http://www.nasa.gov/home/hqnews/2009/nov/H...S_briefing.html

NASA TV Schedule

November 13, Friday
10 a.m. - Countdown Status Briefing - KSC (Public and Media Channels)
11 a.m. - ISS Expedition 21 Commentary - JSC (Public and Media Channels)
12 p.m. - LCROSS Science News Briefing – AMES (Public and Media Channels)

12 PM Eastern U.S. time = 17:00 GMT/UTC

News conference is ready to start right now.

Edit: Water!

NIR pic of the crater - nice!

Phil

Infrared detection of water vapor and ice, ultraviolet detection of hydroxyl (OH). Lower limit of about 100 kg of water was detected. "Twelve buckets full". "Other stuff" found, too. No word yet on what.

Edit 38 minutes past the hour - CH type molecules present (possibilities are methane, CO2, etc.)

Cool!!!!!!!!!!!

And now I gotta run over to the "Earthlike Mars" thread to proclaim that there is almost certainly a frozen Oceanus Borealis under the dust of the northern plains of Mars!!!!

Congratulations LCROSS team. Incredible. You guys sent up your own plume today!

Great News from this not so boring moon!

Is this frozen water the outcome of a meteoritic or cometary impact?
Or is it the "ice tip of the iceberg"?
I'm in favour of the second hypothesis.

If confirmed, why not imagining a network of caves made of liquid water somewhere in the underground!

Cool!
Did they say why the hydroxyl signal levels went below the baseline in the end of that plot (bottom one here http://www.nasa.gov/mission_pages/LCROSS/m...lts_images.html )? Just curious...

CO2 won't have any C-H stretches.

Can someone post a link for that update?

From the press release: "there are hints of other intriguing substances"
http://www.nasa.gov/mission_pages/LCROSS/m...er_results.html

Colaprete at the conference: "and there's a whole lot more beyond the water so that's the exciting part in my mind, it's not only about the water, there's actually a lot more here that we're gonna be talking about in the months ahead looking" with the guy on his left with a monalisesque smile in his face...hmm...almost gives me the impression that they happier about that "extra"
http://www.youtube.com/watch?v=QOpXMJdZGHc..._embedded#at=54

What can it be? Did I miss the answer to this?

Apparently, there's evidence of at least simple organics, Rui. Perhaps that might bolster the cometary origin hypothesis, or imply capture of lunar outgassing products.

The hydroxyl band is seen in emission, so the drop below the baseline at the end is likely due to the fact that the shepherding spacecraft (SSC) passed through the plume, and was no longer picking up emission from the illuminated ejecta. A negative "band strength" probably just reflects the fact that the overall emission was dropping as the SSC dropped into the darkness of Cabeus.

I mentioned it that way because that was how it was presented. Thirty-seven or so minutes into the briefing the question was asked about what else besides water. The fellow mentions "CH type" substances, and rattles off a list of possibilities in which carbon dioxide was included. Methane was another (I guess between it and CO2 you get an average of two), and methanol was also mentioned. I believe the possiblility of some kind of sulfur compound was raised, I can't remember the exact substance.

Before the specific mention of methane as a 'possibility' there was a comment about having found substance(s) that would evaporate at temperatures just 20-30 degrees warmer than ambient ground temperatures of -220C or -230C, possibly sublimed off a wider area around the crater by falling warm debris. Methane has a boiling point in this range - but are there other candidates?

There are quite a few that might move around by sublimation. Among the more interesting (and likely?) are formaldehyde, acetaldehyde, and ethylene oxide. ...the beginnings of a toolbox for organic chemists.

They certainly seemed to hint at there being a lot of highly volatile materials down there. Makes me wonder whether we could get brief, regular bursts of cometary style activity by putting a huge reflective surface in lunar polar orbit. It would make boring old Luna look a bit like Enceladus! (entirely different mechanism, of course)

phew. That settles that, I hope. Glad it didn't end up the dry hole that was feared.

Any comments on the plume size versus any sort of modeling at this point?

