No ice on Moon?

I wrote:
Nothing particularly new, actually, although it's a more detailed
confirmation of previous results. All the negative radar results
establish is that there aren't large near-surface deposits that are
*mostly* ice... which we actually already knew...

Indeed, if you actually read the Nature *paper*, not the press release or
the news reports, the authors are quite careful to limit their claims.
The very title of the paper is clear about it: "No evidence for thick
deposits of ice at the lunar south pole". Note, not "No evidence for
ice", but "No evidence for thick deposits".

The paper mentions the Lunar Prospector neutron data, and the LP team's
prediction of ice at circa 1.5% by mass, and adds: "If this ice is
distributed as grains in the regolith at this concentration... then it
would not be observable with radar."

The paper concludes: "[Our results are] consistent with the presence of
any water ice being only as disseminated grains at 1-2% abundance. Any
planning for future exploitation of hydrogen at the Moon's south pole
should be constrained by this low average abundance rather than by the
expectation of localized deposits at higher concentrations."

Even Nature's news story about the paper rather obscures this conclusion.
But it does add an interesting observation: not everyone agrees about the
interpretation of the radar data. The paper's main point is that the
similarity of radar backscatter from craters Shackleton (permanent shadow)
and Schomberger G (no permanent shadow) suggests that the backscatter from
Shackleton does not signify ice. But the news story quotes Paul Spudis --
of the pro-ice faction -- as saying that he doesn't think the backscatter
patterns from those two craters look all that similar, and that moreover
the differences are about what you would expect if Shackleton had ice and
Schomberger G didn't.

As I've said before, you have to read press releases about academic papers
*really* carefully, because the press-release writer's job is to make the
paper sound like the greatest discovery since the wheel, and they often
end up greatly exaggerating the breadth and significance of the paper.
--
spsystems.net is temporarily off the air; | Henry Spencer
mail to henry at zoo.utoronto.ca instead. |

"Henry Spencer" wrote in message
...
Indeed, if you actually read the Nature *paper*, not the press release or
the news reports

Now, Henry, you know better that that. We got ourselves a Liberty Valance
here.

I've considered becoming a Canadian citizen. I'd do it, but I can't find a
way to handle the residency requirement and also accomplish my other goals.
If I were single, I'd put those other goals on hold. Alas, at the moment,
I'm Al Bundy, only with a better family.

Also, I can't think of what I could offer to Canada, besides my presence. If
I'm going to be a citizen, I should add something.