Re: Iridium Flare beam seen in clouds

Stephmon (
Sun, 19 Apr 1998 13:06:19 EDT

Hello all,

I'd like to take this opportunity to introduce myself to the group.  My name
is Stephen Fels.  I am a Laser Engineer living in Orlando, Florida USA.  I've
recently become interested in plotting predicting and photographing satellite
observations.  I'm particularly interested in the Iridium, Mir, Hubbel and
others that exhibit interesting behavior, such as tumbling.  I hope to be
completing a website "beginner's guide" in the near future and I look foreward
to communications with the group.

Now, on with the discussion... (Jim) writes:
<< Here's a question I hope to answer for myself from observation, but here
 goes. If the mirror like surface is always flat towards the Earth, as
 the flare peak approaches my position, would the beam appear to move
 through the clouds from north to south (the direction of sat travel) or
 south to north?
 I think the beam will move from S-N >>

I think I see what you are getting at.  You are imagining that the reflected
beam would 'sweep' the ground as the axis of the satellite body 'corrects' to
keep the mirror angle face normal to the earth?  I believe this is an
incorrect assumption, since the orbit should actually 'hinge' the beam at the
center of the Earth, not somewhere above the surface.  Imagine slicing an
apple in half by plunging a knife in to the core and rotating the apple.  The
skin of the apple will be cut in the direction of the advancing knife handle
(orbit), not in opposition.

Of course, I could be misinterpreting your statements completely.  

Stephen Fels