Re: Disco ball into orbit

Sean Sullivan (
Tue, 27 Jan 1998 20:21:41 -0500 (EST)

I first saw EGP about 11 months after launch, and the appearance hasn't 
changed noticeably.  I was in very dark skies at the time, and couldn't
see it naked eye, but found it incredibly easy in binoculars.  

I suppose it's possible the mirrors tarnished in that first year, but I 
doubt it (the design was for long-term visual observation).  Also the 
launch trajectory was pretty straightforward, so there was no interim
low-perigee transfer orbit for early observations.

About 6 years ago, I was out with Hal Povenmire (a meteor observer) and
brought out some high-altitude satelite predictions, and we decided to 
make a full-out attempt to see EGP naked eye.  I didn't succeed, though I 
did maybe get one flash when it was about 65 degrees high.  Hal was able
to follow it sporadically when it got about about 50 degrees.  To make this
easier, I was following in binocs every 30 seconds or so, and announcing 
where it was against the star background.  EGP can make leisurely passes :-)

Since the flashes *are* so objectively bright, and they are so easy to 
spot when binocs make them a little brighter (even though the time 
duration isn't imrpoved -- obvious but important) , I think that people's
eyes are probably pretty different with respect to how visible EGP is 
naked-eye.  So it may be easy for one person, and impossible for another, 
even though there may not be an apparent difference in the quality of
their night vision.  It's not that EGP is faint -- it's that the flashes
are brief.  We are not really used to thinking about how people respond
to challenging observations when *time* is the limiting factor.

And hi, Phil!  Ueda's EGP photos are truly wonderful, and his book
is definitely worth looking through, though it's hard to find on this
side of the Pacific.  (Just to second your thoughts)

-- Sean Sullivan