I just watched Robotics;Notes. The manga not yet.
A monopole fell from the sky. And later, lots more begun raining.
It was a recurring theme in the series that there was a solar flare cooking up, so I was under the impression that it was also making funny things in the earth's atmosphere kinda explaining the monopoles.
But later in the series we find out that
There is no solar flare at all. All the info about it is fake.
So, what's up with the monopoles?
My next guess was that it was part of
Kimijima Kou's plan to make the whole solar flare thing more realistic by somehow synthesising monopoles and throwing them off the sky (somehow)
But I'm not sure if that's confirmed in the series or the manga.