Superbird A flashes

Aaron S. Brown (
Fri, 27 Sep 1996 12:55:32 PDT

>                       Subject:                              Time:  11:44
>   OFFICE MEMO         Superbird A flashes                   Date:  96/09/27
> Aaron Brown wrote:
> > Keep in mind that the earth is turning.  The earth's shadow may
> > have been toward the moon at 0315 UT.  A geosynchronous satellite
> > "turns with the earth" in some sense.  It may move into the earth's
> > shadow even if it is nowhere near it in the sky a few hours before.
> True.  However, Robert was indicating that Superbird A was going into shadow
> shortly after the time the flashes were visible -- indeed, that the reason the
> flashes were no longer visible was due to shadow entry.  But this is not the
> case.  The flashes are only visible for a short time because the specular
> geometry is changing.  The earth subtends less than 20 degrees from geosynch,
> so the satellite would have to be less than 10 degrees from the moon (during
> the eclipse) to go into shadow.  

This assumes that the moon was in the center of the earth's shadow during
the eclipse, which was not the case, but nonetheless, I get the idea.

By the way, why do you have all your messages Tagged "Urgent"?