Why haven't any tracks been found yet?

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Why have no tracks been found?

A
3
21%
B
3
21%
C
8
57%
 
Total votes: 14

the moon
Posts: 177
Joined: Thu Aug 03, 2006 12:34 am

Why haven't any tracks been found yet?

Post by the moon »

The forum seems to be dead lately so I thought I'd try to start some new discussion.
The team estimated that around 40 interstellar particles would have hit the collector, and by now something like 25-50% of the collector has been scanned and viewed by us, and yet we have found nothing. I've seen all the possible tracks that people post and honestly none of them look very promising. So what do you think the reason is that no IS tracks have been found yet?

A. They haven't been found because they aren't there. The estimate of 40 particles was way too high.

B. The tracks are there but the methods used to see them are insufficient. For example the tracks might be too small to see at this magnification, or the poor lighting is making the tracks transparent.

C. The tracks are there and viewable, but they look different from what most people are expecting. In other words, I'm wrong and a few of the possible tracks that people are reporting will be found to have IS particles.


Hopefully the answer is C, or B and the problem will be fixed with the new methods of scanning they're working on. That would mean some tracks will eventually be found. But personally I'm leaning towards A.

DustBuster
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Post by DustBuster »

How about an option "D- other"? Here's mine...

The quick-and-easy answer: there are NO tracks found to date simply because they cannot be positively identified until extracted and subjected to authentication tests.

I'm sure a lot of brain-hours went into the 40 particle computation, but those are the same folks that are the first to admit it's a best-guess number- and they're best-guess would be better than mine!

A number of FOV's have been rejected for bad focus, as much as 20% of the viewed movies has been suggested- that could account for some as well.

It may also be that we are unable to 'see' or identify a number of potential tracks, and there are still hundreds of candidates submitted yet to be reviewed.
Again I will point out that we are quite privileged to be the first to view these monumental images, but we will by no means be the last or have the final say whether or not a particle exists in a given movie.

just some brain grain... soup's on!

greuti
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Post by greuti »

http://stardustathome.ssl.berkeley.edu/a_science.php Interstellar dust was first discovered flowing across the Solar System by dust detectors aboard the Ulysses spacecraft in 1993 and was later confirmed by the Galileo mission to Jupiter. The particles were identified as coming from a location in the sky in the Constellation Ophiuchus, looking toward the center of the Milky Way Galaxy
My guess is "A" too. I wonder what the readings of the Ulysses and Galileo spacecraft exactly pointed out about the flow of IS particles across the Solar System. I think the estimate of 40 particles relates to those measurement data. The flow of particles may be more unsteady than expected (or such unsteady as expected on the one hand too). Apropos, what was the result of the Dust Flux Monitor (DFMI) and the Analyzer instrument (CIDA) on Stardust itself?
DustBuster wrote:The quick-and-easy answer: there are NO tracks found to date simply because they cannot be positively identified until extracted and subjected to authentication tests.
But there have to be a clear track even it is smaller than estimated. A track that show a sharp (focused) small spot through the "whole" VM movie at least (beneath the surface). I'm sure they would have released already an update or the finder would have posted here if there is such a thing.

Wolter
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Post by Wolter »

Passed cut 1 possible IS candidates:

http://stardustathome.ssl.berkeley.edu/ ... =9855575V1
http://stardustathome.ssl.berkeley.edu/ ... =6842789V1

Just 2 of my list. Not exactly like the ones from the tutorial but quite close.
Focus only below surface so who knows.

The point is that with this kind of science getting results takes time. And with space science time means more often years then months. So just be patient. Keep on dusting untill we have swiped the entire collector and then wait. Wait for the results to get published. it could take quite some time even then.
Just dusting... Image

the moon
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Post by the moon »

I'm jealous of all your optimism. My biggest fault is that I always look for the negative in everything.
The quick-and-easy answer: there are NO tracks found to date simply because they cannot be positively identified until extracted and subjected to authentication tests.
That would be C. You can't extract anything for further tests until you've identified possible tracks in the focus movies, and like I said I don't see any promising movies.
A number of FOV's have been rejected for bad focus, as much as 20% of the viewed movies has been suggested- that could account for some as well.
That would be B.
There are still hundreds of candidates submitted yet to be reviewed.
C again. The thing is, they have all been reviewed, by us. By the team's own admission, we have just as much experience searching for IS tracks as they do. If there was something to be found, the dusters will find it.
The point is that with this kind of science getting results takes time. And with space science time means more often years then months. So just be patient. Keep on dusting untill we have swiped the entire collector and then wait. Wait for the results to get published. it could take quite some time even then.
Hey I'm not saying they should give up. Of course I'll stay tuned for the final results, but in the mean time I'll speculate like crazy with the data available.