They said the plume was magnitude 8 and had a narrow, vertical and less dense part, which was only visible for a few seconds, and a wider, more dense part that lingered for a longer time. Since the Centaur created a nice crater, they speculated that the ice wouldn't be a solid surface. Overall it fit their models, it just didn't display much over the crater rim.

The 100kg figure would be based in what LCROSS could see from the plume, not the whole plume.

They said also that the analysis from the telescopes was going to take a longer time because their signal vs background wasn't so strong and, if I understood it right, that they have seen changes in the surrounding terrain due to the materials coming from the impact.

Re: what else other than water was in the plume: Colaprete said that he compared the spectra to those from Centaurs and Trojans and found a lot of similarities. There is probably a kitchen sinkful of crud at the poles that has accumulated there through billions of years of comets and asteroids bringing volatiles in that move around the lunar surface & get trapped at the poles. Centaurs & Trojans include water, CO2, CH4, SO2, methanol, ethanol, more complex organics; some of these are certainly present; but which ones and at what abundances are going to take lots and lots of modeling and comparisons among instruments and there may not be a unique model solution. He showed a model solution that was a pretty good fit, just to show that they are capable of fitting spectra, but he declined to indicate which species were in that model.

Any idea what mass fraction that 100kg represents? Based on previous findings I'd guess "around 1%," but I'd love to know how much more (or less) it is.

Rats. Swear I saw an estimate for the dimensions of Centaur Crater somewhere, but can't find it now. Anybody got that?

BTW, check out the Google homepage; a nice little surprise just popped up there within the last hour.

Colaprete mentioned that at the time the target was switched from Cabeus A to Cabeus proper, all the Earth-based observers knew that their prospects for seeing the plume would be much diminished. They could have made that clearer to the general public at the time - it would have avoided the disillusionment when we saw those visuals with very little going on.

Regarding the effect of the water on the cost calculus of lunar exploration (I hope this is permitted...if not, by all means kill it) a useful metric would be to estimate the number of vehicle loads of infrastructure that would be needed to get the variable cost of rendering the local water down to the point where it is no more expensive than bringing water from Earth. If it were a matter of just filling plastic bags with volatiles and dragging them to a sunny slope, you could probably be in position to do that with virtually no heavy equipment. But the implication of twelve buckets from a thirty-meter crater would be that you'd have to set up a major factory to just take an occasional bath. In this case the scientific fascination with identifying all the volatiles, while it fully justifies the present mission, is not likely to translate into any speedup of the exploration timetable. Perhaps some beverage company will be interested to bring a little of the stuff back to Earth and bottle it? http://www.theonion.com/content/node/30505 .

The Centaur crater is 20 or 30 meters in diameter.

Thanks, Emily.

Well, here's my (probably wrong) WAG. Assuming that the crater's only 5m deep & an average soil density of 3.5 g/cc, I get something like 2300 m^3 of material excavated for 8050 tonnes of mass.

They're inferring 100 kg of water from that, but of course that can't be interpreted as a full scan of all exhumed material.

All this says to me is that there's some water there. The means employed for detection really can't determine fine percentages of composition, IMO.

EDIT: Forgot to mention that I assumed crater diameter as 30m.

I did a rough estimate and came up with one part in 40000 of the excavated material.

Actually, thinking about this some more, I don't know how that 100kg H2O figure could have been derived unless it was with respect to the mass of the plume itself, which has to be less than the total mass excavated due to sidescatter, oblique ejecta trajectories, etc.

If that's true, how then did they estimate the mass of the plume since it appeared to differ so significantly in many respects from the pre-impact models?

It could be from the strength of the spectral signal against the background.

They said 100kg is the estimated lower limit in the field of view. Many volatiles were quickly vaporized and expanded away.

Right. I thought the 100kg was an estimate of what was actually seen in a narrow field of view and that they are not ready to estimate what was in the entire plume or in the entire excavated area.

