Water on the Moon, Data from multiple missions seems to indicate... |
Water on the Moon, Data from multiple missions seems to indicate... |
Sep 26 2009, 01:00 AM
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#46
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Junior Member Group: Members Posts: 87 Joined: 17-May 08 Member No.: 4114 |
Will LRO be able to confirm the announcement? It was suggested in the press conference that LROs LAMP may shed light (ahem) on the subject. If there's enough water, it seems like LEND may do so as well. Remember that one of the surprises of the early LEND data was finding hydrogen outside of the permanently shadowed craters. I suspect there is also a rush to re-analyze more existing data. How many other spacecraft have taken calibration data from the moon ? Did Galileo ? Rosetta (which has another earth gravity assist coming up in November) ? It looks like KAGUYAs SP cuts out just short of the spectral feature that M3 detected, but maybe there's something else if you know what you are looking for. What about the Chang'e imaging spectrometer ? I'm sure there's a bunch of people digging through old Apollo papers now too, and thinking about new things to do with those samples. The hype associating this with water as a resource may be overblown, but definitely cool science. |
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Sep 26 2009, 09:35 AM
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#47
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Senior Member Group: Members Posts: 3516 Joined: 4-November 05 From: North Wales Member No.: 542 |
Would seem that on many airless worlds something similar must happen if the solar wind is the hydrogen source. That is the subject of a nice article by Jason Perry at Gish Bar Times: http://gishbar.blogspot.com/2009/09/water-on-dry-worlds.html |
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Sep 26 2009, 12:57 PM
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#48
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Senior Member Group: Moderator Posts: 2785 Joined: 10-November 06 From: Pasadena, CA Member No.: 1345 |
I wonder if MS analysis could help show where the water comes from?
If water is undergoing a diurnal cycle of desorption-vapor-redeposition then that process should favor the heavier H2(18O). Since the lighter molecule would have a better chance of escaping, so the 18O/16O ratio would be larger. If water is continually being destroyed by sunlight and reformed from solar hydrogen combining with oxygen species from lunar rock, and assuming lunar rock doesn't have any isotopic oxygen enrichment, then you'd expect a very light isotopic mixture (H2(16O)) with a 18O/16O ratio similar to that found in lunar rock. -------------------- Some higher resolution images available at my photostream: http://www.flickr.com/photos/31678681@N07/
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Sep 26 2009, 01:01 PM
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#49
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Member Group: Members Posts: 646 Joined: 23-December 05 From: Forest of Dean Member No.: 617 |
The solar wind aetiology is certainly interesting, but practical just doesn't come into it.
Apart from the basic arithmetic about theoretical water yield per square meter and energy required to extract it Doug provided, what would such a vehicle look like? Here's an approximate terrestrial analogue, running at a few km/h, taking the top inch or two of a surface and dumping it harvester-style into a following tender (note: no further processing happens at this stage.) These things mass in the order of 20-30 tons, and of course need regular teardown maintenance and rebuild (neglecting the tender and other supporting infrastructure.) What would a soft-landing of a self-repairing, self-powered, autonomous version of such a machine on the moon look like, as a back-of-a-fag-packet concept? Mars, on the other hand,.. is another thread -------------------- --
Viva software libre! |
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Sep 26 2009, 01:12 PM
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#50
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Rover Driver Group: Members Posts: 1015 Joined: 4-March 04 Member No.: 47 |
A question (can't access the articles right now, so not sure if it's in there): I can understand that these results only say something about the top few millimeter, but where does the statement come from that the OH/water is only there and not also deeper? Does that come from the way it disappears with higher temperature? Although if this is really produced by solar wind I can understand this would be the case, but do we really know?
edit - also, is it significant that the water in the VIMS image and M3 image is mostly confined to the bright regions (e.g. not in a mare) or is it just that the dark regions don't reflect enough light to be able to tell? |
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Sep 26 2009, 02:04 PM
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#51
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Administrator Group: Admin Posts: 5172 Joined: 4-August 05 From: Pasadena, CA, USA, Earth Member No.: 454 |
I think people got confused about that -- the depth comes from the infrared spectrometers' ability to see only the top couple mm. THey were talking about that to contrast it with lunar prospector, which can see deeper. Now, you might argue that if LP didn't see H where the spectrometers do see it, that might be evidence that it's only in top couple of mm, but if the abundance was low enough, LP might not see it.
