Create a plot for the altitudes of the Sun and the Moon in the sky.
Compute a quick estimate of the shadow height above KHO: above this height the atmosphere is sunlit.
The astronomical calculations are done using Astropy and astroplan.
In the standard Ubuntu installation, there was a weird error regarding GTK backends. There is apparently an unnecessary line in backend_gtk3.py. If you get this error, you can comment out the line GLib.source_remove(seld._idle_draw_id)