Re: Iridium flare light across a cloud?

From: djmullen@tds.net
Date: Wed Jun 16 2004 - 03:48:53 EDT

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    I think the light from an Iridium satellite would have to sweep across the clouds in the opposite direction to the satellite's motion.  Iridium satellites are stabilized with respect to the earth.  That is, one particular part of the satellite is always pointing straight down.  That means that if you could telescopically observe the satellite as it passed from left to right, it would appear to rotate clockwise.  It would look something like this at three different points in a left to right pass:
    
         _
       /   \
    
    I hope that makes it through the email process without being mangled too badly.  When the satellite is far to your left, the leading edge appears to be higher than the trailing edge.  When it's directly overhead, the leading and trailing edges are at the same height.  When it's to your right, the leading edge appears lower than the trailing edge.  All of this is necessary to keep it aligned with the earth.
    
    A beam of light reflected off such a satellite would first be reflected ahead of the satellite, then straight down, and then to the rear of the satellite - exactly what Tom Wagner and others have observed.
    
    Dave Mullenix, N9LTD
    
    
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