greuti
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Location: Switzerland

Post by greuti »

Wolter wrote:The point is that with this kind of science getting results takes time. And with space science time means more often years then months. So just be patient. Keep on dusting untill we have swiped the entire collector and then wait. Wait for the results to get published. it could take quite some time even then.
Yea, regarding the analysis on the extracted tracks and particles.
But not regarding highly suspicion IS tracks determined in the collector and still therein. To show them as soon as possible, as special, as good as possible VM movie would be fair (and easy) (and also scheduled I guess).

fjgiie
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SPECULATION

Post by fjgiie »

the moon wrote:So what do you think the reason is that no IS tracks have been found yet?

Hi the moon,
This question has bothered me a lot. I wonder what Dr. Westphal would say other than we don't know yet?

From http://www.berkeley.edu/news/media/rele ... dust.shtml
"Based on previous measurements of interstellar dust by both the Ulysses and Galileo spacecrafts, Westphal expects to find approximately 45 grains of submicroscopic dust in the collector, a mosaic of tiles of lightweight aerogel forming a disk about 16 inches in diameter - nearly a square foot in area - and half an inch thick. Though those searching for pieces of Wild 2's tail will easily be able to pick out the thousands of cometary dust grains embedded in the front of the detector, finding the 45 or so grains of interstellar dust stuck in the back of the detector won't be so easy."

http://stardust.jpl.nasa.gov/mission/details.html
Feb 2000 to May 2000 (first IS dust collection)
Aug 2002 to Dec 2002 (second IS dust collection)

http://stardustathome.ssl.berkeley.edu/ ... ight=#8534
The collector was pointed toward the incomming dust stream.
the moon wrote:But personally I'm leaning towards A.
Everything was done that could be done to make sure that IS dust entered the collector. We need to rule out reason A. from the start. If the dust stream was missed in 2000, maybe it was found in 2002. My feeling is that we have some IS dust in the collector.

I also believe that the 45 dust traces are the amount that went into the collector, not 45 dust tracks that are expected to be found. Of the 45 particles that entered the collector, we may not see the tracks of all of them. Also some of the IS dust particles may not have survived capture. They entered the aerogel at around Mach number 73 or so.

Now with the preliminaries out of the way, let's not cop-out and be afraid to make a good guess as to why the moon and fjgiie have not seen an IS dust track yet.

Without a whole pagefull of math...130 tiles divided by 43 IS tracks = about 3 tiles per track. When we get through searching there will have been 5,000 focus movies per tile, give or take. 3 tiles X 5000 = 15000 focus movies on average per track in the collector, not found in the collector. We should have examined 14 focus movies by now that contained IS dust traces. That is only 14. Why don't we have posted in "I think I've found a track, what do you think?" these 14 movies? Maybe we only saw half of them, 7. Maybe 4 of these were not posted because the searchers that clicked them do not read nor post to this forum.

What I would like to see is these three movies that contain these dust traces. There is only one reason why we have not seen them. They do not look like we thought. What is that letter the moon? Oh yeah, that would be C. "The tracks are there and viewable, but they look different from what most people are expecting."

That's my guess and speculation, :)

fjgiie

greuti
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Post by greuti »

greuti wrote: Apropos, what was the result of the Dust Flux Monitor (DFMI) and the Analyzer instrument (CIDA) on Stardust itself?
Searching the Web, I've found some details about it and last but not least the "master piece", the official data report for the CIDA in Planetary Data System: http://pdssbn.astro.umd.edu/holdings/sd ... taset.html
The only trouble is I'm not able to read TAB files - anybody else? :wink:

Additional a (quick) summary from the CIDA producer (only in German): http://www.vh-s.de/projects/cida-stardu ... 11-de.html
They say that CIDA was able to register a total of 45 IS impacts with an impact velocity of 20 to 40 km/s.

