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

[Curt Nixon]

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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