The best one by far is the crossing the "galactic equator". The so called galactic equator is basically a made up term by astronomers taken from the reference point of Earth (note, earth is not the center of the Milky Way). There is nothing scientific about it at all, just a reference point for astronomers to use but crossing this made up term that really isn't the "galactic equator" will cause all sorts of humanity ending events (depends on which website you go to, super volcano eruptions, the entire landmass on earth shifting, Antarctica being where North America is now, earthquakes that will rip apart continents, etc...)