[meteorite-list] NASA Announces Comet Encounter News Conference

From: lebofsky at lpl.arizona.edu <lebofsky_at_meteoritecentral.com>
Date: Thu, 18 Nov 2010 04:01:18 -0700 (MST)
Message-ID: <a1b248d9c0312cbcd904403c8aeac30c.squirrel_at_webmail.lpl.arizona.edu>

Hi All:

As far as I know, all we are seeing in the comet images in the jets is
dust. If you have fine dust particles and shine light on them, the
scattered light will make them stand out like that. One sees the effect in
a smokey room (or sports stadium) and I demonstrate this in a classroom by
clapping dusty chalkboard erasers together.

Larry

> Images can be deceiving. Certainly, the comet is not lit, except by
> sunlight. As appears to be common with comets, it has a surface coating,
> some sort of weathering, that results in an extremely low albedo. That
> isn't
> apparent in an image that has had its white and dark points adjusted for
> maximum clarity.
>
> I don't think there is any doubt that the body is very cold in its
> interior,
> and is made of some mixture of ices and stony material. The surface may
> well
> approach room temperature, which is what is driving the boiling away of
> ices
> that produces a coma.
>
> Chris
>
> *****************************************
> Chris L Peterson
> Cloudbait Observatory
> http://www.cloudbait.com
>
>
> ----- Original Message -----
> From: <cdtucson at cox.net>
> To: "Meteorite Mailing List" <meteorite-list at meteoritecentral.com>; "Ron
> Baalke" <baalke at zagami.jpl.nasa.gov>
> Sent: Monday, November 15, 2010 2:46 PM
> Subject: Re: [meteorite-list] NASA Announces Comet Encounter News
> Conference
>
>
>> List,
>> I wonder if these new images will shed new light on the definition of
>> what
>> a comet is?
>> Typically the description includes the words frozen and ice in some
>> form.
>> But clearly based on the close-up visual images. It seems that this
>> thing
>> is far from being ice. In fact to me it appears to look more like a
>> fiery
>> hot briquette about ready to throw the steaks on to. It seems from the
>> photos that this thing is fully lit from the inside core to the
>> surface.
>> And could not possibly consist of ice in any of it's forms melted or
>> frozen. Well, maybe the surface stays wet and cold but the inside is far
>> from cold.
>> Hopefully this conference will alert us all with an update as to what
>> we
>> hunters need to be looking for. Because clearly it aint Ice. That's for
>> sure. But I am dying to find out what it is after all! It seems to me
>> we
>> should be looking for melted stuff. Really really melted stuff. Has
>> anyone
>> heard yet what they plan to say the interior is made up of?
>> My 2 more cents.
>> Carl
>
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Received on Thu 18 Nov 2010 06:01:18 AM PST