I don't know why the middle of the moon is not much brighter than the sides. I guess it has something to do with the wide dispersion angles of the light hitting rough matt moon rock and dust.
It's the geometry of a scattering surface. The angle of incidence gets smaller toward the edge of the Moon, but the actual illuminated area gets broader in inverse proportion, so the apparent brightness is the same out to the edge.
Oh I see what you mean.
I don't know why the middle of the moon is not much brighter than the sides. I guess it has something to do with the wide dispersion angles of the light hitting rough matt moon rock and dust.
It's the geometry of a scattering surface. The angle of incidence gets smaller toward the edge of the Moon, but the actual illuminated area gets broader in inverse proportion, so the apparent brightness is the same out to the edge.