrothermal vents.
Where does the article say anything about it being habitable for humans? The article is about the possibility of finding alien life.
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.
There _are_ tidal forces. It's just that they alone don't explain the amount of heat measured by Cassini.
https://en.wikipedia.org/wiki/Enceladus#Tidal_heating
https://en.wikipedia.org/wiki/Enceladus#Tidal_heating
It appears to be tidal: http://www.blastr.com/2017-5-8/no-we-havent-found-signs-life...
(link to bad astronomy, a reasonably good explainer type source)
(link to bad astronomy, a reasonably good explainer type source)
How long has it been tidally locked? Maybe the core is still hot. Or maybe other moons pass close enough to exert enough tidal forces to keep it warm.
Similar to the Earth, it would be a combination of heat from radioactive decay and the original heat of accretion slowly radiating away.
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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 perfectly doable. You can take some solar panels with you, over provision for damage, and build-out capacity over time. Saturn is too far for solar to be of any use. The only power source there is probably geothermal, unfortunately there's no lightweight way to convert geothermal energy into electricity. At least there isn't any that I'm aware of. This is quite a problem, as without electricity most modern conveniences cannot be bought. In fact, modern human life might be very difficult without electricity on a place that is not earth.
The article has nothing to do with human habitability. The potential is that there could be microbes found on a planet other than Earth for the first time.
From the article:
"The amount of molecular hydrogen we detected is high enough to support microbes similar to those that live near hydrothermal vents on Earth," said SwRI's Dr. Christopher Glein, a co-author on the paper and a pioneer of extraterrestrial chemical oceanography.
From the article:
"The amount of molecular hydrogen we detected is high enough to support microbes similar to those that live near hydrothermal vents on Earth," said SwRI's Dr. Christopher Glein, a co-author on the paper and a pioneer of extraterrestrial chemical oceanography.
The link was switched to phys.org. Previous source was scientifically illiterate.
Nuclear reactors still work fine for producing electricity.
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 we can put fission reactors in spaces small enough to run submarines, so that is almost certainly feasible.)
(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 we can put fission reactors in spaces small enough to run submarines, so that is almost certainly feasible.)
While not reactors technically, many of our long-range spacecraft use RTGs: https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_ge...
> 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.
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'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 complexity of a reactor.
[1]https://en.wikipedia.org/wiki/Safe_Affordable_Fission_Engine
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 complexity of a reactor.
[1]https://en.wikipedia.org/wiki/Safe_Affordable_Fission_Engine
> It's nuclear weapons that nobody wants in space
I should have been more specific - isn't the fear that nuclear power generation in space could be utilized as part of a weapons program.
I should have been more specific - isn't the fear that nuclear power generation in space could be utilized as part of a weapons program.
Developing the infrastructure to take moderately enriched Uranium and enrich it to something weapons grade is likely to be outside the industrial scope of any space facility for quite a while. When we've got 10,000,000 people living on the Moon we can use the same enforcement regime as we do with small countries on Earth. Until then it's not worth worrying about.
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.
I don't think you would. They're a lot more potentially dangerous up there.
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.
Just doing some mental back-of-the-envelope stuff, I believe that submarine reactors have more mass than the entirety of the ISS.
Notice I said both "talk about it", and "build a nuclear reactor in space". You get huge wins from any mass you can find in space, and I would imagine a good chunk of a reactor could come from space.
First we really need to capture a good asteroid, though. And have the infrastructure to turn that into useful reactor building material.
My point is not that this will happen tomorrow. My point is that this seems to me to be fundamental to any real exploration or settlement of the solar system and that anyone who is planning on settling Mars or goodness help us, Saturn or Jupiter via chemical rockets is just crazy. Sort of like how we used to do math problems on when it was worth it for some computation to just wait for next year's exponentially-better processors and start it then, anyone running with that plan is going to be beaten by the initially-slower, but way stronger plans that involve building some infrastructure in space first, rather than trying to jump straight for the flashy awesome stuff.
... of course, that also means admitting there's basically no chance that any sort of space settlement can occur in our lifetimes almost no matter what the tech advances might be, because before we can settle there's a lot of building infrastructure that lets us build infrastructure that lets us build better infrastructure to do. And somehow figure out ways to keep this all paying for itself as it goes.
First we really need to capture a good asteroid, though. And have the infrastructure to turn that into useful reactor building material.