Edit: There's also a science publication available from Stardust's data: http://www.sciencemag.org/cgi/content/a ... /5678/1774
And from Galileo's: http://www.agu.org/pubs/crossref/2005/2 ... 0772.shtml
"Thus the available ISD data now cover almost a full 11-year solar cycle. Nonetheless, the flux of ISD grains with radius bigger than 0.4 μm shows no significant temporal variation." (ISD means Interstellar dust)

There's yet an official PDF paper that estimated impact velocities to the collector lower than 15 km/s (as I understand it) http://pdssbn.astro.umd.edu/holdings/sd ... n_supa.pdf (page 13)

fjgiie
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Difficult to see track?

Post by fjgiie »

http://stardustathome.ssl.berkeley.edu/ ... =7932168V1

This hopeful track could fall into reason B. and possibly reason C.
"B. The tracks are there but the methods used to see them are insufficient. For example
the tracks might be too small to see at this magnification, or the poor lighting is making the tracks transparent."


Difficult to see - located in bottom left quarter, at top of that quarter.
Something on the surface comes up first, and the thing I clicked on a little above that.

the moon
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Joined: Thu Aug 03, 2006 12:34 am

Post by the moon »

Strange movie, but what I think is happening is the whole movie is focused below the surface and there's inclusions all over the place. At least 6 of them.

jsmaje
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Post by jsmaje »

I agree with the moon.

fjgiie
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Reason D.

Post by fjgiie »

the moon wrote:So what do you think the reason is that no IS tracks have been found yet?

A. They haven't been found because they aren't there. The estimate of 40 particles was way too high.

B. The tracks are there but the methods used to see them are insufficient. For example the tracks might be too small to see at this magnification, or the poor lighting is making the tracks transparent.

C. The tracks are there and viewable, but they look different from what most people are expecting. In other words, I'm wrong and a few of the possible tracks that people are reporting will be found to have IS particles.
______D.We have not looked long and hard enough yet. <--- link

Look good and try to look under also. Left of center down a little.
Last edited by fjgiie on Wed Dec 06, 2006 8:06 am, edited 1 time in total.

marymouse
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Post by marymouse »

What about this announcement on December 1?
We are finding that this is helpful, and we have made a new discovery: an apparent "swarm" of tracks that enter the collector nearly parallel to the surface. This is probably due to an impact somewhere on the collector. We will be tracking this down in the coming weeks.

the moon
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Post by the moon »

Doesn't sound like an IS particle would be responsible. Sounds like something bigger hit the metal part of the collector at a weird angle and broke apart.

GelDelve

Post by GelDelve »

moon wrote:Doesn't sound like an IS particle would be responsible. Sounds like something bigger hit the metal part of the collector at a weird angle and broke apart.
Yes, that very well could be. Then, again, an interstellar particle could have hit the edge of the metal compartment and splattered at an oblique angle into the collector, also. An interstellar particle would probably be much smaller than one from this solar system, but not necessarily. I can intuitively believe that since the collector was aimed to efficiently intersect the interstellar stream at the optimal angle of 90 degrees, that most of those particles would simply have bounced off the metal frame unless they by chance hit an edge of the frame above the gel. Depending upon how close to the edge they hit, the angles could be widely varied, but would probably average about 45 degrees or so. In addition, no matter what the source of the impact was, I think it is not unreasonable to expect that many of the impacts would be the result of the material from the frame being broken away and impacting the gel, much like in billiards where you could sink the 8 ball in the corner pocket when it is hit by the 7 ball which continues in play. Since it is more likely that non-interstellar particles would likely impact the frame at an oblique angle, even if they were to hit the frame at an edge they would be more likely be totally ejected from the collection gel, while it may be entirely possible that the 8 balls from the frame wall is fanned out into the gel below. In conclusion, and again on an intuitive note, if this new finding is further verified, then I would think that some of the tracks discovered will be nothing other than material from the frame, and that if the impact was from an interstellar impact that the tracts furthest from that frame might contain some interstellar matter. However, if the impact was caused by interplanetary matter, then likely most of the tracks will contain nothing but frame material and it is also likely that a lot of those tracks may begin immediately below the frame wall and then extend outwardly from that wall in ever lesser angles to the surface. There are an infinite number of other interpretations that might be made.

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