[amsat-bb] Re: some additional comments on visual sighting

[Jim Danehy]

Curt

Yup ya got me but you knew what I meant to say . . .  I guess we have become 
used to that over the political season, listening to so much mis-statement . 
. . mea culpa OM    . . .  being informed beats the alternative . . .  ya 
need astmosphere to see those little particles of sand from meteors . . . 
comets are way out there in space where there is no atmosphere . . .  they 
are large too

TNX  73  Jim W9VNE


----- Original Message ----- 
From: "Curt Nixon" <cptcurt at flash.net>
To: "Jim Danehy" <jdanehy at cinci.rr.com>
Cc: <amsat-bb at amsat.org>
Sent: Thursday, November 06, 2008 2:57 PM
Subject: Re: [amsat-bb] some additional comments on visual sighting


> Hi Jim:
>
> You are of course referring to Meteors not Comets.  The 
> gaseous/particulate clouds streaming from comets are visible millions of 
> miles out when they get energy from the sun.
>
> Curt
> KU8L
>
>
>
>
>
> Jim Danehy wrote:
>> the accepted opinion of astronomers is that you can see +6 magnitude 
>> stars without the assistance of a telescope or binoculars . . . . if AO 
>> 51 is +9 then it is virtually impossible to see it with the naked eye . . 
>> .
>>
>> as for comets : well in order for comets to be seen those small particles 
>> that you see must be within the Karman line . . .  which is at 62 miles 
>> (up) . . .  the atmosphere pretty well ends at 75 to 80 miles up . . . 
>> in order for those objects to be seen they must be within the atmosphere 
>> where they "burn up"  by friction against the "air"  atmosphere (. . . AO 
>> 51 is some 300 miles or 400 miles up and the ISS is 200 miles up . . .
>> the sun is  - 27 and we all know the brightest thing out there for us 
>> here on earth . . . . +6 for naked eye viewing . . . +9 is not visible
>>
>> Jim W9VNE
>>
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>
>