LCROSS Did Find Water!!

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MeteorWayne

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Just a brief note, full scribblenotes coming soon.

The LCROSS impact released about 100 kg of water from the 20-30 meter wide crater!!
 
M

MeteorWayne

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From LCROSS Science Briefing Nov 13.

Clear evidence was found of water in the Near Infrared Spectrum (one of the slides). As well, later as sunlight broke the water apart, OH lines were detected in the UV emission spectrum.

The 100 kg (~ 25 gallons) is a lower limit.

In addition, other spectral features were noted, but were not discussed at this news conference.
 
M

MeteorWayne

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The Science Briefing will be replayed at 4 PM EST, and 8 PM EST (2100 GMT, and 0100 GMT Nov 14th) on NASA TV.
 
M

MeteorWayne

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OK, some more from my scribblenotes:

First Anthony Colaprete, the PI, has a big supressed smile on his face.

The plume was about 10-12 km across, perfectly fitting into the 1 degree FOV of the LCROSS sheparding craft.
The crater created (which was imaged in the NIR (Near Infrared) showed a crater between 20 and 30 meters in diameter with ejecta up to 100 meters away as it fell back to the lunar surface.

The measured temp before impact was -220 to -230 degrees C, the impact created temps +400-500 C.

The Infrared Spectrum showed clear indications of water and/or water ice, along with other absoptions which were not discussed. They were able to create a model spectrum that fit the full spectrum very well, but since that didn't involve water (and is under continuing analysis) that wasn't discussed. Certainly his team, as well as the LRO and Ground Based obs has some ideas, but those results will come out in a few months (spring?) when the nalysis and peer review is completed. Sodium was one clear detection from ground based obs.

OH (hydroxyl) was detected in the emission spectrum in UV as the plume was photolysized by sunlight after the impact.

Ground based observations suffered by the last minute change of impact locataion from the Cabeus A crater to Cabeus proper, which made the plume less visible from earth, but increased the value of the obs made by the LCROSS spacecraft.
The earth based astronomers concurred with that decision, since the goal was really to hit the best location.

They came with 100 meters of their targeted impact site (Goal was 3.5 km)

About 2 weeks ago they knew that they had a robust water detection, had team meeting and agreed to go public...after that it was all creating slides :)

If you have any other questions, ask away and I'll see if the answer is in my scribblenotes, or watch the replays!!

Wayne
 
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CommonMan

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O.K. they found water. Will this help Nasa with getting more funding?
 
M

MeteorWayne

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Maybe, Maybe not. It certainly suggests that a robotic mission (while we are waiting for possible human flights) to the polar craters might be a good investment. Now that we know water is there, it's time to find out exactly where it is, in what form, how close to the surface, and in what concentrations.
 
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abq_farside

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Would we expect to find water only at the poles or could it also exist in craters outside the polar regions?
 
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megawatt

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Well done!! 25 gallons in that small area is quite abundant. I'm optimistic this will generate some interesting mission proposals to study it.
 
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MeteorWayne

Guest
Very small amounts of water were detected by the M cubed sensor aboard the Indian Chandrayan spacecraft across the surface, but at teaspoon per ton levels. The polar craters, existing at permanent temperatures below -200 C would be expected to be sinks for such water if it made it's way there. It goes in, but it doesn't come out.
 
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cyclonebuster

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You can look at the moon as a giant sponge absoring water and it adhearing to it with surface tension. Even a dry feeling sponge may contain water that won't come out untill you squeeze it. I would look for springs and artisean wells by drilling many wells like looking for oil. Thing is finding out where to drill?? I would look to mascons and areas where the sun doesn't shine like the poles. I am betting there are underground caves full of water somewhere on the moon.Key is finding them which means we must explore the moon now. Nuking the moon may yield better results thus creating bigger and deeper holes for water to run into.
 
M

MeteorWayne

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You already have a Nuke the Moon thread in The Unexplained. Please confine such posts to there. This topic is to discuss the actual scientific results from the LCROSS mission, not unrealistic "nuke the moon" discussion. Any further off topic posts involving nuking the moon will be unceremoniously moved to the other thread in The Unexplained.
 
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cyclonebuster

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MeteorWayne":1mb04idl said:
You already have a Nuke the Moon thread in The Unexplained. Please confine such posts to there. This topic is to discuss the actual scientific results from the LCROSS mission, not unrealistic "nuke the moon" discussion. Any further off topic posts involving nuking the moon will be unceremoniously moved to the other thread in The Unexplained.

LOL
 
B

bdewoody

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To me, this leaves no doubt as to what our next major goal should be. No more excuses about having to lug all of the supplies needed to survive with us to the moon. For sure we will have to take major amounts with us initially but before long we could have significant colonies on the moon paving the way to other destinations in the solar system.
 
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SpaceTas

Guest
I found one news story with more than 24 gallons from a crater 60 to 100ft across. I am going to convert to metric. That is a radius of 10 to 16m roughly, and 91 liters.

Now to estimate the volume of rock in the crater. Take typical depth to diameter ratio of 1/5 gives the crater a depth of about 4m for a 10m radius crater. Consider the crater as being a cylinder radius 10 m depth 4m (This gives smallest volume and so highest concentration). Then the volume is about 1880 cubic meters . So for 1 liter of water you need to process (1256/91= 14 cubic meters (a block about 2.4meter roughly 7.5ft on a side).

