We will be fighting a two front war against the aliens and AI terminators. Best prepare.
If it were an asteroid or comet, the amateur astronomers all over the planet would be telling us.
If it is an alien contact ship arriving, they would keep it a secret because peoples’ faith in their various religions would be destroyed and global chaos would ensue.
If it was some solar flare phenomena like in the Nicholas Cage movie “KNOWING”, then the world would just go completely insane like at the end of the movie.
If there is a danger, TPTB would not tell us in any case..............