No Ice on the Moon 113
eldavojohn writes "In 1994, there was speculation that there might be a southern ice cap on the moon — something our exploration of it could take advantage of. Unfortunately, recent evidence has come to light revealing that this probably isn't true." From the article: "If there is any ice at the South Pole, it probably comes from tiny, scattered grains that probably account for only one or two percent of the local dust, the authors suggest. "Any planning for future exploitation of hydrogen at the Moon's South Pole should be constrained by this low average abundance rather than by the expectation of localized deposits at higher concentrations," the paper says soberly. The research involved sending a radar signal from the Arecibo telescope in Puerto Rico. The signal hit the southern lunar region and the reflection was picked up by the Green Bank Telescope in West Virginia." Well, it looks like we're going to have to hit Hoth before we hold that kegger on the moon."
This is terrible (Score:1, Funny)
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Oh, no the cheese is there. There's just nothing to keep it cold now. Bet those astronauts are happy they have separate air supplies so they don't have to smell it when they're walking around.
This is not unexpected, and so... (Score:2)
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Green Bank Telescope (Score:5, Interesting)
I live in WV and have seen the Green Bank Telescope. Impressive radio telescope. Not as impressive as Arecibo though. I was expecting more like an array but it really is just one giant dish.
Better link than in the story:
http://www.gb.nrao.edu/ [nrao.edu]
B.
Re:Green Bank Telescope (Score:4, Insightful)
Not as impressive as Arecibo though. I was expecting more like an array but it really is just one giant dish.
It is *just* one big dish.. but it's also the world's largest full steerable telescope (aricebo isn't fully steerable). Also, it's one of very few off-axis paraboloid telescopes. (One of the nice things about this is the collection unit doesn't block any of the light that would be incident on the reflector.)
For impressive arrays, check out the VLA [nrao.edu], ALMA [nrao.edu] (soon), or SKA [skatelescope.org] (later). I was at the VLA last summer as part of my research (I do astronomy), it is very impressive. I was able to go into the dishes.. they're huge.
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They had a telescope almo
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They are impressive especially VLA. I was expecting something similar to that but saw this ginormous (I know it's not a word but still...) dish. All that I could think of besides "WOW!" was "I bet they get HBO real clear." (If you can't tell, I don't do too much astronomy). Isn't it kind of dangerou
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Isn't it kind of dangerous both to you and the dish to be inside it? I'd be too scared of doing it some damage but then again, I'm a klutz.
It is when it's being used.. but I was able to walk around on a dish that was offline (it was also pointing straight up). With radio waves, it's not as big an issue as with optical telescopes. The requirements for the accuracy of the surface are lower due to the longer wavelengths involved. There was a quarter sized hole in the dish I was walking around on, and that
I'm impressed! (Score:3, Interesting)
We bounce some radar off of the freaking
Steve
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mirror of an optical telescope blocks light. FWIW, I wrote the control software and firmware for an instrument on the current Green Bank telescope, and have been working with radio telescopes for 17 years, so I do know what I am talking about.
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Actually this is incorrect, the secondary reflector would have blocked the radio waves, just as the secondary mirror of an optical telescope blocks light.
I thought part of the point of the off axis design was so that the secondary mirror is not blocking the dish. An on-axis parabaloid would suffer from this, but I don't believe the Green Bank telescope does.
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My bad.. I missed the comment you were responding to. Your parent post didn't show up for me.
Geek Card Revoked! (Score:5, Informative)
pick up your dork card, too (Score:3, Insightful)
Smithsonian scientist Bruce Campbell?!? Lol (Score:2)
-Eric
Next week's news: Moon covered by ice (Score:2, Insightful)
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No, it's cheese!
That's just silly (Score:5, Interesting)
Back in the Apollo days, a Saturn V third stage was allowed to smash into the moon so seismographs could pick up the vibrations. This and other tests allowed scientists to get a basic idea of the moon's interior structure. A core or crust of ice would have been pretty obvious. If there was any ice, it would have to be just traces.
Our instruments are getting increasingly better. This is a case of a hypothesis based on observations by a crude instrument being disproved by follow-up investigations by more sophisticated gear.
I'm disappointed, but hey, the universe wasn't designed to things easy for us.
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** - By "colony", I mean at least mostly, i
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</sarcasm>
well let's be careful (Score:5, Informative)
(1) Clementine observed a particular wiggle in the radar reflection. At the time, it was thought the only reasonable way to get that wiggle was to have the radar reflect off ice. Huzzah! Ice! (Well, not really. It hasn't been directly observed -- no one's held it in their hand -- but it seemed no other explanation would account for the wiggle.)
