[sorry: a brief interruption in the ongoing Sedna story for some late breaking news]

Eris, the goddess of discord and strife and the most massive dwarf planet, is up to her usual tricks.
On Friday night Eris was predicted to pass directly in front of a relatively faint star in the constellation of Cetus. You might think that this sort of thing happens all of the time, but you'd be wrong. Eris is