My guess for the additional fitted gases in their plot ( http://www.nasa.gov/images/content/402265m...sults9_full.jpg )
(They look like gases... for instance, the big 1.5 and 2 micron water ice features [ http://www.tng.iac.es/news/2001/02/05/tran...g-trans-nep.gif ] do not seem to be fitted):
CO2 at 2-2.1 micron:
http://vpl.astro.washington.edu/spectra/co...agesmicrons.htm
ethane? or some other hydrocarbon at 1.7 micron
http://vpl.astro.washington.edu/spectra/c2...agesmicrons.htm
http://vpl.astro.washington.edu/spectra/ch...agesmicrons.htm
http://vpl.astro.washington.edu/spectra/c3...agesmicrons.htm
...

edit - added link to NASA plot

I already see a discussion on what 100kg means is going on. 100 kg per 20x20kms crater means it's quite dry. But a narrow field would require a whole new line of calculations and investigations, which I don't see it will happen in the next several weeks.

Z, the crater diameter is actually 20-30 meters, not km.

Again, though, I can't see what these results really tell us other than that water & some other volatiles are in fact present. They may be able to set an upper limit on the amount present at this spot, but any further extrapolation would apparently require a number of assumptions.

That being said, it's still an important & exciting experiment. We are now certain that there is water in this region. How much is still anyone's guess.

The crater diameter is about 20 meters. This gives roughly 1-10 ppm water by volume, if 100 kg represents the total amount of H2O in the ejecta (which is uncertain).

( 3.14*(10 m)^2 * (2 m) = 10^4 cubic meters; (100 kg H2O) * (1 m^3 / 1000 kg) = 0.1 cubic meter H2O; (0.1 cubic meter H2O) / (10^4 cubic meters total) = 10^-5 = 10 ppm H2O )
( changing the depth-to-diameter ratio from 1:10 to 1:5 gives roughly 1 ppm H2O. )

Well we've now got three estimates in the same ballpark. Converting to ppm: nprev 12ppm, myself 25ppm and P Hayne 1-10ppm.

I started wondering - if that were gold would we mine it? So with this thought here's a comparison from Wikipedia:

"Gold extraction is most economical in large, easily mined deposits. Ore grades as little as 0.5 g/1000 kg (0.5 parts per million, ppm) can be economical. Typical ore grades in open-pit mines are 1–5 g/1000 kg (1–5 ppm); ore grades in underground or hard rock mines are usually at least 3 g/1000 kg (3 ppm). Because ore grades of 30 g/1000 kg (30 ppm) are usually needed before gold is visible to the naked eye, in most gold mines the gold is invisible."

I've put together a little finder guide to the LCROSS impact site with an estimate of the SSC impact location. All of the images are from LCROSS except the big one © which is part of a DIVINER (LRO) map.

Phil

Click to view attachment

PS Well duh! My 'C' in parenthesis gets automatically turned into a copyright sign. However, anything I post on UMSF is intended to be public domain in its posted form.

But you are using estimates for pure, solid ice and a solid surface. Colaprete said that looking at the size of the crater that seemed unlikely.

Those 100kg minimum of H20 probably meant more than 0.1 cubic meters, and the average density of the ejected material could have been less than lunar rock.

Organics like methane yield water easily, their mass should count too.

I really appreciated Colaprete being willing to openly mention the possible other volatiles they may be seeing, pending final proof. He would have been well within his rights to say he was holding comment until the analysis was definitive. Now we know that hydrogen compounds in addition to water are probably available, along with sources of carbon.



Clever! One should also mention that it will be a lot easier to bake water out of lunar soil then to extract metal from ore. It can be certain that at this concentration it will be better to mine water than import it. Based on some studies done about mars sample returns that examined the use of refueling on the surface, and given the energy requirements for lunar sample return are similar but smaller, it's possible to speculate about a sample return probe with rover, where the rover processed ascent fuel in addition to gathering samples.

Of course, it would have to be a big sample return mission, and you'd have to be pretty patient with the rover, but there might be enough science here to justify it.

Just out of interest - what would the total organic chemical content of the Centaur amount to? Plastics, wiring etc. Vapourise them via a collosal thud and all manner of fragments will fly.

That's an excellent point.

I don't know offhand but it's obviously very well characterized already. It's not a basis for doubting the results.