(2) Now someone has come up with an alternative explanation for the wiggle, and demonstrated that you can get it from areas (sunlit areas) which really shouldn't have ice. Throws cold water, so to speak, on the idea that only ice can make the radar signature wiggle.
But does this mean no ice? Nope. Now we have two explanations for Clementine's observation: ice or some surface roughness thingy. Which is the right cause? Could be ice, could be merely rough rocks, could be both.
So it's not that ice on the Moon has been disproved. It's that a previous proof (or strong suggestion of) ice on the Moon has been shown to be in error. Doesn't mean the ice isn't there. Just means we no longer know (or think we know) whether it is or not. Have to go take a shovel and find out, I think.
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Hydrogen (Score:2, Insightful)
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As to the energy, well, if we locate at the poles, we are in good shape. If locate on the equator, we have energy only half the time.
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Actually, lunar rocks are unlike Earth rocks in that they contain far less hydrogen. You're right they they do have some. But such a tiny amount that gathering up the regolith would take significant time and energy - heating it to extract the gases is cheap by comparison.
Only 1%? (Score:3, Insightful)
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1% isn't as much as it seems. It's essentially nil. In the Shapotou Region of the Tengger Desert (Northern China), the measured water content of the sand is 1.23%. Bear in mind this is a place that gets rain.
In terms or transport costs you'd be best off shipping water from Mars. The delta-v to get from Mars surface to Lunar sur
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1% is a lot more than it sounds. Distilling it out of rock with a solar still is pretty straightforward- there's plenty of Sun on the moon for 2 weeks out of every 4, and it moves across the sky very slowly, so tracking it is easy.
You really need to compare this with some of the ores on Earth. 1% is a really, really high abundance; abundances are usually measured in parts per million.
Ain't no whales either (Score:4, Funny)
Solution. (Score:5, Funny)
By that I mean, I hate my wife.
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I would be quite happy to have my taxpayer $$ spent on sending Martha Stewart to the moon. But only if there is no return vehicle.
-Eric
ice pirates (Score:2)
Lucky for us! now we don't have to worry about the ice pirates. [imdb.com]
Hardly a surprise, is it? (Score:5, Informative)
Science fiction writers (the hard- variety) like Stephen Baxter have been lamenting the likelyhood of this eventuality for years now. Not that it isn't nice to at least have some closure, but on the other hand it seems like the news is little more than the last nail in the coffin for the most obvious pas-de-terre between Earth and space.
There is one book--Manifold Space, I think it might be--that muses upon the notion that there may be some water deeply buried (e.g. 20+ kilometres) the surface, and all the difficulties involved in getting to it (e.g. standard mining techniques developed on Earth wouldn't work there for a host of reasons). Excellent book/series, incidentally. Strongly recommended for any space science enthusiasts.
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Don't forget the upside (Score:2)
While true, I think you are being needlessly glum here.
For example, it is true that normal pumps would not work for removing rain water from a lunar ice-mine, because they rely on the pressure of the atmosphere. But having your lunar ice-mine fill with water is not nearly as big of a problem as you might think. All you need to do is change all the signage to read "Lunar Well" instead and you're done.
Likewise, a canary can not be used
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-Eric
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There is one book--Manifold Space, I think it might be--that muses upon the notion that there may be some water deeply buried (e.g. 20+ kilometres) the surface, and all the difficulties involved in getting to it (e.g. standard mining techniques developed on Earth wouldn't work there for a host of reasons). Excellent book/series, incidentally. Strongly recommended for any space science enthusiasts.
You're forcing me to read this book. But I should point out that 20 kilometers down isn't that far down with
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What about the deep, icy crater theory? (Score:4, Insightful)
The theory was (and I hope I have this right) that cometary ice must impact the moon from time to time - so there is water there from time to time - but whenever the sun shines, in the absence of an atmosphere, the water will evaporate (sublimate?) away quite quickly during the lunar day - then freeze out of the atmosphere during the night.
This mechanism would generally keep whatever water molecules there is up there moving around...*UNTIL* (by chance) it lands somewhere where there is never any sunlight - inside a cave or a deep crater. At that point it must settle - and there is no longer a mechanism to move it around again. With no atmosphere to scatter sunlight, permenantly dark places will be profoundly cold.
It follows then that whatever water there is will always end up in these relatively rare places EVENTUALLY - so given enough time, all of the moon's water would end up stashed away in just a few easy-to-predict places.
Furthermore, we'd never be able to see those places from earth-bound or low orbit telescopes because any place we can see must also collect sunlight at some point in the lunar orbit.
God has a bad day. (Score:1)
God: "You can stick it where the sun don't shine."
Obligatory Terry Pratchett (Score:2)
What that place over in Lancre?
