[meteorite-list] Antarctic comet dust "perhaps" in better conditionthan Stardust

From: Larry Lebofsky <lebofsky_at_meteoritecentral.com>
Date: Thu Jul 13 08:25:39 2006
Message-ID: <1152793534.44b63bbe7e902_at_hindmost.LPL.Arizona.EDU>

Hi Adam:

Here is my attempt to give a short answer based on very little information on
what they found, but comparing this to what we have seen from Stardust and
what has been collected in the past.

1. From U2 dust collection studies (Brownley Particles), there are mainly two
types of Interplanetary Dust Particles: Chondritic Smooth (amorphous exterors,
hydrated silicates, thought to be related to asteroids(?)). Chondritic Porous
(anydrous, "fluffy," cpntain samll rains that may perdate the Solar System,
comet dust(?)).

2. From what I have seen so far, much of the Stardust material has still
been "altered." If you look at the images, while they did not have the effects
of sitting in space for a few million years and going through Earth's
atmosphere, they did impact the aerogel at a fairly good speed.

Based on this and on the abstract, I am assuming this they found lots of small
particles that are similar to Interplanetary Dust Particles, but that have
made it to the ground (the old look in a barrel of water and you will find
micrometeorites, but on a much longer timescale).

I am not sure that I can give a more better answer until I have actually seen
pictures (or their detailed discussion), so this is a (sort of) educated guess.

Larry

Quoting Adam Hupe <raremeteorites_at_comcast.net>:

> How could this dust be in better condition than Stardust samples when only a
> third of it might have been contributed by a comet? How can they be sure
> this material came from a comet? With Stardust you know with 100% certainty
> where it came from plus there is no terrestrial contamination.
>
> Check out this exact quote from the article:
>
> "When they melted the snow and filtered out anything more than 25
> micrometres across, almost a third of the particles they found were from
> space."
>
> The whole thing stinks of posturing to me!
>
> Adam
>
>
>
> ----- Original Message -----
> From: "Darren Garrison" <cynapse_at_charter.net>
> To: <meteorite-list_at_meteoritecentral.com>
> Sent: Wednesday, July 12, 2006 12:21 PM
> Subject: [meteorite-list] Antarctic comet dust "perhaps" in better
> conditionthan Stardust
>
>
> Anyone have access to the full article?
>
> http://www.newscientistspace.com/article/mg19125594.100.html
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Received on Thu 13 Jul 2006 08:25:34 AM PDT