I'll go ahead and disable specularity for now; to be honest, I don't really like the way it currently looks either. I think it looks nice from an oblique angle, but when the specularity is right in the middle of the view it looks wrong.
In terms of "earth from space has no specularity," it depends on the images you look at. For some examples of earth from space with specular reflection:
[...]
Dropping in to give my 2 cents to that topic one page back...
I also thought that the sun reflection on the earth was looking wrong, so I'm glad you decided to remove it - but looking at the pictures you linked to in the quoted post, I had an idea how you could maybe - instead of removing it - improve it (so it does not look wrong anymore).
My idea is: let the reflection only alter the brightness (aka intensity or value or lightness in
various colour spaces), not the colour.
Actually, this made me think further - maybe the real cause is that the sun is much too yellow? Looking at
your third link (and also
other space images), the sun seems to be much much more white when viewed from space.
Maybe the real solution is not making the reflection only apply to brightness, but making the sun much less yellow in the first place?
Just some thoughts...