My point is not that this will happen tomorrow. My point is that this seems to me to be fundamental to any real exploration or settlement of the solar system and that anyone who is planning on settling Mars or goodness help us, Saturn or Jupiter via chemical rockets is just crazy. Sort of like how we used to do math problems on when it was worth it for some computation to just wait for next year's exponentially-better processors and start it then, anyone running with that plan is going to be beaten by the initially-slower, but way stronger plans that involve building some infrastructure in space first, rather than trying to jump straight for the flashy awesome stuff.
... of course, that also means admitting there's basically no chance that any sort of space settlement can occur in our lifetimes almost no matter what the tech advances might be, because before we can settle there's a lot of building infrastructure that lets us build infrastructure that lets us build better infrastructure to do. And somehow figure out ways to keep this all paying for itself as it goes.
Ah, I misunderstood. Well, for what it's worth, I recommend the book Seveneves by Neal Stephenson, if fiction will make you happier in this respect :)
One possibility for a useful energy source, in a dirty crowded moon system, would be chemical reactors. Rhea has a thin, oxygen-rich atmosphere, and if you have oxygen, you can burn almost anything. Titan's methane seems like an obvious choice of fuel.
It would be really interesting to compare the economics of shipping large volumes of fuel around moon system, to shipping them around a relatively tiny ocean.
It would be really interesting to compare the economics of shipping large volumes of fuel around moon system, to shipping them around a relatively tiny ocean.
What about using wind to generate electricity? How are the winds on Enceladus?
I couldn't read this on iOS as I kept being forcibly thrown into the App Store by some advert. If anyone else is having trouble, you can read the article here: https://archive.is/tPvTT
Purify is an excellent ad blocker for Safari on iOS. I recommend it without reservation.
Sounds like a bug in iOS...
"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.
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.
Just a thought for everyone discussing human settlement - habitable doesn't necessarily imply humans should go there, robots growing stuff far far away would be great as well. I'd say having farming planets (or in this case moons) is worth a sci-fi book at least.
This is quite old news, not sure what it's doing here now, and with a clickbait title too.
Right, about as "habitable" as areas around mid-ocean ridges. Quite the temperature gradient there.
Probably similar are Europa and Triton.
Probably similar are Europa and Triton.
Nothing definite in here, just theories needs more research. Just a shinny news title
Nothing new at all the same thing was said almost word to word about Titan 20 years ago.
This article seems written to sound as spectacular as possible while hiding anything that might lead to real understanding.
"Habitable" makes it sound like we could move there and live there without too much trouble. That's not true. What has been discovered is that microorganisms might be able to live there, near hydrothermic vents that seem to create free hydrogen, which could support primitive life. That life could be similar to life living around hydrothermic vents on the bottom of the Atlantic Ocean. No sign of life itself, though, just a process that could theoretically sustain life without requiring sunlight.
"Habitable" makes it sound like we could move there and live there without too much trouble. That's not true. What has been discovered is that microorganisms might be able to live there, near hydrothermic vents that seem to create free hydrogen, which could support primitive life. That life could be similar to life living around hydrothermic vents on the bottom of the Atlantic Ocean. No sign of life itself, though, just a process that could theoretically sustain life without requiring sunlight.
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Better link : https://phys.org/news/2017-04-scientists-evidence-habitable-...
By the way, it's already a month old, there's nothing new since Cassini's last trip.
Also, can't believe Newsweek did a mistake like that if not for clicks...
"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."
By the way, it's already a month old, there's nothing new since Cassini's last trip.
Also, can't believe Newsweek did a mistake like that if not for clicks...
"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."
Yeah well you cant trust nothIng out of newsweek anyway. Its been as reliable as reading the Daily Mail for most of it.
HN needs to adopt a [clickbait] tag to flag articles like this with misleading titles.
Even better, HN should hide the real title until hover to reduce the number of clicks clickbait articles get.
Even better, ban newsweek which is nothing but a tabloid these days.
If you're going to ban anything that's basically a tabloid these days, doesn't that mean there won't be any news sites left?
I don't really like the NYT that much, but I don't think you can classify it as being a tabloid. At least it's usually well researched and substantiated for a good amount of articles.
Reuters is still pretty good.
Saturn is YEARS away. Like 4-7 depending on where the planets are at.