[meteorite-list] NASA Announces Comet Encounter News Conference

[Chris Peterson]

Carl-

I'd argue that we have not captured MnSi from any comet. We have captured it 
from the interior of interplanetary dust particles. Those particles were 
collected during an influx of dust from one particular comet, and are 
reasonably inferred to be constituents of that comet, but that is not 
absolutely certain. And assuming that they are cometary, the amount of MnSi 
is exceedingly small. I can't see any grounds for thinking it contributes 
more than a trace amount of the total material. This is in contrast to CO2, 
H2O, and other ices which have been observed to constitute a large fraction 
of the total mass of an active comet. Those observations consist of direct 
reflectance measurements of comet nucleuses, as well as of gases in the 
comas and tails.

Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com


----- Original Message ----- 
From: <cdtucson at cox.net>
To: <meteorite-list at meteoritecentral.com>; <warnerem at astro.umd.edu>
Sent: Monday, November 22, 2010 2:31 PM
Subject: Re: [meteorite-list] NASA Announces Comet Encounter News Conference


> Elizabeth,
> You express yourself much better than I do but, I still don't get your 
> reasoning.
> It seems you are very quick to accept that what you *see* is dusty snow 
> and CO2 jets spewing out H2O snow and you may be right.
> So, wouldn't catching actual manganese silicate material spewed out of a 
> Comet tell you at least as much about the make up of a comet as what the 
> *visual only* of the H2O  tells you ?
> I mean if these jets are spewing out H2O from these jets and that leads 
> you to conclude  that this comet is made up of H2O then if you know for a 
> fact they also spew Manganese / silicate. Doesn't that offer even greater 
> evidence than a mere *observation* of H2O does?
> We *captured* Brownleeite (manganese silicate) and we *observed* H2O!! 
> Which scenario holds more weight for  proof ?
> I would thing the verifiable physical evidence would be much more telling 
> about what these comets are made up of And yet no mention of a comet found 
> on earth may have a primary make up of manganese by anything I have read 
> so far? Additionally, To me this suggests that the Manganese being much 
> stronger than H2O might be all that would survive of a comet meteorite.
> Maybe this tells us we should be looking for  manganese meteorites  to be 
> tested to see if they are cometary in origin?
> I mean testing the isotopes in these manganese meteorites  may just 
> surprise some of us? But , again. Only NASA Scientists can do this 
> testing.
> If I were to find a manganese meteorite do you think anyone would help me 
> get it tested?
> Because from a pure Scientific point of view keeping your mind open to 
> this possibility only makes Scientific sense. IMHO. And I can't wait to 
> hear more about your eventual tests on Hartley 2 pics and studies..