staring at 1300 maps

Learned how to read the map (plane chart) images provided by Alister.



The dark shading is obvious: that's night time area.

The thick black line and hatched area... And the black star. Still working on that...

Oh. Found the notes! The star is the point on Earth where the event is at zenith. The white space then, up to the thick black line, is the "zone of visibility," i.e. 90° from the zenith.