M3 only saw the water near the poles. Happens to be in highlands near the poles. Problem is that M3 only goes out to 3 microns, and has trouble detecting the signature where there's also thermal emission, equatorward of 60 degrees or so. VIMS does have holes over the maria, and this was a question I asked Roger Clark...who has never replied to any email I've ever sent to him. Oh well. --Emily -------------------- My website - My Patreon - @elakdawalla on Twitter - Please support unmannedspaceflight.com by donating here.
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Sep 26 2009, 03:24 PM
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#52
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Member Group: Members Posts: 233 Joined: 21-April 05 Member No.: 328 |
. . . "lunar weather" . . . "toilets" . . . "dry sterile thunder" . . . "water on the moon" . . ."electric fingers of light" . . . Snatches of conversation from a widely respected space science forum now gone lunatic! |
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Guest_Zvezdichko_* |
Sep 26 2009, 03:29 PM
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#53
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Guests |
... I wonder what the name of this forum is.
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Sep 26 2009, 04:55 PM
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#54
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Senior Member Group: Members Posts: 2173 Joined: 28-December 04 From: Florida, USA Member No.: 132 |
...the depth comes from the infrared spectrometers' ability to see only the top couple mm.... I wonder if the assumption that the water is limited to the top few mm is the result of an assumption that the water is created by the solar wind. That would limit its presence to the surface. |
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Sep 26 2009, 05:03 PM
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#55
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Senior Member Group: Moderator Posts: 2785 Joined: 10-November 06 From: Pasadena, CA Member No.: 1345 |
-------------------- Some higher resolution images available at my photostream: http://www.flickr.com/photos/31678681@N07/
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Sep 26 2009, 08:23 PM
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#56
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Member Group: Members Posts: 233 Joined: 21-April 05 Member No.: 328 |
Juramike, thanks for making the connection! You have made my weekend as well!!!!
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Sep 26 2009, 09:25 PM
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#57
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Member Group: Members Posts: 258 Joined: 22-December 06 Member No.: 1503 |
The solar wind idea is an interesting one. It might play a role of some kind. I can't help but think the processes involved are probably far more complicated than that. Here is a report from 2008 that suggests evidence for a water source beneath the surface.
http://www.newscientist.com/article/mg19926644.200 I never thought we would see a 'follow the water' strategy for exploration of our moon! Maybe a water cycle on our nearest neighbor... It does sound a little lunatic. ha ha ha! |
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Sep 26 2009, 09:59 PM
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#58
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Member Group: Members Posts: 293 Joined: 22-September 08 From: Spain Member No.: 4350 |
As a curiousity, would water ice survive a lunar day inside the descent stage of the Apollo Lunar Module?
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Sep 26 2009, 11:48 PM
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#59
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Merciless Robot Group: Admin Posts: 8785 Joined: 8-December 05 From: Los Angeles Member No.: 602 |
Not to be a wet blanket about the whole lunar water thing, but I still think that this discovery will ultimately prove to be solely of mineralogical/scientific interest rather than a practical future resource.
If there were endogenous water deposits at anything like an accessible depth anywhere on the Moon you'd think that aeons of slow outgassing would have built a pair of substantial polar caps in the permanently shadowed regions, even though most of the H2O would have been photodissociated upon release (most of which probably would have happened in the daytime). These caps would have been 'gardened' by macro/micrometeorite impacts, sure, but there would still be quite a bit of water at or near the surface. Evidence to date indicates that, at best, there is a very sparse amount of ice in the polar regions throroughly mixed with the regolith. So...I wouldn't be investing in any lunar well-digging companies just yet. -------------------- A few will take this knowledge and use this power of a dream realized as a force for change, an impetus for further discovery to make less ancient dreams real.
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Sep 27 2009, 04:31 AM
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#60
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Senior Member Group: Members Posts: 1018 Joined: 29-November 05 From: Seattle, WA, USA Member No.: 590 |
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