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Vaporization is conversion to gas, regardless of original state (sublimation and evaporation are both types of, and the only types of, vaporization).
And my CAPTCHA is "inform".
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Wheres the missing cheese? (Score:3, Funny)
One or two percent? That's rich ore. (Score:5, Interesting)
Water is going to be more valuable than gold to someone on the Moon.
Water is way easy to extract.
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No, it's not--because, at present, there is no sound economic reason to go to the moon or stay there. And water is only valuable THERE. Barring a new space race, a desperate last effort by NASA to justify its budget, or a space tourism boom; it's unlikely that we will ever send men back to the moon even on a temporary basis, much less in long-term colonies
-Eric
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Thing is, the processing costs are WAY up on the moon.
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Ever see the sheer size and mass of the equipment for that?
Water is going to be more valuable than gold to someone on the Moon.
Not really. You'd be suprised at how well we can recycle water. Separation of greywater from blackwater combined with greywater reuse and reclamation (wetlands, plant growth, dish tanks) allow not only water re-use but reuse of the material we normally waste - nitrogen for example. It also dramatical
No ice? Deliver it. (Score:3, Interesting)
But, that doesn't mean that there can't be a whole lot of ice there someday. In the future, about the time when interplanetary travel becomes feasible and large quantities of water are needed, we will also have the technology to go out and capture water. One of the great motivations for interplanetary travel is mining asteroids for their abundant mineral wealth. Some consider capturing and towing an asteroid into Earth orbit for better availability. Why not capture and tow a water-rich comet, too? If there are grave concerns about it hitting the earth, just bring it very slowly towards the moon and orbit it there. It would be easily accessible there from the moon and from spacecraft, much higher in Earth's gravity well than LEO.
This is hardly a new idea - I think Arthur Clarke was a big proponent of it. I'm not advocating that we try it out in the next few years, either - I'm just saying that getting water to the moon, by the time we need lots of it, isn't that farfetched.
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Thomas Gold [wikipedia.org] used radar studies to show that the surface of the moon was made entirely of soft dust which an astronaut would sink right through. And he was right. The top millimetre of the moon (which is all the radar could see) really is like that.
A highly oblique illumination of the lunar south pole from 4000000km away can not prove that there is no ice
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As comets approach the sun, they develop a tail, caused by the solar wind. If you keep a comet "tethered" in orbit around the earth, it is going to be constantly eroded by the solar wind, and the earth will be bombarded by the crap falling off whenever we are "downwind" of it.
If it was in orbit around the moon, the same would happen, which may or may not be a useful way to get the comets conte
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This is good to know because... (Score:1)
No ice!? (Score:1)
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Carry your own ice to chill yur beer if u r 'Man on the Moon'
sitcom laugh track----^
Doesn't prove much (Score:2)
So all this proves is that the Clementine experiment may not have detected ice after all. There is nothing in this experiment which would have directly measured ice if it had been present.
mandatory joke (Score:1)
Grammar Nazi Hell (Score:2)
Jesus Tap-Dancing Christ.
Obligatory Jack O'Neill (Score:2)
And the movie ? (Score:2)
That was mars (Score:2)
That's OK because... (Score:1)
Didn't they go to the moon a few times? (Score:2)
Leave the Moon alone (Score:1)
I hope we don't infect the rest of the solar system until we're more responsible. This could mean just being good stewards of "our" own planet before we hope to know what to do with others.
Not a Luddite; robotic expl
NOTICE: No impact on space elevator! (Score:3, Funny)
Misleading article title! (Score:3, Insightful)
1) Lunar Prospector found elevated hydrogen near the poles using a neutron spectrometer
2) Clementine bi-static radar (and later ground-based measurements) found backscatter effects that looked like ice
Most planetary geologists weighted (1) more heavily. There was always a lot of argument about interpretation of (2).
Now this study comes along and fairly definitively throws out (2) by showing the data has another explanation. Fine. From (1) we still have solid evidence of hydrogen near the poles, and most geologists would agree that the likeliest explanation of that hydrogen is water ice deposits in permanently dark crater interiors (the only places cold enough for ice to be stable in a vacuum).
So the main impact of this study is to suggest (but not prove) that ice, if present, is not found in clumps of centimeter scale or larger. And the 1% concentration figure they cite is a *lower* bound, not an upper bound. That is, ice could be more concentrated than 1% in some regions below neutron spectrometer resolution (e.g. kilometer scale) and we would have no way to know.
Dangit! (Score:1)
No ice (Score:1)
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It happens sometimes when you click the link too soon after it shows up on the main page.
Sarcasm because 50-60% of the discussions have quite a few jokes about that message...
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