Thanks and "About That Plume"

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Oct 11, 2009, 1:02:31 PM10/11/09
to LCROSS_Observation
I have been a lurker here and want to thank the group for getting me
ready for the impact and teaching me about areas of the moon I had
never observed. Like most everyone here I hope that LCROSS is very
successful scientifically, and it appears that all the instruments
were working well and that they have much space-based and ground-based
spectroscopic data in addition to the LCROSS instruments.

On the other hand, NASA went through a big PR campaign, talked about
how amateurs could and should observe, gathered together folks at this
ridiculous hour at Ames, and surrounded them with amateur telescopes
and feeds from professional telescopes. In my view, NASA worked hard
to get the layman to watch this event. Was I the only one observing
who was disappointed?

There was a degree of surprise and what I would interpret as
disappointment in the faces of the panelists in the impact broadcast.
The news conference that followed at 7 AM Pacific was "spinning" like
crazy. I appreciate that there is little or no immediate data and it
is a mistake to jump to conclusions. OTH, the lack of visible plume
was the elephant in the room and it was studiously avoided. By that
time there were reports out on the internet from professional
observatories that no plume was visible. During Q&A when asked a
direct question about whether they were disappointed that they did not
see a plume, the answer was a side-step. To paraphrase, it depends
what you mean by "see" and "plume." Finally we were told that
imaging, and presumably visual observation was not really what was
important because all the science was in the spectroscopy. At a
minimum, someone at the news conference could have empathized with all
the people who were trying to observe a predicted visible plume at
NASA's urging. No need to be disappointed in the mission, but they
could have been disappointed that the observing program for amateurs
and laymen was frankly a bust. My own hypothesis, based on watching
the NASA telecasts is that they were disappointed that it was not a
better public show. How could they not be?

NASA science lives or dies according to funding from public sources
and the NASA relationship with the public is quite important to
continuing its science. In my view, they made a serious error going
into "damage control" mentality in the post impact news conference.
Hopefully scientific results from the mission will help smooth this

Thanks again for all the great information through this site.


Tim Swanson

Oct 11, 2009, 2:02:06 PM10/11/09
Why would they shoot for a crater?  Would the previous impact from what ever created the created mean that the you would need something equal too or greater than what created the crater to make a noticible impact?  Would all the noticible plumable dust be gone? 
I would only think in my novice mind that you would shoot for some other "virgin" landing area not impacted or crater created for the most noticible impact and plume. 
> Date: Sun, 11 Oct 2009 10:02:31 -0700
> Subject: [LCROSS_OBS: 1257] Thanks and "About That Plume"
> From:
> To:

jim phillips

Oct 11, 2009, 2:24:46 PM10/11/09
First of all there is no more virgin land on the Moon than this. The surface of this crater is billions of years old. And, they went for a crater near the S Pole because it is always in shadow so the hope was/is that water ice might still be there.

Jim Phillips

Subject: [LCROSS_OBS: 1258] Re: Thanks and "About That Plume"
Date: Sun, 11 Oct 2009 14:02:06 -0400
> </html

Arnold Ashcraft

Oct 11, 2009, 2:30:13 PM10/11/09
As I understand it, they shot for a crater because of the hypothesis that extreme polar craters on the moon were places where, literally, the sun didn't shine and that they would be cold traps in which cometary ices would collect after all the collisions that happened since the moon was formed.  That all makes nice sense.  What does not make sense to me is why they picked Cabeus which has a sunlit floor and inner walls some of the time rather than Faustini which IS perpetually dark inside.  I know they were saying that the high hydrogen concentration in that particular patch inside Cabeus was the reason for the impact.  Trouble is, that does not necessarily indicate water, but could be some other form of hydrogen, like the stuff recently found further towards the equator as the result of the interaction of the solar wind with the lunar regiolith.  So they ended up testing another hypothesis (what is the form of hydrogen in these surface regions), rather than the one originally stated (are there cold traps loaded with ice in the perpetually dark interiors of extreme polar craters).  I think they made a late-in-the-game misjudgment of what the best impact point was and directed the rocket upper stage to a location containing a surface concentration of hydrogen from the solar wind, not a place likely to have a "glacier" of trapped water that might prove useful for a Lunar base or colony.  This was very disappointing to me.
Just my opinion,
Clif Ashcraft, NJ

Arnold Ashcraft

Oct 11, 2009, 2:31:07 PM10/11/09
They sure picked the wrong crater for that purpose though.
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