Lunar polar ice results (thread renamed from upcoming)

[Sam Fraser]

NASA's Lunar Crater Observation and Sensing Satellite is scheduled to drop its Centaur upper-stage rocket on the lunar surface at 7:31 a.m. ET.

Four minutes later, the LCROSS will follow through the debris plume, collecting and relaying data back to Earth before crashing into the Cabeus crater near the moon's south pole.

http://edition.cnn.com/2009/TECH/space/10/08/probe.moon.crash/index.html

[RaresH]

Was it just me, or did the NASA live footage seem on the dull side? I woke up 6:10 CT to see it. I was watching very closely as the centaur flew to impact and I saw no plume whatsoever. Maybe those watching nasa tv on tv as apposed to online had a better look. I don't know since I could only watch online.

[joertexas]

Was it just me, or did the NASA live footage seem on the dull side? I woke up 6:10 CT to see it. I was watching very closely as the centaur flew to impact and I saw no plume whatsoever. Maybe those watching nasa tv on tv as apposed to online had a better look. I don't know since I could only watch online.

I'm willing to bet that the impact occured between refreshes in the camera. I watched it live, and it was underwhelming. But, it's still a big deal, especially if they made it snow on the moon :)

JR

[Sam Fraser]

The problem was animations like this were a bit misleading about the debris cloud:

http://www.youtube.com/watch?v=rsH9NZMLrik&feature=player_embedded

If the Centaur was solid, sure, it might've looked like something out of Armageddon (the movie). However, it's just a metal shell with an engine on the end, right? It would've mostly vaporised, I imagine.

LCROSS image gallery here:

http://www.nasa.gov/mission_pages/LCROSS/multimedia/index.html

[Phenix]

NASA has found significant water quantities after bombing the moon.

A new Big Deal for tax payers ?

http://abcnews.go.com/Technology/nasa-moon-bombing-finds-lunar-water/story?id=9076967

[Mark Prado]

NASA has found significant water quantities after bombing the moon.

http://abcnews.go.com/Technology/nasa-moon-bombing-finds-lunar-water/story?id=9076967

In this news article, they quantified the ice as 24 gallons from a 60 foot [diameter?] crater. For simplicity just to get an order-of-magnitude rough idea, assuming a semicircular deep crater (half a sphere of ejecta), then a top-of-my-head calculation puts the volume density of ice at somewhere around approximately 1/20,000 or .00005 volume, but please somebody double check my 1:30am tired calculation...

Sorry, I haven't yet reviewed the original literature coming out on this yet, and from lots of experience I know that things reported in the news are often way wrong.

Based on this 10 meter radius crater (sorry, I think in metric):

A gallon is 4 quarts whereby a quart is roughly 1 liter, so ...

24 gallons = 100 liters = 1/10th of a m^3

Half a sphere = pi r ^3 (2/3) = 2 r ^3 = 2000 m^3

So it's about 1/20,000 or .00005 ice or 50 parts per million volumetrically.

If it was truly just 24 gallons total out of a 60 foot crater.

Someone please:

1. Tell me if I've made any mistake above, and

2. Research for another source stating the results of the measurements, not relying on a news article like the above as the source.

Good night and sweet dreams ... of NEOs.

[Mark Prado]

The 24 gallons out of a 60-100 foot crater statements are in many articles quoting NASA officials associated with this LCROSS probe, and the 50 parts per million volumetric appears to be approximately accurate, more or less.

The data analysis from this latest probe is recent and hasn't undergone much scientific scrutiny from outside sources. A quick Google search indicates that it's probably mainly hydroxide (OH) rather than water (H2O), i.e., hydroxyls bound to minerals, not water ice.

Previous probes (lunar prospector, Clementine, others) put it at up to 200 parts per million and some experts said water ice.

Compare this with hydrogen in ordinary lunar soils far from the poles, www.permanent.com/l-minera.htm which has around 50 ppm but that's not volume percent. However, water is 89% oxygen and 11% hydrogen, whereby oxygen is the most abundant element in lunar soil at roughly 40% albeit bound into various metal minerals.

Some minerals tend to retain solar wind hydrogen better than others, so this concentration can be increased by simple physical beneficiation.

The poles don't get significant solar wind compared to other parts of the Moon. The poles get hydrogen and other volatiles migrating from comet impacts of the moon and some migratory solar wind hydrogen that evaporates. Just how much has been a topic of a long debate and I'm not sure anybody has put together a model that has reached any consensus of agreement.

About 90% of the solar wind hydrogen in ordinary soils is released by heating to 700 C whereas the polar hydrogen is much more easily liberated, so this is a good argument for going to the poles, though other issues would come into the entire equation.

In any case, these are all very small concentrations of hydrogen.

It's not as if you can scoop up some lunar polar crater soil and see frost or ice sitting on it. It's still a dry desert in those permanently shadowed lunar craters.

Very disappointing.

It's enough to supply a lunar base, but for large scale colonization of space, we need to start assessing near Earth objects on-site, and as a fallback plan maybe develop some Earth based electromagnetic launcher of ice and frozen nitrogen compounds to supply space in the early years.

To say we've got all the hydrogen we need at the lunar poles, in an economically feasible way, simply would not look true. Rather than hype this up and divert focus onto the lunar poles, we should look at the realities and keep looking for alternative solutions.

It's funny how they state these things, like "we found 24 gallons of water". Yeah, out of 500,000 gallons of soil.

[Rhyshaelkan]

Best source for water still seems to be an dormant-comet masquerading as an NEA. Or asteroids bearing chemically locked water.

http://www.space.com/scienceastronomy/050907_ceres_planet.html

"But computer models now suggest Ceres has a differentiated interior – dense material in the core and lighter stuff near the surface. Possible configurations include a mantle rich in water ice around a rocky core.

If this mantle is composed of at least 25 percent water, Ceres would have more fresh water than Earth, according to a statement released by the Space Telescope Science Institute, which operates Hubble for NASA and the European Space Agency. "

With useful gravity, and seemingly abundant water. Ceres could be an excellent source of water and other materials. Farther distance from the Sun might hamper the use of solar ovens and degrade the performance of P-Vcells.

[JohnHunt]

This calculation was posted by Rei on DailyKos

Let's do the math. If we assume a perfect cone 80'x13', v = 1/3 * pi * r^2 * h = 1/3 * 3.14159 * 40^2 * 13 = ~21,800 cubic feet = ~617 cubic meters. "At least" 24 gallons of water is "at least" 0.091 cubic meters. This means that water made up "at least" 147 ppm.

I'd say that's a mixed result. Not great, but not too bad either.