[Allan_L (Allan)]

I guess I will kick this off this month.

I took this yesterday after sunset, specially for this month's challenge.
It is from the end of my street, looking East-wards over Tuggerah Lake, towards Toukley.

You can clearly see the Earth's Shadow (cast onto the atmosphere) as the dark blue band rising at the anti-solar point (ie: as the sun sets behind me).
Above that, the so-called "Belt of Venus" (or Anti-Twilight Arch). The arch's light pink color is due to back-scattering of reddened light from the setting Sun.
With the pink reflected in the surface of the lake.
[Warning Science Content, courtesy of Wikipedia]
Light from the sun near the horizon is red because the light passes through an especially thick layer of the atmosphere, which works as a filter, scattering all but the red light.
The red sunlight directly illuminates small particles in the lower atmosphere on the other side of the sky from the sun.