Phil

The 100 kg reported was based on a column abundance (# per-square-meter), derived from the H2O band depths in the near-infrared spectra. This represents water molecules only. However, this number is derived from a model fit to the data, so uncertainties are large, as is typical for remote sensing spectroscopy. Regardless, the order of magnitude result will likely stand up, meaning the uppermost layers of the cold traps are about as "wet" as predicted (c.f. Campbell et al, Nature, 2006; Siegler et al, LPSC, 2009). That is, it's pretty dry, but not hopeless. Also, don't forget that we're only sampling the uppermost ~1-5 meters (including the ground-based radar results), so there could still be slabs of ice below.

Perhaps even more interesting are some of the other compounds, including several organic volatiles, that were observed in the ejecta plume. An interesting take on the smorgasbord of volatiles likely to accumulate at the lunar polar cold traps, is provided by Zhang and Paige, "Cold-trapped organic compounds at the poles of the Moon and Mercury: Implications for origins" Geophysical Research Letters 36, L16203.

Regarding the comparison of water to gold, remember that on the moon, water will be needed in much greater quantities than gold. This applies whether the need is for human consumption or, broken into its elemental components, as a fuel source. In the lunar environment, water would be more difficult to process than gold in one important respect - the gold wouldn't need to be constantly confined to prevent its escape to the vacuum of space. Any attempt to set up shop and utilize trace amounts of lunar water will have to invest heavily just in thermal insulation alone, otherwise those trace amounts are going to prove very difficult to corner. Remember those discarded Russian RTG's in Georgia that were located in the wintertime by hunters because they were surrounded by large circles of snow-free terrain? It's pretty hard to do industrial-scale work without generating waste heat, and at the local temperatures and vapor pressures prevailing in Cabeus, a little waste heat will quickly disrupt the delicate environmental balance that trapped the water in the first place.

This mission has told us a lot we didn't know. I'm intrigued by what these deposits can teach us when we determine where the water came from, and this should be answerable either by further work on the LCROSS data set or with some sort of sample return mission. But to significantly lower the costs of exploration we need at least a recognizable "dirty snowfield," not the Atacama desert.

A serious concern is the presence of hydrazine fuel from the Centaur rocket, which does have some poorly-characterized absorption bands in the near-infrared. From what I have seen, it might be possible to reproduce one of the bands attributed to water, by using hydrazine, but not all of the water bands. If anyone can dig up (or measure!) a decent hydrazine absorption spectrum, that would be very helpful. The best I have seen was from the 1950's and was basically qualitative (can't recall the author).

Did the Centaur actually have hydrazine? The main engines use LOX & LH2, and attitude control was provided during cruise by the LCROSS spacecraft itself.

Yes.

As I recall from the blog site (someone correct me on this if I'm wrong), every bit of the hydrazine was successfully vented, or used.



I'm afraid I must disagree. In a vacuum, you don't have to invest heavily in thermal shielding. Proper reflection and disposal of waste heat (here, it would be upward toward the sky) and careful use of insulating materials in the proper location (thermally isolate the wheels on a rover, keep them cold) would enable the enviroment to be maintained as long as the rover didn't stay in one spot very long. Witness the Spitzer telescope, which maintains its innards during the current warm mission at 30 degree K, even in constant direct sunlight.

Earlier, use of the 100 ppm implanted regolith hydrogen was considered as a cost effective resource (by Harrison Schmidt, among others), even though it would require much higher roasting temperatures to obtain. Water ice will require less energy to get out.

As far as infrastructure, a landed vehicle could be refueled over time using its own propellant tanks for storage. You just need the rover dropping off its load multiple times.

Last night we had quite a bit of rain here in the "jungle" of northeast Thailand, and rain in this time of the year is a bit exceptional.

However, our local radiostation just announced the reason in its hourly news bulletin: the rain was caused by the American moon rocket, crashing on the moon. It had taken the water a bit of time to reach Earth, but last night it arrived!

No kidding, this is the official news bulletin..

Um...we're sorry?

Better get under cover Geert; there should be a nasty shower of red rocks coming your way soon, knocked off Mars by the impact of Beagle 2. On behalf of the British people, I apologise in advance...

post a link
That is , sad to say, something i might expect to hear on the news these days .