You’re talking Hunger Games.
I had wondered about something like that, but I don’t know if it is possible. It would be scary if it were.
I’m hoping for large amounts of military planes flying banners, even if most of them are prop jet trainer planes, or the equivalents of bikes with training wheels.
There would be plenty of people on the ground looking up and hearing from their contacts who are still in the military to explain to people that they are military planes and what the significance of that is.
Going really out on a limb here, but what if the sky event is confirmation of the existence of extraterrestrial life?
That, or we’ll get a glimpse at where our technology really is.