That's German for "counter glow".
On the darkest nights, 180 degrees around from the sun there is a reflection of light from the sun called the Gegenschein. This is a reflection of light off of dust particles in the asteroid belt.
Check it out.
The black part in the middle of the picture is the Pipe Nebula. It is not a dark window into the background, but a foreground BLACK cloud of dust.
Info here: panther observatory