The average resting person needs 2 liters per day of drinking water ie 28 cubic meters (2 7.5ft by 7.5ft by 7.5ft holes) worth of lunar soil a day. Lets say we have a 90% efficient water recycling system that 28 cubic meters of soil (2 liters extracted water) would last 10 days.

Even to just get drinking water for 1 astronaut we are going to need a digger. Semi autonomous because you don't want your astronauts driving machines all day.

It would be far easier, less exciting, to have a tele-operator(s) (the 1 sec delay is not too bad) running the diggers, water extractors and fuel makers. The operators could be sitting in a nice comfortable office drinking their favorite cup of joe, breathing free air, ordering in pizza, and just be able to flush the toilet.

You'd still need a repair crew every now and then, to go visit the moon. But the astronauts could spend their time exploring.
 
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SpaceTas

Guest
The next science steps are to ground truth the LCROSS results;
1> send in a tele-operated rover to the south pole with a core borer, measure the water content, and the other volatile components. A prototype called Scarab already exists!
2> Measure from orbit how the water is moving about on the Moon. Also more detailed mapping of the polar water.
3> A sample return of a core from the south pole. In conjunction with a rover to get a wide variety of cores.

Then it's time for the astronauts.
 
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SpaceTas

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Historical note:
The Apollo samples showed trace amounts of water, but this was put down to contamination by Earthly water. I wonder where our thinking and space program would be now if we had had "air tight" knowledge of lunar water back in the 70's.

Water on Mercury as well.
The conditions at the lunar poles are replicated on Mercury. So there may be similar deposits there. So far radar searches from Earth have been inconclusive. Keep an eye on Messenger results once it is orbit about Mercury.
 
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kelvinzero

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I hope at least a robotic mission on the ground is likely now, and given we develop the technology for one mission I hope we see more than one.

It will be interesting to learn what percentage of water and also what other chemicals they find, although there will still be the question of whether it was in a thin layer or evenly distributed, or many layers giving a history of the solar system?

I got the impression they are likely to soon become confident enough to identify certain hydrocarbons also, just not confident enough for this briefing.

It would also be good to hear from more of the experts here!
 
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SpaceTas

Guest
The absorption bands OF IR spectroscopy are mainly from vibrations so the band identify the bonds between say H and O or C and H (methane), the details depend upon the whole molecule. Also the details like depth and width of bands depend upon temperature pressure. So it is possible for the same spectrum to be the result of different combinations of composition, temperature, pressure ... In the press conference they used words like "unique solution" to show that the water detection was actually water. The analysis don't rely on just the IR spectrum. The visible-near UV spectrum gives the abundances of bits of the molecules like the Oh mentioned. 1 Oh and 1 H leads back to water H2O. Also the visible-near UV spectrum can show up ionized versions of molecules CH3+ etc. The UV light from the Sun does the breaking up and ionizing. The additional ingredient is information about the physical conditions in the plume; some of this can be measured and the rest can be modeled (the red curve in the IR spectrum) plot. So when the scientists responsible start saying they have unique solutions they have gone through a lot of modeling and comparison to all the data.

The firm detections of other molecules would be a big bonus; as the whole mission was geared toward finding water.

That's my understanding from a combination of advanced Uni spectroscopy classes (a while back), doing other astronomical spectroscopy, and following research on exo-planet atmospheres. Not quite my field by fairly close.

Have a look at the sub-links about mission rational, instrumentation and particularly water detection in the NASA/LCROSS link
http://lcross.arc.nasa.gov/tech.htm
 
M

MeteorWayne

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SpaceTas":490t7rmd said:
I found one news story with more than 24 gallons from a crater 60 to 100ft across. I am going to convert to metric. That is a radius of 10 to 16m roughly, and 91 liters.

Just a minor correction; that's about 20-30 meters, which is the diameter they gave in the news conference, but then gave the water volume in gallons :roll: (They also said 100 kg water).

Also, those water figures are a lower limit, the actual value may be higher once the analysis is further along.
 
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nimbus

Guest
Metric crater size / imperial water volume - It is a news conference for the general public after all.
 
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Eman_3

Guest
These missions take years to plan and execute, the timing is just co-incidence.

But what does make me concerned is how quickly NASA released it's conclusion that water is on the moon. Usually, in the case of real science, the data is carefully examined before conclusions are made. Usually months, years. Then it goes through a peer review before publication. In this case, I do believe NASA went public about water on the moon based solely on initial data, and since it came out almost immediately after the event, politically motivated.
 
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MeteorWayne

Guest
It's not immediately, it's more than a month later. As they said in the News Conference, they had robust data that showed that water ws clearly detected, debated the value of releasing the info before full peer review, and all agreed the data was firm enough to make the announcement. Don't forget, people were screaming for their heads because they couldn't make the announcement 2 hours after the imapct!
 
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SpaceTas

Guest
Correction not needed.
I did the conversion from feet to meters and diameter to radius together, hence half size of numbers.
24 US gallons = 91 liters which would have a mass of 91kg close enough to 100 kg when you are rounding for the press.
Also I did say these are lower limits to concentration, because greater than 24 gallons were detected.
 
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SpaceTas

Guest
Doing the analysis and checking the results within the group and hopefully externally takes time. 1 month is very quick. say 1 week to do analysis, 1 week to check internally, 1 week to get external opinions and 1 week to answer any critics. They deserve a break !

Doing science by press release and news conference is a dangerous thing. NASA has been burned badly in the past aka the first exo-planet image (it turned out to be a background star), micro-fossils on Mars
 
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