[X] My Assistant

[ollopa]

Can we change the thread? It's about the science/spectroscopy, not about the media. A science thread would be nice, since there IS science and this forum will suffer if it follows the media trail.

[ollopa]

Is this better, Emily?

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[djellison]

there IS science

When we get some - then we can start a new thread. This was (and continues to be) an as-it-happened discussion thread. When the science comes out (and we were told it is 2 weeks away) then we can have a new thread for it.

[jmknapp]

Given that they saw sodium in the early results, this item from 1999 concerning natural impactors may be of interest:

The Moon's Sodium Tail and the Leonid Meteor Shower

Boston University astronomers announced today the discovery of an enormous tail of sodium gas stretching to great distances from the moon. The observations were made at the McDonald Observatory in Fort Davis, Texas, on nights following the Leonid meteor shower of November 1998. The tail of sodium gas was seen to distances of at least 500,000 miles from the moon, changing its appearance over three consecutive nights...

Also

Sodium reflects sunlight very efficiently and so has become a standard way for space scientists to study gases that are otherwise difficult to see. ...

In trying to determine if this comet-like appearance of the moon occurred only on nights following a strong meteor shower, as happened with the Leonids, the BU team examined some earlier data taken at their site in Texas. During the previous August, similar observations were made, fortuitously on the nights following the new moon of August 21, 1998. "It was there," Dr. Smith said, "several times fainter, but with the same shapes over the same three nights spanning the new moon, just as occurred in November."

Taken together, the August observations without meteors and the November observations with meteors imply that the daily flux of micrometeors that strikes the moon's surface creates an extended tail at all times; it was just so enhanced during the strong Leonid storm that it was observed rather easily.

"What we do not know yet is whether the entire atmosphere of the moon is produced by meteors, or just the small component of fast sodium atoms that can escape from it," Mendillo said.

[antipode]

Surely what might be useful at a press conference would be to show:

1) The Deep Impact images (yes, apples to oranges comparison, but stay with me)
2) The Smart 1 impact movie (from memory hardly any flash, but clearly visible material in a ballistic trajectory, and yes, I know that was a glancing impact from a smaller impactor)

...and just go - "look, we really didn't know what to expect, we are as surprised as you are about the lack of a visible flash, but its that very uncertainty that has brought us here in the first place, this is still a mysterious area and we are trying to probe those mysteries. And you were/are along for the ride, we are all learning new things at the same time"

P

[ngunn]

I'd just like to report that the BBC news coverage was very good. The emphasis was on the success of the impacts and data collection process. They reviewed the hoped-for science and mentioned the absence of a visible flash almost in passing. As usual radio was better than TV.

[glennwsmith]

As someone who has called attention to the LCROSS mission in another thread ("Earthlike Mars?"), and who was in fact expecting the mission to be a "game changer" in terms of immediately clearly identifying water at the lunar south pole, let me express some thoughts that others of my ilk may be feeling.

The basic idea is that a disappointment is best handled by acknowledging it as such -- THEN you can wake the morrow morn with some more hopeful thoughts. As it is now -- due to the hemming and hawing of NASA and the media -- we are still stewing over the question of whether the initial results of the mission were or were not a disappointment -- and of course they were.

NASA absolutely did publish statements to the effect that the impact might be detectable through a 10" telescope, when in fact some of the largest telescopes in the world saw virtually nothing.

The shepherding spacecraft itself detected, as far as publishable images are concerned, only a changed pixel or two, and that in only one of the monitored bands.

And none of this bodes well for establishing the presence of significant amounts of water. I'm not saying that this is now impossible -- I'm just saying that when there is virtually no data in the visible band, there's probably not going to be much in the other bands; not to mention that we were only looking for small amounts of water to begin with.

So c'mon, NASA, help me get over this -- let's admit that the initial results have been a big disappointment -- and then let's carry on from there.

