IIRC, the '2 meters of solid ice' idea was the default upper limit on the CPR readings by Chandrayaan-1 Mini-SAR,
We interpret this relation as consistent with water ice present in these craters. The ice must be relatively pure and at least a couple of meters thick to give this signature.
The basic idea is that the Russian LEND instrument does not have as prophylactic a collimation as was intended...
Quote from: Hernalt on 02/03/2014 05:48 pmThe basic idea is that the Russian LEND instrument does not have as prophylactic a collimation as was intended...Prophylactic collimation? I'll have you know that this is a family site!
The thing is nobody has yet extracted water from an actual meteorite.
On the other hand, the Moon probably has Hg at the ppt level. Dealing with that isn't going to be easy, considering that the EPA's drinking water standards are 2 μg/L (i.e., 2 ppb)...
Lunar Polar Regolith: Plans to Study in situ and Perspectives of Samples Return (Mitrofanov, 2013)http://meetingorganizer.copernicus.org/EPSC2013/EPSC2013-475.pdfShort letter on Russian lunar missions, including cryogenic sample return.
Quote from: Warren Platts on 02/03/2014 05:57 pmThe thing is nobody has yet extracted water from an actual meteorite.Really? Even a meteorite on Earth? If not why not? Sounds like something Planetary Resources could be working on, far cheaper than any in-space activity - meteorites are not that rare/expensive.
QuoteOn the other hand, the Moon probably has Hg at the ppt level. Dealing with that isn't going to be easy, considering that the EPA's drinking water standards are 2 μg/L (i.e., 2 ppb)...(I assume ppt is parts per thousand, not per trillion?)
Could it be removed by distillation? Mercury boiling point is way different from water...
There are only like 4 known sizeable chunks of CI type meteorites--their first choice. Probably too rare for destructive testing. However, last I heard they have given up on CI asteroids because they are too rare. So second choice is CM meteorites. Problem is the mix of chemicals is such that upon heating, all sorts of compounds are formed except water. There was a thread a while back where a guy who seemed to know what he was talking about pointed this fact out.
ppt = parts per thousand
Paragon has been doing some work on how to filter asteroid water--once you get it.
Quote from: Warren Platts on 02/07/2014 08:37 pmThere are only like 4 known sizeable chunks of CI type meteorites--their first choice. Probably too rare for destructive testing. However, last I heard they have given up on CI asteroids because they are too rare. So second choice is CM meteorites. Problem is the mix of chemicals is such that upon heating, all sorts of compounds are formed except water. There was a thread a while back where a guy who seemed to know what he was talking about pointed this fact out.Still, if I was running an asteroid mining company I'd want to try it with all different kinds of meteorites I could before I got too far along.
Quoteppt = parts per thousandIt is ambiguous; ppt = part per trillion is also used, and it's what I immediately read it as when you used it. Different fields though, I think - for salinity of water ppt = part per thousand is normal.
Actually, in mining, ppt often means parts per ton but oz. per ton or g per ton is more directly relatable to $.
Quote from: aero on 02/09/2014 10:05 pmActually, in mining, ppt often means parts per ton but oz. per ton or g per ton is more directly relatable to $. "Parts per ton"? I don't understand. What are the parts?
Quote from: Warren Platts on 02/11/2014 11:01 amQuote from: aero on 02/09/2014 10:05 pmActually, in mining, ppt often means parts per ton but oz. per ton or g per ton is more directly relatable to $. "Parts per ton"? I don't understand. What are the parts?Truth is, I've used parts per ton in my prospectors club to describe concentrates from placer mining. Concentrates are what is captured by the sluice. Its mostly black (iron) sand with some gold flakes, maybe a small nugget if you're lucky. The parts refer to the gold and convert to grams (changing to metric) at 1 mg/tonne.
Placer mining is probably not something that will be done on the Moon. It needs water.
An upper limit for ice in Shackleton crater as revealed by LRO Mini-RF orbital radar (Thomson, 2012)GEOPHYSICAL RESEARCH LETTERS, VOL. 39http://adsabs.harvard.edu/abs/2012GeoRL..3914201T (paywall)
Quote from: Hernalt on 02/11/2014 08:20 pmAn upper limit for ice in Shackleton crater as revealed by LRO Mini-RF orbital radar (Thomson, 2012)GEOPHYSICAL RESEARCH LETTERS, VOL. 39http://adsabs.harvard.edu/abs/2012GeoRL..3914201T (paywall)Found a free version. 5-10% is consistent with LCROSS, and these results wouldn't apply to the northern anomalous craters like Whipple and Rozhdestvensky N.