Comets are bullshit. Yes, we need some kind of mechanic to decrease stability, but comets have to be the one case of deus ex machina that I don't find hilarious. Why not economic collapse? Plague? The best thing would be ticking stability decay. Something believable, rather than "Oh, look, I've spent ten year's worth of ADM points on +3 stability, I'm golden for a few decade- oh, a comet. And another. And another. Shit."
It's just one of the many ways that the game arbitrarily kicks you in the balls with no way to get out of it. At least give it two choices, or the chance of a positive outcome - say, how about:
"A comet has been seen."
"It's divine intervention!" - 50% chance of -1 stability, 50% chance of +1 stability.
"Dumb-ass peasants." - Decreases legitimacy, increases revolt risk, or something like that.
Removed foul language - Seelmeister