All the planets in a line
Fairly stupid title, but I know that the astronomical terminology for this sort of thing can get pretty specific.
I was just watching BBC stargazing live, and Brian Cox had a model of the Solar System with all the planets in a line on one side of the Sun, and jokingly said that this would happen in 2012, before hastening to remind the viewers that it was a joke.
But I've always wondered, how long would it take for all 8 of the planets to form a line on one side of the Sun? I know that simultaneous transits of Venus and Mercury only happen once about every 2-300,000 years, so I imagine the timespan for a full lineup of the usual suspects must be pretty vast. Could it happen in the lifetime of the Sun? Or at least before the planets are ripped from their orbits?
"Occam" is the name of the alien race that will enslave us all eventually. And they've got razors for hands. I don't know if that's true but it seems like the simplest answer."