Space Shuttle

[Daniel Minge]

I presume the shuttle will be quite a bit btighter now
with the new solar panels. Wish I could see it,
but it's not presently visible from Australia.

Minge.

[Bruce Watson]

In article <bv9ms4dultrq9e89e...@4ax.com>,

You mean the International Space Station.

Somewhile back someone suggested the ISS would be less bright
when the solar panels are all in place.

They are perpendicular to the sun. They aren't positioned
so they reflect the sun to the earth.

[flyguy]

It's been my experience that the ISS appears brightest when the observer
has the sunset location to his back and the ISS is moving away from him
to the east after reaching it's highest point in the sky. This would
also be when the solar panels are reflecting more light from the sun to
the observer because they are aimed toward the sun which has set behind
him. It's not always possible to meet these conditions precisely,
depending on the particular pass of the ISS over the observer, but in
general it seems to be true. The brightest observations of the ISS are
those where it passes nearly over head. Then the observer is positioned
to view the ISS for the longest duration as it goes away from him to the
east and the sunset point is almost directly behind him. It should be
noted that the opposite conditions apply for viewing the ISS in the
morning before sunrise. In that case the ISS appears the brightest when
it's approaching the observer from the west while his back is to the
sunrise location in the east.

[Bruce Watson]

In article <oy3zl.218$426...@nwrddc01.gnilink.net>,

I've noticed that.

That would be because the station is showing a more full phase.
There is more light reflected (diffusely) from the panels to
the observer.

[Daniel Minge]

Yes, of course. My mistake. I was referring to the ISS.

Before the space station came into being. people suggested that
when complete, it would be at least as bright as Venus.

It seems to be getting there, but quite a bit to go.

Minge

[flyguy]

Yes, when the ISS is going away from the observer during an early
evening pass, more of the surface area of the panels are exposed, thus
relecting more light from the sun to the surface of the earth. This is
because the panels are aimed at the sun which has set behind the
observer. It also applies in general to the other reflective surfaces on
the ISS which present more area to the observer as the ISS receeds from him.