[nprev]

Well...It's definitely far far far too soon to rush to judgement about any aspect of the science return. Consider the frenetic pace of the data acquisition period, and now the big job of reducing this vast mass of data begins...and only after that's done can analysis begin. "Instant science" JPL-style really only works with pictures, and that aspect of the LCROSS payload was mostly for nav/post-impact localization.

However, it's hard not to say that expectation management was not well performed. Perhaps it should be called the "Kohoutek Effect": an interesting and/or unusual astronomical or space event is oversold in 'ooh-aah' potential to the general public, and the result is disappointment...even worse, a percieved lack of credibility ("But they PROMISED Kohoutek would be the comet of the century!"...or even "Does a fizzled flash mean no water?") As has been stated earlier, it's damn hard to predict the results of a novel experiment or event, and if the outcome WAS known with certainty then it wouldn't really be science.

The lesson that should be learned here for future space would-be spectaculars is beware the Kohoutek Effect. It can be done; JPL's getting pretty good at it. It may explain ESA's PR efforts in part as well; one way to manage expectations is to not foster any, but that's the other extreme from today's experience. There's a balance to achieve.

Wow; that sure was a long way to say "patience, grasshoppers!", huh?

[glennwsmith]

Nprev, Kohoutek may be a better example than you realize! For are not comets bodies of rock and ice which sometimes flare spectacularly and unexpectedly, and sometimes not? And do we not hope the floor of Cabeus to be of the same composition? So maybe there are related phenomenon at work here . . .

[stevesliva]

While the fizzle nature of this one is sort on an opposite of Deep Impact, my cynicism tells me that what's it's probably going to be most like is the Galileo probe... a we-just-hit-the-wrong-place-and-we're-not-changing-the-models kind of sentiment. It's hard for me to put a happy face on that sort of result. And everything worked perfectly in both cases! Sigh. Ah well, if this sort of thing went by the book, it'd be pretty boring, too.

[Hungry4info]

I'm pretty sure they didn't know what to expect as far as the kind of plume seen. I'm getting the feeling that the media over-hyped this (and the animations we were shown didn't help much either). Science isn't just pretty pictures. I'm quite happy-faced about the spectroscopy. Even if there wasn't a wonderful ka-boom, there's still great data gathered, and I look forward to seeing the results of this mission.

[djellison]

I'm pretty sure they didn't know what to expect as far as the kind of plume seen.

Then why did they put out figures? 350 tons, 6 miles high, 30 miles across, 10-12 inch telescopes.

Which leads to dissapointment when..

It turns out no telescope, even the giant Keck and Gemini observatories in Hawaii, saw obvious signs of the impact in visual and infrared imagery.

spaceflightnow.com

The media (apart from using the word bomb a lot) seemed to accurately retell the story that LCROSS told them in press releases etc.

It will be scientifically interesting to find out how or why the predictions were so very different to reality.

[nprev]

Yeah...that really is a million-dollar question. Hell, amateurs with modest scopes have picked up flashes from shower meteor hits (particularly the Leonids, IIRC) before, which are really small & really fast but nowhere close to that Centaur in terms of impact energy.

Somebody half-jokingly said something about it being gulped up by a deep dust pile. That's almost beginning to sound plausible!

[Guest_PhilCo126_*]

Although no spectacular impact plume was observed, some reports:
(Nothing so far on IRTF and Lick observatory websites)

Keck 10.0 m
http://keckobservatory.org/index.php/news/...ew_of_the_moon/

Hubble Space Telescope 2.40m
http://hubblesite.org/newscenter/archive/r...s/2009/26/full/

Palomar 5.00m
http://palomarskies.blogspot.com/

[Fran Ontanaya]

I didn't expect much.

"When you kick the surface, [the dust goes out in] a little fan which, to me, is in the shape of a rose petal," recalls Armstrong. "There's just a little ring of particles--nothing behind 'em--no dust, no swirl, no nothing. It's really unique."